裂叶沙参与泡沙参种群分布格局分形特征的分析

ANALYSIS ON THE FRACTAL CHARACTERISTICS OF DISTRIBUTION PATTERNS OF ADENOPHORA LOBOPHYLLA AND A.POTANINII

本文应用分形理论和方法比较分析了濒危种裂叶沙参与广布种泡沙参种群的空间分布格局及其分形特征。裂叶沙参与泡沙参种群在不同海拔区域分布格局的计盒维数与其在群落中占据空间的能力成正比，并且与环境因素密切相关。在裂叶沙参与泡沙参种群较为适生的区域，海拔２７００～３１００ｍ，两者在群落中占据空间的能力最强，他们的计盒维数达到最高。在低于海拔２７００ｍ或高于海拔３１００ｍ，环境条件严酷的区域，裂叶沙参种群与泡沙参种群占据空间的能力不同程度的下降。在不同的海拔区域，广布种泡沙参种群占据空间的能力均比裂叶沙参种群高，而其受环境因素影响较弱。在海拔２７００ｍ以下地区，泡沙参种群水平分布格局的计盒维数比裂叶沙参种群高４５倍；在两种群较为适生的区域，海拔２７００～３１００ｍ，泡沙参计盒维数比裂叶沙参种群高１５倍，差异最小；在泡沙参与裂叶沙参种群分布的上限，海拔３１００ｍ以上地区，两者计盒维数差异又增加，泡沙参计盒维数比裂叶沙参种群高１８倍。这说明裂叶沙参种群的内在适应力、竞争力比泡沙参种群相对较弱。

The horizontal patterns of the endangered species, Adenophora lobophylla and the widespread species, A.potaninii populations at different altitudes have been studied by the Box Dimensions of Fractal Theory.The Box Dimensions of the horizontal distribution patterns of A.lobophylla and A.potaninii populations was direct rate to the ability for A.lobophylla and A.potaninii populations to occupy the space in the communities and which is closely related to the environmental factors.At altitude 2700～3100m,where there are the better environmental conditions for A.lobophylla and A.potaninii populations to live, the Box Dimensions of both speeies reached the highest value.Below altitude 2700m or above altitude 3100m,because the harsh environmental condition,the ability for both species to occupy space become weaker.At different altitudes,the ability for A.potaninii population to occupy space in the communities was always stronger than that of A.lobophylla populations.Below altitude 2700m,the Box Dimensions of A.potaninii populations were 4.5 times as higher as that of A.lobophylla populations.At altitude 2700～3100m,where there was the better environmental conditions for both A.lobophylla and A.potaninii populations to live,the Box Dimensions of A.potaninii was 1.5 times as higher as that of A.lobophylla population.Above altitude 3100m,the Box Dimension of A.potaninii populations was 1.8 times as higher as that of A.lobophylla population.It is reasonable for us to believe that the intrinsic adaptation,competition of A.lobophylla populations were weaker than that of A.potaninii population.