F\^5/oe>S-^7/s7
Biological Services Program
FWS/OBS-77/37
APRIL 1978
CONTRIBUTED PAPERS
ON COASTAL ECOLOGICAL
CHARACTERIZATION STUDIES
Presented at the
FOURTH BIENNIAL INTERNATIONAL ESTUARINE
RESEARCH FEDERATION CONFERENCE
Mt. Pocono, Pennsylvania
2-5 October 1977
Interagency
Energy-Environment
Research and Development
Program
/"^
Office of Research and Development
Ui. Environmental Protection Agency
use
Fish and Wildlife Service
U.S. Department of the Interior
The Biological Services Program was established within the U.S. Fish
and Wildlife Service to suppl,
key environmental issues that
supporting ecosystems. The mi
t^rogram was estaoiisnea wiinin ine u.j. r ibn
y scientific information and methodologies on
impact fish and wildlife resources and their
ission of the program is as follows:
■ To strengthen the Fish and VJildlife Service in Its role as
a primary source of information on national fish and wild-
life resources, particularly in respect to environmental
impact assessment.
• To gather, analyze, and present information that will aid
decisionmakers in the identification and resolution of
problems associated with major changes in land and water
use.
• To provide better ecological information and evaluation
for Department of the Interior development programs, such
as those relating to energy development.
Information developed by the Biological Services Program is intended
for use in the planning and decisionmaking process to prevent or minimize
the impact of development on fish and wildlife. Research activities and
technical assistance services are based on an analysis of the issues a
determination of the decisionmakers involved and their information needs,
and an evaluation of the state of the art to identify information gaps
and to determine priorities. This is a strategy that will ensure that
the products produced and disseminated are timely and useful.
Projects have been initiated in the following areas: coal extraction
and conversion; power plants; geothermal , mineral and oil shale develop-
ment; water resource analysis, including stream alterations and western
water allocation, coastal ecosystems and Outer Continental Shelf develop-
ment; and systems inventory, including National Wetland Inventory,
habitat classification and analysis, and information transfer.
The Biological Services Program consists of the Office of Biological
Services in Washington, D.C., which is responsible for overall planning and
management; National Teams, which provide the Program's central scientific
and technical expertise and arrange for contracting biological services
studies with states, universities, consulting firms, and others; Regional
Staff, who provide a link to problems at the operating level; and staff at
certain Fish and Wildlife Service research facilities, who conduct inhouse
research studies.
FWS/OBS-77/37
AprU 1978
CONTRIBUTED PAPERS
ON COASTAL ECOLOGICAL
CHARACTERIZATION STUDIES
Presented at the
FOURTH BIENNIAL INTERNATIONAL
ESTUARINE RESEARCH FEDERATION CONFERENCE
MT. POCONO, PENNSYLVANIA
2-5 October 1977
Edited by:
James B. Johnston
National Coastal Ecosystems Team
Office of Biological Services
Fish and Wildlife Service
U.S. Department of the Interior
NSTL Station, Miss. 39529
and
Lee A. Barclay
Fish and Wildlife Service
U.S. Department of the Interior
P.O.Box 12559
Charleston, S. C. 29412
DISCLAIMER
The opinions, findings, conclusions, or recommendations expressed in
tiiis publication are those of the authors and do not necessarily reflect the
views of the Biological Services Progi'am, Fish and Wildlife Service, U.S.
Department of the Interior, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use by the Federal
Government.
PREFACE
A session on the U.S. Fish and Wildlife Service's Coastal Ecological
Characterization Studies was held on 3 October 1977 at the Fourth Biennial
International Estuarine Research Conference in Mt. Pocono, Pennsylvania, to
highlight the important components of the characterization process.
The papers in this report are those presented at the session, with two
exceptions. First, the paper entitled Interim Hierarchical Regional Classifica-
tion Scheme for Coastal Ecosystems of the United States and its Territories
is not included and may be secured from the author— Terry T. Terrell, U. S.
Fish and Wildlife Service, Office of Biological Services, Room 206, Federal
Building, Fort Collins, Colorado 80521. Secondly, papers entitled The Con-
struction of a Conceptual Model of the Chcnier Plain Coastal Ecosystem in
Texas and Louisiana and Maine Coast Characterization User's Guide are
included in the proceedings. The first paper summarizes the modeling effort
for the first coastal characterization study— Chenier Plain of Southwest
Louisiana and Southeast Texas; while the second paper describes how a user
would utilize products from the Maine characterization study.
Funding for the initial characterization studies was provided through the
Interagency Energy/Environment Research and Development Program which
is planned and coordinated by the Office of Energy, Minerals, and Industry
within the Environmental Protection Agency's Office of Research and
Development. Inaugurated in fiscal year 1975, this program brings together
the coordinated efforts of 77 Federal agencies and departments. The goal of
the Program is to assure that both environmental data and control tech-
nology are available to support the rapid development of domestic energy
resources in an environmentally acceptable manner.
Any suggestions or questions regarding this publication should be direc-
ted to:
Information Transfer Specialist
National Coastal Ecosystems Team
U.S. Fish and Wildlife Service
National Space Technology Laboratories
NSTL Station, Miss. 39529
This report should be cited as follows:
Johnston, J. B. and L. A. Barclay, eds. Contributed papers on coastal
ecological characterization studies, presented at the Fourth Biennial Inter-
national Estuarine Research Conference, Mt. Pocono, Pa., 2-5 October 1977.
Office of Biological Services, U.S. Fish and Wildhfe Service. FWS/OBS-
77/37. 66 pp.
ui
CONTENTS
PAGE
Preface iii
Coastal Ecological Characterization— An Overview
/. B. Johnston 1
Ecosystem Characterization— An Approach to Coastal Planning and Management
A. W. Palmisano 4
Evaluation of Methodology Used in Ecological Characterization of the Chenier P'ain
R. H. Chabreck, J. B. Johnston, and J. B. Kirkivood 10
User-Oriented Conceptual Modeling in the Ecological Characterization of the Sea
Islands and Coastal Plain of South Carolina and Georgia
John J. Manzi and Robert J. Reimold 19
The Construction of a Conceptual Model of the Chenier Plain Coastal Ecosystem in
Louisiana and Texas
L. M. Bahr, Jr., J. W. Day, Jr., T. Gayle,J. G. Gosselink, C. S. Hopkinson,
and D. Stellar 32
Maine Coast Characterization User's Guide
Stewart I. Fcfer, Curtis Laffin, Larry Thornton, Patty Schettig,
and Russ Brami 44
COASTAL ECOLOGICAL CHARACTERIZATION
AN OVERVIEW
J. B. Johnston^
INTRODUCTION
The United States Fish and Wildlife Service
(FWS), in response to accelerated development
pressures upon the coastal zone of the United States
and its territories, has developed an ecological
characterization approach for describing these
valuable areas.
An ecological characterization is a description
of the important components and processes of an
ecosystem. The emphasis of ecological characteri-
zation, however, is placed on understanding func-
tional relationships.
The objective of ecological characterization is
to develop an ecosystem information base, and is
unique in that it:
1. Focuses on functional relationships.
2. Relates to specific and geographically well-
defined ecosystems.
3. Integrates existing multidisciplinary in-
formation.
4. Represents state-of-the-art understanding
of the ecological relationships.
5. Provides an ecologically based framework
for comprehensive coastal planning.
6. Develops tools for assessment of environ-
mental impacts.
7. Identifies information deficiencies and re-
search priorities.
Among the principal users of the study results
are those entitites within the FWS which are in-
volved in programs oriented toward the manage-
ment of coastal areas of the U.S. and its territories.
FWS has mandates under the Fish and Wildlife Co-
ordination Act of 1958 and the Water Pollution
Control Act of 1972, and has responsibility for the
National Coastal Ecosystems Team, Office of Biological Semces,
Fish and Wildlife Service, U.S. Dept. of the Interior, NSTL Sta-
tion, Miss. 39529.
review of permits for development and discharge
activities in U.S. wetlands and aquatic systems. Prin-
cipal permit authority lies with the U.S. Army
Corps of Engineers (USACE) or the Environmental
Protection Agency (EPA). Within the FWS, the
Division of Ecological Services (ES) Land and
Water Resources Development Planning Program
has lead responsibility.
Although a characterization will not provide all
tiie answers for reviewing a permit application, it
will provide an ecological data base (bibliography,
site-specific data, maps, etc.) and describe the area
o.n an ecosystem level. Supplemental data, i.e.,
field inspections and review of developmental prac-
tices for an area, wall still be needed by the ES
biologist and his counterparts in other agencies, for
the preparation of final reports.
Characterizations will be available for use by all
FWS programs related to coastal resource manage-
ment and planning. Other applications are assessing
the Outer Continental Shelf (OCS) development,
Coastal Zone Management (CZM), and Section 208
water (quality planning. Characterizations will iden-
tify fish and wildlife populations and their habitats
that coidd be impacted during ecological emergen-
cies such as oil spills. Perhaps of even greater value,
characterizations will provide foundations for plan-
ning during formulation of emergency response
plans, i.e.. Coast Guard and EPA oil-spill contin-
gency plans.
Government agencies other than the FWS are
also considered to be primary users of characteriza-
tions. These agencies include the National Marine
Fisheries Service, Bureau of Land Management,
EPA, USCG, COE, State CZM, and fish and game
agencies. Additional users could include conserva-
tion groups, academic institutions, and the various
industries or service companies involved in coastal
developments. Any aj^ency or private group with
an interest in coastal resource decisionmaking
should be able to carry out its responsibilities more
effectively by applying a coastal characterization.
Coastal areas presently being characterized and
anticip^iteU study completion date are: (1) the
Chenief Plain (Southwest Louisiana and Southeast
Texas^^winter 1978; (2) the Sea Islands and
CoastaJ Plain of Georgia and South Carolina—
sumn^er J979; (3) the Pacific Northwest (Northern
Califo><-|\ia» Oregon, and Washington)— winter 1978;
anc^ (4) \\y^ Rocky Coast of Maine— winter 1979.
These sm^y areas were delineated on the basis of
ecolo^i,^ characteristics; consequently the charac-
terizaiyp^s a^ije primarily regional in scope and are
not n^-q?^s^ifi;ty limited tu political or geographic
bounda^es;.. Sipme states, like Florida and Alaska,
includq. aH Qjf parts of more than one distinct
coastal ^OiS;ys,■
in
O
u
lU
Supplemental
Data
OCS
Development
Planning
OBS
ocs
Development
USGS
Supplemental
Data
CZM
Planning
CZM
Plan
Implementation
ES / OBS
NOAA / State
Supplemental
Data
Permit
Review
Sec 10 & 404
Permit
Decision
ES
USAGE
Supplemental
Data
Water Quality
Management
Plans
Water
Quality
Standards
ECE 1 ES
EPA
ES/ECE
Supplemental
Data
on Spill
Contingency
Plan
Oil Spill
Response
Activity
CG
— OTHER
Figure 4. Relationship of ecosystem characterization information to supplemental data requirements
and selected Fish and Wildlife Service-related action programs in the coastal zone.
required for OCS leasing. Ecosystem characteriza-
tions, however, could provide information on the
distribution and vidue of wetlands and fish and
wildhfe resources in the vicinity of the proposed
development. Much of the basic site-specific infor-
mation will be contained in the data source appen-
dix. Furthennore, the ecosystem characterization
report would assist in assessing impacts on the
important natural functional processes of the
system, e.g., alteration of salinities and currents,
effects on primary and secondary productivity,
sediment transport processes, etc. Information
regarding the effects and mitigation procedures
specifically associated with dredging must be pro-
vided from supplemental sources such as the
U.S. Army Corps of Engineers Dredge Material
Research Program. The ecosystem characteri-
zation should be regarded as one of a number of
tools required to protect and manage living
resources. To be effective, other more specialized
tools will also be required. It is important that
users recognize the tools available to them and the
purpose for which they were designed.
PROJECT STATUS
To date, four coastal ecosystems are being
characterized using the approach described. The
Chenier Plain study of southwestern Louisiana and
southeastern Texas was initiated in April 1976 and
is scheduled for completion in late 1978. The
other three studies were started in February 1977.
They include the coast of South Carolina— Georgia,
the rocky coast of Maine, and the Pacific coast
from Cape Mendocino, California to Cape Flattery,
Washington. These studies are due for completion
in 1979. Funding has been provided through the
Federal Interagency Energy-Environment Research
and Development Program (FIE/ER&D) adminis-
tered by the Environmental Protection Agency.
The Fish and Wildlife Service has been responsi-
ble for the design and management of the charac-
terization contracts. There are approximately
15 coastal ecosystems fringing the 48 contiguous
States. The FIE/ER&D program has provided a
mechanism to rapidly advance our understanding
of a significant portion of the coastal zone and
it is hoped that the techniques developed in this
program will have broad application by other
agencies to other areas.
CONCLUSION
Decisions facing natural resource management
become increasingly complex as knowledge
advances and interactions are better understood.
Improved methods of data integration will become
more essential to the appHcation of existing
information. Until holistic systems analysis
becomes more effective, we will have to rely on
modular components to integrate information.
Such modules, especially regarding natural systems,
can readily be adapted to more comprehensive pro-
grams, if properly designed.
The characterization process, as outlined, add-
resses an important functional unit of the environ-
ment—the ecosystem. The approach involves the
delineation of the physical boundaries of the
system, preparation of a functional conceptual eco-
system model, synthesis and analysis of existing
information using the model as a "blueprint," and
the preparation of an interim pilot characterization
report. The latter report, after review by the user
group, will permit the effective production of the
final ecosystem characterization report. During the
process most of the relevant information about the
system will be brought together in a data source
appendix. Guidance throughout the project is pro-
vided by a user committee to assure that the
information will meet action program needs.
The current energy dilemma may be the first
true test of our nation's ability to marshal the
diverse knowledge we have accumulated over the
past few centuries into a program which assures
our survival and strives at least to maintain the
cultural standards to which we have become accus-
tomed. Ecosystem characterizations can provide an
important ecological foundation from which to
plan and manage our natural resources.
EVALUATION OF METHODOLOGY USED IN ECOLOGICAL
CHARACTERIZATION OF THE CHENIER PLAIN
R. H. Chabreck,' J. B.Johnston,' and J. B. Knkwood-
INTRODUCTION
Increasing uses of coastal areas by developers,
plus increasing public awareness of the value of
living resources in these areas, have resulted in in-
creasing conflicts concerning land and water uses.
These conflicts can be resolved and reasonable de-
velopment can proceed while, at the same time,
productivity is maintained, if a good understanding
of the functions of these fragile areas and more pre-
cise methods of predicting the effects of further
alterations can be developed. The ecological char-
acterization process was devised by the Fish and
Wildhfe Service (FWS) as a procedure for providing
this understanding. Characterizations provide a de-
scription of the important environmental and
socioeconomic resources and physical processes
comprising coastal ecosystems, and an understand-
ing of the dynamic relationships of these systems
by integrating existing resource data as a functional
ecological unit.
The area selected for the initial ecosystem char-
acterization was the Chenier Plain of southeastern
Texas and southwestern Louisiana. This area is an
important producer of fish and wildlife resources;
it is subjected to a wide variety of land use prac-
tices; it contains large areas of vital natural habitat
such as coastal marshes, estuaries, and shallow off-
shore waters; and it supports several endangered
and threatened species. There is a large amount of
biological and environmental data available from
previous studies of this ecosystem, and the Chenier
Plain area has a long history of development associ-
ated with industrialization, mineral extraction,
navigation, flood control, and agriculture. Through
investigation and evaluation of the productivity of
resources that have been subjected to various in-
tensities of development, it should be possible to
iormulate precise impact predictions.
National Coastal Ecosystems Team, Office of Biological Services,
Fish and Wildlife Service, U.S. Dept. of the Interior, NSTL Station,
Miss. 39529.
Office of Biological Services, Fish and Wildlife Service, U.S. Dept.
of the Interior, Atlanta, Ga. 30347.
Since the Chenier Plain characterization was
the first investigation of this type to be initiated,
an important aspect of the project was an evalua-
tion of the methodology used. This evaluation was
needed also for the orderly execution of subse-
quent characterizations of other coastal ecosys-
tems. A methodology evaluation made it possible
to identify techniques which effectively served to
meet project objectives, and at the same time it
identified procedures that had not contributed sig-
nificantly.
Important aspects of the characterization
metht)dology to be evaluated in this paper include
the steering committee concept, user needs sur\ey,
conceptual modeling, area delineation, type of map-
ping, data search and presentation, and pilot study.
This paper presents the results of these evaluations
and suggests alternative procedures where unsatis-
factory results were obtained.
STEERING COMMITTEE CONCEPT
In order to facilitate active input into the char-
acterization study by others within and outside the
FWS, various State and Federal agencies closely in-
volved with activities within the Chenier Plain were
asked to assign a representative to a steering com-
mittee. These committee members were assigned
on the basis of their iniderstanding of tiic area or
special knowledge of certain aspects of the charac-
terization process. The Steering Committee re-
viewed progress made by contractors at regularly
schedided periods, assessed this progress, and made
recommendations to the FWS Project Officer re-
garding future study areas.
The initial meeting of the Steering Committee
was held prior to the beginning of work. Most
members showed a strong interest in the project
and responded with both oral and written reviews
of materiiil presented to them. Enthusiasm re-
mained high during the project and attendance at
meetings was even higher than anticipated. The
committee size (six) for Chenier Plain was accept-
10
able and each person had adequate time to actively
participate in the discussion.
The Steering Committee concept proved to be
an important aspect of the characterization and
assured establishment of priorities necessary to
cover all areas of potential interest to resource
managers and other user groups. The Steering Com-
mittee concept has been continued in the other
characterization studies.
USER NEEDS SURVEY
The Chenier Plain characterization was in-
tended to serve primarily as a resource manage-
ment tool. Thus, in order to develop a characteri-
zation methodology which would achieve this ob-
jective, it was necessary to first identify the nature
and relative magnitude of the various types of on-
going resource management efforts and other re-
lated activities occurring within the study area. The
data required to enable managers to make sensible
decisions for resource utilization were identified
for various regulatory organizations. Also, it was
necessary to ascertain the level of detail and pre-
ferred formats for data presentation which were
most directly applicable and interpretable within
the context of these management activities.
A preliminary list of users to be contacted was
compiled and circulated to Steering Committee
members and other contacts for review. The addi-
tions and modifications to the list which were sug-
gested were then incorporated into the survey plan.
Further additions to the list were made based on
the recommendations of several respondents to a
questionnaire. The potential users were then classi-
fied into two groups: those to be interviewed per-
sonally and those to be contacted only by ques-
tionnaires and telephone followup, as necessary.
Those organizational representatives selected for
interviewing were thought to be more immediately
involved in policy formulation, decisionmaking,
and research activities within the Chenier Plan.
A questionnaire was used to determine user
needs. The questionnaire was designed as a check-
list of all resources and possible areas of interest.
The draft questionnaire was circulated to members
of the Steering Committee for comments and
proposed revisions before it was distributed to the
users that had been identified. Less than half of the
questionnaires were returned by the date re-
quested. Three out of over 90 recipients reported
that they elected not to respond. A telephone fol-
lowup was employed to maximize the information
yield. When a 90 percent return was achieved, a
final analysis was perfomied on the responses.
The returns were grouped into categories ac-
cording to the management responsibilities of the
users, as indicated by responses. Those categories
are identified below:
1. Project and permit review on a case-by-
case basis.
2. Environmental planning for water re-
lated projects (including coastal engi-
neering, flood control, water allocation,
etc.).
3. Resource management for fish and wild-
life habitat maintenance.
4. Coordination of coastal zone activities.
5. Design and enforcement of environ-
mental legislation.
6. General land use planning.
7. Research and experimentation.
8. Environmental health and agricultural
interests.
Clearly, the management responsibilities of the
various groups overlapped into a second or even
third category. This categorization was designed to
identify the respective groups by what appeared to
be their major management focus. One objective of
this categorization was to ascertain if the data
utilized and the data preferred were significantly
different according to the responsibilities of the
various user groups. In some cases, therefore,
responses were included in two categories.
Data needs showed equal weighting by users in
regards to their reliance on floral, faunal, and
physical area features. There was no difference
demonstrated among the management groups
except that the water-related management groups
expressed preferential dependence on physi-
cal data. Answers to questions on environmental
data needs may be ranked into data categories. The
most important categories (over 70 percent in-
terest) to users are shown in Table 1.
The user needs survey is not being used in
other characterization studies because it did not
prove to be cost-effective and the required Office
of Management and Budget clearance causes
untimely delays. It appears that steering committee
members and FWS personnel provide the most
economical and effective means for acquiring
necessary information on user needs.
11
Table 1. Potential User's Interests by Data Category'
% of respondents
Category
indicating
interest
Habitat classification
80.6
Based on dominant \
egetation
83.3
Based on physical parameters
77.8
Productivity
80.6
Dominant fish
72.2
Sport species
77.8
Endangered species
77.8
Food webs
75.0
Salinity regime
77.8
Precipitation
72.2
Sediment type
75.0
Soil type
72.2
Water quality
86.1
Industrial projects
72.2
Table 2. Percent of Respondents Indicating a Preference
for Various Data Presentation Techniques
3 Includes only categories in which at least 70% of respon-
dents indicated interest.
DATA PRESENTATION FORMATS
The survey of potential users of environmental
data indicated little preference for data formats.
Ail groups reported that they employ maps, charts,
tables, and reports with about the same frequency
and all groups rely to a lesser extent on computer-
ized information. The apparent tendency to de-
emphasize computerized information may reflect
economic constraints, limited computer access,
lack of valid data banks, or mistrust of computer-
ized printouts. In response to the survey concern-
ing preferred data presentation formats, computer
tape and flow diagrams were again deemphasized,
but maps were preferred (Table 2). There was no
difference in the format preferences among differ-
ent management interests. However, the permit
and project review group preferred a significantly
higher scale than presently available. For example,
representatives of the Galveston and Lafayette
FWS field offices indicated that maps and photos
currently used are at the 1:24,000, and 1:62,500
levels of resolution. The representatives expressed a
desire to have the information provided at the
1:2,000 and 1:5,000 levels. Potential users for the
other characterization studies have expressed essen-
tially the same type of data format priorities.
CONCEPTUAL MODEL
Construction of a conceptual model of the eco-,
system was one of the first tasks performed during
Data presentation techniques
% of respondents
indicating preference
Maps
88.9
Tables
75.0
Graphs
75.0
Narratives
69.4
Computer data tapes
33.3
Flow diagrams
27.8
the characterization of the Chenicr Plain. The
model identified, as accurately as possible, the sys-
tem components and their functional interactions
and regulatory processes. The initial model served
as a guide for development of the characterization
and identified the data that should be assembled
and where the data would be applied in the charac-
terization. In addition to functioning as a guide in
the data collection effort, the model also assured
what appropriate focus would be given to the vari-
ous components of the ecosystem.
After the data was assembled, analyzed, and
applied to the appropriate components, the result-
ing model served to identify data gaps and provid-
ed insight to areas requiring special attention.
The conceptual model of the Chenier Plain eco-
system characterization contained components,
flows, structure, and external forcing functions and
presented them in proper relationship. It further
provided the organizational framework for devel-
opment of the products of the characterization.
Description, explanation, and prediction followed
the outline of the conceptual model so that the
ecosystem, its basins, habitats or communities,
populations, and individuals could be elaborated
more systematically in the characterization.
Data, flow diagrams, or other forms of infor-
mation proposed for inclusion in the characteriza-
tion were tested for (1) reliability; (2) clarity of
content; (3) relevance, i.e., identifiability and
specificity of the information, interaction, etc.,
and (4) redundancy. The conceptual model was
also checked for organization and completeness.
The conceptual models for the other character-
ization studies have evolved from an initial guide to
data collection and utilization, to a system of qual-
itative ecological modeling for user orientation.
This approach includes modeling ecosystems by in-
corporating generalized energese diagrams with
coincidental graphic displays that illustrate repre-
sentational ecosystem cross sections and appropri-
12
ate Holistic and faunistic cliaracters. Thus each
ecosystem is introduced by a combinatorial model
merging classic Odum energese symbolism with
graphic (pictorial) presentations. This combination
should give the wide range of user groups a maxi-
mimi understanding of each ecosystem by stressing
the identification of primary ecosystem compo-
nents and the relationships between these compo-
nents.
AREA DELINEATION
The coastal zone in western Louisiana and
eastern Texas is a large integrated system which de-
veloped during 7,000 years of deposition of river-
ine sediments, mostly from the Mississippi River,
coupled with the continual erosion, sorting, re-
working, and longshore transport of these sedi-
ments by marine forces. The entire system can be
functionally divided into two broad zones, the
eastern deltaic plain and the western Chenier Plain.
The geological formation of the Chenier Plain was
studied during the characterization of this area so
it coidd be demonstrated that the entire region is a
system, the parts of which are functionally connec-
ted by dynamic long-temn physical processes.
During the characterization of the Chenier
Plain ecosystem, it was appropriate to delineate the
area into functional subsystems. A hierarchy of
resolution was used; at the top is the entire Chenier
Plain, which consists of a group of individual drain-
age basins, each of which is further subdivided into
distinct regions (habitats) with characteristic organ-
ismal communities and physical components, and
habitats that are further subdivided into individual
species units (Table 3). Each higher level of resolu-
tion obviously includes more detail (complexity),
although increasing the detail in a system model
does not necessarily confer more understanding of
the entire system.
As the level of resolution is increased to a small
system, the time frame becomes shorter. For ex-
ample, the entire Chenier Plain system evolved and
is changing on a time scale of thousands of years,
keyed to such geological processes as the periodic
switching of the Mississippi River and eustatic (sea
level) changes. Individual habitats, on the other
hand, have been affected by annual cycles of solar
energy flux, animal migrations, etc., and even were
radically altered by such short-term events as storm
surges and local "eat outs" by geese or muskrats.
Table 3. Units within the Chenier Plain Ecosystem Hierarchy-
Basins
Habitats
Populations
and/or species
Vermilion Wetlands
Mermentau Impounded areas
Chenier Salt marsh
Calcasieu Brackish marsh
Sabine Intermediate marsh
East Bay Fresh marsh
Swamp forest
Aquatic
Nearshore gulf
Inland open water
Ridges
Beach
Cheniers, natural
levees, Pleistocene
islands
Upland and manmade
spoil areas
Agriculture
Rice and other crops
Pasture
Urban
Shrimp
Menhaden
Finfish
Oyster
Blue crab
Crawfish
Clam
F'urbearers and
other mammals
Alligator and
other reptOes
Bullfrog
Waterfowl and
other birds
Each level of the hierarchy was set in a natural
ecological context in the characterization in keep-
ing with the following rationale:
L The whole Chenier Plain region is unified
by a common geological and climatic his-
tory that explains its origins.
2. The drainage basin is the wetland analog of
the watershed, and it is tiie mc^st nearly
self-contained or autonomous ecosystem of
the Chenier Plain. It is composed of a set of
habitats or communities integrated by the
flow of water through the basin.
3. "Habitats" or communities are not as
sharply defined. A habitat refers to an or-
ganized unit that has characteristics in addi-
tion to its individual and population com-
ponents and it functions as a unit through
coupled metabolic transformations.
4. Populations of individual species are intui-
tively unique. The organisms have a com-
mon gene pool, and harvest statistics are
usually reported by species. Individual
species often occur in a number of differ-
ent habitats.
This method for delineating study area is being
used in some of the other characterization studies
and provides the framework for understanding the
functional relationships within an ecosystem.
However, other methods are also being explored.
13
LAND USE DATA AND TYPE MAPPING
Previous studies had proven the usefulness of
remote sensing techniques for coastal mapping.
They had also proven this tool to be cost-effective,
efficient, and relatively accurate. The degree of ac-
curacy, however, depended upon the resolution de-
sired. Techniques tested in devising a methodology
suitable for ecological characterization were
Landsat imageiy, black and white photographs,
infrared imagery, aerial and ground obsen'ations,
and various combinations of these.
Landsat imagery was tested with the most
sophisticated equipment available at Bendix Cor-
poration, Ann Arbor, Michigan and National At-
mospheric and Space Administration, Slidell, Lou-
isiana. Training sites were adequately identified by
ground truth to identify spectral signatures dis-
played on Landsat imager^'. Maps were quickly
generated by this procedure in pilot study areas
and quantitative data were displayed according to
the frequency of various signatures.
Resolution appeared to be within acceptable
limits. However, checks of the maps generated in
this manner revealed that there was not always a
distinct signature for each habitat; consequently,
map displays sometimes differed significantly from
actual conditions.
Coastal marshes make up a large portion of the
Chenier Plain and they contain a wide array of
plant species varying in composition, density, and
growth stage. These differences could not be ade-
quately categorized from Landsat scenes, as re-
quired for the characterization process.
The procedure that proved most desirable is
similar to that currently used for the National Wet-
land Inventory being conducted by the Fish and
Wildlife Sei^vice. This procedure requires a combi-
nation of data obtained from infrared imagery and
other aerial surveys. Aerial sui"veys by persons able
to identify plant types from low-level flights over
the area are a strategic part of this type mapping.
This procedure, coupled with land-use mapping
from black and white photographs, produced data
with accuracy satisfactory lor characterization
purposes. Also, this procedure proved to be more
cost-effective than all other adequate procedures
tested.
PILOT STUDY
The overall objective of the pilot study was to
gather sufficient information to develop a "mini-
atlas," which was used by project reviewers and
others to evaluate a "finished" product with re-
spect to the cost effectiveness of specific methods
used, and the usefulness of the information to
prospective users. In addition, it provided oppor-
tunities for the researchers to correct any misjudg-
ments and possibly give insight to new methods.
Data processing included investigation of data
availability, collection, coding, analysis, and pre-
sentation. Data gaps were identified and filled
where possible.
Criteria initially used for selection of the pilot
study area included that the area be large enough
and variable enough to be representative of the
problems encountered over the entire Chenier
Plain, and that previous investigations completed in
the area would provide adequate background data
for characterization. Those involved in the actual
choosing of the site deemed that these criteria
alone were insufficient to permit a final decision.
Other criteria, therefore, had to be considered. In
brief, some of these additional factors used were:
1 . A representative display of habitats was lo-
cated within the area.
2. A major urban complex was located within
the basin.
3. Prevalence ot petro-chemiciil industries.
4. Diversified fisheries and wildlife resources.
The pilot study concept proved to be an effec-
tive part of the characterization process. It met the
primary objective of providing a preliminary for-
mat which could be reviewed and modified to
maximize the effectiveness of the final product in
meeting needs of user groups.
CHARACTERIZATION STUDY
The general structure developed for the pilot
study was used for the characterization atlas. This
facilitated assessment and, to some degree, made
known what could be expected in the final charac-
terization atlas. Results were presented in several
forms; maps, figures, tables. The written portion of
the atlas was designed, to the extent possible, to
stimulate the use of the material by resource man-
agers.
Drafts of the atlas, maps, and other documents
that are considered as the final products of the
Ecological Characterization of the Chenier Plain
are being reviewed and revised, and should be pub-
lished during 1978.
14
THE USE OF A PILOT STUDY IN DEFINING CHARACTERIZATION
PROCEDURES AND PRODUCTS-COOS BAY, OREGON
Jay F. Watson/ Charles M. Proctor,^ and Robert L. Holton^
INTRODUCTION
In 1804, when Captains Meriweather Lewis and
William Clark began their historic expedition to the
Pacific Ocean, they carried with them an extraordi-
nary document, a copy of President Thomas Jeffer-
son's instructions to them (Cutright 1969). Presi-
dent Jefferson directed Lewis and Clark to observe:
. . . climate as characterized by the thermom-
eter, by the proportion of rainy, cloudy, and
clear days, by lightning, hail, snow, ice, by the
access and recess of frost, by the winds prevail-
ing at different seasons, the dates at which par-
ticular plants put forth or lose their flowers, or
leaf, times of appearance of particular birds, or
reptiles, or insects (Thwaites 1904).
Their expedition coOected an incredible amount
of information concerning botany, zoology, car-
tography, meteorology, and ethnology. Much of
their information was collected at Fort Clatsop
near the mouth of the Columbia River.
The U.S. Fish and Wildlife Service's (FWS)
Pilot Study for the Ecological Characterization of
the Pacific Northwest Coastal Region, although not
of the historical significance of the Lewis and Clark
expedition, has many similar characteristics.
The Service's study is a two-year effort. The
Lewis and Clark expedition took two years and
four months to complete. The expedition's en-
campment at Fort Clatsop was only part of their
total project. The Pilot Study at Coos Bay is just a
part of the total characterization process.
Secondly, the expedition's objective was to
reach the Pacific Ocean. The FWS's objective is to
characterize the Pacific Northwest coastal region
from Cape Flattery, Washington, to Cape Mendo-
cino, California. Their objective was approximately
in the center of our study area.
Ipish and WUdlife Service, U.S. Dept. of the Interior, Portland,
Ore. 97232.
^Ryckman, Edgerly, Tomlinson, and Associates, Envirodyne Engi-
neers, Bellevue, Wash.
Dept. of Oceanography, Oregon State Univ., Corvallis, Ore.
Thirdly, it was hoped that the Lewis and Clark
expedition would be the first of a continuing effort
in the far west. The Pilot Study of Coos Bay is the
first of 10 units in the process to characterize the
Pacific Northwest coastal region.
Fourth, Captains Lewis and Clark were given a
general set of instructions by President Jefferson
with which to guide their data collecting efforts.
The FWS contractor has also been given a general
set of instructions to guide the characterization ef-
fort. History will have to teD us if the FWS writes
instructions the way President Jefferson did.
And last, Lewis and Clark were directed to
"characterize" the route they traveled, i.e., to pick
out the significant things, the important items that
separated one area from another. For example,
while at Fort Clatsop, Lewis and Clark noted the
dominant plants and animals. The characterization
is also attempting to pick out or define the impor-
tant features of the area.
As an additional comment, there is one major
difference between the Lewis and Clark expedition
and FWS effort. The Lewis and Clark expedition
cost $38,722.25 (Jackson 1977). The characteriza-
tion study will cost approximately 12 times as
much.
A characterization may be defined as: A
study to obtain and synthesize available environ-
mental data and provide an analysis of functional
relationships and dynamics. The final products
from a characterization will include: (1) a concep-
tual model, (2) a characterization atlas with narra-
tive text, figures, tables, and charts, and (3) a data
source appendix. An intermediate step in this pro-
cess is a "Pilot Study" or test characterization
which is the subject of this paper.
It is the mission of the FWS to conserve, pro-
tect, and enhance fish and wildlife and their habi-
tat for the benefit of the people of the United
States. In order to carry out this mission, the FWS
is authorized or required, among other things, to
conduct investigations, surveys, and research. An
Ecological Characterization of the Pacific Northi
15
west Coastal Region is one of the investigations
that is being conducted to meet these responsibili-
ties.
The study area, extending from Cape Flattery,
Washington, to Cape Mendocino, California, and
from the crest of the coast range to the 200-m con-
tour line of the Pacific Ocean is an area of high fish
and wildlife values. To help maintain these values
the Sei"vice operates eight wildlife refuges along the
California, Oregon, and Washington coast. These
National Wildlife Refuges, including Oregon Island,
Three Arch Rocks, Lewis and Clark, Columbia
White-tailed Deer, Willapa, Copalis, Quillayute Nee-
dles, and Flattery Rocks, provide habitat for water-
fowl, shorebirds, endangered species, and seabirds.
In addition, the FWS is active in reviewing and
commenting upon proposed activities that could
cause adverse impacts upon fish and wildlife and
their habitats in the coastal region. The FWS is also
concerned about the possible impacts of energy
development projects upon the area. These projects
include foreign oil imports, Alaskan oil tranship-
ment, liquified natural gas import, petrochemical
industry development, and Outer Continental Shelf
activities. The Coos Bay Unit was selected as a
Pilot Study because it is representative of the area
in habitat diversity, resources, and development.
The Coos Bay Unit includes all of the major
components that were included in the first product
of study, the conceptual model. The unit contains
agricultural, recreational and commercial develop-
ments, logging, light industry, shipping, fisheries,
and undeveloped areas. It was the opinion of the
FWS and our contractor that the Coos Bay Unit
would provide the kind of information and prob-
lems necessary to test the characterization process.
The point of conducting the Pilot Study was to pro-
vide an example of the framework, data collection
and coverage, map resolution, and synthesis of in-
formation that the contractor proposes to use in
the final products. The success of this effort will
probably not be fully apparent until the entire
characterization is complete.
METHODS
The Ecological Characterization o{ the Pacific
Northwest Coastal Region is being conducted
under contract by Ryckman, Edgcrley, Tomlinson,
and Associates, a St. Louis, Missouri, consulting
firm with offices in Bellevuc, Washington, and San
Jose, California. They are being aided in the study
by two subcontractors and several consultants. Dr.
Charles Proctor is the Project Manager, Mr. John
Garcia is Technical Director, and Dr. Robert Holton
is the Technical Coordinator for the Oregon area of
the characterization. Dr. Jay Watson is Project
Officer for the FWS.
For the Pilot Study, basic guidelines have been
developed for the preparation of products. First,
we have defined our user. It was stated early in the
project that our target user was an FWS - Ecological
Services field biologist.
Although we want the characterization to be
aimed primarily at FWS biologists, the characteri-
zation must also be acceptable to a wide range of
users. In an attempt to meet this guideline we have
included and are continuing to include several Fed-
eral, State, and local agencies in the review process.
In addition, we are attempting to provide enough
information in the text so that anyone, given the
time and interest, can understand all aspects of the
characterization. For example, if we take a concep-
tual model of the external factors important in
understanding an eelgrass (Zostera spp.) communi-
ty, and present it without clearly developing an un-
derstanding of the energy-mass flow symbols used
in the model, it is not of a great deal of use to our
field biologists or other people who may wish to
use the conceptual model. However, if we take the
user through an exercise in using the various sym-
bols, developing the vocabulary and syntax of this
new language in a structured manner, then the con-
ceptual mt)del becomes a useful product. That is, if
we move progressively through our conceptual
model from a pictoral representation of a simplified
hydrologic cycle to a general energy-mass flow dia-
gram to a more detailed energy-mass flow diagram,
we think the user can more easily understand the
special language of the diagrammatic models of the
ecosystems processes.
The conceptual model is used as a template or
guide for data collection. The conceptual model
was completed with the intention that it would
lead to a structured collection and synthesis of ex-
isting information for the pilot study and the rest
of the characterization. For example, there is a
great deal of information available concerning the
distribution of zinc in the lower Columbia River and
Willapa Bay, Washington. However, all of the mod-
els to date seem to indicate that zinc distribution
data are not a key factor in our understanding of
the structure and function of coastal ecosystems. If
we were not careful, however, we could have spent
a great deal of time trying to work the zinc infor-
mation into our analysis.
16
The text of the characterization, or in this case
the text for the pilot study, is to start at the begin-
ning or at some point near the beginning in our un-
derstanding of a particular process or system. Dr.
Tim Joyner, a consultant on this project who is
writing the section concerning geologic processes,
located a discussion by William Maclure which
seems to establish a base for further analysis. Mac-
lure's observations (1817) seems to give us a starting
point for our discussion of the geologic processes
for the Coos Bay Pilot Study. Another starting
point that was selected for the discussion of Trophic
Structures was Lindeman's analysis of The Trophic-
Dynamic Aspect of Ecology (Lindeman 1942).
Whether we like to admit it or not, most of the
information transferred within the FWS and from
the Service to other agencies is in black and white
and reproduced on copying machines. Therefore,
to obtain the greatest long-term use of the maps
and other graphic materials being produced for the
characterization, we are using black and white. The
pilot study contains several different approaches to
information presentation, and the reviewers are se-
lecting the ones that they consider the most useful.
Furthermore, we are attempting to avoid oversized
documents by fitting most of our information on
8'/2-by-l 1-inch pages. A few foldout pages have been
included, which are 11 by 17 inches.
One of the most perplexing problems in com-
pleting the pUot study of Coos Bay has been to
match the depth or extent of information coverage
with manpower. Actual data collection and analy-
sis for the Coos Bay Watershed Unit (one of 10
units to be characterized) began on 1 June 1977,
and was completed 4 months later on 30 Septem-
ber 1977. If 4 months are required for each water-
shed, we will not complete the project by the
scheduled completion date of December 1978.
However, we think that future units will be com-
pleted more rapidly because the conceptual model
has been refined using actual data, the graphics and
format will stabilize, and the amount of information
required for each new unit will decrease as the proj-
ect nears completion.
For example, the FWS is providing the wetland
maps for the Pilot Study area and also for the en-
tire characterization area. Our first efforts on the
Coos Bay Unit took approximately 1.5 man-months
to locate and delineate the wetlands found within
the five quadrangle maps that make up the unit.
The process of wetland mapping proceeds as fol-
lows:
1. Aerial photographs obtained;
2. Field reconnaissance of the study area com-
pleted;
3. Classification and delineation of wetlands
completed according to the FWS Classifi-
cation System; and
4. Field check sites as necessary.
During our initial effort on Coos Bay the pho-
tographs were delineated and then 17 sites were
checked. One major problem was identified during
these checks; mapping conventions must be well
established. For example, originally the photointer-
preters were using tidegates as the head of high tide.
Ground checks indicated that about half of the
tidegates were inoperable and that head of tide was
actually further upstream. The mapping conven-
tion that was chosen to remedy this mapping prob-
lem was modified from a definition in Oregon Es-
tuaries (Oregon Division of State Lands 1973). The
head of tide, as we are defining it now, is a point of
continuous diking along the river edge where the
tideland narrows to a width of approximately 6 to
9 m (20 to 30 ft).
Now that the first set of wetland maps has
been produced, we believe that the effort required
for future mapping can be greatly reduced. Ground
truth sites can probably be reduced from 17 to 10
or less and the final field checks eliminated entirely.
We believe that the mapping effort will be 0.5 man-
month per unit as opposed to 1.5 man-months re-
quired for the Coos Bay Unit.
CONCLUSION
What have we learned from the Pilot Study of
Coos Bay, Oregon? Although we have just com-
pleted the pilot study, it appears that:
1. The conceptual model is a suitable frame-
work for data collection;
2. The contractor has adequate manpower to
complete the characterization on schedule;
3. The depth of coverage is sufficient for an
understanding of functional relationships
and dynamics of the processes described in
the characterization; and
4. The amount of information collected is not
so extensive that it cannot be synthesized
into a comprehensible document.
However, there are also some problems that
have been identified during the pilot study. One of
the most persistent problems is showing the rela-
tionship between natural resources and socioeco-
nomic processes. We are having difficulty showing
17
just how natural resource utilization relates to
socioeconomic processes. For example, if we are
managing our natural resources effectively, our eco-
nomic activity should be dictated by the resources
available. If on the other hand, we cannot identify
important processes or the levels of resources avail-
able, then economic activity is probably dictating
the rate of utilization. That is, are we cutting trees
faster than we are growing them? In any event, the
information contained in the conceptual model
and the pilot study does not clearly show the rela-
tionship between man's activities and the natural
resource base. It is hoped that during the course of
this project we will be able to improve our under-
standing of this relationship.
Another problem that has become apparent in-
volves the various ecosystem models. For example,
the different systems vary with high and low tides,
night and day, summer and winter, and high and
low flows. We are looking over various options that
could be used to modify the models to show these
variations.
REFERENCES
Cutright, P. R. 1969. Lewis and Clark: Pioneering
naturalists. University of Illinois Press, Urbana.
506 pp.
Jackson, D., ed. 1977. Letters of the Lewis and
Clark expedition with related documents,
1783-1854. University of Illinois Press, Urbana
(cited in Cutright, 1969).
Lindeman, R. L. 1942. The trophic-dynamic aspect
of ecology. Ecology 23:399-418.
Maclure, W. 1817. Observations on the geology
of the United States of America with some
remarks on the nature and fertility of soils by
the decomposition of the different classes of
rocks; and an application to the fertility of
every state in the Union in reference to accom-
panying geologic map. Read as a memoir
before the Am. PhUos. Soc. and inserted in the
first volume of their Transactions, New Series-
Philadelphia.
Oregon Division of State Lands. 1973. Oregon
estuaries, Portland, Oregon, n.p.
Thwaites, R. G., ed. 1904-5. Original journals of
the Lewis and Clark expedition. Dodd, Mead
and.Co. New York. 8 vols (cited in Cutright,
1969).
18
USER-ORIENTED CONCEPTUAL MODELING IN
THE ECOLOGICAL CHARACTERIZATION OF THE SEA ISLANDS
AND COASTAL PLAIN OF SOUTH CAROLINA AND GEORGIA
JohnJ.Manzi^ and Robert J. Reimold^
INTRODUCTION
The Division of Marine Resources, South
Carolina Wildlife and Marine Resources Depart-
ment, began work in February 1977 on an eco-
logical characterization of the sea islands and
coastal areas of South Carolina and Georgia. This
work is under contract to the U.S. Fish and Wild-
Hfe Service and has as its principal goal "a descrip-
tion of the important components and processes
comprising (sea island) ecosystems and an under-
standing of their important functional relation-
ships" (Palmisano, 1978). The final products of
the characterization include (1) a conceptual
model which identifies system components and
their interactions; (2) a characterization atlas
which illustrates through graphs, pictorials, tables,
and maps the socioeconomic, physical, and bio-
logical aspects of the study area; (3) a characteriza-
tion narrative and bibliography which summarizes
available published and unpublished data on the
study area; and (4) a data appendix containing un-
published data used in the characterization effort
(U.S. Department of the Interior, Fish and Wildhfe
Service, RFP FWS-8-206, 25 June 1976). These
products should provide essential information to
decisionmakers concerning proposed or existing
perturbations in the coastal areas of South Carolina
and Georgia. In addition, the characterization
should also indicate where serious data gaps exist
and perhaps place priorities on the direction of
future research.
The conceptual model, as originally outlined
by the U.S. Fish and Wildlife Service (RFP FWS-
8-206), was to function primarily as an instrument
to assist in collection and organization of data. In
this context, the model would form a framework
of the coastal ecosystems indicating principal com-
ponents and the relationships between them. The
model would then act as a guide to project partici-
Marine Resources Research Institute, Charleston, S.C. 29412
■'Georgia Department of Natural Resources, Brunswick, Ga. 31520
pants in their individual assignments and thus
provide the cohesion necessary to produce a uni-
form and consistent characterization. In practice,
the conceptual model for the ecological characteri-
zation of the coastal areas of South Carolina and
Georgia has evolved into a user-oriented- (rather
than producer-oriented) guide to the coastal eco-
systems characterization products (narrative, atlas,
and data appendix). The present paper traces this
evolution and describes the model/user package
concept adopted for the sea island characterization
project.
CONCEPTUAL MODELING-
INITIAL PROPOSAL
In August 1976, the Division of Marine Re-
sources, South Carolina Wildlife and Marine Re-
sources Department, responded to RFP FWS-8-
206 with a proposal to develop a comprehensive
ecological characterization of the sea islands and
coastal plain of South Carolina and Georgia. In this
document we proposed a schedule of ecosystem
modeling strongly based in systems analysis (Dale
1970). The model we initially proposed to develop
was to serve four primary functions: (1) orderly
accumulation of knowledge about the ecosystem;
(2) synthesis of this knowledge into functional
relationships; (3) definition of areas in need of fur-
ther study; and (4) systems analysis for planning
and management of resource utilization and con-
servation. Thus, it would indicate what data are to
be collected and where they would be used in the
actual characterization.
The model was to be characterized by four
basic elements: compartments, flows between
entities, major inputs or external driving forces,
and major outputs or products. The compartments
would identify major entities and sets within enti-
ties. In principal subsystems, the compartments
would identify habitats and then major storage
areas (biotic and abiotic) within the subsystems.
Major driving forces (inputs) and products (outputs)
19
would be used to bidance flows within the model
and to identify primary areas of concern for
management and development activities.
We proposed to illustrate the model with
Forrester Diagrams, foUowing the pattern adapted
by the IDOE-CITRE group in their proposal
(1972). The units of the compartments and flows
would change in relationship to the subsystem
under study, i.e., gC/m"^ for energy flows,
mg/m /yr for nutrient flows, etc. Because the
Forrester Diagrams (Forrester 1961) would quickly
become unmanageable in an ecosystem as complex
as sea islands, each set within each subsystem was
to be treated independently. The subsystems
would then be abbreviated when combined to form
the principal model. It would thus be possible to
maintain a manageable matrix for the ecosystem
model as a whole and still have high resolution as
each major entity is encountered.
In practice, the major entities (habitats) incor-
porated into the sea island ecosystem model would
include, but not be limited to, the following: off-
shore euhaline, inshore euhaline, ocean beach (in-
cluding shifting dunes), stable dunes, maritime
forest, pine forest, coastal plain, marsh (including
tidal creeks, river beaches, mud flats, freshwater
marsh, brackish water marsh, salt marsh, high
marsh, low marsh, marsh impoundments), fresh-
water, and estuary. Within each subsystem the
principal physical, chemical, geological, and bio-
logical entities would be compartmentalized. For
example, in modeling the chemical processes of an
estuary, the important variables would include
salinity (as an index of mixing and a habitat
determinant), temperature, concentration of dis-
solved oxygen, pH, alkalinity, concentrations of
organic materials (dissolved and particulate),
nutrient levels, concentrations of certain metals,
etc. Biological modeling within subsystems such as
estuaries would not proceed to the individual
species level but would deal with spatial variation
as distributed sources and sinks (Nihoul 1975).
Biological subsystems would be comprehensively
resolved into component biotic subsets (e.g., phyto-
plankton, zooplankton, nekton, benthos, etc.) and
linked through major variables (nutrients, carbon,
etc.) within the system. In addition, external driv-
ing forces (temperature, salinity, light, alloch-
thonous materials, etc.) for each subset, and export
links to other subsets or subsystems, would be
identified. The final model was envisioned as a
block diagram with blocks representing the major
components and lines indicating flows (of carbon.
energy, etc.) from one component to another and
the relationships between subsystems (Patten 1971;
Odum and Odum 1972).
CONCEPTUAL MODELING-
INTERIM PROCEDURE
The above protocol for conceptual modeling
was initiated in February 1977. However, we
quickly found that these models actually had oiily
narrow application to the project. Also, it became
apparent that the list of major entities (habitats) to
be incorporated into the ecosystem model would
have to be revised. The revision was accomplished
by using a synthesis of aquatic and terrestrial
terminology and the U.S. Fish and Wildlife Service's
Interim Classification of Wetlands and Aquatic
Habitats of the United States (Cowardin et al.
1976). This synthesis resulted in the identification
of seven primary systems (marine, estuarine,
riverine, palustrine, lacustrine, maritime, and
upland to be modeled encompassing a total of 32
major subsystems (fig. 1). Various subsystems will
also be modeled. The ecosystem models were
to be used to identify system components and to
structure them into an expanded subject outline
for the characterization.
The value of the conceptual model in relating
functional interactions and regulatory processes, as
well as identifying system components, prompted
us to pursue models which could be integrated
with the characterization atlas and narrative. There
the models would present a preface summary of
each ecosystem and also function as a user tool in
understanding the impact of impingments or
perturbations on system components. To perform
as part of a user package, the complexity of the
master" models would often be dissected into sub-
system models or submodels. Submodels are
generally divided into four formats:
1. Terrestrial or hydrological submodels (soil
types, elevation, wind, wave action, cur-
rents, tidal action, dispersed, diffusion,
etc.);
2. Environmental quality submodels (physical
states, chemistry, etc.);
3. Microbiological submodels (viruses, bac-
teria, fungi, microscopic algae, and inverte-
brates); and
4. Macrobiological submodels (macroscopic
plants and animals, population dynamics,
etc.). These submodels are rarely indepen-
20
MARINE (M)
Subtidal Systems
— Coastal Waters ( I ) '
ESTUARINE (E)
Subtidol Systems
— Open Waters and Boys ( I
RIVERINE (R)
'-tLow Gradient Reach
— Open Waters ( I )
^Tidal Reach
Subtidal Systems
— Open Waters (4)
PALUSTRINE (P)
LACUSTRINE (L)
■Profundol
— Natural Lakes and
Reservoirs ( I )
•Littoral
-Nalurol Lokes and
Reservoirs
(WETLANDS)
-intertiddl Systems
L-Beach (2)
-Intertiddl Systems
-Flats (2)
— Impoundments (3)
— Emergent Wetlands (4)*
(salinity modifier)
-Emergent Wetlands (2)
-Forested Wetlands (3)^^^
-Intertiddl Systems
— Ricefield Impoundments (5)
—Forested Wetlands (6)-
'— Emergent Wetlands (7)
-Emergent Wetlonds ( I )
-Forested Wetlands (2 ) (7)
-Emergent Wetlands (2)
-Forested Wetlonds (3) (9)
I Li:
MARITIME (M)
I ) Keys and Bonks r
(3) Dunes
(4) Transition Shrub-
(5) (Maritime Forest —
UPLAND (U)
( I ) Agriculture —
(2) Old Fields—
Pine Forest-
(4) Woodlond
Mixed Pine/Hcrdw'd-
(5) Woodlond-
•AMIOOO Marine Subtidal Systems Coastal Waters
AIVI2000 Marine Intertidal Systems Beach
AE1000 Estuarine Subtidal Systems Open Waters & Bays
AE2000 Estuarine Intertidal Systems Flats
AE3000 Estuarine Intertidal Systems Impoundments
*AE4000 Estuarine Intertidal Systems Emergent Wetlands
(Salinity Modifier)
AR1000 Riverine Low Gradient
AR2000 Riverine Low Gradient Emergent Wetlands
*AR3000 Riverine Low Gradient Forested Wetlands
AR4000 Rivering Tidal Reach Subtidal Systems Open Waters
AR5000 Riverine Tidal Reach Intertidal Systems Ricefield Impound-
ments
AR6000 Riverine Tidal Reach Intertidal Systems Forested Wetlands
AR7000 Riverine Tidal Reach Intertidal Systems Emergent Wetlands
AP1000 Palustrine Emergent Wetlands
AP2000Palustrine Forested Wetlands
•Models selected for Santee test characterization.
AL1000 Lacustrine Profundal Natural Lakes and Reservoirs
AL2000 Lacustrine Littoral Emergent Wetlands
AL3000 Lacustrine Littoral Forested Wetlands
TM1000 Maritime Keys & Banks
TM2000 Maritime Keys & Banks Beach
TM3000 Maritime Dunes
TM4000 Maritime Transition Shrub
TM5000 Maritime Forest
TU1000 Upland Agriculture
TU2000 Upland Oil Field
TU3000 Upland Pine Forested Wetland
•TU4000 Upland Pine Forest
TU5000 Upland Mixed Pine/Hardwood Forest
TU6000 Upland Mixed Pine/Hardwood Forested Wetland
TU7000 Upland Mixed Hardwood Forested Wetland
TU8000 Upland Mixed Hardwood Forest
TU9000 Upland Mixed Hardwood Forested Wetland
Figure 1. Master models - Sea Island Characterization
21
dent and often overlap or partially fuse.
The relative importance of each submodel
within the ecosystem model is, of course,
variable among ecosystems. In aquatic and
wetland ecosystems this submodel interde-
pendency is epitomized (Hansen 1975),
and submodels of major ecosystems have
metamorphosed into integrated subsystem
models.
Modeling biological systems or attempting
biological simulation has evolved into the concep-
tualization of biological components and processes
against a background of physical and chemical
variables. Such models are often considered to
belong to one or more of the following hierarchical
classifications:
1. Ecosystem models;
2. Productivity models;
3. Population models; and
4. Process models.
These are listed more or less in order of decreasing
complexity, but no hard and fast definitions are
possible. In our attempt to provide conceptual
modeling to a user package, the master models
(fig. 1) probably best demonstrate the ecosystem/
process model approach while submodels are more
often population/process model oriented.
The following display illustrates how we
expected the conceptual models to function in the
user package. Figure 2 is master model AE4 (fig. 1),
a simplified ecological/process model of an
estuarine intertidal system— emergent wetland with
salinity modifiers (i.e., salt and brackish marsh).
It is this model to which the user is first directed in
order to convey the physical, chemical, and biologi-
cal interactions and the primary driving forces.
This model is further dissected into component
system submodels: figure 3, AE41 (marsh);
figure 4, AE42 (water); and figure 5, AE43 (sedi-
ment). The user can refer to the appropriate sub-
model for specific information on master model
components. For example, if the user is interested
in evaluating the impact of dredge-and-fill opera-
tions in an estuarine emergent wetland, he is
directed by the master model to the marsh and
water submodel primary producer components. All
compartments in the submodels are numbered
(01-99) and specific organisms can be identified as
components by their associated alphanumeric code
(see submodels tor specific examples). Ecologically
and/or numerically important species could be
identified by this code in the characterization
narrative and atlas.
CONCEPTUAL MODELING-
CURRENT APPROACH
The interim procedure described above, while
attractive in theory, was extremely cumbersome to
use. The total number of master models and sub-
models needed for the entire study area would
have amounted to well over 100 and the technique
for referencing key species into the models would
have resulted in thousands of manhours for cita-
tion and annotation in the other characterization
products. In addition, the interim procedure did
little to communicate the contents of the charac-
terization products to primary users (i.e., field
biologists).
The present approach attempts to provide a
user-oriented system of access to product informa-
tion as well as an ecological understanding of the
various habitats comprising the study area. The
modeling effort has been altered appreciably to
enhance the value of the models as primary com-
ponents of a "user package." The materials con-
tained in this "package" are assembled to supple-
ment and provide rational entry into the principal
products of the characterization project (i.e., nana-
tive, atlas, data appendix, and bibliography). The
package is a user guide and is composed of four
major parts: an executive summary, models,
habitat distribution of various species, and inter-
action matrices. The executive summary' will pro-
vide an introduction to characterization concepts,
a brief summary of the sea island ecosystems and
general instructions for using the package
components for data search and retrieval. Models
are included to acquaint the reader with the princi-
pal components of each ecosystem and the extrin-
sic forces and intrinsic relationships associated with
these components. The models are presented in a
diagrammatic (energese) and a pictorial mode,
hence combinatorial. The ecological sketches are
brief narratives on "high priority" species, and
summarize their reproductive and cover require-
ments, and impinging human activities. Finally, the
interaction matrices will form the central com-
ponent of the user package. Each ecosystem will be
supported by a single matrix which cross-references
common environmental alterations with existing
environmental characteristics. Each intersection of
the matrix will thus provide appropriate entry into
the characterization products.
The functional components of the user package
are the combinatorial models, ecological sketches,
and the interaction matrices. The combinatorial
22
other
Consumers
Nutrient
Regeneration
-Nl — >- Pollution
1
(Modified from Day et al. 1973)
Migration
Figure 2. Master Model AE 4000: estuarine intertidal system— emergent wetland (salinity modifier)
General increase in organic carbon flow
^^ Prlmory
Rica 1 Consumers
rot
I IrxKIl I
Snalh
s.t4
Bird*
01 /
X
03/\
ybeod^
'iStondir*
\Xrop .
V . Decomposers
V 1 ^^HBoctsrid Fungi x^^
y-
»tes
>
^-TSecondory r
^/ / Consumerk'
Tertlory
Consumer*
Votculor \
Plontt j
1 \ /V^/
^
\,
/^ Blus
(,^Crraaco in ctrtmrl enerov
(Submodel AE42)
■>
Figure 3. Submodel AE41: estuarine intertidal emergent wetland-marsh.
23
EMERGENT
WETLAND
EXPORTS
eg
AE4202 Sk«lelon«mo coilohim
AE<»<:04 P«ng«ui lellferut
AE4205 Cro»»otlr«o virglnico
AE4206 Acorllo tonio
AE42IO Collln«cl«« topldm
AE42il Archotorgui proboloc«pholu>
AE42I2 Egfilta Ihulo
EXPORT
■Ii4a
M
FROM SYSTEM
Figure 4. Submodel AE42: estuartne intertidal system - water
eg
AE430I OscHiotorlo sp.
AE4303 Nitrosomonos spi
AE4304 Horpoctlcus llttorollg
EMERGENT
WETLANDS
WATER
Figure 5. Submodel AE43: estuarine intertidal emergent wetland -- sediment
24
models for the entire characterization are listed in
figure 1. The four models compiled to date for the
Santee Test Characterization Area (fig. 1) are: the
marine subtidal system, the estuarine intertidal
emergent wetland system (fig. 6), the riverine fore-
sted wetland system, and the upland pine forest
system. The user would first be directed to these
and should pursue the appropriate model(s) for the
system(s) in question. Each system is displayed in
dual form: an energese diagram showing energy
flow into the system, interrelationships between
components of the system, and flow from the sys-
tem (fig. 6), and an accompanying pictorial or pic-
tograph (fig. 7) illustrating representative flora and
fauna tagged with appropriate producer or consu-
mer symbols. The user should examine the model
to either reaffirm presumptive relationships or
establish initial relationships.
At this time, the user may also wish to review
species abundance and distribution charts if his/her
interests encompass or center on a specific group
or individual organisms. These charts are arranged
taxonomically and each is composed of representa-
tive species from the group. The reader may now
return to the models, or advance to the characteri-
zation products through the interaction matrices.
The matrices provide points of entry to the
characterization products based on specific interests
of the reader. A customized matrix (e.g., fig. 8) is
constructed for each ecosystem modeled and pre-
sents intersections between primary existing envi-
ronmental characteristics and proposed environ-
mental alterations. Each intersection will provide a
coded entry (blanks will indicate data gaps and an
"x" will indicate an inappropriate interaction) to
the characterization narrative and atlas, and back
references to the models and ecological sketches.
The narrative, atlas, and sketches will, in turn, pro-
vide entry to the data appendix and bibliography.
In plan, the system should function as illustrated in
figure 9. The matrix is the central reference, keying
to, and being keyed from, all other products of the
characterization. In combination, the models,
ecological sketches, and interaction matrices
should reveal to the reader ramifications and rela-
tionships that are not at first apparent. They should
also allow full utilization of the characterization
products by a wide spectrum of users with diverse
educational backgrounds, interests, and needs.
organizing the package materials. We also thank
Drs. Lee Barclay and Paul Sandifer for reviewing
the manuscript, Ms. Jane Davis, Karen Swanson,
and Rose Smith for preparing the figures, Mr.
David Chamberlain for constructing the ecological
sketches, and Ms. Mary Anne Carson for prepara-
tion of the typescript.
ACKNOWLEDGEMENTS
We thank Mr. John Miglarese for his valuable
assistance in planning the user package concept and
25
Nitrogen
Fixation
Other
Consumers
Nutrient
Regeneration
KEY
a Energy > >» Wo
Source j^
T
j/\. Passive |>^V.
\_/ Storage l^
I
rkgate
Consumer
Plant
I J Popu-
lations
Sink
(after Odum, 1971)
(UoililUil liom Doy •! Hi , 1973)
Seasonal
Triggers
Figure 6. Master model AE4000: estuarine intertidal system - emergent wetland
(salinity modifier)
26
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^ COMBINATORIAL /Z
■^ MODELS //.
ATLAS
ANNOTATED
BIBLIOGRAPHY
V//7///M
ECOSYSTEM;
MATRICES
NARRATIVE
ATLAS
DATA
APPENDIX
ANNOTATED
BIBLIOGRAPHY
ATLAS
DATA
APPENDIX
ANNOTATED
BIBLIOGRAPHY
Figure 9. Flow diagram for user orientation to characterization products.
30
LITERATURE CITED
Cowardin, L. M., V. Carter, F. C. Golet, and
E. T. LaRoe. 1976. Interim classification of
wetlands and aquatic habitats of the United
States. U.S. Fish and Wildlife Service. 109 pp.
Dale, M. B. 1970. Systems analysis and ecology.
Ecology 51(1): 1-16.
Day, J. W., W. G. Smith, P. R. Wagner and
W. C. Stowe. 1973. Community structure and
carbon budget of a salt marsh and shallow bay
estuarine system in Louisiana. Center for Wet-
land Resources, Publ. LSU-SG-72-04.
Forrester, J. W. 1961. Industrial dynamics. MIT
Press, Cambridge, Massachusetts. 464 pp.
Hansen, J. 1975. Aquatic ecosystem analysis and
modeling. A Sea Grant perspective. The
Oceanic Institute, Waimanalo, Hawaii.
IDOE-CITRE Group. 1972. International decade
of ocean exploration: a proposal for compara-
tive investigations of tropical reef ecosystems.
Nihoul, J. C. J.; ed. 1975. Modeling of marine sys-
tems. Elsevier Scientific Publ. Co., Amsterdam,
the Netherlands. 272 pp.
Odum, E. P., and H. T. Odum. 1972. Natural areas
as necessary components of man's total envi-
ronment. Trans. N. Am. Wildl. and Nat. Resour.
Conf. 27: 178-179.
Palmisano, A. W. 1978. Ecosystem characteriza-
tion—an approach to coastal natural resources
planning and management. In: Proc. of a Con-
tributed Session on Coastal Ecosystem Charac-
terization and Management— Fourth Biennial
International Estuarine Research Conference,
Mt. Pocono, Penn. 2-5 Oct. 1977. U.S.Fish and
Wildlife Service-Office of Biol. Serv. Publ.
77-37. Washington, D.C.
Patten, B. C, ed. 1971. Systems analysis and simu-
lation in ecology. Academic Press, New York.
607 pp.
31
THE CONSTRUCTION OF A CONCEPTUAL MODEL OF
THE CHENIER PLAIN COASTAL ECOSYSTEM
IN LOUISIANA AND TEXAS
L. M. Bahr, Jr.,1 J. W. Day, Jr.,i T. Gayle,2
J. G. Gosselink.i q s. Hopkinson.i ^nd D. Stellar^
INTRODUCTION
Increasing interest in coastal areas on the part
of environmentalists, developers, and managers has
generated the need to understand the function of
these productive and fragile areas, and to predict
the effects of further alterations to them. The term
"function" as used throughout the following
description of the Chenier Plain conceptual model
is intended to describe the mechanics of the eco-
system, i.e., the pathways and processes by which
energy and matter are captured, transferred, par-
titioned, stored, cycled, and degraded by the
system. Examples of functional processes include
primary production, water flow, trophic exchanges,
and animal migrations. Functional understanding
of an ecosystem includes much more than an
inventory of important physical parameters and
organisms; it requires a holistic, systems-level
analysis which identifies important interactions
among biological and physical components of the
system, and all important control features and
feedback mechanisms.
In late 1975, the Fish and Wildlife Service
(FWS), U.S. Department of the Interior, funded a
study of the Chenier Plain coastal ecosystem(s) of
southeastern Texas and southwestern Louisiana
(Galveston Bay, Tex., to Vermilion Bay, La.) in
which the area would be characterized ecologically
by the development of a conceptual model of the
system and a synthesis of all extant data. This char-
acterization was designed to serve as a pilot study
for similar projects which will eventually describe
all U.S. coastal ecosystems. The specific request was
for a "description of the important resources and
processes comprising the ecosystem and an under-
standing of their functional relationships." (FWS
Request for Proposal, 4 December 1975.) The
first requirement of this study (and the key to the
^Center for Wetland Resources, Lxjuisiana State University, Baton
Rouge, La. 70803
^Center for Wetlands, University of Florida, Gainesville, Fla. 32601.
entire project) was the formulation of a conceptual
model of the ecosystem(s). The model was to con-
sist of a schematic framework of ecosystem func-
tion in which all important processes and inter-
actions among components would be identified in
a qualitative manner. The completed model would
identify data requirements and gaps, and set the
stage for the two remaining portions of the study,
a characterization atlas, and a quantitative ecologi-
cal simulation model of the study area which could
be used to aid in making management decisions.
The study area is called the Chenier Plain, so
named because of a series of prominent ridges
known as cheniers that transect the region from
east to west. "Chenier" is a French word meaning
"place of oaks;" the vegetation of undisturbed
chenier ridges is characteristically dominated by
live oak (Quercus virginiana) trees. /
This report describes the structure of the con-
ceptual model developed for this study and dis-
cusses the technical and management problems it
was designed to solve.
PROBLEM
Any ecological model of the Louisiana-Texas
Chenier Plain must take into account the following
four factors:
1 . Spatial heterogeneity. The area described as
the Chenier Plain (fig. 1) is highly variable
in space; from east to west it is broken up
by a series of rivers flowing southward into
the Gulf, through lakes of different sizes
and salinities, and over thousands of square
miles of wetland. The wetlands themselves
are not all homogeneous; vegetation ranges
from pure stands of saline oyster grass
(Spartina alterniflora) to fresh water bull-
tongue (Sagittaria falcata) and maidencane
(Panicum hemitomon). They are cut by ele-
vated cheniers or ridges which function
32
X
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S
3
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s
o
s
.e
.1
33
ecologically much differently from the adja-
cent wetlands. Large areas, wetland and
highland, have been modified for agricul-
ture or are managed for waterfowl or fur-
bearers. The region is far from homogeneous
and any model that ignores this will produce
information of limited management value.
2. Ecological or functional complexity. Aside
from this spatial heterogeneity, within any
small, fairly homogeneous area, the ecologi-
cal food web is enormously complex and,
on the whole, poorly understood.
3. Time scale of events. Events of ecological
interest in the Chenier Plain, which deter-
mine the physiography of the whole region,
occur on the scale of hours, days or seasons
for many biological processes; years or tens
of years for many cumulative impacts, such
as canal dredging and eulrophication; and
thousands of years for geological processes.
It is difficult to visualize a useful model
which can simultaneously simulate geologi-
cal processes and microbial kinetics in
terms usefvd to a manager.
4. Management needs. In addition to the above
considerations the model must enable a
manager to evaluate the consequences of
alternate management strategies at appro-
priate levels of spatial, ecological and
temporal resolution. Existing models cover
a wide range of approaches, including
strategies to exploit or manage single com-
mercial species [such as fishery models
(Wagner 1969) or alligator models (Nichols
et al. 1976)]; models which treat ecosys-
tems as homogeneous in space in order to
elaborate the energetic interactions (Patten
et al. 1975; Wiegert et al. 1975); models
which treat spatial heterogeneity but con-
sider only a limited number of chemical or
biological parameters (Kremcr and Nixon
1975), and dramatically simplified, dynamic
world-view models (Forrester 1971).
SOLUTION
The problems of resolution, complexity, and
time frame were addressed by the construction of
nested hierarchical conceptual models at four levels
of resolution: region, drainage basin, habitat, and
population levels (fig. 2). Individual populations
are components of habitats, the smallest ecological
units described in the Chenier Plain. Each habitat is
considered homogeneous in space. Each of the six
Chenier Plain basins is a spatially heterogeneous
area composed of a number of interacting habitats.
The time scale of events of interest increases from
habitat to region.
THE CHENIER PLAIN REGION
The Chenier Plain region is unified by a com-
mon geologic history; the sediments that underlie
this major coastal system originated primarily from
riverine sediments supplied by the Mississippi River.
The primary geophysical process responsible for the
unique physiography of the Chenier Plain has been
the periodic alteration in course of the main dis-
tributary of the Mississippi River. This switch has
occurred on the average about every 400 years over
the last 7,000 years, and has caused major changes
in sediment input to the Chenier Plain region. For
example, when the river is discharging on the eastern
side of its delta (as it is presently, see fig. 1), little
sediment reaches the Chenier Plain. But when the
discharge is on the western side much sediment
reaches the Chenier region. In the former case, ero-
sion dominates, and in the latter, deposition and
growth dominate. The Atchafalaya River, just east
of the Chenier Plain (fig. 1), is beginning the long
process of capturing the main channel flow of the
Mississippi River, and accretion is beginning to re-
verse the shoreline retreat measured over the past
several decades.
Change in sediment availability has in turn
been reflected in the formation of the cheniers,
which are stranded dune ridges parallel to the
present shoreline. Man has had little effect on the
regional development of the Chenier Plain.
The conceptual model of the Chenier Plain
region is primarily a model of geological processes
(fig. 3). The symbolic "energese" language (Odum
1972) is used in the models illustrated. It is dis-
cussed more fully in Bahr et al. (1977). Figure
legends are complete enough for readers to follow
the diagrams without full comprehension of the
symbols. These processes are not strongly influ-
enced by man, except as he controls the flow of
the Mississippi River.
BASINS
Drainage basins represent perhaps the most
natural category of ecological systems in the
Chenier Plain region, because each basin is integra-
ted by the flow of water over and through it; yet
34
REGION
CHENIER PLAIN
TIME SCALE
1000 ■¥ YEARS
BASIN
CALCASIEU
BASIN
I -100 YEARS
HABITAT
i.
"^
O.OI- 10 YEARS
OPEN WATER
~ BRACKISH MARSH
POPULATION
O.OI -10 YEARS
Figure 2. The Chenier Plain conceptual hierarchy.
Figure 3. A simplified model of the formation of the Chenier Plain system. Geologic processes (a)
lead to the Mississippi River switching course and control the supply of riverine sediments (b).
These sediments form an offshore mud flat. If sediment supply dwindles, the wave energy causes
the offshore mud flat to form a beach (c). The beach gains and loses sediment through littoral
drift (d). As the beach grows up, it strands the mud flat and forms a stranded Chenier Plain
marsh (e, f). Subsidence or sea-level rise can transform this marsh into open water.
35
each basin is relatively autonomous from adjacent
basins in terms of water circulation. Six fairly dis-
tinct basins have been identified in the Chenier
Plain (fig. 4). Each basin has its own hydrodynamic
characteristics determined by such parameters as
size, drainage density, downstream flow, elevation
and slope of the basin, and extent of its connec-
tion with the Gulf via tidal passes.
Most significant changes in a basin occur
through large-scale and cumulative effects over a
period of time measured in years, rather than in
hundreds of years. Examples include: effects of
deep shipping channels on saltwater intrusion;
changes in hydrology associated with stream chan-
nelization; canal dredging and associated spoil bank
formation; and cumulative wetland drainage for
urban and industrial development.
HABITATS
The habitat is the smallest ecological system
considered in our conceptual model. Wherever a
particular habitat occurs on the Chenier Plain it is
treated as the same basic functional unit, and can
therefore be treated as homogeneous, even though
we recognize the existence of gradients, specialized
niches, and discontinuities. Each habitat is a com-
plex ecological system characterized by its own
species, carrying capacities for those species, levels
of production, food web, nutrient cycles, and
physical inputs. The time scale of important events
is often seasonal, and short term impacts are
important at this level.
Most habitats are intuitively distinct. For
example, aquatic systems are quite different from
upland forests; however, different kinds of natural
wetlands are not so clearly unique. For the Chenier
Plain we have identified and mapped 10 natural
habitats: nearshore Gulf; inland open water; salt,
brackish, intermediate, and fresh marsh; wetland
forest; upland forest; beaches; and cheniers and
ridges. Large areas have been modified by human
activity, which we have catalogued into four
additional habitats as impounded marshes, pastures,
rice and crop habitat, and urban habitat.
Complex habitat level models have been con-
structed for each of the 14 habitats to give a quali-
tative functional understanding of each habitat,
and to guide the acquisition of data. As illustra-
tions of the habitat models, figure 5 shows the
aquatic inland open habitat model as it appears in
the conceptual model (Bahr et al. 1977). Figure 6
represents simplified version of the aquatic habitats
(inshore open water and nearshore Gulf of Mexico).
In the conceptual model document, figure 5 is
accompanied by a detailed interaction matrix
keyed to each of the compartments. Figure 7 is the
generalized wedand habitat model, and figure 8 is
the agricultural model, both from the characteriza-
tion atlas. We are at present relatively ignorant of
the internal working of most habitats; thus, those
that are managed/exploited are manipulated at
some peril to the function of the whole system. A
better approach to management is to recognize
that certain renewable resources (or nonresources;
Ehrenfeld 1976) are associated with any habitat,
and in order to protect the resource, one must pro-
tect the habitat.
POPULATIONS
Habitats can be considered as ecological land-
scape units composed of many different popula-
tions interacting with each other and with their
physical surroundings. At the bottom of the con-
ceptual hierarchy of natural history, growth
dynamics and environmental limits are considered
for species of economic, recreational, or functional
importance in the Chenier Plain region. The carry-
ing capacity of a habitat for a particular species is
an important concept that relates the species to its
habitat. Major opportunities for management of a
single species or group of related species occur
through manipulation of habitat (for instance, by
impounding wetlands), or through direct control of
population size through harvesting (fig. 9).
THE BASIN-LEVEL CONCEPTUAL MODEL
The major kinds of manageable processes and
the time scales of manageable events appear to
occur at the basin level. For this reason, major em-
phasis in this discussion is placed on the basin-level
analysis.
Figure 10 summarizes basin-level processes and
interactions. This model is the result of a series of
iterative changes and simplifications of earlier,
more detailed, models of basin function (Bahr et al.
1977). It is extremely aggregated and simpHfied in
order to include only the most critical components
and processes, and to show how water, wetlands,
and man interact in a hypothetical drainage basin.
The basin model is divided into four linked
submodels (fig. 10) each representing a different
set of processes, and each in part responsible for
the present state of a basin, and for the rate at
which it is changing. The four submodels are:
36
I
K
■a.
3
3
.X
-a
o
•a.
S
o
ln runoti
^ NulrMnI and toxin tunoil
Figure 8. The agricultural sector is much simplified ecologically, because cultural practices
subsidized by heavy fossil fuel and fertilizer inputs simplify the food chain. Heat sinks
representing energy loss are implied at each interaction.
39
Wt«t*
Removal
Oyttac
Larva* Production
and Migration
Figure 9. This representation of the major factors controlling the survival and growth
of oysters is an example of population-level models.
Hypothetical Basin Model
B««ln Hydroloqic PTOc»«f «
B«»ln N««uf«l R»aoufC« Productivity
Figure 10. For simplicity, the basin is considered as four interacting sets of processes.
40
(A) Basin hydrologic processes, or water storage
and flow through a basin;
(B) The natural resource productivity of a
basin, or its capacity to support wildlife
and fishery species, and to perform other
work services for man, such as the purifi-
cation and storage of fresh water;
(C) Land modifying processes, particularly
those which result in loss of natural wet-
land; and
(D) Basin-level socioeconomic processes, or
those human activities and management
decisions that impinge directly on natural
processes in a basin.
HYDROLOGY (A)
The hydrologic regime at any specific site within
a Chenier Plain basin is ultimately responsible for
determining the kind of habitat that develops at
that site. Basin hydrology results from interactions
among three modules (fig. 10); water storage in a
basin (Aj^); upstream riverine and rainfall inputs of
water and sediment (A2); and downstream water
with accompanying salts and sediments and tidal
and oceanic storm forces (A3).
The role of hydrology in determining habitat
type is primarily mediated via water levels and
durations, and salinity levels and durations. Water
levels are controlled by the pressure head between
water level at a given site, and upstream and down-
stream water levels. If rainfall raises water levels
upstream, water flows toward the Gulf; likewise, if
tidal stage or a southerly wind raises sea level at the
Gulf, a wave proceeds upstream, gradually diminish-
ing as it goes.
Mean salinity and salinity range at a given site
in the basin are determined by mixing, over time,
of upstream and downstream inputs, and by the
relative volumes of fresh and saline water inputs.
Sediments are carried into a basin by the currents
produced by salinity (density) and pressure
gradients. Sediment deposition is a function of cur-
rent speed, sediment load, salinity, and in some
cases, biological activity.
In summary, the hydrologic submodel sym-
bolizes the complex physiographic configuration of
a basin, which, together with upstream and down-
stream water mputs, determines water level, water
flow, salinity, and sediment regimes at any point in
a basin. These parameters, in turn, constrain the
type of habitat that can develop at any site in ques-
tion. For example, if water level is always below
the land surface, then the habitat is terrestrial. If
the water level is always above the land surface,
then the habitat is aquatic. If water level alternates
above and below the land surface, the habitat is
wetland. Salinity dynamics determine whether a
habitat will be fresh or saline, and sediment
dynamics (either gain or loss) can change one
habitat to another. Man's activity is an important
factor affecting water, salinity, and sediment
cycles.
NATURAL RESOURCE PRODUCTIVITY (B)
Submodel B (fig. 10) represents the natural
work services of a basin; that is, the quality of a
basin with respect to its ability to do such things as
support important fishery and wildlife species, and
to "purify" and store water, all at no cost to man.
"Quality" refers to both the particular blend of
habitats that comprise one basin, and to the fact
that two areas having similar habitat types can vary
greatly in their abUity to support consumer or-
ganisms. For example, the open water habitat can
be in a balanced state with respect to nutrient
input and use, or it can be degraded (by excess
nutrient loading) into various degrees of eutrophica-
tion.
The natural resource productivity (NRP) sub-
model consists of four components (fig. 10): pro-
ducers (Bj), consumers (B2), a refugium (B3\ ^nd
a water storage module (B4). Bj and B2 represent
the species that occur naturally in all wetlands,
water bodies, and ridges in a basin. A particular
habitat can be characterized by its carrying ca-
pacity for these species; as its quality diminishes,
so does its carrying capacity. Diminishing quality
may also lead to changes in community structure
such as the proliferation of undesirable fish species
in eutrophic waters.
Wetlands are natural water reservoirs. Fresh
wetlands and water bodies are especially valuable
for storing surface water, which is often used by
man. For example, much of the irrigation water for
rice in Louisiana and Texas is stored in fresh
marshes. Ground water often extends beyond basin
boundaries, becoming a regional resource.
As water flows over wetlands, many chemical
transformations take place. Inorganic nutrients,
which could encourage eutrophic conditions in
aquatic habitats, undergo important changes. The
41
nutrients may be taken up during plant growth or
by bacteria during detritus formation. Some of
these nutrients may be exported later as organic
detritus, a form more compatible with natural
populations. Phosphorus may physically bind with
sediments, and nitrogen may be denitrified.
The natural resource productivity of a basin is
thus a function of the particular mix of habitat
types, especially the relative proportions of natural
wetlands and water bodies, and the degree of
human perturbation.
LAND MODIFYING PROCESSES (C)
Submodel C (fig. 10) represents the dynamic
habitat area changes that occur within a basin of
constant area. Over the past several thousand years,
the dominant trend has been the growth of the wet-
land habitat concurrent with the formation of new
chenier ridges. The aerial gain of these habitats was
at the expense of aquatic habitats (nearshore Gulf
and inland water bodies). During the past 50 years,
however, the major change has been loss of natural
wetland (C^), either to open water (C2), or by im-
poundment for waterfowl and/or agriculture (C3).
Basically two processes cause loss of natural wet-
land: hydrologic changes resulting from canalling,
marsh burning, or impounding; and natural sub-
sidence and erosion. Hydrologic changes are not
always local phenomena. For example, artificial
maintenance of the present Mississippi River course
on the eastern side of the delta means that very
little new sediment is reaching the area.
SOCIOECONOMIC FACTORS (D)
Submodel D represents human effects at the
basin level (fig. 10). Socioeconomic factors have
been lumped into five main components:
1. The tolid human population in a basin (D^),
its energy and material requirements and its
waste production;
2. Commerce and industry (D2) such as manu-
facturing, refining, retail sales, etc., that
occur in a basin, along with the concomi-
tant waste release;
3. Mineral resources in a basin (D3), primarily
petroleum and natural gas (port and naviga-
tion facilities are included here); the extrac-
tion of minerals and maintenance of naviga-
tion channels entails release of waste, as
well as extensive disruption of natural habi-
tats (dredging, etc.);
4. Fishery' and wildUfe resources harvested by
man (D4) both commercially and for sports
purposes; and
5. All agricultural activity (D5), especially rice
and cattle. This activity also entails signifi-
cant waste release, especially nutrients and
pesticides.
D^, D9, and D5 all require large quantities of fresh
water. Some species in D4, especially waterfowl,
are limited by freshwater bodies, and D3 requires
fresh water for some processes.
BASIN SYNTHESIS
The water requirement of the socioeconomic
submodel (fig. 10) is a convenient place to begin
a discussion of the connections among the four
basin submodels. The basin natural resource fresh
water (B) is required by all five components of sub-
model D, as indicated by the broad-branched arrow.
Many of these water needs are met by groundwater
pumping, but surface fresh water is also used,
especially for rice irrigation and waterfowl habitat.
The other input to submodel D from submodel B
represents the harvest of commercial and sports
fisheries and wildlife, which is a function of basin
quality or natural resource productivity.
Effects of the socioeconomic sector on other
submodels ai'e broken down into waste effects,
effects on hydrology, and developmental decisions
based on market conditions (economics) that lead
to habitat changes.
Wastes, which include nutrients, toxins, and
dredged spoil, affect the natural resource pro-
ductivity of a basin. Nutrient wastes, such as
sewage or fertilizer, can decrease NRP by causing
eutrophication, or if applied judiciously to wet-
lands, can actually increase NRP. Toxins such as
pesticides and heavy metals generally lower NRP,
and may selectively reduce higher consumers with-
out affecting lower trophic levels. Another form of
waste is dredged material which can create silting
problems, e.g., destruction of oyster beds by silta-
tion.
The socioeconomic sector affects basin hy-
drology via activities that disturb natural circula-
tion patterns, especially by dredging canals or navi-
gation channels (Stone and McHugh 1977). Fresh-
water pumping can also affect hydrologic change
by lowering the water head relative to sea level and
causing salt water intrusion. Freshwater availability
is so critical to all socioeconomic sectors that it can
set ultimate limits to economic growth and develop-
ment in a given basin.
42
Socioeconomic effects on physiography (C) in-
clude decisions that lead to development of natural
wetland areas for economic gain, or for human
leisure use. Examples include decisions to "reclaim"
wetland for agriculture or for duck habitat.
Another major cause of wetland loss arises
from long-range hydrologic changes that accom-
pany canaling and other local wetland perturbation
(arrow from A to C in fig. 10). This same change in
local hydrology affects the natural resource pro-
ductivity (arrow from C to B).
SUMMARY
The generalized Chenier Plain basin ecosystem
and its critical wetland component is basically
driven by hydrologic forces. Habitat area changes
are primarily wetland loss to open water and to im-
poundments, resulting in modification of natural
resource productivity. All three of these processes
(hydrologic, habitat, and resource productivity
changes) are strongly influenced by the intensity of
human socioeconomic activity in the basin.
LITERATURE CITED
Bahr, L. M.,J. W. Day, Jr., T. Gayle, and C. S. Hop-
kinson. 1977. A conceptual model of the
Chenier Plain coastal ecosystem of Texas and
Louisiana. Louisiana State Univ. Cent, for Wet-
land Resour., Baton Rouge.
Ehrenfield, D. W. 1976. The conservation of non-
resources. Am. Sci. 64(6):648-656.
Forrester, J. W. 1971. World dynamics. Wright
Allen, Cambridge, Massachusetts. 142 pp.
Kremer, J. N., and S. W. Nixon. 1975. An ecologi-
cal simulation model of Narragansett Bay— The
plankton community. Pages 672-690 in L. E.
Cronin, ed. Estuarine Research, Vol. 1. Aca-
demic Press, New York.
Nichols, J. D., L. Viehmaw, R. H. Chabreck, and
B. Fenderson. 1976. Simulation of a commer-
cially harvested alligator population in Louis-
iana. La. State Univ. Agri. Exp. Stn. BuU. 691.
59 pp.
Odum, H. T. 1972. An energy circuit language for
ecological and social systems: its physical basis.
in B. C. Patten ed., Systems Analysis and Simu-
lation in Ecology, Vol. 2. Academic Press., N.Y.
Patten, B. C, D. A. Egloff, and T. H. Richardson.
1975. Total ecosystem model for a cove in
Lake Texoma. in B. C. Patten ed.. Systems
Analysis and Simulation in Ecology, Vol. 4.
Academic Press, N.Y.
Stone, J. H., and G. F. McHugh. 1977. Simulated
hydrologic effects of canals in Barataria Basin:
A preliminary study of cumulative impacts.
Rept. to Louisiana State Planning Office.
Wagner, F. H. 1969. Ecosystem concepts in fish
and game management. Pages 259-307 in
G. Van Dyne ed.. The Ecosystem Concept in
Natural Resource Management. Academic Press,
N.Y.
Wiegert, R. G., R.R.Christian, J.L.Gallagher,
J. R. Hall, R. D. H. Jones, and R. L. Wetzel.
1975. A preliminary ecosystem model of a
coastal Georgia Spartina marsh. Pages 583-601
in L. E. Cronin ed., Estuarine Research, Vol. 1.
Academic Press, N.Y.
43
MAINE COAST CHARACTERIZATION USER'S GUIDE
Stewart I. Fcfer,^ Curtis Laffin,^ Larry Thornton,'
Patty Schettig,' and Russ Brami'
INTRODUCTION
The evaluation of natural resources, and tho-
rough reviews of their alternative uses, are essential
components of any decisionmaking process affect-
ing our environment. There must be a basis for es-
tablishing policies affecting land use and conserva-
tion of resources; a holistic approach integrating
the many disciplines of natural resources is th*e
foundation upon which these policies can be built.
The objective should be to maintain a diverse and
productive natural environment. The holistic
approach set forth here is known as the Ecological
Characterization of Coastal Maine.
An environmental management program must
embrace whole ecosystems (Van Dyne 1969,
Odum 1971, Moen 1973, Clark 1977, Likens et al.
1977). "Ecosystem" is defined by Odum (1971) as
". . . any area of nature that includes living or-
ganisms and non-living substances interacting to
produce an exchange of materials between the
living and the non-living parts." It is a general term
concerned with structural and functional relation-
ships, but without precise information about these
relationships, it is difficult to assess the impact of
human activities on an ecosystem. Lack of ecosys-
tem understanding has caused management prac-
tices to emphasize strategies that maximize the
output of some desirable product, i.e., species man-
agement of waterfowl or fishes. It is evident that a
new conceptual approach to the management of re-
sources is desirable (Likens ct al. 1977). The charac-
terization is designed to provide an ecosystem view
of the Maine coastal zone, from Cape Elizabeth to
Eastport (fig. 1) by treating entire ecological sys-
tems as single interacting units and describing:
1. Driving forces of the Maine coastal ecosys-
tem;
Energy Resources Company, Inc., Cambridge, Mass.
Fish and Wildlife Service, U.S. Dept. of the Interior, Newton
Corner, Mass.
2. The components of the ecosystem;
3. Functions of componenls;
4. Interrelationships of components and fimc-
tions; and
5. Seasonal and long-term changes of compo-
nents.
Specific objectives of the ecological characterization
are to:
1. Obtain and synthesize available ecological
data which describe important resources,
processes, and their interrelationships with-
in the study area;
2. Identify information deficiences and re-
search priorities; and
3. Provide an assessment of the state of know-
ledge for the Maine coast ecosystem.
The characterization sei"ves the needs of (1) the
administrator and planner when making decisions
on land-use planning and natural resource manage-
ment and (2) the scientist seeking the status of
Maine coast ecological knowledge in disciplines
relative to his or her field.
The Maine Coast Ecological Characterization
will be completed in late 1979. This User's Guide,
in its revised form, will be a part of the completed
characterization; it directs various users how to
manipulate the materials in the characterization to
satisfy their specific needs.
THE PHYSIOGRAPHIC ECOSYSTEM-
THE MAINE COAST
Land forms rellcct the geologic events which
have had a major influence on the evolution of the
biota because the types and structures of bedrock
exposed to uplifting, weathering, and glaciation
have had a great influence on the physiography of
the Maine coast. The development of vegetation is
controlled by these factors, climate, and animals
(including man). The native fauna has evolved be-
cause of its compatibility with the established vege-
tative community (Shelford 1963). The land-use
activities of man have also been influenced by
physiographic constraints. Thus, physiography is a
major influence on the physical, biological, and
44
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50
basic laws which govern the behavior of
energy. The conceptual energese model
(fig. 6) illustrates the flow of energy
through an ecological system. Figure 7
applies this energese model to the naturally
occurring eelgrass community. Figure 8 fur-
ther illustrates the relationship between the
energy flow model and the natural system,
in this case the intertidal emergent wetland.
Biogeochemicals— Elements and inorganic
compounds, many of which are essential
components for growth, circulate through
the biosphere (soil, water, and air) in
characteristic patterns known as biogeo-
chemical cycles (fig. 9).
3. Abiotic factors— Essential environmental
factors which make life possible on the sur-
face of the earth are the constant inter-
actions of geologic, climatic, hydrologic,
and oceanographic changes.
4. Biotic factors— The biotic world is classified
in respect to energy through trophic levels,
each of which is one exchange step beyond
the energy source which drives it (fig. 10).
Web diagrams will be used to depict trophic
levels and energy flows by using food webs
as examples.
These concepts have been described by various ,
prominent ecologists as being illustrative of the
interactions within a system. H. T. Odum (1966)
Figure 6. Conceptual energy flow model.
MkiohUI calMM
Figure 7. Energy flow model of a natural eelgrass community.
51
Figure 8. A simplified energy flow model typical of an estuarine system.
y^^.^ ^y ""---.rfs
Trophic level 4
Trophic level 3
Trophic level 2
Trophic level 1
ih.
INCIDENT LIGHT ENERGY
Top carnivore!
Carnivores
Herbivores
'ENERGY
LOST
AT
, EACH
Photosynlhetic \ LEVEL
plants, primary
producers
Figure 9. Conceptual model of the hydrologic
cycle (adapted from Caswell 19/7). Elements and
inuriianic compounds, many of which are essential
components for the biolta, circulate through the
biosphere dissolved in waters.
Figure JO. Simple trophic pyramid of energy
(Odum J 971).
52
has developed the concept of energy flows and
interactions, which can be illustrated through ener-
gese diagi'ams. This energy concept can be
developed to a sophisticated science of quantitative
ecological system modeling when such data are
available (Hall and Day 1977). Flow diagrams can
be used, for example, to translate an understanding
of biogeochemical cycling which is essential to the
appreciation of the interactions among living and
nonliving components (Hutchinson 1944, 1950).
Likens et al. (1977) have studied these cycles in
depth and have quantified certain biogeochemical
pathways in a terrestrial system in New Hampshire.
Food webs are used to illustrate interactions
between the plant and animsd components of a sys-
tem. Abiotic factors interact to form the habitat
templates governing the use of an area by the biota.
Ecologists apply any one or combinations of the
four primary concepts to illustrate and compre-
hend interactions in ecological systems; we have
attempted to apply all of these concepts to illus-
trate interactions. It is important to realize that
these concepts are not exclusive of each other but
overlap and are complementary. Here they are
applied to the ecosystems, systems, and classes
found on the Maine coast and become the frame-
work of the conceptual model (fig. 11).
THE GROUPS-OF-INTEREST APPROACH
Another approach to understanding the Maine
coast ecosystem is to translate an organism's de-
pendency on and participation in the interactions
previously discussed.
The ecosystem approach emphasizes the habitat
as an entity. In the groups-of-interest approach,
interrelationships between commercially and
ecologically important groups of species and their
environments are emphasized (fig. 12). The uses of
habitats for various life stages, reproductive strate-
gies as controlled by limiting factors, and the
importance of man and management are discussed.
Case studies illustrating the above concepts are in-
cluded within the discussion of each group of in-
terest.
This section complements the ecosystem
approach in that it illustrates the varied needs of
important organisms in terms of habitats and com-
ponents of habitats.
THE ATLAS
The Atlas presented as a volume of the report
is to be used in conjunction with the text. Table 1
lists the contents of the Atlas. The specific maps
and overlays illustrate locations of selected com-
ponents and aid in directing interactions of driving
forces and components.
Table 1. Overlays of the Maine Test Characterization Atlas
Figure 11. A conceptual model illustrating the
interactions of the primary concepts applied to the
Mame coast ecosystem.
National Wetlands Inventory
Land cover
Marine geology
Soils
Substrates
Sea bird, wading bird,
shore bird, eagle, and
osprey nest sites
Shellfishes, marine worms
Harbor seal haulout sites
Tidal range, currents
High and low water
Point sources
Named lakes with sum-
marized data
Wedands important to
waterfowl; rivers evalu-
ated for fisheries
Migratory and anadrom-
ous fish
Estuarine and riverine
fish
Marine fish, lobsters
53
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54
DATA SOURCE APPENDIX
The Data Source Appendix, a computer-based
information storage and retrieval system based on a
key word index, is used to present data source
reference information. It includes all information
used for analysis in this characterizaton as well as
general references that apply to the characteriza-
tion; it is not an all-inclusive source of information
dealing with resources of the Maine coast. Two lists
of reference citations arc provided. One list will
present the citations in alphabetical order by
author. The second list will arrange the citations by
key words associated with the classification model;
key words are presented in table 2.
APPLICATIONS OF THE PRODUCTS
The products of the characterization could be
used to gain an understanding of the entire Maine
coast ecosystem. However, most users will be
interested in a particular area, species, or group of
species. The products are presented so that the
needs of varied users are met.
A user interested in a particular area would
look at Atlas maps to determine where the area fits
into the classification model. The particular classi-
fication of concern would then be found in the
Atlas text where components and interactions are
discussed. It is recommended that the user start at
the general level and work toward the specific for
the most complete understanding of how the
particular area interacts with others.
If the user is interested in a particular impact,
table 3 should be used. This matrix informs the
user of the impacts of selected human activities.
After these impacts have been identified, table 4
can be used to s*ee which systems are affected and
how the biological and cultural factors may be im-
pacted. A check indicates an interaction. Following
the matrices will be an index of interactions with
appropriate references to the characterization
indicating where such impacts are discussed or
implied.
For example, the effects of the paper and pulp
industry are indicated in table 3 and include an in-
crease in turbidity, a rise in temperature, changes
in water and air composition, and the addition of
nutrients, metals, and chemical pollutants. If the
user then locates these physical and chemical
effects on table 4, he will find that each of these
effects has impacts upon biological and cultural
factors. An increase in chemical pollutants affects
the terrestrial, wetland, and deepwater habitats,
impacting upon phytoplankton, zooplankton,
invertebrates, fish, birds, and mammals. Some of
these effects are direct; others are indirect via a
predator-prey or food web interaction. Reading
further across the matrix, one then finds that
wilderness areas, parks and refuges, fishing, swim-
ming, bird watching, hunting, and aesthetics are
also impacted. For specific discussions of any of
these interactions, one would consult the index
and refer to specific sections in the characteri-
zation.
A user interested in a particular species or
group of species would refer to the group in the
index where the appropriate Groups-of-Interest
section and/or Systems section is listed. The Atlas
maps referred to in the text should be studied to
gain an understanding of the distribution and re-
quirements of a species.
As an example: A utility is planning to site a
liquid natural gas facility in a town. The user con-
cerned with the planning of this development and
associated support developments would refer to
the Atlas to determine the class system or habitat
the proposed developments could impact, i.e.,
what classification the area fits. The user would
then be referred to appropriate Ecosystem, Habitat,
and Systems sections. Application of the Atlas
would augment the discussion so that interactions
would be illustrated. The User's Guide matrix
would direct the user to a listing of the general im-
pacts anticipated from the proposed activities.
These impacts are referred to in the index which
would lead the user to pages in the text where the
impacts on the particular system/species of con-
cern are explained.
If specific information from the various sources
is desired, the data sources and references are listed
by habitats and species in the Data Source Appen-
dix of the original report.
LITERATURE CITED
Caswell, W. B. 1977. Groundwater guidebook for
State of Maine. Maine Geological Survey, open
file report, Augusta, Maine. 202 pp.
Clark, J. R. 1977. Coastal ecosystem management.
A technical manual for the conservation of
coastal zone resources. John Wiley and Sons,
New York. 928 pp.
55
Table 2. Key Words Used in the Data Source Appendix
Agriculture
Air quality
Algae
Bacteria
Behavior
Benthos
Biogeochemistry
Biology
Birds
Chemistry
Climatology
Communities
Crustacea
Deep water
Degradation
Disease
Dissolved oxygen
Distributions
Diversity
Drainage
Ecology
Estuarine
Fauna
Fisheries
Fishes
Flooding
Flora
Food and feeding
Forestry
Freshwater
Fungi
General
Geology
Harvest
Heavy metals
Herbicides
Hydrocarbons
Hydrography
In-document
Industry
Insects
Intertidal
Invertebrates
Islands
Lacustrine
Land use
Legislation
Macroalgae
Mammals
Management
Mapping
Marine
Marine mammals
Marsh
Methodology
Microorganisms
Molluscs
Mortality
Mud flat
Nitrogen
Nutrients
Nutrient cycling
Nutritive value
Oceanography
Palustrine
Passerine
Perturbation
Pesticides
Phosphorus
Physical parameters
Physiography
Phytoplankton
Plant ecology
Pollutant effects
Pollution
Populations
Precipitation
Predator-prey
Production
Productivity
Recreation
Remote sensing
Reproduction
Riverine
Rocky shore
Salinity
Sea birds
Sedimentation
Sediments
Shore birds
Socioeconomic
Soil
Species interaction
Subtidal
Temperature
Terrestrial
Terrestrial birds
Terrestrial mammals
Tides
Trophic relations
Vegetation
Vertebrates
Wading birds
Water chemistry
Waterfowl
Water quality
Wetlands
Wildlife
Zonation
Zooplankton
56
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Table 3. (concluded)
Catastrophic
events
Physical & chemical changes
in the envoronment
Loss of habitat
Removal of vegetation
Removal of topsoil
Increase in surface runoff
Increase in soil erosion
Increase in slope grade
Lovk'ering of water table
Loss of groundwater
Alteration of drainage areas
Modification of seasonal
flow patterns
Drastic fluctuations in
water level Sc flow rates
Reduction in flow volume
Increase in dovvTistream
flooding
Canal creation in wetlands
Increase in turbidity
Increase in sedimentation
Alteration of bottom topog.
Reduction in light penetration
Elevation of temperature
Modification of chemical
composition:
Soil
Water
Air
Increase in oxygen demand
Addition of nutrients
Addition of metals
Addition of chem. pollutants
Change in salinity
Disturbance (noise poll.)
Explosions
Floods
Droughts
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65
LITERATURE CITED (CONTINUED)
Cowardin, L. M., U. Carter, F. C. Golet, and E. T.
LaRoe. 1977. Classification of wetlands and
deepwater habitats of the United States (an
operational draft). U.S. Fish and Wildlife Ser-
vice. 100 pp. (mimeo).
Hall, C. A., and J. W.Day, Jr. 1977. Ecosystem
modeling in theory and practice: an introduc-
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