基于MaxEnt模型的凉山山系珙桐种群适宜生境分布及其影响因素分析

Analysis of suitable habitat distribution and its influence factors of Davidia involucrata in Liangshan Mountains based on MaxEnt model

摘要:

珍稀物种的分布特征是物种濒危等级评定和保护策略制订的基础资料.本文利用MaxEnt模型对分布于凉山山系的珙桐Davidia involucrata(包括光叶珙桐Davidia involucrata var. vilmoriniana)种群的生境分布及其影响因素进行了模拟分析，结果表明：在垂直方向上珙桐主要分布在海拔1500~2300 m的中山地带；在水平方向上珙桐基本分布在凉山山系东坡的小凉山地区. 珙桐总分布面积为1832.446 km2，其中最适宜生境面积为958.448km2，次适宜生境面积为873.998km2.刀切法检验结果及限制因子分析表明影响珙桐分布特征的主要环境因子有温度季节性变异系数、海拔、最冷月最低温、最冷季降水量、降水季节性变异系数、到居民点距离. 本文建议应加强对凉山山系保护区外的大面积珙桐生境的保护及关键连接区域的恢复，以促进山系内珙桐资源的增长和生境的连接.

Abstract:

Based on field investigations, in the presentstudy, we analyzed the habitat distribution and its influence factors of Davidia involucrata (including Davidia involucrata var.vilmoriniana) in Liangshan Mountains by MaxEnt model. The results showed that, in the vertical direction, dove trees are mainly distributed at an altitude of 1500~2300 m，which is named as the mid mountain zones; in the horizontal direction, dove trees are mainly concentrated in Xiaoliang Mountains, which is located in the east of Liangshan Mountains. In the study area, the total distribution area of D. involucrate is 1832.446 km2, which includes the most suitable habitat (958.448 km2) and the sub suitable habitat (873.998 km2). The Jackknife Test and Limiting Factors Analysis indicated that temperature seasonality, altitude, min temperature of coldest month, precipitation of coldest quarter, Precipitation Seasonality and the distance to settlements have great contributions to the distribution of D. involucrate.So we suggests that the conservation of the habitat of Davidia involucrate population outside the reserve and the restoration of key connecting areas should be strengthened to promote the growth of Davidia involucrate population in the mountain and the connection of habitats.