Table 3 Estimates of SGS and parameters of gene dispersal for four populations

From: Population history and gene dispersal inferred from spatial genetic structure of a Central African timber tree, Distemonanthus benthamianus (Caesalpinioideae)

Sampled population

N

D (Ind/km2)

SGS parameters

 

Gene dispersal parameters

      

S p (s.e.)

S p (s.e.)

 

σg (m)

σg (m)

σg (m)

   

F IS

F (1)

b F

for d ij ⩽60 km

for d ij ⩽10 km

N b

(D=D/2)

(De=D/4)

(De=D/10)

1 AbongMbang

40

10.7

0.094**

0.054***

−0.007*** (0.004)

0.008 (0.004)

0.017 (0.005)

–

–

–

–

2 Ebolowa

50

68.5

0.016NS

0.052***

−0.011*** (0.003)

0.011 (0.003)

0.024 (0.007)

107 (28–∞)

–

993† (391–∞)

1155† (578-∞)

3 Sangmelima

52

55

0.012NS

0.047**

−0.010*** (0.002)

0.010 (0.002)

0.010 (0.009)

56 (26–∞)

438† (283–∞)

601 (441–1072)

746 (623–1783)

5 CEB

62

60

0.055NS

0.105***

−0.012*** (0.004)

0.013 (0.004)

0.027 (0.006)

47 (18–∞)

396† (218–∞)

426† (310–∞)

–

  1. Number of genotyped adult trees (n), estimated density of trees over 40 cm d.b.h. (D). SGS parameters: inbreeding coefficient (FIS), average kinship coefficient between individuals separated by less than 1 km (F(1)), slope, and its s.e., of the regression of kinship coefficient values on the logarithm of spatial distance between individuals (bF), and the intensity of SGS (Sp) and its s.e. Calculated for pairwise distances between individuals up to 60 km, and up to 10 km, in each population. Gene dispersal parameters within the spatial range σg-20σg: neighbourhood size (Nb) and 95% confidence interval, gene dispersal distance (σg) and 95% confidence interval for three effective densities (De) estimated from the density of adults (D). Absence of values indicates that the estimation procedure did not succeed (see text). Nb was little affected by the assumed De, so that the value given is the mean estimate under the three assumed De (values in italics when the estimation procedure did not succeed for all assumed De), and the confidence interval considers the lowest lower and highest upper interval values.
  2. P-values: not significant (NS) for P>0.05; ** for 0.01 ⩾P>0.001; *** for P⩽0.001.
  3. †Averaged σg over the different values between which the iteration procedure cycled.
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