Newsletter

Volume 1 1 , Number 5
September - October 1994

Director’s Note

The summer months find the Institute’s
scientists doing field work at sites
across the Arboretum and elsewhere.
Because so much research is going on,
and because many traditional educa-
tional programs take a recess in
summer, the tendency may be to
overlook the Institute’s education
component at this time of year.

As you will read in this issue of the lES
Newsletter however, during the
summer, students of all ages expand
their scientific horizons through
participation in special programs at the
Institute. Highlighted here are the
Research Experiences for Undergradu-
ates program — one of our longest-
running summer education efforts —
and the lES Ecology Day Camp, the
most recent addition to our program.

The lES Newsletter is published by the
Institute of Ecosystem Studies, Millbrook,
New York. All newsletter correspondence
should be addressed to the editor.

Gene E. Likens, Director
Joseph S. Warner, Administrator
Alan R. Berkowitz, Head of Education

Editor: Jill Cadwallader
Printing: Central Press

INSTITUTE OF ECOSYSTEM STUDIES
Education Program
Box R (Route 44A)

Millbrook, NY 12545-0178
(914) 677-5359

Out of the Classroom and Into the Field:

Research Experiences for Undergraduates - 1994

Weekly REU seminars focus on
“Research Strategies”, about
scientific methods, theory etc., and
“Research in Context”, designed to
help students put their own
research into the broader perspec-
tive of the discipline of ecology,
the scientific community and
society in general. During summer
1994, the students looked at issues
relating to the New York City
water supply, considering the
social, economic, ethical and

political ramifications of New York state’s
watershed protection programs. For the past
two summers, also as part of Research in
Context, REU students have spent a day
with at-risk high school students through
the Liberty Environmental Science Acad-
emy (a joint program of Bank Street
College of Education, New York City; Bard
College, Annandale, N.Y.; and lES),
working at field sites around the Institute.

Mellon Foundation Support

This year, 209 college undergraduates from
across the country applied for the 10 REU
internship positions at lES. Eight of the
recipients were supported by the NSF grant.
A donation to the Institute by The Andrew
W. Mellon Foundation, through its
Minority Undergraduate Fellowship
Program, supported two additional stu-
dents.

1994 REU students and their research
projects were:

• Kristin K. Arend (Oberlin College, Oh.):
Feeding selectivity of larval white perch
(Morone americana) and striped bass
(Morone saxatilis) in the Hudson River
estuary. Dr. Michael L. Pace, mentor.

• Cynthia S. Davis (Virginia Union Univ.,
Va.): The effects of biofilm on removal of
dissolved organic carbon from shallow
ground water. Dr. Stuart E.G. Findlay,
mentor.

continued next page

In 1988, the National Science Foundation
(NSF) selected the Institute of Ecosystem
Studies to be one of the sites for an
initiative called Research Experiences for
Undergraduates (REU). The goal of NSF in
developing the REU program was to
improve science education in the U.S. and
to help assure an adequate supply of top-
notch scientists, mathematicians and
engineers for the future. Since the start of
the REU program, many institutions across
the country have competed for annual NSF
funds to support students, and lES is proud
to have been among the recipients for seven
consecutive years.

The Institute’s REU program is adminis-
tered jointly by Drs. Alan R. Berkowitz,
Stuart E.G. Findlay and Steward T.A.
Pickett and facihtated by REU coordinator
Stephanie Shoemaker in the BBS Education
Program office. The three-month program
begins late in May. REU students function
independently in collaboration with an lES
ecologist, designing their own studies,
doing field and laboratory research and
analyzing results. In late August they
present their findings at a symposium
attended by Institute staff and members of
the public. Research papers are published
by the Institute as an lES Occasional
Publication.

Research isn’t the only learning opportunity
the students enjoy during their summer at
the Institute. At a mid-summer “Forum on
Opportunities in Ecology”, REU partici-
pants meet with professionals from 12
science-related fields. This program, also
attended by students from nearby
colleges and universities, offers an
opportunity to experience vicari-
ously the challenges and rewards
of careers in academia, museum
curatorship, field research, science
writing, education, consulting,
apphed ecology, industry, city
government, environmental
regulation, environmental activism
and environmental law.

REU student Cynthia Davis

t

S

Student Science: REU 1994, continued

• Amanda Fuller (Denison Univ., Oh.):

A comparison of nitrogen mineralization
rates for four species in the Catskill
Mountains, N.Y., and White Mountains,
N.H. Drs. K.C. Weathers and G.M. Lovett,
mentors.

• Emiliano V. Gaytdn (Univ. of California
at Davis, Ca.): Seed bank density and
distribution in the forest edge.

Dr. S.T.A. Pickett, mentor.

• Carol S. Pabin (Ohio State Univ., Oh.):
The influence of hyporheic upwelling on
invertebrate drift in a small stream.

Dr. S.E.G. Findlay, mentor.

• Ellis J. Still (Rutgers Univ., N.J.):
Earthworm populations along an urban to
rural gradient in schoolyard ecosystems.
Drs. Alan R. Berkowitz and Patrick J.
Bohlen, mentors.

• Pamela Templer (Univ. of California at
Santa Cruz, Ca.): Uptake rates of nitrate
and ammonium between red oak (Quercus
rubra) and Norway maple (Acer
platanoides) seedlings. Dr. R.V. Pouyat,
mentor.

• Martin M. Traynor (Univ. of Connecticut,
Ct.): Physical environmental gradients
across the forest edge. Dr. S.T.A. Pickett,
mentor.

• David R. Whitall (Pennsylvania State
Univ., Pa.): Variations in dissolved organic
carbon in leaf litter leachate along an
urban-rural gradient. Dr. R.V. Pouyat,
mentor.

• Wendell D. Whitehead (Talladega
College, Ala.): Animal activity on the forest
edge. Dr. S.T.A. Pickett, mentor.

Summaries of selected projects:

Hudson River Ecology

A tiny crustacean called the “water flea”
(Bosmina longirostris) is only about 0.5
millimeters long (0.02 inches), but when
these cunimals reproduce in the Hudson
River early in summer the biomass is
substantial. Simultaneously, fish eggs are
hatching in the Hudson River and the larval
fish are starting to feed. Dr. Michael L.

Pace, an aquatic ecologist at the Institute, is
studying the ecology of the Hudson River
and is especially interested in the relation-
ship between zooplankton — the animals
living in the planktonic community — and
their consumers.

Kristin K. Arend, a junior at Oberlin
College in Ohio and a 1994 lES REU
student with an interest in aquatic ecology,
read about Dr. Pace’s research and wanted
to learn more about whether or not Bosmina
— especially during its annual peak in
abundance — is a major source of food for
larval fish. White perch (Morone
americana) and striped bass {Morone
saxatilis) are commercial and recreational

resources as well as important components
of the Hudson River ecosystem. Ms. Arend,
above, studied the larval forms of these two
fish species in her summer’s research into
feeding selectivity.

Her first challenge was learning to tell the
larval fish apart. Netted in the Hudson
River in June, not long after hatching, the
larvae were from 3-10 mm long (0.12 - 0.4
in.) and the only distinguishing features
were the patterns of pigment cells on the
animals’ abdomens and the arrangement of
internal organs. (Since fish at this early
stage of development are transparent, major
organs are visible through the body wall.).
Ms. Arend spent long hours at the micro-
scope, first separating and counting the two
species, then looking at the gut to identify
what they had eaten.

After examining 360 fish, her findings were
not what she had predicted. She counted an
average of 1 - 5 Bosmina in each fish’s gut,
but discovered an average of 1 - 1 8
copepods. Copepods, members of another
family of crustaceans, are larger than
Bosmina (while still microscopic) but their
population in the Hudson River is consider-
ably smaller. In spite of this, they were
clearly the preferred prey by both fish
species. When asked to speculate on the
reason for this, Ms. Arend said that she
suspected the larger size may be an
important factor.

Biofllm and DOC

As decomposition of organic material
proceeds in the ecosystem, carbon and other
breakdown products reach the groundwater.
Mysteriously, dissolved organic carbon
(DOC) is lost as it percolates through the
groundwater. Where does it go? Is it lost

abiotically, through adsorption onto
sediment particles? Or is the process a
biotic one, through bacterial uptake? Could
the agent for whatever biotic processes are
occurring be the microorganisms in the
“biofilm” layer that surrounds sediment
particles in the groundwater system?

The question interested Dr. Stuart E.G.
Findlay, an lES aquatic ecologist who was
mentor to REU student Cynthia S. Davis.
Ms. Davis, a senior at Virginia Union
University in Richmond, Va., is a biology
major and found a study of invisible
interactions to be an interesting challenge.

At a site along the East Branch of
Wappinger Creek, in the Arboretum
lowlands, she collected samples of sediment
and streamwater. To test whether the
presence of living material in the sediment
affected DOC levels, she treated one of the
sediment/streamwater samples with
mercuric chloride, a poison, to kill all
microorganisms. Then, to learn whether or
not the biofilm itself had an influence on
DOC removal even when the organisms
had died, she removed all traces of organic
material from the sediment by incinerating
it at 450°C (842°F).

After measuring DOC levels with an
instrument called a total organic carbon
analyzer, Ms. Davis found that the rate of
DOC removal was identical in the sedi-
ment/streamwater samples with a living
biofilm and the poisoned samples. When
she compared the untreated samples to
those that had been incinerated, however,
she found that DOC removal was faster in
the untreated “living” sediments. These
findings suggest that the presence of
biofilm, regardless of whether the organ-
isms in it are alive or dead, facilitates the
removal of DOC from groundwater through
both physical adsorption and biological
uptake.

Contaminants in groundwater are a major
threat to our drinking water. Understanding
how the soluble compounds that make up
DOC are removed from water in under-
ground aquifers would add to our knowl-
edge of how to remediate contamination
problems. Ms. Davis’ work, and other
related studies, help to increase this
understsanding.

Earthworms

Earthworms are decomposers, eating plant
and animal debris as well as soil. Ingested
materials pass through the worm’s digestive
tract, where organic matter and soil
particles are ground up by the gizzard.

Some nutrients are absorbed by the intestine
while the other material is excreted in the

top soil and on the soil surface. These
nutrient-rich deposits, called castings,
improve the soil. Also, through their
tunneling behavior, earthworms help keep
the layers of surface soil mixed, aerated and
permeable to rainwater.

Ellis J. Still may be the first lES REU
program participant to be a student of
landscape architecture. His course work at
Rutgers University is strong in environmen-
tal design and he applied for an REU
internship to learn more about how to link
landscape design with ecological principles.
His project at lES, which compared
schoolyard earthworm populations along an
urban to rural gradient, brought him in very
close touch with the landscape.

Mr. Still’s goal was to extend the results of
research done in 1993 by lES REU student
David Steinberg, who found that earthworm
activity is significantly greater in soils in
urban forests than in rural forests. One of
his mentors, lES head of education Dr.

Alan R. Berkowitz, is directing an Institute
education initiative called SYEFEST
(Schoolyard Ecology for Elementary School
Teachers — see lES NEWSLETTER
Volume 11 No. 2). Mr. Still, Dr. Berkowitz

and soil ecologist Dr. Patrick J. Bohlen
chose schoolyards as research sites, not only
because they were interested in turf versus
forest soils, but also because data would be
relevant to ecological research projects by
SYEFEST teachers and students. The
selected schoolyards represented a range of

urban to rural environments, in the Bronx
and Manhattan, in Sussex County, N.J., in
Dutchess County, N.Y., and in Litchfield
County, Ct.

Mr. Still, left, sampled earthworms at 24
sites, digging holes 20 x 20 centimeters
square and 30 centimeters deep (8x8x12
inches) and searching for the animals by
hand. Worms were brought back to the
laboratory for identification by Dr. Bohlen,
and Mr. Still recorded information on the
soils, comparing soil moisture, organic
matter content and the degree of compact-
ness. He hoped to determine the distribution
of earthworms and to correlate animal
density with soil characteristics.

One of the realities of science is that not all
projects have a tidy ending. In contrast to
the pattern seen in forest soils, there were
no consistent differences in earthworm
populations between urban and rural
schoolyard sites. Mr. Still suggests that his
methodology might be refined by a future
REU student to learn what may explain
why certain schoolyards — urban and rural
— had many earthworms while others had
very few.

Student Science: Ecology Day Camp for Elementary School Children

Cary Pond hides on the flank of one of the
Cannoo Hills at the Mary Flagler Cary
Arboretum. With a surface covered by tiny
aquatic plants called duck weed, it has the
appearance of a primordial swamp. It is
home to turtles, frogs, salamanders and a
tremendous variety of invertebrate animals.
For many of the 75 first- to sixth-graders
attending the lES Ecology Day Camp,
exploring this pond was the highlight of
their summer adventure at the Institute.

Conceived and planned by lES head of
education Dr. Alan R. Berkowitz, the camp
opened its first season with close to
maximum enrollment. Younger campers
alternated with the older ones for the seven
one-week sessions. Camp educators were
Jennifer Hauxwell, a May 1994 graduate of
the University of Michigan with teaching
certification in biology and chemistry, and
Frederic Shaw, a wood sculptor and avid
naturalist who currently is earning a biology
degree from the State University of New
York in New Paltz.

The Ecology Day Camp was based at the
Institute’s Carriage House. Aquaria with
live pond and stream animals shared the
countertops with cages of insects and other
land creatures. Microscopes, books and
crafts projects covered the tables, while

collecting nets and buckets were stacked in
the comer. Campers worked with miniature
ecosystems in the mini-ponds at the
adjacent Outdoor Science Center, and, in
addition to their morning at Cary Pond,
traveled to Wappinger Creek, Fowler Pond
and other areas on the Arboretum to study
and observe.

One project that spanned the full seven
weeks was the creation of a diorama. From
natural materials collected during their field
trips, campers made models of local
animals and plants for which Mr. Shaw
built a frame. The completed piece now
hangs in the lobby of the lES Plant Science
Building (see calendar on page 4).

Camp educator
Jennifer Hauxwell
led campers into
the shallows of
Cary Pond to
collect animals and
plants for observa-
tion.

CONTINUING EDUCATION

Fall semester catalogues are available from the
Gifford House. Among the late fall offerings are:

Natural Science Illustration
Nov. 3 (6 sessions): Drawing II
Nov. 5 &/or Nov. 6: Drawing in the Greenhouse
Workshops

Nov. 5: Careers in Horticulture

Nov. 15: Particular Plants for Particular Places

Natural Crafts

Oct. 29: Grapevine and Bittersweet Wreath
Nov. 5 and 19: Pine Cone Wreath
Nov. 12: Victorian Tree Centerpiece
Dec. 3: Cranberry Wreath
Dec. 3: Outdoor Holiday Wreath
Dec. 17: Fresh Holiday Arrangement

Call 914/677-9643 for information on certificate
programs or individual offerings, or to register.

Winter/Spring semester catalogues will be
available early in December.

SUNDAY ECOLOGY PROGRAMS

Free public programs are held on the first and
third Sunday of each month, except over holiday
weekends. Programs begin at 2 p.m. at the Gifford
House on Route 44A unless otherwise noted.
Last-minute schedule changes are sometimes
unavoidable, so call 914/677-5359 to confirm the
day’s topic:

Nov. 6: Tour of the Institute’s Laboratories,
led by Dr. Kathleen Weathers
Nov. 20: Fish of the Hudson River, a slide talk
by Dr. Karin Limburg

Dec. 4: An Origami “Lowlands Ecosystem”, an
activity for age 8 - adult, led by Jill Cadwallader

• In case of poor weather, call 677-5358 after
I p.m. to learn the status of the day’s program.

Calendar

ESPECIALLY FOR CHILDREN

• Ecosystem Diorama, made by children of the
1994 lES Ecology Day Camp, on display in the
lobby of the Plant Science Building. Weekdays, 9
a.m. - 4 p.m., through December. Free.

• Ecology of a Christmas Tree, a mini-adventure
for children and their escorts, led by Mike
Weintraub. 2-3 p.m. on December 17. Meet at the
Gifford House. Dress for the weather. Free.

• Plant Power in the Greenhouse. Coming soon ! !

DES SEMINARS

The Institute’s program of scientific seminars
features presentations by visiting scientists. Free
seminars are held each Friday at 3:30 p.m. in the
lES Auditorium.

Nov. 4: The Effects of Eutrophication on Higher
Trophic Level Production in Estuaries,

Dr. Linda A. Deegan, The Ecosystems Center, Ma.
Nov. 1 1 : Potential Impacts of Zebra Mussels
(Dreissena polymorpha) in New York Waters:
Case Studies of the Seneca River and Lake
Champlain, Dr. Clifford Siegfried, New York
State Museum

Nov. 1 8: Characterizing Controls on Forest N
Retention Using Large-scale 15N Additions,

Dr. Knute Nadelhoffer, The Ecosystems Center,
Mass.

Dec. 2: Forest-Atmosphere Water Vapor and
COj Fluxes in Siberia, Dr. David Hollinger,

USDA Forest Service, Durham, N.H.

Dec. 9: Memory and Sense of Place in Southern
Culture, Dr. William R. Ferris, Center for the
Study of Southern Culture, Univ. of Mississippi
Dec. 14 (Wednesday): The Solar Bottleneck
Hypothesis: Conflicting Selective Pressures in
Natural Zooplankton Communities,

Dr. Craig Williamson, Lehigh Univ., Pa.

Seminars begin again in mid-January.

GREENHOUSE

The lES greenhouse, a year-round tropical plant
paradise and a site for controlled environmental
research, is open until 4:00 p.m. daily except public
holidays. Admission is by free permit (see below).

lES GIFT AND PLANT SHOP

New in the Shop!! ... for children ... “Bandana
Games”: Nature Quest, Bug Bingo and ABC
Discovery, “See for Yourself’ science experiment
kits; ... and, for all ages ... 1995 nature and
gardening calendars; hand-carved ironwood animals
Senior Citizens Days: 10% off on Wednesdays

HOURS

Winter hours: October 1 - April 30
Closed on public holidays.

Public attractions are open Mon. - Sat.,

9 a.m. - 4 p.m. & Sun. 1-4 p.m.

The lES Gift and Plant Shop is open Mon.- Sat.,

1 1a.m. - 4 p.m. & Sun. 1-4 p.m. (The shop is
closed weekdays from 1-1:30 p.m.)

•All visitors must pick up a free permit at the
Gifford House Visitor and Education Center on
Route 44Afor access to lES public attractions.
Permits are available until 3 p.m. daily.

MEMBERSHIP

Become a member of the Institute of Ecosystem
Studies. Benefits include a member's rate for lES
courses and excursions, a 10% discount on Gift
Shop purchases, a free subscription to the lES
Newsletter, and participation in a reciprocal
admissions program, with benefits at over 100
nature centers, forest preserves, gardens and
conservatories in the U.S. and Canada. Individual
membership is $30; family membership is $40. For
information on memberships, call Ms. Janice
Claiborne at 914/677-5343.

For general information, call the lES Education Program Office at theGifford House Visitor and Education Center:

914/677-5359 weekdays from 8:30 - 4:30.

INSTITUTE OF
ECOSYSTEM STUDIES

Education Program
Box R

Millbrook, New York 12545-0178

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IIESI

Newsletter

Volume 11, Number 5
September - October 1994

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