3物种食物链的集合群落中捕食者追赶和猎物逃逸对空间同步性的影响

空间同步性能够导致区域物种灭绝从而降低集合种群的续存.在集合群落的框架内建立了两斑块3种群食物链联立模型来研究捕食者追赶和猎物逃逸对空间同步性的影响.由于种群存在较大的群落中,从集合种群向集合群落扩展是很自然的.表明了在集合种群中猎物逃逸降低空间同步性的结论在集合群落中有所改变.得到一个有悖直觉的结果:3物种食物链基层物种的逃逸并没有保护自己,反而增加了所有这3物种集合种群的空间同步性,因此也增加了灭绝的风险.这个结果说明在制定关于种群同步性也即续存的保护措施时,物种间的相互作用也必须考虑.

Influence of predator pursuit and prey evasion on synchrony in the metacommunity of a three-trophic-food chain

Spatial synchrony can increase the risk of regional extinction and hence, shrink metapopu-lation persistence. Coupled patch model, based on a within-patch three trophic food chains model, isadopted to investigate the impact of predator pursuit and prey evasion on the spatial synchrony in themetacommunity framework. As populations occur in the context of larger communities, moving from ametapopulation to a metacommunity model framework is a natural extension. Considering a metacom-munity can modify the conclusion that prey evasion decreases the degree of metapopulation synchrony.We obtain a counter-intuitive result that the evasion of basal species in three trophic food chains does notprotect itself, but enhances the degree of synchrony for all species and then increases the risk of extinctionof each metapopulation. These results indicate that species interactions need to be considered when theeffect of conservation measures on population synchrony, and ultimately persistence, is addressed.