Biology Reference
In-Depth Information
growth for all trials (Fig. 15.1A), most likely because of the increased
offspring dispersal to outside the preserve (a higher percentage of seeds
die). Lending support to that notion is the relative increase in population
growth rate when offspring dispersal is nearer the parent in trial n (fewer
offspring fall out of the preserve). In Fig. 15.1B, N shows the lowest rate of
population growth, which is most likely related to more competition for
points when seed dispersal is nearer the maternal plants when the founders
are in one contiguous, central square.
8000
8000
P
A
B
P
M
P
6000
6000
M
P
M
P
O
M
p
P
n
O
O
N
NNNN
NNNNNNN
NNN
NNNN
NNNNN
NNN
NN
NN
N
NN
N
NN
NN
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
nnnn
nnnnnnnnn
nnn
nnnnn
nnnn
nnn
nn
nn
nn
n
nnn
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
p
P
mmmm
mmmmmmmmm
mmm
mmmmm
mmmm
mmm
mmm
mm
mm
m
mm
mm
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
M
MMMM
MMMMMMM
MMM
MMM
MMMMM
MMM
MM
MM
MM
M
MM
M
MM
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
pppp
ppppppppp
pppp
ppppp
pppp
ppp
pp
pp
pp
p
ppp
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
O
OOOO
OOOOOOO
OOO
OOO
OOOOO
OOO
OOO
OO
OO
O
OO
O
OO
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
P
P
PPPP
PPPPPPP
PPP
PPP
PPPP
PPPP
PP
PP
P
PP
P
PP
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
oooo
ooooooooo
oooo
oooooo
oooo
ooo
oo
oo
oo
oo
oo
oo
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
4000
4000
2000
2000
0
0
0
10
20
30
40
50
60
70
0
10
20
30
40
50
60
70
GENERATION
GENERATION
Fig. 15.1
Mean population growth for trials modeling establishment of the dioecious shrub
Lindera benzoin
. 172 founders were placed either in squares of 43 at each corner with no founder
closer than 80 grid units from a border (graph A, lowercase letters), or in a single central square
in the preserve (graph B, uppercase letters). In every trial, there were 4 grid points between
all adjacent founders. The different trials are compared to the basic trial M, in which 25% of
offspring are dispersed to, and 25% of pollen comes from, each of the four dispersal distance
frames (see
Table 15.1)
.
Comparative trials differ as follows:
In trials N and n, more offspring are dispersed more closely to the maternal plant; 25% pollen
from each frame.
In trials O and o, 25% of an individual's offspring are dispersed to each frame; more pollen
comes from nearer the maternal plant.
In trials P and p, 25% of an individual's offspring are dispersed to each frame; more pollen
comes from a greater distance from the maternal plant.
Of these trials, only trials n and p do not differ signifi cantly (p > 0.05). For more details on
the trials, see text and Table 15.1.
For both types of founder placement, trials o and O rank at or near
the bottom in population growth rate. The shift in more pollen coming
from nearer a maternal plant seems to suppress full population growth. In
contrast, population p and P exhibit the fastest growth rates, indicating that
having more pollen arriving from greater distances benefi ts growth rates.
Note that in both the O-o and P-p trials, 25% of the offspring are dispersed
to each frame, including the 23-301 grid units frame. But when more pollen
Search WWH ::
Custom Search