物种多样性对栖息地毁坏时间异质性的响应

栖息地毁坏是物种多样性丧失最重要的因素之一.通过多物种竞争共存的非自治动力模型,利用香农多样性指数,研究并比较了不同结构集合种群群落的物种多样性对不同程度和不同速度的栖息地毁坏时间异质性的响应.结果表明:在栖息地瞬间毁坏下,物种多样性先快速下降,之后得到一定程度的恢复,最终在下降中走向平衡;在栖息地持续完全毁坏下,栖息地毁坏速度对物种多样性随累积栖息地毁坏率变化的影响,只有在最强物种多度 (q)较小时比较明显,而在q较大时较小;对于栖息地持续部分毁坏,栖息地毁坏速度只影响物种多样性振荡的幅度,而不影响其变化的最终结果,并且速度越快,物种多样性振荡幅度越大,越不利于群落的稳定.

Species diversity under effects of temporal heterogeneity of habitat destruction

Habitat destruction is one of the main factors inducing the decrease of species diversity. By using a non-autonomous multi-species competition-coexistence model and Shannon diversity index, the responses of different metapopulation species diversity to the temporal heterogeneity of different rates and velocities of habitat destruction were analyzed. The results showed that under instantaneous destruction, the species diversity decreased rapidly first, recovered to a definite extent sooner, and went to equilibrium then. Under continuous and complete destruction, habitat destruction rate had obvious effects on species diversity when q was lower, but few effects when q was higher. Under continuous and partial destruction, the higher velocity the habitat destruction, the greater amplitude the species diversity had, which was not beneficial to the stabilization of community.