Takahara Y
Department of Geology, University of California at Davis, Davis, CA 95616, USA.
Biosystems. 2000 Aug-Sep;57(3):173-85. doi: 10.1016/s0303-2647(00)00096-4.
Individual base model of predator-prey system is constructed. Both predator and prey species have age structure and cohorts of early reproductive age have competitive advantage. The model has linear functional response in predation behavior and includes the effect of interference among predators and delay of population growth from resource intake, not by functional response but by calculation procedure. Each foraging action is calculated successively and surplus or scarce of acquired resources is interpreted into population size through individual birth and death. This model shows that biomass of prey killed by predator is dependent on demand of predator and that heterogeneity in predator population is essential in persistency and stability of predator-prey system. Heterogeneity of predator makes predator individuals of less competing ability die rapidly. Rapid death of weak individuals causes rapid decrease of total demand of predator and that makes enough room for survived predators. Therefore, the biomass of killed prey is dependent on predator's demand. As young or infant population of predator are the more vulnerable to shortage of prey, and when many of them cannot survive to reproductive age, they can stabilize the system by wasting excessive prey with only temporal numerical increase of predator population.
构建了捕食者 - 猎物系统的个体基础模型。捕食者和猎物物种都具有年龄结构,且早期繁殖年龄的群体具有竞争优势。该模型在捕食行为上具有线性功能反应,并包括捕食者之间的干扰效应以及种群增长因资源获取而产生的延迟,这种延迟不是通过功能反应,而是通过计算过程来体现。每次觅食行动都依次进行计算,获取资源的盈余或短缺通过个体的出生和死亡转化为种群规模。该模型表明,捕食者捕杀的猎物生物量取决于捕食者的需求,并且捕食者种群的异质性对于捕食者 - 猎物系统的持久性和稳定性至关重要。捕食者的异质性使竞争能力较弱的捕食者个体迅速死亡。弱势个体的快速死亡导致捕食者总需求迅速下降,这为存活的捕食者留出了足够的空间。因此,被捕杀猎物的生物量取决于捕食者的需求。由于幼年或幼体捕食者更容易受到猎物短缺的影响,当其中许多个体无法存活到繁殖年龄时,它们可以通过仅使捕食者种群数量暂时增加来消耗过多的猎物,从而使系统稳定下来。