Hanski Ilkka, Woiwod Ian, Perry Joe
Department of Zoology, Division of Ecology, University of Helsinki, P.O. Box 17, SF-00014, Finland.
AFRC Farmland Ecology Group, Entomology and Nematology Department, Rothamsted Experimental Station, AL5 2JQ, Harpenden, Hertfordshire, UK.
Oecologia. 1993 Oct;95(4):595-598. doi: 10.1007/BF00317446.
Wolda and Dennis (1993) suggest that no valid conclusions about population regulation can be drawn on the basis of statistical tests of density dependence in time series data of population abundance. They give some examples in which a 'population' persists even if it is not regulated by a density-dependent process: a sequence of independent, identically distributed random variables, the numbers of the migrant moth Autographa gamma in Britain, annual rainfall data. We suggest that such time series data may show persistence because of a static constraint, which compels the numbers to remain within finite, positive limits, or to fit some prescribed distribution. But this mechanism can explain persistence in a biological population only when the 'population' represents a sample from a regulated population (the case of A. gamma). We also comment on some suggestions made by Wolda and Dennis (1993) concerning the general value of statistical tests of density dependence, frequency of delayed versus non-delayed density dependence in natural populations, relative performance of different kinds of insect traps in sampling local populations, and the wider issue of how ecologists are likely to make progress in the study of population dynamics.
沃尔达和丹尼斯（1993年）指出，基于种群数量时间序列数据中密度依赖性的统计检验，无法得出关于种群调节的有效结论。他们给出了一些例子，其中一个“种群”即使不受密度依赖过程的调节也能持续存在：一系列独立、同分布的随机变量、英国迁徙的γ银纹夜蛾数量、年降雨量数据。我们认为，此类时间序列数据可能由于静态约束而表现出持续性，这种约束迫使数量保持在有限的正范围内，或符合某种规定的分布。但只有当“种群”代表来自受调节种群的样本时（γ银纹夜蛾的情况），这种机制才能解释生物种群中的持续性。我们还对沃尔达和丹尼斯（1993年）提出的一些建议进行了评论，这些建议涉及密度依赖性统计检验的一般价值、自然种群中延迟与非延迟密度依赖性的频率、不同类型昆虫诱捕器在抽样当地种群中的相对性能，以及生态学家在种群动态研究中可能取得进展的更广泛问题。
