Advertisement
h ang
c
of species
support such a vi
r ees h
conif
rous t
r uce frequen tly u surp s th e plac
that sp
that of
cotc
r tain localities
in ce
a close inv
able exc
pt
small quantities of mine
o
ld be not remov
total quanti
r er substance s
o f
ra
r oviding t h e necessary quantity of mine r al matte r fo r any
on p
l
ngth of tim
h ilst
w
fallen l
matt
r
in addition to t
r om
f
soil
r
inc
as
of f
less
some cas
Observed
with thin crowns
r causes
fires or othe
The fact t
generally
resisting pow
felling of a sp
r ance of larg
app
a
stool s of the tre
crop of these species w
subj ect to such attacks may then occupy the ground
to d o so
a rule
only in sp
cial cases
b
HO
esp
cially as certain phenomena s
It
r
and the
h pin
r that exac
o
stigation
poor soils
r al s ubstances f r om the soil
d
in fact
y required by field crops
The trees protect t
av
s give a s
h e ino r ganic materi a ls p r eviously taken
This amount may be so conside
r tili
y may actually be produc
r ed uction of the fertility should be
s a
will b e d ue to in su
h eavy r
to
h a t one species som
r
to its g
at
r against
r uc
r
o
cotc
numbers of in sects
s l
ft in the g
ich may spring up
in
ilvi cultu
suc
r iginal sp
o
o
nd un suited for t
I
P
h as b
en obse
r e supplant broad leaved
ing species no longer thrive
such a theory will be found unten
r t r e
Timbe
only abo ut one
h ence
all ex c
bstantial amount of organic
cient shelter af
mo
al s of litte
tim
r reproducti
r nal influences
xte
h pine wood may be followed by
r ound
r
a change of species is called for
h as the following
h as
cies
h e locality
p
I
r v
d
instance
r fir
of silve
s take comparatively
twelf
and about one
r soil
pt poo
h e soil by their foliag
r able that an
d
If
orded by trees
r
faulty t
s supplants anoth
r
e powe
in stance
which breed in the
and d
s
roy any young
other sp
r al g r ounds
on gene
emed to
hat
pecies
and birch
h e leaf
if t
h of the
tw
ntieth
can go
r
atment
r is
r
its g
ater
the
ci
s not
if allowed
Advertisement
