The Sunday herald. [volume] (Washington [D.C.]) 1866-1887, 1885-07-19
influence Of Forests on Climate.


The third number Of Psterrmann's MittheHuigen
for t' year contains an article by Herr a. Woeikof
of the influence OF forests on climate The COM
mencement OF scientific Investigation OF this sub
ject was made when the Bavaran forest meteoro-
Logical stations were established, and when Prussia,
Asace lorraine France Switzerland and Italy fol-
lowed :he example. AS general rule IT may be
laid down that in the warm seasons, as between
forests and places close at hand which are treeess
~ the temperatures OF the earth and air are lower
in the former, (2) their variations are less @ the
relative humidity is greater. After examining OBJ
that the influence of forests In diminishing evapora-
ton from water and the soil Is great that ii can
OF the hot months. the great humidity, or even by
the shade. An important influence, which has
hitherto been out little appreciaed Is the proec.
the writer regards as more important than all the
others together in reducing the degree of evapora-
tlon. With regard 10 the influence OF forests on rain
and snowfall, there Is yet only a single series Of
observations supplying comparative statistics,
and extending over a sufficiently long period.
These were taken in the neghborhood OF Nancy,
and they show an important influence OF forests In
increasing % the rainfall; It might appear that the
Europe in winter would be small. for the difference
between the temperature and humidity OF the forest
fure in fhe atmosphere Is small. But the observa-
tions show that Is at this time of the year that for
ests get much more rain. This the writer attributes
10 the clouds being lower, the resistance which the
forest offers TO the movement OF the air and 10 the
moist west WIND. Forests retain ram by the under
growts OF grass moss, etc, much better than open
ground, and let water OIL specifically only after
heavy rainfall; the remainder filters upward slowly,
and much OF II Is used for the evaporation Of the
trees. Although forests, especially thick, luxuriant
forests, cannot exist without certain supplies OF
moisture, yet II is the same 10 them when the sup
piles come, for they retain what they get, and use 1t
over long period. one example OF this Is the Len
koran forest the west coast Of the Caspian, where
the vegetation ID more uXnriant than In any other
part OF Europe, yet very little rain falls In summer
but the rainfall In the autumn and winter Is great
The water Ii stored up by the Forest and IL used In
evaporation during the heat OF summer Humidity
OF the atmosphere, however y not inconsistent with
nigh temperature, as the Red Sea shows; but in
leaves in other words, 10 process by which heat
y converted into work, and hence the GOODNESS.
Herr Woekof then endeayors 10 ascertain the innu-
ence of forests on the climatic conditions Of their
neghborhoods In the western parts OF the Old
World between the $50 and 52o N. latitude, the
places selected being In all cases In the open. Thus
for 62o degree eight stations are taken between
valentia In Ireland on the west and the Kirghlz
steppes on the east; for the 800, Guernsey on the
west, Sempalatinsk on the east, and thirteen sta
TONS and 30 on for each two degrees OF latitude TO
1872 The general result OF the observations In nifty
stations in six different degrees OF latitude Ii that
in Western Europe and Asia large forests have great
influence on the temperature OF places near them,
and that by their influence the normal increase OF
temperature as we travel eastward from the Atlantic
ocean 20 the Interior OF the continent IL not merely
interrupted, but they give places far removed from
the coast cooler summer than those actually on
The sea. striking example OF this Is Bosnia. An
examination Of the statistics shows "a that In Bosnia
the summer Is 2o.5 10 4o.5 cooler than In Herzego
yina; W even on the Island OF LISA, In the full In
nuence Of the Adratlc Sea- the summer tenn
is more than degree higher than that OF Bosnia
which Is separated by lofty mountain ranges from
the sea- Bosnia owes this comparatively cool sum
Iner 70 its great forests while Herzegovina Is amos
dlsanorested. To sum up: Forests exercise am In
nuence on climate which does not cease thei
borders, but extends over larger or smaller adj
1acent region according TO the size, Kind, and posi-
hon OF forest. Hence man by aHorestaiOn and dis
aiiorestatlon can modify the climate around him
but II 10 an extreme position 10 mold that By
anorestation the waste places OF the earth can bt
made fertile. There are places incapable OF beinl
aiioIested, which would not give The necessar,
nOuTlshtnent to trees.