Homework Assignment #5: Population Growth
Due: Wednesday, 18 October 2006
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1. You are studying a population of prickly sow thistle (Sonchus asper), which is an annual Asteracea. When you arrive at your study site, an initial survey results in 202 individuals being found. You spend the next year studying the survival and reproductive success of this species and find the following data:
|
Age (x) |
nx |
lx |
mx |
lxmx |
|
0 |
202 |
1.000 |
0.000 |
|
|
1 |
156 |
0.000 |
||
|
2 |
123 |
10.583 |
||
|
3 |
50 |
3.586 |
||
|
4 |
25 |
2.585 |
What kind of survival curve does this population exhibit?
Is this population growing or decreasing?
Calculate:
Net reproductive rate (R0)
Population size for the next year (N1)
Population size for three years from now (N3)
Population size for five years from now (N5)
2. After studying the plant population for a year, you decide to switch gears and study something more interesting. You decide on mountain sheep, which you know are going to take several years to get data on so you decided to follow them for five years and then make some projections of what is going on with this population.
Not only do you find the following data on survival and fecundity, you find out the carrying capacity for this population (K) is 600.
|
Age (year) |
nx |
lx |
mx |
lxmx |
xlxmx |
|
0 |
500 |
1.000 |
0.000 |
||
|
1 |
489 |
0.000 |
|||
|
2 |
460 |
0.000 |
|||
|
3 |
350 |
1.004 |
|||
|
4 |
284 |
1.500 |
Calculate:
Net reproductive rate (R0)
Generation time (T)
Per capita rate of increase (r)
Growth rate during the fifth year (Age = 5)
Hint this requires several steps not given!
Estimated population size during the sixth year.
Estimated population size after 10 years.