1、http:/ 起重機 立體停車設備 電動葫蘆 http:/ 襯塑復合管 涂塑復合管 鋼塑復合管 消防涂覆鋼管reindeer, st. paul, alaska. started in 1910 with only 4 males and 22 femalesin 1940, there were nearly 2000 how to calculate r? software, excel (trendline)aransas national wildlife refuger determines the shape of the growth.r=0, no change in popu

2、lation sizer0, increase in population size. widely used in biologyn(t)=n(0)exp(rt)give a time t, we can predict the population size.an example: deer population: n(0)=300, r=0.5, after 5 years, whats the population size?n(5)=n(0)exp(rt)=300*exp(0.5*5)=3655(495, 815, 1344, 2216, 3655) t=10, ?44524elf

3、opinelog scale for y axistype i (convex) humans and other mammals and some plants (k-selection)type ii (survival rates do not vary with age) adult birds, rodent, and reptiles, perennial plantstype iii. concavemortality rate high in the beginning (r-selection)oysters, fish, many plant species (most t

4、rees)crude birthrate (demographers): # of birth over a period of time divided by population size at the beginning of the period*1000age-specific birthrates, bxmean # of females birth to a female in each age group. (only females give birth; birth rates vary with ages)gross reproduction rate: sum of t

5、he bx values across all age classes, provides an estimate of average offspring born to a female over her lifetime.calculate age-specific survivor rate: sx=1-qxbx is age-specific birthratepopulation size (n) increases every year. lambda (finite multiplication rate): =n(t+1)/n(t).stable age distribution: by year 7, the proportion of each age group remain the same year after year.population is still growing.allee e