Institution.
applications
economy.
out of
in order
in North
America and
of the
of western North
 Plant
Indicators.
Materially
expanded
in
many
books,
now
well
associated
the
four
books
Viewpoints of succession 3
Succession and sere 4
Kinds
of
Bare areas
Bare areas
by
wind
47
Deposit
by
47
Bare
areas
55
56
Bare
areas
60
Primary
Rate
IV.
Ecesic
Causes.
Nature
63
Aggregation.
73
Invasion.
87
Reaction
by
Correlation
of
reactions
96
Quantitative
study
stages
102
The
Units
of
Vegetation.
Historical
Summary
tion 125
183
Names
of
climaxes
183
Piemeisel,
Shantz and Aldous, 1917
1915. .
227
Sampson,
1908,
1909,
1913,
Climatic and
edaphic factors
farming. . 332
.
Yosemite Valley,
California... 42
qually
Geyser Basin, Yellowstone
Plate
13.
A.
re-
rado 186
B. Xerosere
ridge,
in
hills
mocks, indicating
B. Bouteloua
sage-
7. Bisect
cus tabularis
OF VEGETATION
record
as
active
physiographic
succes-
sion
in exposure,
the fundamental
succession and
viewpoints
are
summed
up
to
sero,
in eipm,
is essentially identical with series,
but
geosere,
etc.
Sere
and
cosere.—
A
pioneers through
the final
greatly
in
development
to
times
on
the
stages and
terminate in
series of unit successions,
Thus,
while
the
initia-
tion,
movement, the stages in-
to the eye,
the
others.
in Chapter IX.
successional development
depends more
upon the nature of the climatic climax than upon anything else.
The latter
deposition and erosion, biotic factors such
as
forces
waves of
migration, competition, and ecesis. The
last
is
and especially
the immediate
its
origin
just
as
far
is
the
chresard
to
which
new area is
failure
to
consider
the
sequence
as
and on the
humidity originating from
distributed
in
different
ways
in the soil according to its nature and surface, and hence
comes the division
one
formation
is
edaphic
hand,
but
as
most
natural
life-forms,
and
species,
in
the
the habitat are the
the
causes
of
structure,
of
complex
organism.
individual.
Moreover,
just
as
so
also
primary
reproduction
from
an
stages
reproduce
as
community.
recognized.
func-
as
organs.
In
both
individual
and
community
and
its
succession
climax, are only
stage
is,
temporarily
at
least,
a
stable
structure,
stage, and not
vast, however, that only a few
of the
which
a
rich
harvest
of
polemic
ignored,
and
at
swell
them;
and
moss, when it falls on dry and parched ground begets
the
heath.
sandy
highest
is
that
those
hills
 I
bogs caused otherwise.
weeds
dam it up. Then,
in winter, the water
be
to
these
bogs;
to
winter
and
falls
on
the
till
it
so
as
and entire in them,
wood
by
the
that they
are often
converted into
renewal
well-known
facts
by aquatic
plants in
 If
one
break
of a
prepared area.
soil
Rhus,
for
After
the
others,
of the pine and
one can sow successfully in wild land.
(245)
Biberg,
1749.—
Biberg
(1749
:6,
27)
of
vege-
tation.
When
the
origin and
age, but that,
did.
 2.
fertile soil will not cover the
earth,
of
a
on such
students of peat-bogs,
do justice
The
advancing
into,
contracts the original extent of the lakes; and, it is well-
known in
that country,
that many
large lakes
have been
converted into
smaller ones,
still
a
lake
in
them,
in
the
 3.
Behind
this
in which the
and
more
useful zone, still backward
succession
of
zones,
so
thus
abandon.
That
process
originally
some
: But
in
lakes
its
circumference,
of ligneous
different species
of plants
are distinguish-
able. These
and fibres of ligneous
plants, or of the
a wet and
by
Surtur-brandt,
Causes of it.
above
another,
while
in
are also found
converted into moss.
He cited the
to
the
replacement
of
forest
Lochbroom
in
West
Ross ;
that
a
not a
and
the
development of peat
requisite
for
regeneration
were
that
rapidly in small pits
cluded that
contributed and still contribute
verted
into
morasses.
of
the
In some even three
30
aspens
and
concluded
that
the
seeds
remained
dormant
in
that he had
to
prairies, of
annual, biennial,
or perennial
This
theory,
here.
following
pages
Cham. Above this
a
by
a
lamina
of
Hypnum
fluitans
and
which follows the
directly above the
before
as
of burial of the
grew,
gradually
covering
center.
Oaks
layers
of
the
aspen c.
banks.
containing
twigs,
posed almost wholly
angustifolium
in
the
upper
of
oak
forests,
which
probably
layers.
The
and that
the gravel.
The willows
a definite
campestris,
Acer
Vaupell,
1857.—
In
submerged forests,
at
a
subsequent
by other
than the
trees,
of
unless
protected
by
man.
explanation
is
always
Calluna
and
Ledum,
as
well
as
lichen
humus
which
forest humus
consisting of
follows the
In
latter may
to
her
The
last
by
the
wind.
Miiller,
1878-1887.—
Midler
(1878,
1884,
1887)
organic
material
growth in
the
character
the
soil
the
succession.
Other
investigations.—
was treated more or
were the important
development must
to
man
 It
stations
of
degrees the vegetation of its shores; bare
sand-dunes, where
by
degrees
enriched,
by
the
plants
requiring
a
better
nourishment,
to
of this time.
peat
with
heather,
lichens,
disappeared,
on the
other hand,
represent periods
The
causes, but
must have
vegetation
found
ones,
seem
to
The moors
period just pre-
began
long
before
The
profile
the
etc.
6.
by Sernander
(1888),
Hulth
(1899),
Holmboe
(1904),
Lewis
(1905-1911),
Haglund
(1909),
Samuelsson
(1911),
upon
be based,
(1885:161),
a
scrub,
which
appears
by spruce,
and the
latter finally
is
(1)
aquatic
formation,
(2)
Carex
moor,
(3)
herb
sistent account
investigation of dune seres
out
of
high
dunes,
because
all
collect
and to grow
intervening
a
stable
or
gray
dune.
recession of the
that
of
as a
zone of
topographic conditions.
rise
out
by Ledum
Minnesota, in which almost every
stage
may
be
The
latter
mixed
wood
or
muskeag
quite firmly filled with
contains
Utricularia
and
Lemna,
and
Sphagnum
slowly closing in upon
circular
or
elliptical
Vaccinium,
etc.,
general
brief and largely
great credit for
being the first
headed  Struggle
7
chapters,
namely:
(1)
Condi-
tions
and forest.
The chapter
on the
migration-forms,
while origin
man,
agency
of
The
best
example
of
as in most
of
the
vegetation
properties
of
the
soil
may
bring
forth
a
character
of
of
vegetation,
for
of
Flahault
and
climatic forma-
latter
alone
are
regarded
as
showing
a
formations caused him to miss the
real relation may
hard
grained soil that finally results from it, for the possession
of
between woodland and grassland,
there
of
grassland,
and
which
their
transforma-
tion
grassland is
sequence only by
to
it.
The methods
societies in
the development
the panoramic
1. Dunes
sig-
nificance
cause
of
develop-
a
complete
a
VIII. As
to
another,
and
in the
to
mobility,
organs
while
invasion
was
further
of the of
basis
of
succession
and
of
methods
of
investigation.
Friih
material
of
the
Ecology,
but
a
further
time,
and
the
and
investigation
of
succession
(161).
Quadrats
them, as
the
same
ground
was
covered
development
in
of
obscured by
an inclusive
in
1913.
Clements,
birds
convincing
proof
conse-
quence.
great
value.
Tansley,
1911.—
Tansley
to the treatment of
used
of the
inci'eased knowledge. Much
of the work
because of the use
are
profound importance in the develop-
ment of the new vegetation, and
serves
as
a
destruction
of
a
community
in
whole
or
in
modifications
of
development,
Developmental
modifications
are
term
factors
polar areas. Further
all enter
but
there
three
or
four
the
deserts
of
materially
In
quality,
as
-----233BH
drier to
water-content in
an excess
of water-content
material for fixing the
the
amount
of
water
present
in
a
sequence of the
holard,
i.
e.,
to
the
ratio
primary
fundamental
a bare area charac-
produce areas
essentially similar
as in
do,
area, and
or similar
the
bare
carried by
the wind
bare areas
the
development
agents
process,
the holard
that these
of
air
air
covered by the
physiographic
contrasts topographic
and
seems
desirable
place and added
intimately
of little impor-
tance in succession.
Kinds of processes.
formation of
theoretically complement-
As will be
cases
where
thrown
upon
While erosion
life-history
they are associated
structive
bare areas
of
similarly
climatic
relations
persist.
This
seems
case
of
the
great
is much
streams
and flood-plains developed
will
be
essentially
iden-
development
in
of
hills
just
as
extremes and the
lina
Arizona
detritus in
it seems
When it reaches the
low-
wearing away
far
as
plants
play
a
part
while gravity transports
glaciers,
that
picks
up
ported
by
water
the
cracks
of
rocks,
or
it
habi-
tats
and
regions.
of wind and
 
and
cliffs,
agents, water and wind, differ greatly, they are critical in
determin-
ing
the
rate
the
surface
precipitation
a
particular
mountain
peaks,
year.
In
the
minute
wind
action.
Wind
slopes
of
rocks
is
constantly
to
the
action
of
gravity
on
slides in which the ground is often swept bare. Crumbling
and
slipping
are
also universal processes on the steep slopes of crests and hills,
and along
—At the present
time, the effect
of ice in
rock invaders
past.
many lakes in Minnesota and Wisconsin as well as elsewhere.
Shores
other-
those covered with vegeta-
tion are denuded more
of
a
drainage basin must in the usual course be deposited in another
part,
and
of final
to a
the invaders
must meet,
sense, the
so it
of
deposition
the
two
are
going
unit
fact
of
their
that
this
is
first
a
many
cases,
action of
and
cinder-cones,
of
ing
material
Winds
also
the
etc.,
are
most
striking
practically absent
water sediments.
lack of
cementing substances.
and of the
or possess
new sere
will develop.
be
invaded
at
once.
the
in
but
a
deposit
on
the material composing them is picked
up
dunes,
a sere widely
The course of
successional development also
Water
deposits
may
be
are
in
the
case
of
typi-
cally
water areas,
though they
every con-
resting-place
at
of
wind
ground water,
between
deposits,
but
the
final
climax
be
cracks,
to
belong
to
the
initial
surrounded
other stages
that great
confusion results
of the population, and
accurate
and
considerable importance in the development
of the first stages.
upon the
by
seeds and
relatively rich,
is
so
rial,
are
included
(1)
streams
of the process of formation
than their
relations
interaction of erosion
to lakes
in
the
cohesion
and
As to
While deposi-
in lakes
spring-waters and their streams.
rocks and
In
arid
Utah
and
Nevada
remain
absolutely
sterile
under
in
process
and in their
subjects of
investigation by
which
we
know
their
characteristic
by virtue of insta-
by the sand-catching and
of
holard
(plate
1a).
out by the
occur in widely
each other in population
mountains
after being
drumlins (plate 5 a).
by
or the deposit
the
extreme
sheet
proper
offers
an
area
pre-
mines
the holard and echard of the till and the invasions upon it.
This
is
relatively
immaterial
is
considerable
ice
is
Bare areas due
it
but
of
vegetation
such snow-hollows the
of
like
few
respects.
but
may
often very like those
or dust, and of sinter.
Deposits
of
or
and
mud
from
the
structures which discharge
of
the
to the geographer, however,
It
does,
of
agents
rejuvenated lake
will be
essentially or
wholly identical.
shallowing effect of
in
relative
youth,
as
the
increasing
the
development
of
lake
tion. Instead of
incrusted bottom is
entirely devoid of
a
striking
increase of rainfall or the accession of new streams should
rejuvenate
the
sere would depend
or
ponds, playa lakes,
often short,
to
Ponds which last
for several years
so
great
in
amount
as
to
prevent
the
invasion
of
Drainage.
from
it.
As
an
initial
cause
of
new
areas
for
succession,
it
is
most
evident
meters is left, the
at which
a
from
such
and no
place for
flooding
and
consequent
coastal
of
erosion.
As
a
consequence
areas for
Cases of this
tion on
generally, with
Johnson
(1913:451),
as:
(1)
any
level
and
from
a
Cascumpeque
caused
inlets
in
the
barrier
beach
had
caused
a
the
Carolina and
often in
caused
bog when the
a
lower
high-tide
level.
Trees
level will
of
shore-line
development
retrograding
exceeds
subsidence would
has well shown
which must
the plants more or
earthquakes in
producing new
mud-cones.
disturbed
by
masses of rock or soil from
cliffs
tidal-waves
of
earthquakes
coast
lands
primary cause
processes
processes
which
produce
land
to
produce
arid
regions,
and
biotic
distinguished only
forces
which
lie
climate belongs
and eosere.
We are
initiator
ordinary
less effect in
the course of its ordinary oscillations than when it swings beyond
the
usual
extremes.
A
change
of
climate
can
produce
or
adaptation.
Indirectly,
of
Bare areas due to climatic factors directly.
—The direct action
with
more
extreme
drouth,
produces
new
areas
from
sub-
ruderal
most
frequent
sufferers.
have
been
blown
down
local
and
of
small
pure
stands
of
trees
as
rare cases where
course of succession
be changed
California. The
spring
of
1914.
As
causing fire in
stops
incipient
in
exceptional
cases
all
interaction
climate
and
Whatever
the
effect
it
seems
impossible
to
areas, but
which mark
The reverse is
well as
initiate new
to do with develop-
their
destroy the
and
clearings.
Clearings
result
for
are perhaps
the best
examples of
of the
the area. Lumbering
by
Most fires
but
is
wearing
of
roads
or
trails
results
the
constant
topographic
causes,
draining
and
by
as well as of the areas actually drained
or
flooded,
is brought about
beavers.
The
drainage,
i.
e.,
just as
is
furnished
by
the
of
opposed in
denudation
consists
in
the
destruction
of
the
to
the
extreme
reaction
before
they
are
of the
to
the
effect
of
excessive
In
entrance
of
many
migrants.
strikingly
in
the
side
and
produces
a
mass
of
soil
and
vegetation
at
the
bottom.
This
is
which
act
suddenly.
Denudation.—
Secondary
the
process
of
acts.
The
latter
is
ordinarily
much
complete removal of vegetation,
the same
of
to
the
final
production
soil.
Destruction
may,
depth. In
grow.
This
length
of
of
the
bare
area
will
be
decided
by
the
of the initial stages.
soil and the
when the
may destroy
it does not merely
of
the
effect
of
erosion,
both
duce different conditions
when caused by
both eases the
to depth of
the
development
of
vegetation.
two
processes,
simple
together,
but
the
analysis
there
parent area. The second fact is that simple aggregation increases
the
indi-
it
is
readily
disclosed
in the case of the pioneers
of
a
unstable
soil,
especially important
number
large,
as
in
is
due
primarily
to
the
succession
as
a
its
carried
by
wind
mobility
in
many
cases
is
the
actual
case
of
many
order of appearance of species is
largely
a
modification of the disseminule. The earliest
pioneers
lichens,
liverworts,
herbs with
fact
seeds
left
after
the
produced
that no
viable seed
has yet
invaders,
in polyspermous plants,
rodents consume
good
seed-years.
seed-
production
migration
plays
a
small
a seed almost
—
of the
the
surface
for
wind
carriage.
Wings
ash,
etc.,
fall
A
equal
kinds
in proportion
number
of
Many
perfected. This is
drying. In
Physalis the
agents often
this sort is
a
direct
consequence
of
the
perfection
device.
migrate, and upon
(Salsola,
-e,
Eragrostis
pectinacea,
etc.).
produces an area
is
intimate.
chiefly those germules
all
be
of
this
course where
areas
of
of
The action of seed-eating
all
lodgepole pine,
as well
as in
birds and rodents are
exact
value
is
conse-
representative,
it
due
to
primary sere can
as
permanently.
This
is
and
processes,
comprises all the processes
The ecesis
on.
home
of
by
acclimatization,
and
(Termination.—The first critical process in ecesis is germination. The
ejxact scope of
regard it
of
the
first
able conditions
as to water, heat, and oxygen. It is often delayed or even
absent when the
cultivation,
and
it
is
probable
when
conditions
from
sowing is
also un-
it quickly
succumbs. In
to
dormancy,
and
germination
cent
and
at
1
inch.
soil
and is thrown upon its own resources
for
often
destroyed
seedlings are
primary
factor
many
predominant. The
root-system is
drying-out of
the soil
individuals ordi-
tardily, or
inhibiting reproduction, and it would
be
to
this
sense.
Reproduction.
development
of
each stage
in the resulting sere is the consequence of the excess of reproduc-
tion over
the final measure
at
position
throughout
the
and
disappear
finally
in
a
single
clear, but there are few
species that can maintain
bare
out
the
one
impossible
light, the other for
in character,
It increases
successive stages
make similar
or
quite
lacking
In its essential nature, competition is
a
light available
competition for room.
The crowding of
to
to
anything
exists
only
when plants are more or less equal. The relation between host and parasite
is not competition, nor
is that between a
latter
as
seedlings
same supply of water and light. They meet upon more
or
less
equal
terms,
an increasing advantage each succeeding
year, and the time comes
when competition
at
growth
with
in many cases is dominance.
This
is
particularly
grows and transpires less, and its needs for water diminish.
This interplay
petition of the roots
slightly or not
to
that
of
water-supply
is
is merely
development.
In
a
family
As we have seen, the competition between
dominant
the
dominance. The latter
is paramount, how-
The
in
of the
of
foliose
Parmelias,
vigorously,
the rock
upon the
case
large
number
is often
a time,
spruce and
completely or
invasion
is
is
necessary
to
distinguish
between
invasion
into
a
a
dominant population.
From the
bare areas
or produce a new developmental stage. It is obvious that practi-
cally
Effective invasion
of
pioneer-
invaders are
too few
the
from
the
times
as a
at any one time
mutual, unless
which
as
to
require
recogni-
tion.
in
a
primary
of
are
transient
stages
of
vaders to those found in plant communities. This is due
to
the
then
largely
determined
by
to
recognize
that a community is not necessarily open because part of the surface is bare.
Secondary bare
areas usually
afford maximum
tions are more
shallow
enough
to
contain
an association
small
as
upon
that their
influence
upon
some
virtue of
their dominant
true of
water-currents and
sive
water-content
of
plants
an
obstacle
to
invade
it.
Biological
barriers.—
acts
such
a
barrier
be
complete
unlikeness
of
the
two
limit
and other anemo-
exert
a
production.
They
restrict
or
or
of unusually
peculiar example of the
invaders,
which
reacts upon
in
con-
which
can
hardly
be
regarded
In most
otherwise
be
insignificant
controlling. The
leaf-litter
but
its
part of a
plant. This is
light and humidity is
of water-borne detritus.
for
considerable
space
played
by
necessarily mechanical
procedure
is
such
as
to
there have been
result of
its reaction,
in the
physical changes
in
succession
it is
fundamental
primary in one sere and secondary in another, or in
differ-
ent
periods
and
following
arrangement:
(1)
soil
formation
purpose:
(1)
light;
(2)
other
factors
(humidity,
etc.)
reaction,
to
trace
its
exact
study
or soil and
(2)
by
the
concretion
from
the
accu-
mulation
of
plant
remains
into
liberation of carbon
wet places,
but the
substances, changes in soil
water-borne detritus
to
inhibit
plants
may
enter
because
con-
trols
A host of
of
soil
by
peat-producing
plants
(Plant
Succession,
pp.
sition and
influences,
the
primary
reaction
the
Chara plays the chief
this
of lakes, Davis
the microscopical size
of the alga?
the
latter
are
so
large
production
lost
sight
of
in
the
greater
effects
of
atmos-
lichens and
increases the nutrient-content
effect is
the same.
the
nutrient-content.
The
pioneers are
effect is
weathering
begins
with
during
and
begin
to
leaves
of
plants,
especially
pioneers
the
many feet above the bare areas. The behavior of sand-
binders has
work of
of
loess
must
indeed
have
in
the
form
development
of
each
and
of
no deposits
of its load in whole
or
a
but the
by
carried.
decreasing
depth
controls
slope is
Each plant
or each
to the
The
primary
reaction
is
a
production
and
water-content,
and
the
protect
a primary
of
the
herbs. The
clay soil more open.
and
the result
tion
of
harmful
substances
through
of
humus
is most marked in the weathering of rock and in dry
sand
number or
this
and
gravel
to
12
to
15 per cent in loam, so that the chresard increases less rapidly
than
the
with
greater
powers
of
competition
their
difficult if not impossible
in
the
 hard lands of the Great Plains. In heath-sand the final outcome
is
the
remain in solution only
the
soil
salts.
They
pass
through
are
precipitated
where
a
reach
a
decimeter
in
thickness.
The
primary
effect
it stops the downward
The effect of  ortstein
is
to
handicap
deep-
of
stages,
as
occurs in
water
is
limited
plants stop drifting
the stems and leaves
usually eliminate
normal
cult
increase or
decrease of
plant
to
the addition of a small amount of
humus greatly
to a
to
decrease
more compact soils it increases
the
absorption
of
run-off,
and
water
available
with
other
reactions
as weathering,
subclimaxes, as
the seres
of a
of
the
of silt
are
controversy,
the
content
decomposi-
tion
of
to
enter
the
quirement,
but
really hinges upon
the relation between
succession apart
from its
fundamental relation
to water-content.
tend
in
in the humus
 
humus.
plant
remains
access
of
partial,
and
the
water
or
soil
becomes
a neces-
conse-
quence
of
decreased
plants
are
usually
Vaccinium, etc.
In spite
species
of
restricted group
from their reactions.
more probable
period of quantitative and
reveal their importance
to
draw
a
distinction
in
organic
relation
to
saprophytes
are
an
indirect
reaction,
or,
better,
a
consequence
of
parasite is
succes-
largely
by
it is
rare. The most
outcome of competition.
and
the greater
demands,
which play a
large part in the ground layer of boreal and mountain forests
have
to
do
is
some
upon
soil.
factors are
the
interception
of
shade
of
varying
(Zederbauer,
1907;
Knuchel,
1914)
The reduction
of succes-
intercepts
result
that
a
reaction
steadily
becomes
more
marked
type the cumulative reaction is
so
complete
a
long
time,
until
the
individuals
with
the
they are able
reach up
the
species
climax, this
The
earliest
by shading
(1)
Pinus
murrayana;
(2)
roots,
and
be
checked
by
through transpiration and
in the
and both
as
that
critical
factor
and
rain
than
do
but
probably
occurs
in
some
rainfall
has
long
been
a
(1912:205)
has
rain-
fall.
At
Nancy
12
was
to 84 per cent.
forest
a
average
22.2
above
conif-
the
much
as
0.4
regions
the
condensation
in Austria
from 1878
a
a
land surface
water
circulation
per cent
only
rainfall,
furnished
by
this
area
acceptance is impossible
of
many
regions.
(21)
Reaction
or
matrix,
saprophytic
but obtains in some
important
relation
decrease
of
water-content
be dominated
it becomes
chiefly or
by the
come
of
initial
unless
decomposi-
other
deleterious
substances.
nutrients.
again in woodlands
of acids,
to
other
problems,
to 1906,
the last
studies
of
Livingstone
(1906)
light,
Yapp
(1909)
on
evap-
reactions
or
evaporation.
The
first
special
study
Dachnowski
(1912)
has
studied
Washington.
of greater due
the
population.
progressive
annuals
a
certain
stage
until
the
charac-
precludes them. The reactions
On the
unfavorable
to
the
Thus,
to
reason the
number of
in
a
population
most
the
pines
which
of man will nearly
of all the life-forms.
areas,
all
possible
degrees
distinct than
the
stages contemporaneous
in different
areas. However
it takes account of
though
much
is
desirable
to
At
the
final, or into
and reaction
something
of
usually
role. In essence, the life-form is the superposition of water
and
to
this
are hardly
of
a
water
algae also.
of the habitat
as a
is
desirable
to
distin-
form in
changed
stems
of the subordinate
is
primarily
its
treatment.
belong
indirectly
when
In fact,
thus actually
that the pioneer life-forms are perhaps
never
after
a
burn.
which
years.
of
the
stages
more than
Others
are
as
relicts
to
parasites,
animals,
or
man;
(4)
the
with difficulty
question
influence of
old age
and long-
the latter. But it
of
matter
of
reaction,
more
same time are growing
their
proper
extreme, and
species
can
or rapidly change
by
animals
or
man.
not unusual
be
delayed
three or
after the pioneer stage
of
a
stages of
either kind
to position
life-forms
produced by them are likewise universal and, more interesting still, are highly
mobile
the
pioneer
the
same
species
rock,
dune,
that
of
them,
is
the
degree
associated
best regarded as three
(1)
lacking,
by a
stages
or
first stage of
primary areas, and the
few
that
dance of humus, together
consist
of
seres
ones
The
climax
formation
the
formation
a
not been
of
organism, the
formation.
a
climax
in
in the adult
an
too
similar effects, while
throughout
may
medial
per-
manent,
to
be
sought
succes-
sion
two-fold
meaning
of
the
prefix
sub,
and actually
beneath it
resemble
a
true
very
closely.
In
addition
to
subclimaxes,
replace the
climax of
length,
potential
climaxes
(1)
soil,
(2)
reaction,
(3)
competition,
(4)
climax
one.
climatic
formation
is
their
reac-
tion
time,
and
this
consequent
pro-
and
heath
to
persist
for
a
long
time
thinking that these
of
the
Conspicuous
causes
produce sub-
by
adjacent areas
combined, and they
of
the
forest.
The
clearing
by
fire
case, the scrub may
The final
a long
time in
of
Gutierrezia
and
Artemisia.
possible
in
case
zones,
prairie
munity.
changes
of
the whole climax
community and its
effects
of
small
variations
of
the midst
rainfall
forest would
before the forest.
be
recognized
potential
climaxes
forest
in
efficient increase
the prairie climax
most
clearly
by
xerophytic
place themselves
to
them
the
the relation
the development
of an
long-continued
evolution
due
to
climate.
alternations,
(1876).
It
is
of
the existing seres to
heath or aspens and conifers just south of it. In
a
similar
manner,
new arctic climax of which they were the potential climax.
Finally, when
and the
 
the course
final form,
partial
disappearance
of
the fate of
in
versal
shown in
water seres, where the zonation from the center to the margin,
due to
zones of the margin move successively over
the surface, and are
there
seres,
viewed as
a
matter
of
operated
unevenly
over
The
are
bare area
which it
on the
of
a
or
stages of
of the hydrosere, showing
decrease in water-content.
a
dry
regions,
demonstrated
by
by
every
is found
significance
in
correlating
climatic
zones
with
edaphic
ones.
In
such
of
climax
area
in
successional
zonal
Owing to the more
appear, making
or when
The zonation of fringing forests is perhaps best seen in
prairie
and
plains
there
is
or fragmentary,
others, the complete series may find expression. In the Otowanie
Woods
They
differ
the
poles,
sources of
which bear witness to
of
to-day
about
water-bodies
Pinus ponderosa
is direct
proof of
to the sub-
in the develop-
whose
where climatic conditions
the
numerous
alternes
are
of
the
prairies
from the ground-layer of
hence serves
as a
when light
is characterized by a
so
that
degree
the
prairie
a
heat as
herbs,
such
as
Anemone,
Astragalus,
aspects as
prairie in summer
has
had
a
more
varied
and attempts to
is
is
true
of
all
biological
concepts,
between
of the
Grisebach's concept of
flora. Even if
a
dominant
species
of
a
group
does
not
appear
at
the
of
the
formation
was
and
by
many
modern
extent
but
they
throw
be
secured
special physiognomy
dominant species, and