高原鼢鼠土丘空间格局及主要特征研究

The study of patterns and characteristics of plateau zokor mound

通过对高原鼢鼠土丘的数量、植被、分布格局、形态演化等内容的分类研究表明，高原鼢鼠的土丘可依据其形成时间分为1年龄、2年龄和3年龄3种类型。3类土丘的面积和数量关系分别为1：0．96：1．01和1：0．97：1．10，说明近3年来鼠群数量基本保持稳定。通过对3类土丘比例关系的分析，可预测鼠群数量的消长趋势。由于当年8月前形成的土丘具有易于识别、代表性强、稳定性好等特点，因此作为高原鼢鼠相对密度的指标更为适宜。在正常情况下．鼠丘植被的恢复周期在3年左右。3年龄土丘的植被盖度、物种组成等指标与背景植被已无显著差异．但鼠丘地仍有较明显的凸起，平均高出背景地约7～8cm，而鼠丘占地面积则较新生土丘有显著缩小。

This study was conducted to quantify plateau zokor mound, vegetation on mound, distribution pattern of mound,and shape change of mound in alpine grassland. The results indicated that according to the formation time, the mounds could be divided into three types, one-year mound, two-year mound, and three-year mound. To a certain degree,the spatio-temporal relationship between the three types of mounds could be represented by a ratio of 1 ： 1： 1. By this characteristic,the dynamics of zokor population can be predicted by comparing the dynamics of the three mound types. The mounds formed in August could be used for a relative density index of zokor due to the relative ease of their identification, high representation, and good stability. In general conditions,t he restoration period of mound vegetation is approximately three years. There were no significant differences in vegetation coverage and species composition between three-year mounds and adjacent vegetation, how ever the mounds are slightly higher than adjacent ground,and on average 7--8 cm higher than adjacent ground. Compared with the new mounds,the area of three-year mounds was significantly reduced.