Density dependence in blowfly populations: experimental evaluation of non‐parametric time‐series modelling
Density dependence in blowfly populations: experimental evaluation of non‐parametric time‐series modelling
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苍蝇种群的密度依赖性：非参数时间序列模型的实验评估
DOI：
10.1034/j.1600-0706.2002.980317.x
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发表时间：
2002
期刊：
影响因子：
3.4
通讯作者：
Robert H. Smith
中科院分区：
文献类型：
--
作者：
S. Jannicke Moe;Nils Chr. Stenseth;Robert H. Smith
本研究比较了描述阶段结构人口的人口比率密度依赖性的两种方法。实验室绿蝇种群（Lucilia sericata）的时间序列数据已在另一项研究中进行了分析，采用统计建模方法，将密度依赖性纳入未指定（非参数）函数。在这项研究中，我们通过操纵绿头蝇群体中幼虫和成虫的密度并测量人口统计率来评估密度依赖性结构。我们在这里将队列实验揭示的密度依赖结构与非参数模型估计的密度依赖结构进行比较。该模型估计人口统计率具有以下密度依赖结构：（i）幼虫存活率呈非线性密度依赖性（“驼峰”函数），（ii）成虫存活率与密度无关，（iii）繁殖率随成虫密度下降。在此报告的队列实验中，（i）幼体存活率在低密度（促进）下表现出正密度依赖性，在较高密度（竞争）下呈负密度依赖性。蛹和成虫的大小随着初始幼虫密度的增加而减小。 (ii) 成虫存活率因初始幼虫密度高而降低，但与成虫密度无关。 (iii) 繁殖率因初始幼虫密度高和大型个体种群中成虫密度高（幼虫密度低）而降低。因此，这些实验的结果支持关于绿头蝇种群人口统计率的密度依赖结构的非参数模型估计。然而，该模型显然低估了平均人口比率。我们的结论是，非参数建模是生态时间序列数据探索性分析的第一种有用方法。
Two approaches for describing density dependence in demographic rates of stage-structured populations are compared in this study. Time-series data from laboratory blowfly populations (Lucilia sericata) have been analysed in a separate study, with a statistical modelling approach that incorporated density dependences as unspecified (non-parametric) functions. In this study, we assessed density-dependent structures by manipulating densities of larvae and adults in cohorts of blowflies and measuring the demographic rates. We here compare the density-dependent structures revealed by the cohort experiments with those estimated by the non-parametric model. This model estimated the demographic rates to have the following density-dependent structures: (i) larval survival was non-linearly density-dependent (a 'humped' function), (ii) adult survival was density-independent, and (iii) reproductive rate decreased with adult density. In the cohort experiments reported here, (i) juvenile survival exhibited a positive density dependence in low densities (facilitation), which became negative at higher densities (competition). Pupal and adult size decreased with initial larval density. (ii) Adult survival was reduced by high initial larval density, but it was independent of adult density. (iii) Reproductive rate was reduced by high initial larval density, and by high adult density in populations of large individuals (from low larval density). Hence, the results from these experiments support the non-parametric model estimates regarding density-dependent structures of demographic rates in the blowfly populations. The mean demographic rates, however, were apparently underestimated by the model. We conclude that non-parametric modelling is a useful first approach for exploratory analysis of ecological time-series data.