濒危植物毛柄小勾儿茶的生态位研究

采用生态学样方调查法,测定了濒危植物毛柄小勾儿茶(Berchemiella wilsonivar.pubipetiolata)所在群落主要物种的生态位宽度和它在其它物种上的生态位重叠,通过Shannon-Wiener生态位宽度公式和Levins生态位重叠公式计算分析,研究了该物种在浙江临安的马啸、湍口和安徽大别山地区的舒城、霍山等四个分布点群落中的生态位特征。结果显示:(1)位于马啸的毛柄小勾儿茶生态位宽度值相对最大,而其余三个地方的都较小,说明该物种对资源的利用能力较弱;(2)毛柄小勾儿茶与群落中少量生态位较小的伴生物种有较大的生态位重叠,而与大多数物种仅有极小的生态位重叠,表明该物种生态位特化明显;(3)毛柄小勾儿茶在几乎所有群落优势种上的生态位重叠值都较小,而主要优势物种与大部分伴生物种的生态位重叠值也较小,表明群落中存在明显生态位分化。研究认为:人为破坏和生态位特化导致的分布区狭窄、对生境要求特殊是毛柄小勾儿茶濒危的重要原因。

Niche Characteristics of Berchemiella wilsoni var.pubipetiolata,An Endangered Species in China

Shannon-Wiener coefficient of niche breadth and Levins coefficient of niche overlap were used to study the niche characteristics of Berchemiella wilsoni var.pubipetiolata based on large numbers of plot investigations in Huoshan and Shucheng of Anhui Province,Tuankou and Maxiao of Zhejiang Province,China.The results showed that(1)the niche breadth of B.wilsoni var.pubipetiolata were narrow in Huoshan,Shucheng and Tuankou,except Maxiao,(2)the niche overlap between B.wilsoni var.pubipetiolata and a few other species with narrow niche breadth were great.Moreover,at all communities,main dominant species had also narrow niche breadth too,and the values of niche overlap for these dominant species with most associated species were very small,including B.wilsoni var.pubipetiolata,and(3)the niche differentiation among all the species was obvious.In conclusion,B.wilsoni var.pubipetiolata had weak ability to utilize resources because of its small niche breadth value,niche specialization and poor competition with the other species,and human disturbance and niche specificity are greatly related to the species endangerment.