甘南亚高寒草甸土壤纤毛虫群落结构变化对不同坡向的响应

土壤纤毛虫不但是土壤生态系统的重要组成部分,而且是生态系统物质循环、能量流动过程的重要驱动因子。为了查明甘南亚高寒草甸不同坡向土壤纤毛虫群落特征,于2015年7月21—26日对同一山头的阳坡、半阳坡、西坡、半阴坡、阴坡五个坡向进行了调查。结果表明:(1)经"非淹没培养皿法"鉴定得到纤毛虫142种,隶属于9纲18目32科55属,各坡向物种数、个体数大小关系呈现出西坡半阳坡阳坡半阴坡阴坡;优势类群有旋毛纲、裂口纲、寡膜纲、肾形纲其优势度依次为28.17%、19.72%、13.38%、12.68%。(2)不同坡向上土壤纤毛虫的物种数、个体数、Shannon指数均具有显著性差异(P0.05),表明甘南亚高寒草甸生态系统中的土壤纤毛虫对于坡向这一微气候环境的变化具有敏感性。(3)各坡向土壤纤毛虫的物种数、个体数都具有明显的表聚性。(4)利用皮尔森相关性分析得出,在所测得的土壤理化因子中对纤毛虫的物种数、个体数均具有显著正相关(P0.05)的是全氮、有机质。综合分析,影响甘南亚高寒草甸不同坡向上土壤纤毛虫群落结构变化的主要因素为全氮、土壤有机质以及地上植被状况。

Effect of different slope characteristics on the soil ciliate community structure in an alpine meadow in southern Gansu

Soil ciliates are an important component of soil ecosystems and ecological systems, and are fundamental in material circulation processes and energy flow. To determine the effect of different slope directions on soil ciliate community characteristics in a South Gansu alpine meadow, five different slope characteristics-same hill slope, sunny slope,half-sunny slope, west slope,half-ngative slope, and shady slope to five slope-were investigated between July 21 and 26, 2015. The results showed that: (1) 142 species of ciliates, belonging to 9 classes representing 18 to 55 genera and 32 families across the different slopes were identified using the "non-flooded petri dish method", and the slope and relationships between species and individual size numbers were: west slope > half sunny slope > sunny slope > half-ngative slope > shady slope; spin polychaetes showed several advantages with split classes, a reduced membrane, and kidney-shaped outline, and showed a dominance of 28.17%, 19.72%, 13.38% and 19.72%, respectively, for the slopes above; (2) different slopes showed varying species and individual numbers of soil ciliates, and the Shannon diversity index was significantly different (P < 0.05) between slopes, indicating that soil ciliates in Gansu alpine meadow ecosystems in South Asia were sensitive to microclimate changes on different slopes; (3) the slope to the species and individual number of soil ciliates showed obvious table cohesion; (4) the Pearson correlation analyses for soil physical and chemical factors and species and individual number of ciliates were significantly positively correlated (P < 0.05), notably total nitrogen(TN) and organic matter; Therefore, a comprehensive analysis of the different influences in the Gansu alpine meadow on the south slope indicated that the main factors of soil ciliate community structure change were TN, the condition of soil organic matter, and ground vegetation.