第16章：群落的演替Chapter16 Succession L Teaching Objective: Know community succession.succession types.causes Understand the community succession theories ad human disturbance L.Focal Points and Difficulties in the Chapter(教学重点和难点) 1.Focus Succession types and human disturbanc Succession sere(演替系列) Climax community Factors determining community succession Role of keystone species 2.Difficulties Succession theories III.Methodology Powerpoint presentation will be the main method.Blackboard will be an assistance.Case studies will be provided. V Presentation(课堂讲解，学时分配为2学时左右) Succession:Changes on scale of 1-500 yrs due to disturbances and changes in land forms Directional replacement of species Theoretically ending in climax community that is self-replacing Sereall stages of successional change Disturbance initiates succession:occur in all communities and vary in: Types of succession Primary On new bare substrate:no so No seed bank:seeds dispersed from outside Extreme abiotic conditions Very slow