The multispecies LVM is given by dni/dt=(ri- for i=1,...,N (3) j=1 where have we set the carrying capacities of all species to 1 without loss of generality.(This is equivalent to expressing the density of all species relative to their carrying capacity and re- scaling the interaction and growth rate parameters accordingly.)The parameters ri describe the (rescaled)growth rates.N is the number of species.The interactions between species are defined by the parameters a,which describe the effect of species j on species i.The effect of all species on themselves is set to one (i.e.a=1 for i 1,...,N),since we set the carrying capacities to 1.If aij>0 then the species j inhibits the growth of species i.Furthermore,if Sceals the sript of S.Bonhoeffer's kcture"Ecology and Evolution II:Populations"on the main course web pnge. aij 1 then the effect of species j on i is stronger that the effect of species i on itself.If all aij>0 then the multispecies LVM describes a community with only competitive interactions (i.e.without predator-prey relations between species).Predator-prey relations are characterized by interactions where aij <0 and aj>0.(Here species i is a predator of species j).Note, however,that for reasons of simplicity we will focus only on competitive interactions.(One of the advanced topics suggested below is to extend the approach to include predator-prey type interactions.) 图2叫 该文章作者Sebastian Bonhoeffer不仅继承和发展了前辈May于 1973年发表的同名著作，而且推翻了May的一些观，点，给读者以及 生物界开辟了新的思路，这是最为突出的贡献。 我们都生活在地球这一大的生态系统中，人类也是生态系统的组 成部分，人类生活的好坏与生态系统的平衡与否有着很大的关系，并 且人类的各种生产活动也时刻影响着地球的生态系统的稳定。因此， 人类增强意识，懂得在复杂的环境中，维护生态系统的稳定。 11 Bonhoeffer S.Stability and complexity in model ecosystems[M].Institute of Integrative Biology.(701-1418-00 SS)图 2 [1] 该文章作者 Sebastian Bonhoeffer 不仅继承和发展了前辈 May 于 1973 年发表的同名著作，而且推翻了 May 的一些观点，给读者以及 生物界开辟了新的思路，这是最为突出的贡献。 我们都生活在地球这一大的生态系统中，人类也是生态系统的组 成部分，人类生活的好坏与生态系统的平衡与否有着很大的关系，并 且人类的各种生产活动也时刻影响着地球的生态系统的稳定。因此， 人类增强意识，懂得在复杂的环境中，维护生态系统的稳定。 [1] Bonhoeffer S. Stability and complexity in model ecosystems[M].Institute of Integrative Biology.(701-1418-00 SS)