关键词: 植物群落, 土壤线虫群落, 生物多样性指标, 草原旅游

Abstract: [Objective] To assess the effects of tourism activities on diversity of plant and soil nematode communities in Huhenuoer scenic spot in Hulun Buir City. [Method] According to the tourists′ aggregation degree and the vegetations′ trampling status of the grassland in the scenic spot, four experimental areas were set, including a severe disturbance area, a moderate disturbance area, a mild disturbance area, and a fenced area. The height, abundance and coverage of the plant community as well as the species, quantity and diversity of the soil nematode community among the four tourism disturbance areas were statistically compared. [Result]There were significant （P<0.05） differences in Margalef richness index and Simpson dominance index among severe disturbance area and the remaining areas, and significant （P<0.05） differences in Shannon-Wiener diversity index among severe disturbance area and moderate disturbance area, mild disturbance area were observed. A total of 6 444 soil nematodes belonging to 56 genera were isolated, with an average density of 437 nematodes per 100 g dried soil; the isolated number of bacterial-feeding nematodes, fungal-feeding nematodes, plant parasitic nematodes and predatory/omnivorous nematodes accounted for 56.24%, 20.79%, 18.72% and 4.25% of the total number of the captured nematodes, respectively; the number of individuals of the dominant nematode′ genera isolated from severe disturbance area, moderate disturbance area, mild disturbance area and fenced area accounted for 70.17 %, 67.47 %, 39.72 % and 48.42 % of the total number of the captured nematodes in the corresponding areas, respectively. For the 0-10 cm soil layer, the number of the isolated nematodes in fenced area was significantly （P<0.05） higher than that in the remaining areas, and the number of the captured nematodes′genera in moderate disturbance area and fenced area was significantly （P<0.05） higher than that in severe disturbance area and moderate disturbance area; the value of the diversity index H′ in the 0-10 cm and 10-20 cm soil layers in mild disturbance area was significantly （P<0.05） higher than that in the remaining areas; for the 0-10 cm soil layer, fenced area had significantly （P<0.05） higher MI value and significantly （P<0.05） lower NCR value compared with the remaining areas, and had significantly （P<0.05） higher BI value compared with severe disturbance area. [Conclusion] The tourism activities change the composition and diversity of the plant community in grassland of the scenic spot, and have impacts on quantity, diversity and functional structure of the soil nematode community. Moderate human disturbance is conducive to the positive succession of plant and soil nematode communities, and fencing is conducive to the restoration of degraded grassland. The grassland tourism activities with severe disturbance have obvious negative effects on diversity of plant and soil nematode communities, and relevant tourism control and soil restoration measures are necessary.

Key words: plant community, soil nematode community, biodiversity index, grassland tourism