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Some Observations ‘or=tfawaiian
Forests and Forest Cover in
Their Relation to Water

Supply

BY WALTER M. GIFFARD

HONOLULU, HAWAN
JANUARY, 1913"

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Some Observations on Hawaiian
Forests and Forest Cover in
Their Relation to Water

Supply

By WALTER M. GIFFARD

HONOLULU, Hawaii
JANUARY, 1913

LETTER OF TRANSMITTAL.

To the Joint Committee on Forestry,
Tlawaiian Sugar Planters’ Association and
Board of Agriculture and Forestry.

Dear Srrs:—I beg to submit you for your consideration a
paper entitled “Some Observations on Hawaiian Forests and
Forest Cover in Their Relation to Water Supply.”

Respectfully,
W. M. Grrrarp.
Honolulu, January 20, 1913.

JOINT COMMITTEE ON FORESTRY.

H, © PF: As Bd. of A. & F.
Albert Horner, Chairman, W. M. Giffard, Chairman,
E. D. Tenney, H. M. von Holt,

EH. F. Bishop. A. H. Rice.

SOME OBSERVATIONS ON HAWAIIAN FORESTS
AND FOREST COVER IN THEIR RELATION TO
WATER SUPPLY.

A paper by W. M. Giffard read before the Joint Committee on
Forestry of the Hawaiian Sugar Planters’ Association and the Ter-
ritorial Board of Agriculture and Forestry.

The Nature and Peculiarities of the Wet Forests of Hawau
and the Cause of Their Deterioration and Decline.

Much has been written on this subject and at first thought
it may appear quite unnecessary that further explanation be
made of the composition and nature of the Hawaiian forests
that are needed for drainage or the conservation of water sup-
ply. It is, however, very ‘apparent that there are still a num-
ber of individuals in the Territory that up to the present have
ignorantly, carelessly or wantonly disregarded the oft repeated
warnings of foresters and botanists as to the necessity for pro-
tecting these forests. Clearings ¢ontinue to be opened up
through the encroachment of man and beast, and the forest in
places is still being pushed back by the making of clearings and
roads to these that ought never to have been permitted. Else-
where, the cutting of the forest for posts and for firewood is
still going on, and again, where wild cattle and hogs are at
large in the forest, general destruction is caused by their roam-
ing around grubbing and feeding on and trampling down the
herbaceous undergrowth so necessary for soil and water pro-
tection.

It is well understood by all having knowledge of the peculiar
nature of these virgin forests that much of their natural under-
growth, composed as it is of climbing vines (lianes) and herb-
aceous plants, ferns and mosses, not only protects the soil from
erosion but furnishes a protective cover for the surface growing
roots of our indigenous trees.

Take for instance the native Ohia Lehua, which attains such
fine growth in these wet forests and of which they are in the
main composed. No observing person passing through such a
forest can have failed to notice the peculiar stilt-like roots of
the Ohia. This characteristic habit of growth is explained by
the epiphytic habits of the Ohia. The tree has developed from

6

seed, which dropped on the stem of some stately tree fern or
Cibotium; germinated there and sent down its own roots, sur-
rounding the fern, until both for a time became as it were,
one. Later, the fern stump having decayed, the Ohia stands
supported by its 6wn roots.

Further, it will be noticed that not only the Ohia, but also
several other species of trees peculiar to these forests have only
surface roots, and that these are not altogether dependent on
the usually thin layer of rich but boggy humus, but as well,
rely on the ground cover of mosses and roots of ferns with
which their own roots are intermingled.

Very many of our land owners, or those having the use or
care of such forests, have the idea that if the trees themselves
are not destroyed or disturbed, the forest will continue in its
virgin state. These people forget that the very act of disturb-
ing or destroying the undergrowth is in itself the main factor
in causing.the trees themselves eventually to die back. The
loss of numbers of trees from one cause and another naturally
admits more sunshine to the undergrowth than the latter has
ever been accustomed to or can stand. The natural conse-
quence is its death, which in turn leads to the dying back of
more trees, and to the still further destruction of the forest.

Under such conditions it then becomes merely a matter of a
short time, especially if animals are allowed to range in the
forest, or if clearings are made for any purpose, before the
Hilo grass or other rank growing introduced plant pests get a
foothold. By the crowding out and prevention of the repro-
duction of the native flora, there follows either the general de-
struction of the forest outright or its degeneration to such an
extent that it ceases longer to be of use for the purpose which
it origmally served, viz—the retention and conservation of our
water supply.

As regards the encroachment of grasses into the forests and
their effect on trees and other growths, it has been scientifically
demonstrated by a long series of experiments in Europe and
elsewhere, that the injury is not altogether due to the grass
crowding out and mechanically interfering with the roots of
other plants, but to a toxin excreted from, or resulting from
the growth of the grass. However, as both effects are injurious
to the forest it is clear that such pests must be excluded.

From what has been said above the following can. be scienti-
fically and therefore safely deduced, viz:

T

(1). That to keep our forests and sources of water supply
in a natural condition the jungle of woodland and under-
growth therein must be left altogether undisturbed by
man or beast.

(2). That preventive measures for safeguarding the exist-
ing forests by fencing, ranging and policing as well as
destroying wild cattle, hogs and goats, should be sys-
tematically undertaken by the Forestry Division of the
Territorial Board of Agriculture and Forestry.

(3). That in order effectively to undertake such important
work the privately owned areas within the water-bearing
forest reserves should be brought under the same system
of management that is here recommended for the Gov-
ernment lands, in such manner as is already provided
for by law. A proper system of forest protection hav-
ing been established by the Government, failure to as-
sign forest lands to the Territory for the specific purpose
of protection might, as a last resort, be followed by con-
demnation proceedings, it being understood that any
neglect on the part of the Government properly to pro-
tect and police such acquired reserves would forfeit the
latter’s right to the ownership; and

(4). That the Legislature appropriate sufficient funds for
the special purpose of fencing and policing the forests
above referred to, and excluding therefrom wild cattle,
ete.

The Intermediate Forest Areas and Their Relation to the
Water Sheds.

From an economic point of view the so-called intermediate
forests, i. e. the areas of woodland between the agricultural
and mountain zones and the wet forests on the water sheds are
of as much importance for the protection and preservation otf
the areas forming the virgin wet forests as these latter are in
helping to control the drainage, retention and conservation of
water for the supply of agricultural lands, or such other pur-
poses as the water may be needed for. The close observer of
our natural forests and water sheds will at once notice that
where the wet forests are still in their virgin condition, the
areas both above and below the wet forest are of somewhat
different nature than those from which we expect to and do
receive our water supply.

8

Taking Hawaii and Maui as examples, one finds that ung
extreme upper sections of the middle forest zone, above the tr
wet forest, are composed of a more or less scrubby growth ©
indigenous trees with an undergrowth of dry district ferns
and raspberries, technically described as semi-xerophytic 1m
character. ' :

This upper belt of rather open forest gradually increases 1n
density as one descends into the true wet forest zone, until it
intermingles with the latter. The undergrowth also becomes
thicker and composed of a greater number of species, until it
reaches the ideal wet forest conditions, which are so necessary
for a continued water supply at all periods of the year. Tech-
nically this type of forest is said to be mesophytic in character.

Again, taking the same islands for an example we find on
the lower edge of the wet forest belt a similar state of things.
There also the typical wet forest merges into a transition type
which may or may not be composed of the same species that
are to be found in the wet forest, but which in character is
different from the wet forest above. In places also the section
between the wet forest and the area of land now under culti-
vation is covered by a scrub forest and the introduced guava.

The point to be made is that it is of paramount importance
to protect, as necessary adjuncts of the forest system, not only
the main wet forest but also these intermediate areas. Nature
has provided that these so-called intermediate conditions of
forest are requisite to the proper and natural protection of the
flora contained in the wet forests on the water sheds.

Of course the formation, botanical composition and geogra-
phical position of some of our water sheds on other islands
than those named, where they are not of the same general
character as those described, are equally worthy of considera-
tion when studying the natural conditions which are necessarv
to their proper protection. Let us take for instance Oahu.
This Island has had all the lands adjacent to the mountains,
i.e. the water shed areas, stocked with cattle, so that com-
paratively little is left of any forest other than what may be
found on the high ridges and plateaus. Even in these places,
which might be supposed to be almost inaccessible mee ane
also goats have trespassed more or less and damaged the forests
on which so much depends in the way
The result is that there are practically no intermediate or seat-
tered forest areas existing on Oahn at this time, this Seetim
having been in the main given up to the graziers and others, "

of water conservation.

9

The Oahu Water Sheds and Their Relation to the Water Supply
of the Llonolulu and Ewa Basins.

As to the Oahu water sheds, more can be said as to what has
not been done than otherwise, when it comes to their protection
and conservation for water supply. Take the Waianae moun-
tains for instance, their present condition and what they were
years ago when the forest extended down the slopes of the val-
leys and ridges adjacent to the Waialua plains.

A similar condition exists and tends to become worse on the
slopes of the Koolau range, the backbone of Oahu, from the
forest areas of which so much artesian water is drawn for agri-
culture and city uses. What do we find today on these slopes
as protective cover in place of the indigenous vegetation so
necessary for our important water sheds? Hilo grass and scrub
guava is practically all that remains of what was once a valu-
able adjunct to the virgin forests which conserve our water
supply. Even these latter, excepting perhaps sections on the
western half of the range, are daily suffering from the hands
of man.

Fortunately cattle are practically excluded from the forested
slopes in the Ewa District, and so far goats are not much in
evidence. But what do we find in the way of forest protection ?
The water sheds above the City of Honolulu, from Moanalua
to Waialae, although mostly Government land are not yet even
included in a forest reserve, anl much less are they protected
(with exception of portions of upper Nuuanu and Makiki val-
leys) by either the Government or private owners. So-called
trails are being cut out of the face of the steep declivities on
the mountains for the pleasure of those inclined to tramp, but
outside of such pleasures no thought is taken of the forest ridges
and wooded gorges which are simply allowed to take care of
themselves.

As a result of the trails cut by pleasure seekers, and of the
depredations committed hy those apparently ignorant of the
peculiarities of our forest growths and the disaster which fol-
lows interference with them by man or beast, we find that
eroded slopes caused by land slides are fast taking the place of
what not so long ago were ideal conditions for conserving the
precipitation. It goes without saying that the construction
and further maintenance of trails on the steep sides of these
mountain areas should be forbidden. Those pleasure bent, if

10

allowed to trespass at all in our water sheds, should be alto-
gether confined to the ridges where ran the ancient trails of
the natives in olden days. ;

What are we to expect of Nature when man so wilfully, or
is it ignorantly, defies and interferes with her course, especially
when as in this particular instance the matter is of paramount
importance to the City of Honolulu and its environs? What
are we going to do in the very near future for a normal water
supply if such lack of foresight on the part of the Govern-
ment and of its citizens continues? Are we to trust to Provi-
dence in this as in other things?

It is quite certain that with the continued dying back of
what little indigenous forest remains on the mountains back
of Honolulu, and with the worse conditions of erosion which
are taking place, the “run-off” from precipitation will be
more than is now bargained for. In such case what is going
to feed the springs and artesian wells upon which we absolutely
depend for a normal supply of water?. Even now the slightest
appearance of dry weather indicates a great falling off in the
water supply and this is immediately followed by a threatened
curtailment for the time being of water rights.

If the agriculturists on this and the other islands are de-
pendent on water for irrigation purposes, as they surely are,
then it behooves them systematically to protect the forest and
prevent disturbance of the conditions which conserve such sup-
plies.

If the people of Honolulu desire to be assured of a constant
future supply of water for domestic and other uses then simi-
lar protection must be enforced as to the mountains back of
this ‘city.

That this is by no means too highly colored a picture is prov-
ed by the following official figures, compiled by the Territorial
Department of Public Works:

Petes betta bus dan 350,000,000 gallons of water are
an annual a eer nae of fence ae male

““The annual consumption of en ee
Shafter and Diamond Head (Honolulu) from flowing and
pumped wells 1s more or less 12,700,000,000 gallons, thes dake
consumption being about 35,000,000 gallons. We believe the
amount of water actually leaving the artesian basin is more
than this, owing to leakage through defective casing, ete,

11

“Tt is almost impossible at the present time to give anywhere
near approximate figures on the average annual consumption
of water as it is only recently that stream measurements have
been taken up by the Hydrographic Survey. The Nuuanu
dam, with the spring water used by the Water Works, probably
amounts to about 1,450,000,000 gallons annually or 4,000,000
gallons per day. As a very rough estimate, the springs that
are delivering water at the surface of the ground, may he
placed at about 80,000,000 gallons per day, or 29,000,000,000
gallons per year. The flowing streams, are of course, also great
sources of water supply. In accounting for the distribution of
the rainfall, however, the underground springs which show
themselves at the sea, and the evaporation, must be taken into
consideration.

““As to the levels in artesian wells, about 1889 there was a
drought, in which the artesian wells fell about 214 feet. The
following season there were heavy rains and the wells in Fono-
lulu again rose to the 421% ft. level. There have been no
available records showing the exact height fifteen years ago,
but from our knowledge of conditions of the wells at that time,
we place it at about 38 feet.

“Ten years ago the maximum was 34.50 feet, the minimum
32.55, and the average 33.62.

“In 1908, say five years ago, the maximum was 31.81, the
minimum 30.41, average 30.74.

“The lowest during the present year has been 28.25. In
1910 the level fell to 29.5 feet then rose during the winter
season to 32.5 feet, giving us a total fall of over 4 feet. The
recent rains have caused the wells in Honolulu to rise a little.
Under normal conditions, we will get a seasonable rise of 114
to 2 feet. This year’s level is the lowest on record.

“Tt has been estimated that there annually falls on the
Tsland of Oahu, which is roughly 600 square miles in area,
enough rain to cover the island to a depth of five feet. Of the
total precipitation it is estimated that there reaches the sea,
or is lost through evaporation, the equivalent of a depth of 334
feet, leaving 114 feet of water over the 600 square miles to
he the flow of the artesian wells and surface springs together.”

With so large a percentage of the water coming to the sur-
face in this way, under conditions where it can at least in
part be controlled, the need is brought home of enforcing
greater care than is now used in looking after this source of

12

supply. Any one who knows anything at all about artesian
wells in Hawaii, knows that frightful waste of water 1s con-
stantly going on. It has been stated that the waste alone from
uncapped artesian wells in the Honolulu basin amounts to
10,000,000 gallons of water per day. This water, now per-
mitted to flow away to the ocean, might be stored for future
usc. In other ways, too, reasonable measures of economy as
to the use of water are not now enforced as they should be.
At present there appears to be no legislation under which
abuses of this kind can be checked.

We have reached a stage of economic development in this
Territory when we can no longer afford to allow such reckless
and unwarranted’ carelessness. Water itself, as well as the
forest that clothes the catchment areas, must be conserved, and
what is more, action must be taken at once. The people of
this island face a serious condition, one that can no longer
brook delay.

The Need for Hydrographic Investigations in Conjunction With
Systematic Forest Work in Hawait.

Since writing the main portion of this paper the author has
received a communication from G. K. Larrison, the local dis-
trict engineer of the Hydrographic Service of the United States
Geological Survey, from which the following is quoted relative
to Hawaiian forest conditions and their relation to the hydro-
graphic work which he is at present conducting and which he
is desirous of extending:

“The direct and beneficial relation of forest cover to sur-
face, stream and underground water regulation has been so
thoroughly demonstrated and widely accepted by the world’s
water users that it may seem superfluous to invite attention to
this relation again. However, the writer has observed an at-
mosphere of indifference on this subject in the Hawaiian
Islands, which is all the more remarkable, because the supply
and regulation of fresh water is, by far, the most important
factor in the material life and development of Hawaii.

“The Hawaiian Islands are primarily agricultural, and for
the greater part dependent on irrigation. While the rainfall
is heavy, the catchment areas are comparatively small, the
stream gradients very high, and the run-off from deforested and
barren regions very rapid, with resulting heavy erosion and

13

damage to agricultural lands and property. Further, there are
very few natural storage sites in the Territory, and the run-off
of barren regions may be likened to the run-off from a roof
without gutters or rainspouts. In a great many locations porous
or fissured conditions of the drainage areas result in a light
surface run-off, and a heavy absorption of the rainfall. This
water may sometimes be picked up by water tunnels or wells,
but as a rule it appears in springs near or below sea level. The
comparative cost of irrigating by pumping against the cost of
surface gravity supplies is too well known to be discussed here.
With the intermittent rainfall of the Territory, without regula-
tion of some kind, the resultant run-off of surface streams would
consist of short periods of high erosive and destructive floods
followed by long periods of drought. Underground supplies
would be similarly affected to a less degree.

“There is but one way by which Hawaiian streams may be
economically regulated, and that is by retaining or developing
a heavy blanket of forest cover over as much of the streams’
catchment areas as may be consistent with the demand for
water from these areas. The heaviest rainfall is, with few
exceptions, above the levels at which agriculture is carried on
and it is at these upper levels that the heaviest forest cover is
needed as a water supply regulator. This spongelike cover
receives and retains the rainfall, and feeds it gradually to the
surface and underground water sources, serving as a regulator
to decrease floods and to increase dry season discharge.

“The United States Geological Survey in collaboration with
the National Bureau of Forestry, is now making careful and
detailed experiments in the White Mountains of New Hamp-
shire on the effect of deforestation and reforestation in its
relation to surface stream regulation. While these experiments
have not been completed, the results so far have proved conclus-
ively that forest cover is a most important factor in the regula-
tion of stream run-off. In the Hawaiian Islands and under
tropical conditions, the forest cover is much more dense, and
the beneficial or destructive effects of forest cover or the lack
of it is much greater than in the White Mountains.

“The Territory of Hawaii, has, since 1910 maintained a
hydrographic survey in cooperation with the United States
Geological Survey. Limited funds have restricted operations
to low level accessible localities with insufficient and temporary
equipment. The 1911 and 1912 reports of this Survey are

14

now being prepared, and should be given to the public within
the next few months. These data will give the daily, monthly,
and annual discharge of such streams as have been under in-
vestigation, and should furnish abundant proof of the necessity
of forest cover as a stream discharge regulator. These reports
will also show the amount of water that is being utilized, and
the amount being wasted at a number of localities. In a num-
ber of cases seepage loss of irrigation ditches is also given.

“Tt is estimated that, during the drought of the past year on
Kauai, enough water was wasted through lack of proper regu-
lations to have increased the value of the sugar output of that
island by more than one million dollars.

‘From rainfall records available it is believed that sufficient
rainfall is precipitated on the Hawaiian Islands to supply all
possible needs, if the forests are properly maintained to regu-
late the run-off of this rainfall.

“The forestry and hydrographic operations are so closely re-
lated that the two services should be maintained in the closest
possible form of cooperation.

“The development and conservation of Hawaii’s water re-
sources demand the following operations:

1. The maintenance of the forests over the heavy rainfall
catchment areas to regulate streams and to prevent erosion.

2. The construction and maintenance of stream discharge
measuring stations at points at which water supplies mav be
diverted for irrigation, city supply, power or other purposes.
This means that these stations should be installed at points
now inaccessible by most of the roads and trails, and that clock
registers, which give continuous records of stream fluctuations,
should be installed. Trails should also be built in order that
the stations are accessible at all times, and cable or foot bridges
should be constructed for flood measurements.

3. Climatological and meteorological stations should be con-
structed and maintained at different elevations in the rainfall
and forest cover areas to measure the rainfall, evaporation, tem-
perature, mud, sunshine, ete. These will also require the
construction of many miles of trails.

4. After the surface water investigation is well under wav
an investigation of underground water resources should he
made.”

Tt will be made apparent from the above communication that
the Hydrographic work and that of Forestry as already or-

15

ganized under the Division of Forestry of the Board of Agri-
culture and Forestry are:closely associated, and should, as Mr.
Larrison states, be maintained in the closest possible form of
cooperation. It is believed that such cooperation as will pro-
duce the best practical results would be the creation of a Divi-
sion of Hydrography under the Board of Agriculture and For-
estry. This Division, if created, should consist of the present
Hawaii District organization of the Water Resources Branch
of the U. S. Geological Survey, in so far as the expenditure of
the Territorial appropriation or allotment for this purpose is
concerned. This organization is now indirectly reporting to
the Department of Public Works.

This arrangement would also eliminate the additional expense
of maintaining separate offices, as is now being done by the
Hydrographic Survey, and would keep the Divisions of Forestry
and Hydrography directly in touch with each other, and under
one administrative head.

Additional reasons why the forestry and hydrographic oper-
ations in the Territory should be maintained in the closest pos-
sible cooperation are:

(1) The data collected by the hydrographic survey show
directly the effects of forestry operations.

(2) In the routine field work of each service there is much
work that will be duplicated by employees of both services, if
it is not done in cooperation. The larger part of the time of
field men of either service is consumed in traveling. A eonsid-
erable portion of the field work done by the hydrographic service
consists of stream and rain gage reading which requires that
both classes of stations shall be visited at regular intervals.
‘This duty does not require the services of an especially trained
man, and a large part of this work could be done, and on the
mainland is done, by forest rangers. On the other hand field
men of the hydrographic service could, in the rounds of their
duties, assist in exterminating wild cattle and goats, inspect
fences, report depredations, fires, ete. It is believed that the
cooperation of the two services would eliminate the cost of at
least one field assistant or ranger in each island.

Indigenous Forests in IIawaa Not Essentially Needed for Con-
servation Purposes.

Of these there are several important areas, notably among
which are those of the lower forest zone of Puna and certain

16

sections of Kau and Kona, all on the Island of Hawani.. Of
these in particular-a word may be said and will suffice for a
few similar arcas in certain other districts or sections on other
Islands.

Tt has been contended that our indigenous forests not essen-
tially needed for water conservation, might well be used for
other purposes, such as agriculture, lumbering, ete. | This is
quite true insofar as agriculture is coneerned, provided that
these areas after being cleared are found to contain soil in such
chemical condition as will permit of intensive cultivation. This
condition can better be ascertained and a policy arrived at as
to whether it is right or wrong to clear off these forests, by first
opening up an experimental area and testing the cultivable con-
ditions of the soil.

To have done this on portions of the upper Olaa lands would
have decided the question as to their adaptability for growing
coffee. It is well known that after sacrificing thousands upon
thousands of indigenous forest trees in the upper Olaa section
it was found that the land was not suitable for the crops in-
tended to be placed thereon by the homesteaders. Had the Gov-
ernment first experimented with the upper Olaa lands and found
out that they could not be made of good economic use for coffee,
not only would very many thousands of dollars have been saved
to the many homesteaders who took up the lands in large areas,
but tens of thousands of trees might have been spared the axe
or been left to die of themselves because of the disturbance to

their natural surroundings.

Fortunately for some of the homesteaders a corporation un-
dertook, also at some loss to itself, as well as to those who
planted these upper forest lands, to grow sugar cane on some
of the areas cleared. This Company may, later on, by adapting
certain varieties. of cane to the land, redeem much which has
been so far apparently wasted. Should success attain the efforts
of these planters an unnecessary loss of sections of a large forest
area will have been averted. Today may be seen in itera upper
areas thousands of acres, of what 15 vears or so
impenetrable forest, now covered with de
a thick growth of Hilo grass.

As to the lumbering proposition, it mav be said that althongl
heroic efforts have been put forth to make it pay, it h 8 =
fav failed. This is perfectly natural in view of fhe cng
forests on these islands adaptable to the full growth of mar-

ago was an
ad or dying trees and

17

ketable lumber are extremely limited. The head of a lumber
concern on the Coast once told me that he would hesitate to
tackle any lumbering proposition on such comparatively small
forest areas as we have in this Territory. The clear marketable
lumber would be so limited in quantity that it would and could
not pay. What has been done thus far on these lines has caused
but little harm and it is hardly likely that further operations
will be undertaken for a long while to come, if ever, unless it
be by the saw mills now in Puna which still have limited areas
of forest trees at their command.

« have in the previous section referred to the protective effect
which intermediate or adjacent forest cover has on the water
forests. Much more might also be said as to the modification
of climate and rainfall which wholesale denudation of indige-
nous forest areas, such as those existing in the upper sections
of Puna, Kau and Kona might eventually bring about. It is
not only the large agriculturists who suffer from a lack of water
supply. The smaller farmers, the graziers and residents gen-
erally are all more or less effected when such modifications of
climate take place as bring about long and protracted droughts
in certain sections or districts where there are no springs or
running streams. :

It would be well to study the reasons for such protracted
droughts in sections where in old days these were never known.
One certain conclusion, however, is apparent and that is, that
the less we disturb natural forest conditions the better. When
such disturbance appears necessary for the purposes of agricul-
ture, experimental work extending over a reasonable period
should first be undertaken, lest there result an altogether un-
necessary destruction of forest growth and a further disturbance
of climatic conditions. Surely there are sufficient cultivable and
grazing lands for all without our taking such chances as the
jeopardizing of our sources of water supply or changing our
climatic conditions.

Forests Intended for Purely Economic Uses.

Of these there are practically none in this Territory beyond
the small areas which have been planted in recent years. The
fuel so necessary for our plantation laborers and other country
residents has been mostly derived from these planted stands, or
where no such plantings existed, from wild guava or other ad-
jacent. indigenous forest areas.

18

The old time practice of denuding the native forest areas in
proximity to sugar mills, in order to secure fuel for the fac-
tories, has practically ceased, but there are many sections on
some of the islands where the native forests are still used as a
source of fuel supplies, regardless of the disturbance and subse-
quent harm it does to them.

The modern practice of planting, with introduced trees for
fuel and fence post purposes, areas in close proximity to agri-
cultural and grazing estates is to be highly commended. * Much
has been done in such work by private individuals or eorpora-
tions, as well as under the duspices of the Board of Agriculture
and Forestry. The time is past for our indigenous forests to be
used for such wholesale slaughter as once prevailed. Local agri-
culturists and others are now alive to the fact that it is far
more reasonable, and better for their own interests, to plant
bare areas with large copses of Eucalyptus and other quick
growing and fuel-producing’ timber trees, rather than to make
further unwarranted onslaughts on the native forests.

For plantings in copses, wind breaks and fence rows such
introduced trees as the Silk Oak, various species of Eucalyptus
and many others are admirably adapted in this tropical climate.
The practice however of reforesting or regenerating our indi-
genous forests with such trees as these is not to be recommended.
Their habits and our requirements from such forests are inimi-
eal. What we require in forests intended for water conservation,
or in those which are adjacent and contributary to them, are
plantings, when necessary, of either some of our quick growing
indigenous trees, such as Koa, or else of other trees which are
closely associated allies in other tropical countries, which will
admit of a thick, indigenous forest undergrowth to cover and
protect the soil from erosion, as well as to retain the free per-
colating qualities which the constant moisture under such con-
ditions brings about.

Introduced trees from temperate climates will not admit of
such qualities and even those from tropical countries unless
carefully selected are liable to be worse than useless. .\s far as
Euealyptus are concerned they are as previously stated, admir-
able for certain purposes but not for those of water conserva-
tion. Their roots are great ‘feeders of moisture and but little
undergrowth will mature where numbers of these are planted.
Neither of these characters are suitable for the special condi.
tions required in indigenous forest areas, and the practice of
using them for such purpose should, if possible be deprecated.

19

Forest Plantings on Areas Above the Wet Forest Zones on
Certain Islands.

Here we have an opportunity of testing what such trees as
the Conifers may do in reclaiming areas which have never to
our knowledge been under forest cover. The altitude from
6,000 feet ypwards, and the consequent climatic conditions ob-
tainable at these high elevations, make it quite possible to have
some of our upper mountain slopes on Haleakala, Mauna Kea
an Mauna Loa planted with species of Pines, ete., which are
so admirably suited for lumbering purposes in other countries.

There is no known reason why some of the Conifers which
attain such size and height in Southern California and Mexico
could not be made to thrive at those very high altitudes, pro-
vided that nurseries were started and maintained and the plant-
ings conducted under systematic supervision. It is to be hoped
that the finances of the Board of Agriculture and Forestry will
be such in the near future as will admit of the establishment
of several of these nurseries on the mountains named. This
could no doubt be undertaken in cooperation with some of the
adjacent graziers or large land owners. The work of these
high altitude stations should not be confined to the growing of
introduced pines, ete. alone, but also should include the raising
of many of our valuable high elevation indigenous trees. Such
stations should be convenient to both upper indigenous forests
and also to the unforested areas intended to be planted on the
mountain slopes.

Appended to this paper is a list by Mr. J. F. Rock, Consult-
ing Botanist of the Board of Agriculture and Forestry, giving
the scientific names of certain quick growing exotic trees from
other tropical climates, all of which he suggests may be of use
in reforesting areas in our wet forest zones.

Besides being indebted to Mr. Rock for the compilation of the
list above referred to, I have also to thank the Department of
Public Works, the local branch of the U. S. Hydrographic
Service, Mr. Ralph S. Hosmer, the Territorial Forester and
Dr. H. L. Lyon of the H. S. P. A. Experimental Station for
data besides much valuable information and assistance.

21

LIST OF TREE-SEEDS ADAPTABLE FOR PLANTING IN HAWAIIAN
FORESTS, WITH ESPECIAL ADAPTATION TO ALTITUDE,
CLIMATE AND SOIL CONDITIONS.

(Victoria, Kamerun, Africa)

African species adapted for the lower rain forest zone in
the Hawaiian Islands.

FAM. MYRISTICACEAE.

Coelocaryon Preussit.
Staudtia kamerunensis.

FAM. LEGUMINOSAE.

Cassia Manni. (Lower forest zone, rain forest 1500 feet.
elev.).

Afzelia africana. (Lower forest zone, rain forest 1500 feet
elev.).

Erythrina excelsa. (Lower forest zone, rain forest 1500 feet
elev. ).

FAM. GUTTIFERAE.
Mammea ebboro.

FAM. BURSERACEAE.

Canarium auriculatum.

FAM. LILIACEAE.

Dracaena kamerunensis.

Dracaena Deisteliana. (Elev. 4500-5000 feet).
FAM. RUTACEAE.

Clausena anisata. (Rain forest 2400-3000 feet).

FAM. EUPHORBIACEAE.
Macaranga Preuss.
Treculia africana.
FAM. ARALIACEAE.
Polyscias Preussit.

Schefflera Barteri. (1500 feet elev.).
Schefflera Mannn.

22

FAM, LEGUMINOSAE.

Albizzia adiantophylla.
Erythrina lanata.

Sokode District, Togo, West Africa

Limonta Warnecker.

Diospyros mespiliformis.

Strophantus sarmentosus. (Beautiful shade trees of the

Strophantus hispidus. ' lower rain forests used for re-
foresting).

German East Africa.
Amani, East Usambara. (2800 feet elev.)

Allanblackia Stuhlmanni.
Dracaena papahu.
Morinda asteroscepe.
Sapium Abyssinicum.

Especially noteworthy are the following trees:

Anthocleista orientahs. (Native name mbogo).
Strombosia Schefflert.

FAM. LEGUMINOSAE.

Schefflerodendron usambarense.
Englerodendron usambarense.
Pterocarpus Holtz.

Milletia ferruginea.

FAM. MELIANTHACEAE.

Bersama usambarensis.

FAM. EUPHORBIACEAE. .

Crotogynopsis usambarica.

23

Cape Town, South Africa

The following trees are very common and form the major
part of the forests of the table mountain.

FAM. OLEACEAE.
Olea laurifolia.

FAM. APOCYNACEAE.

Gonioma Kamassi.

FAM. CONIFERAE.

Podocarpus Thunbergii. (Common name Yellow wood).

Central American Trees of the Rain Forest Type.
Cuban rain forests.

Swietenta Mahagont.

Cedrela odorata. (The Spanish Cedar. elev. 2000 feet).
Hibiscus elatus. (Dense rain forest).

Calophyllum calaba.

Ochroma lagopus.

Genipa americana.

Jamaica.
Dense tropical rain forests.

Ceiba pentandra—=Eriodendron anfractuosum.
Podocarpus Urbanit. (Well adapted for the rain forests of
the higher elevation).

Santo Domingo.

Guatacum officinale. (Lignum vitae).
Zanthoxylum flavum or satin wood.

Porto Rico.

Coccoloba macrophylla. (2000 feet elev. rain forest).
Dacryodes hexandra. (Native name tabanuco tree one of the
, most common forest trees reproduc-

ing very freely, growing in the U.
S. Luguillo Forest Reserve).

Bucida capitata.

Andira inermis.

Ternstroemia luguillensis.

Hura crepitans.

Mammea americana.

24

Orizaba, Mexico.

Quercus polymorpha.

Quercus tomentosa.

Quercus jalapensis.

Quercus calophylla.

Quercus galeottu. (4000-5000 feet and higher).

Quercus germana.

Dendropanax arboreum.

Banara mexicana.

Platanus mexicanus. (Along stream beds, 4000-5000 feet).

Yucatan.

Inga xylocarpa. (Most common tropical rain forest tree).

Guatemalan Rain Forests.

Haematozylon campechiana.

LIiquidambar styraciflua. (2400-5700 feet).

Perymenium Tuerckheimii. (Native name Ta:vico tree, elev.
2100-5400 feet, in tropical
and subtropical rain forests.

Mention may be made of the following trees which may be
obtained from Buitenzorg, Java.

Sterculta spectabilis.

Dysoxylum mollissumum.

Vitex tumorensis.

Vitex leucoxylon.

Schizolobrum excelsum.

Of value for the Hawaiian forests may also be the introduc-
tion of some of the Fijian Conifers.

Dammara vitiensis. (Native name Dakua tree, adapted for

the more mixed forest).

Podocarpus vitiensis. (Native name Nau solo, one of the

finest Conifers found on Viti
Levu).

Dacrydium elatum. (Native name Lemeninini, a mediwn
sized tree found in mixed forests;
adapts itself to almost any environ-
ment. Found in Fiji from the sea

i to the highest peaks, (4000
t.).

H3G45 University Library

Some observations on Hawaiian forests an