不同生境四合木种群数量特征比较研究

对不同生境四合木种群的个体与综合数量指标进行了比较分析,测定了各生境区内四合木植株的地径与幼苗补充量。结果表明:不同生境的四合木种群个体及其综合数量指标均有一定差异,其中密度与多度以海南、低山、千里山种群较高,乌家庙、乌达与棋盘井种群较低;盖度、高度、冠幅以低山、乌家庙种群较大,海南、千里山和棋盘井种群较小;平均地径以乌家庙、低山种群较大,乌达、棋盘井种群较小;幼苗补充量以千里山种群最多,乌家庙种群最少;重要值和综合优势比以低山、乌家庙、海南、千里山种群为多,表明其生境条件较为适宜,而乌达与棋盘井种群较低,说明工矿发展和由此引发的土地沙化、环境恶化是四合木生存的主要威胁。

Comparative Study on Quantitative Characteristics of Tetraena mongolica Populations in Different Habitats

The individual and general quantitative indices of Tetraena mongolica populations in different habitats were compared and analyzed. The radius and recruits of T. mongolica populations were measured and counted. The study shows that the differences of individual and general quantitative indices between T. mongolica populations in different habitats are distinct.The density and abundance are higher in populations of Hainan, Dishan and Qianlishan, but they are lower in populations of Wujiamiao,Wuda and Qipanjing. The coverage, height and crown breadth are higher in populations of Dishan and Wujiamiao, but they are lower in populations of Hainan, Qianlishan and Qipanjing. The average radius is higher in populations of Wujiamiao and Dishan, but they are lower in populations of Wuda and Qipanjing. The individual recruit is the most in the population of Qianlishan, while it is the least in the population of Wujiamiao. The conspicuousness and summed dominance ratio are higher in populations of Dishan, Wujiamiao, Hainan and Qianlishan, but they are lower in populations of Wuda and Qipanjing. It shows that the environment condition is fitting to T. mongolica populations in Wujiamiao, Hainan and Qianlishan, and the industry development, land desertification, and environment deterioration are the main threatens to T. mongolica.