Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-07-11
! forests ana Climate,

1IoIu feicruaui l0lttneliullgen.
LIE CONNIE ncement Ola scientific investiga-
ton of thi. subject was made when the Bava-
rian forest meteorological stations were e.tab.
llshed, and when Prussia, Al.ace- Lorraine,
France, SwitZer land and Italy followed the ex-
ample As general rule, it may be laid down
tltt IN the warm Seasons, As between forests
and places close at hand which are treeess III
the temperatures OF the earth and air are lower
iii the bonner; t2) their variations are less: (:S)
the relative humidity is greater. After exam
Woelkof states that the iutiue noe OF
forests in diminishing evaporation from
water and the soil Is so great that It
cannot be accounted tor alone by the lower
temperature or ths hot months, the
greater humidity, or even by the shade.
An important influence, which has hitherto
from the wind afforded by the trees, and this
the writer regards y. more important than all
evaporation. With regard to the influence Of
forest. ON rain and snow all, there Is as vet only
single series OF ooservatiOns supplying COM
parative statistics and extending over a sutti.
cisntly long period. These were ia ken in the
nsignborhUod Of Nancy, and they show an i'm
porsant innusnce OF IOrs.ts in Increasing the
rainfall. IL might appear that the effect or for
ests on rain in the Climate OF central Europe in
winter would be small, tor the difference be-
tween the temperature and humidity of the
forest ana the open Is very little and the GUAM
tlty OF moisture in the atmosphere is small
But the observations show that it il at this time
Oh o., tne year that forests get much more rain
This tine writer attributes to the clouds being
lower, the Resistance which the forest offers to
the movement oil the air and to the moist west
wind. Forests re tain rain by the underyrowths
OF grass, moss, ETC., much better than open
ground, aud let water OFT super1ciaIIy only
after "a heavy rainfall; the remainder filters
upward slowly, and much of it il used for the
evaporation of the trees. Although forests
especially thick, luxurant forests cannot exist
without certain supple. Of moisture vet is tine
same TO them when the supplies come, for thew
retain what they get and use it over q long ne
ROD One example OF this Is the Lenkoran
i ,o on tae west coast OF the Caspian, where
other part OF Europe, yet very little rain I,lIs in
summer, but the rainfall in autumn and winter
ID great. The water Is stored up by the forest
and IL used in evaporation during the heat ~
summer. Humidity of the atmosphere how
ever, Is not inconsistent with q high tenn pera-
humidity Is due to the evaporation of the
leaves-in other words, to a process by which
heat Is converted into work. and hence the cool
ness. Herr Woeikof then endeavors to ascer-
tain the influence OF forests on the climatic con.
dltlons OF their neighborhoods in tue western
parts Of the old word, between the 3Sth and
SD deys n. latitude, the places selected heinz
in ali cases In the open. Thus for the sgd deg
eisht stations are taken between Valeptia in
steppes on the east; tor the. 5Oth, Guern-
sey on the west, Semipalatinsk on the east
ana 'r.esn a 1 s and SO on for each
OF The observations i'll fifty stations in six dii-
ierent degrees Of latitude is that in Western
Europe and Asia large forests have a great in
and that by their influence the normal increase
of temperature as we travel eastward from the
is not merely interrupted, but they give places
far removed from the coast a cooler summer
than those actually on the sea- A striking ex-
ample OF this is Bosnia. An examination OF
the statistics shows ~ that in Bosnia the sum
mer is 20 deg. to is cooler than in Herzsgov.
MIA; 81 even on the Island OF Lissa in the full
influence OF the Adriaitc sea- the summer tenn
perature is more than degree higher than that
OF Bosnia, which is separated by lofty moun-
tain ranges from the sea. Bosnia owes this
comparatively cool summer to its great forests
while Herzegovina is almost disaffOrested. To
sum up, forests exercise an influence on climate
which does not cease on their borders, but ex-
tends over a larger or smaller adjacent region
according to the size, kind and position OF
forest. Hence man by affOrestation and disaf-
forestation can modify the climate around him:
but 1t Is an extreme position to hold that by
anorestation the waste places Of the earth can
being atforested, which would not give the ne.
cesSary nOurishnent to trees.