云南省高黎贡山土壤线虫群落结构及多样性

Composition and diversity of soil nematode community in Gaoligong mountains in Yunnan province

对云南省高黎贡山国家自然保护区不同海拔高度0～10,11～20,21～30 cm土层土壤线虫群落进行调查,共获得线虫2纲9目28科79属,其中基齿属Iotonchus和孔咽属Aporcelaimus为优势属,捕食/杂食类群为主要营养类群,占60.01%.相关性和显著性方差分析表明,土壤全N含量与线虫密度呈显著正相关(F=0.628,p=0.038).不同海拔高度线虫群落结构比较稳定,在海拔2 021 m的中山湿性常绿阔叶林中线虫类群和个体数最丰富,然后向高、低海拔逐渐递减.成熟指数值表明,高黎贡山土壤线虫群落结构较稳定;线虫通路比值(NCR)计算表明,土壤有机质主要依靠真菌分解途径;Shannon-Wiener多样性指数(H′)、Simpson优势度(D)和多群落间比较多样性指数(DIC)在低海拔的灌丛林与半湿润常绿阔叶林和中山湿性阔叶林有显著差异.

Soil nematode community with 3 stratification （0-10, 11-20, 21-30 cm） was respectively investigated in Naturel Preserves of Gaoligong Mountains in Yunnan Province. 4 784 individuals from 79 genera in 28 families of 9 orders in 2 classes were isolated between Iotonchus and Aporcelaimus as the dominant genera predators/omnivores as dominant trophic group accounting for 60.01% of total nematodes. Among all the soil factors investigated, there is only nitrogen concentration correlating with nematode population density（F=0.628, p=0.038）. Nematode genera diversity and density were both the highest in zone of 2 021 m covered with wet evergreen broad-leaved forest, dropping gradually upward and downward along hillside. Community structure of soil nematode changed little with altitude, and soil organic matters were mainly decomposed by fungi. Among the three vegetations including sparse shrubland, semiwet indeciduous broad-leaved trees and wet indeciduous broad-leaved trees, there are significant differences in Shannon＇s diversity index（H＇ ）, Simpson＇s dominance（D） and diversity index among different communities（DIC ）.