生物多样性研究及其问题

围绕生物多样性主要有3个理论问题需要进一步深入研究，（1）生物多样性与生态系统稳定性的关系：本世纪70年代以前，生态学家普遍认为，稳定性随生物多样性增加而提高；自70年代初一些理论生态学家向这一普遍看法提出挑战以来，在物种多样性层次出现了观点截然不同的两大阵营；（2）生物多样性和土地生产力的关系：达尔文（1872）的研究表明，生物多样性有利于土地生产力的提高，这一结论已被许多国家运用于指导农业实践；然而，本世纪70年代以来，一些生态学家向达尔文的这一观点提出了异议；（3）生物多样性与景观连通性：本世纪90年代以来，一些景观生态学家认为，景观连通性与生物多样性有正相关关系，但目前为数不多的研究还不能肯定这一结论的正确性。通过总结生物多样性的研究历史，发现，以上的急诊和结论基于27种不同的分析模型；并且这些模型中的大多数在理论上是不完善的，认为，运用理论上合理的模型、有关概念的统一正确定义和全面系统的实验对以上急诊和结论进行更进一步的论证与实证是必要的。

Studies and questions of biological diversity

Three questions on biodiversity need to be continuously studied. (1) The relationship between biodiversity and ecosystem stability: before 1970s, ecologists believed that diversity begets stability; since some theoretical ecologists challenged the conventional wisdom that stability increases with species diversity in early 1970s, there have appeared two camps who have opposite opinions. (2) The relationship between biological diversity and land productivity in terms of Darwin (1872), the biodiversity of communities is caused by niche diversification of the co occurring species and such diversification will lead to greater community productivity due to more effective resource exploitation, which has been applied to agricultural practices by many countries; but in the early 1970s, some ecologists made an objection to Darwin's results; (3) The relation between biological diversity and landscape connectivity: since the middle 1990s, some landscape ecologists think that landscape connectivity with biological diversity is positively interrelated, but the achievements from few studies are not enough to ensure the validity of this conclusion. Our study shows that the arguments and conclusions above are based on 27 different models for biodiversity, of which most are theoretically incomplete. It is necessary to use the theoretically perfect models, unified definition of the relative concepts and completely design biodiversity experiments to give satisfying solutions of the three questions.