山西崦山自然保护区侧柏林植物生态位特征

应用Shannon-Weaver指数和Petraitis指数,研究了山西崦山自然保护区侧柏林主要植物的生态位(包括生态位宽度和生态位重叠)。结果表明:侧柏林36个优势种中,乔木中侧柏生态位宽度最大(3.56)、白皮松次之(3.12);灌木中荆条生态位宽度最大(3.43),黄刺玫(3.09)和多花胡枝子次之(3.09); 草本中披针苔草和山蒿生态位宽度值较大(分别为3.39、3.03),主要是由于这些种具有较为广泛的适应性。生态位宽度与物种分布频数呈正相关(r=0.941, P<0.01), 这说明物种的分布范围越广,它的生态适应性越强,因而生态位就越宽。36个优势种群并不存在完全普遍重叠,主要原因是环境的异质性较大和物种之间的生态互补性所致。在36个优势种中,表现出生态位重叠的有1099个种对,占总种对数的87.22%。侧柏与大多数种的重叠值较小,这意味着与其他种相比,在对资源利用的竞争中侧柏处于相对有利的位置,对群落的适应性要优于其他植物。 

Niche characteristics of dominants in Platycladus orientalis forests in Yanshan ;Nature Reserve,Shanxi

We studied the niche breadth and niche overlapping of the dominants in Platycladus orientalis forests in Yanshan Nature Reserve, Shanxi Province by applying Shannon-Wiener index and niche special and general overlapping indices ( Petraitis indices ) . The results indicated that the niche breadth of P. orientalis was the largest (3. 56) and Pinus bungeana the second (3. 12) among all dominant species. For the niche breadth of shrub species, Vitex negundo var. heterophylla was the largest ( 3. 43 ) , Rosa xanthina and Lespedeza floribunda were tied for second ( 3. 09 ) , while for herbaceous species, Carex lanceolata (3. 39) and Artemisia brachyloba (3. 06) exceeded others. It was mainly because of their extensive adaptability to the environment. The relationship between niche breadth and distribution frequency of the species was positive ( r=0. 941 , P<0. 01 ) , indicating that the lager the distribution area, the greater the ecological adaptability to the environment for a species, and thus a wider niche breadth could be. All dominant species were not extensively overlapping in the communities due to high environmental heterogeneity and mutual ecological complementation among species. A total of 1 099 species-pairs had niche overlapping, accounting for 87. 22% of the total 1 260 species-pairs from 36 dominants. There was little niche overlapping between P. orientalis and other species, implying that P. orientalis is more competitive and extensively adaptive than the other species.