Table VIII-6. | Simulation of exchange between habitats under different spatial conditions: the influence of the number of habitats, the variability between habitats and the distance between habitats upon the population-dynamic effects of dispersal. The table gives the mean results of 10 simulations per situation. |
(a): | 20 habitats. exchange between habitats random. variation coefficient v.c.=0.5 |
(b): | as (a). but only 5 habitats |
(c): | as (a). but exchange between habitats related to the distances between them |
(d): | as (a). but values for reproduction. survival and dispersal synchronized between the habitats (see text) |
(e): | as (a). low variability v.c= 0.3 (see text) |
dispersal: | |
- = | no dispersal activity |
1.5 = | 1.5% emigration. I/E = 0.5 |
30 = | 30% emigration. I/E = 0.70. |
For further explanation. see Table VIII-4. Numbers of populations per size group are given as percentages. |
dispersal | population sizes after 25 years | ||||||||
---|---|---|---|---|---|---|---|---|---|
0 | 101 | 102 | 103 | 104 | >104 | Rg | v.c.Rg | LR | |
(a) 20 habitats | |||||||||
- | 79.00 | 7.00 | 4.00 | 4.00 | 5.00 | 1.00 | 0.974 | 0.621 | 1.385 |
1.5 | 0.00 | 2.50 | 35.00 | 40.00 | 19.00 | 3.50 | 1.018 | 0.439 | 1.237 |
30.0 | 0.00 | 0.00 | 25.00 | 70.50 | 4.50 | 0.00 | 0.970 | 0.199 | 0.608 |
(b) 5 habitats | |||||||||
- | 90.00 | 0.00 | 4.00 | 4.00 | 2.00 | 0.00 | 0.695 | 0.711 | 2.436 |
1.5 | 16.00 | 22.00 | 30.00 | 24.00 | 8.00 | 0.00 | 0.901 | 0.563 | 1.597 |
30.0 | 0.00 | 22.00 | 26.00 | 50.00 | 2.00 | 0.00 | 0.921 | 0.365 | 0.966 |
(c) distance | |||||||||
- | 80.00 | 8.75 | 4.58 | 2.50 | 2.92 | 1.67 | 0.950 | 0.639 | 2.314 |
1.5 | 0.00 | 7.50 | 28.75 | 38.75 | 16.25 | 8.75 | 1.047 | 0.456 | 2.902 |
30.0 | 0.00 | 19.50 | 68.00 | 12.50 | 0.00 | 0.00 | 0.898 | 0.253 | 1.202 |
(d) synchronized | |||||||||
- | 100.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.260 | 1.435 | 4.997 |
1.5 | 100.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.293 | 1.509 | 5.203 |
30.0 | 100.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.308 | 1.493 | 5.207 |
(e) low variation | |||||||||
- | 5.50 | 8.50 | 20.50 | 33.00 | 18.50 | 14.00 | 1.109 | 0.299 | 1.399 |
1.5 | 0.00 | 0.00 | 0.00 | 24.50 | 61.50 | 14.00 | 1.097 | 0.207 | 1.222 |
30.0 | 0.00 | 0.00 | 4.50 | 66.00 | 29.50 | 0.00 | 1.010 | 0.166 | 0.412 |