Tuljapurkar S, Istock C
Department of Biological Sciences, Stanford University, California 94305.
Theor Popul Biol. 1993 Jun;43(3):251-80. doi: 10.1006/tpbi.1993.1011.
We analyze a stage-structured model of a population that displays variable diapause in a randomly varying environment. The ruggedness of the environment is measured by the extent of random variation in per-capita reproductive success. We show how variable diapause and environmental characteristics affect the population's stochastic growth rate. In rugged unpredictable environments, phenotypes that show some tendency to diapause are found to have a higher growth rate than nondiapausing phenotypes. In harsh rugged environments, some tendency to diapause may be all that permits population persistence. Positive serial autocorrelation causes the optimal diapause fraction to decrease, while negative autocorrelation causes that fraction to increase. The structured model behaves very differently from a scalar model for large diapause fractions even in uncorrelated environments, and in many cases predicts a broad optimum. The difference between models is due to the extreme variability of stage structure in populations subject to even small variability when diapause tendency is high.
我们分析了一个种群的阶段结构模型，该种群在随机变化的环境中表现出可变滞育。环境的崎岖程度通过人均繁殖成功率的随机变化程度来衡量。我们展示了可变滞育和环境特征如何影响种群的随机增长率。在崎岖不可预测的环境中，发现表现出一定滞育倾向的表型比非滞育表型具有更高的增长率。在恶劣崎岖的环境中，一定的滞育倾向可能是种群持续存在的唯一条件。正序列自相关导致最优滞育比例降低，而负自相关导致该比例增加。即使在不相关的环境中，对于较大的滞育比例，结构化模型的行为与标量模型有很大不同，并且在许多情况下预测出一个宽泛的最优值。模型之间的差异是由于当滞育倾向较高时，即使是很小的变异性，种群中的阶段结构也会有极大的变异性。
