林窗与生物多样性维持

自 2 0世纪以来 ,森林群落演替更新与生态系统的空间异质性 (ｓｐａｔｉａｌｈｅｔｅｒｏｇｅｎｅｉｔｙ) ,逐渐成为当前生态学研究的热点。干扰 (自然或人为干扰 )作为群落时空格局及其动态的驱动力 ,是森林群落发展变化和结构维持的必要成分。将干扰状况与森林群落特征结合起来的研究方法 ,有助于对群落动态变化规律的深入理解 ,从而加深人们对森林群落调控机理的全面认识。生物多样性是全球关注的热点问题之一。对于生物多样性的维持与保护 ,提出了众多的理论与假说 ,但尚未形成一个完善的理论体系。空间异质性、物种竞争、边缘效应等都…

Gap Dynamics and the Maintenance of Biodiversity

This paper reviewed the concept,formation and function of gap and developed a new concept,canopy rift.It refers to the small 1-25m2 rift in the canopy caused by the different distribution pattern of the canopy species or breakage,standing death and treefall.Canopy gap,mainly caused by small-scale disturbances including natural disturbance regime and human disturbance regime,is an important phase in the forest regeneration cycle.It plays a leading role in the formation and maintenance of the patches mosaic structure in a forest community.Corresponding to the three phases of the forest regeneration cycle,patches can be classified into three types:gap phase,building phase and mature forest.Many factors may contribute to the maintenance of biodiversity.Here we divided them into ① intrinsic factors,mainly including the biological and ecological characteristics of the species and ② external factors,the heterogeneity of habitat.The formation of gaps leads to the diversification of micro-environment,and changes the type and magnitude of understory.Gap impacts the forest micro-environment,community structure and dynamic process.Gap causes different status of renewal between pioneer species and climax species,and generates the patch which is the different in the constitute of woods,population dynamic and growing speed.It leads to the diversity of community difference and species component,which is the difference of species between community patches.Gap is of great significance in enhancing and maintaining species diversity for it may enhance habitat heterogeneity.