松嫩平原典型黑土耕作区中小型土壤动物时空分布特征

为了考察松嫩平原黑土耕作区中小型土壤动物时空分布特征,在松嫩平原东南至西北选取5个典型区域,于2009年5、8、10月进行调查研究,共获取土壤动物15058只,分别隶属于54个类群,其中甲螨亚目、前气门亚目和节跳虫科3类为优势类群,占总数的69.94%,常见类群为8类,占总数的25.20%。分析结果表明:(1)不同采样区域土壤动物差异明显(P0.01),海伦区域样地的土壤动物密度、多样性指数、均匀性指数、优势度指数最高。绥化地区土壤动物类群与丰富度指数最高。(2)月份变化对土壤动物群落结构影响明显,土壤动物多样性特征随着月份变化起伏较大,8月份的土壤动物特征显著区别其它取样月份。(3)垂直分布上,土壤动物的个体数和类群数总体上是随土壤随着深度增加而减少,但不同采样区域土不同采样月份土壤动物垂直分布规律有一定差异。(4)从土壤动物与土壤环境关系来看,土壤环境的p H、全氮与全磷与土壤动物群落结构显著相关(P0.05),土壤动物个数、均匀性指数、丰富度指数、密度与土壤理化性质关系显著相关(P0.05),土壤动物优势类群和常见类群的数量与土壤中全磷、碳氮比、总有机碳关系较为密切。

Spatio-temporal distribution characteristics of meso-micro soil fauna in typical cultivated blacksoil in the Song-nen plain area

Soil fauna is an important part in the soil ecosystem and plays important roles in material cycling. Furthermore, soil fauna, which is affected by tillage of the soil, is a good indicator species for the soil environment. The Song-nen plain is an important area for food production in China. To investigate the spatio-temporal distribution characteristics of meso-micro soil fauna in cultivated blacksoil in the Song-nen plain area, five typical areas, including Hulan, Suihua, Hailun, Yian, and Nenjiang, were chosen from southeast to northwest in the Song-nen plain. The study was conducted in May, August, and October 2009. Our study will provide a fundamental theory and method for biodiversity conservation and land management in the cultivated blacksoil area. Samples of meso-micro soil fauna were collected from soil layers at depths of 0-5, 5-10, 10-15, 15-20 cm. We extracted and identified 15,058 individuals, belonging to 54 groups. Among them, Oribatida, Prostigmata, and Isotomidae were the dominant taxa, amounting for 69.94% of the total individuals in the soil fauna. The eight common groups were Mesostigmata, Hypogastridae, Entomobryidae, Chironomidae, Onychiuridae, Sminthuridae, Nematoda, and Staphylinidae larvae, totaling 25.20% of all individuals. The results derived from this research are as follows: (1) Differences in soil faunal characteristics were observed in different sampling areas (P < 0.01). The density of meso-micro soil fauna was highest in Hailun, whereas it was lowest in Nenjiang. The group number and richness index of meso-micro soil fauna were highest in Suihua, and were lowest in Nenjiang. The Shannon-Weiner and Evenness indices for meso-micro soil fauna were highest in Hailun, and lowest in Yian. The Simpson Dominance index was highest in Hailun, and lowest in Hulan. (2) Seasonal variation exerted a significant influence on community structure of soil fauna in the cultivated blacksoil area. The number and density of meso-micro soil fauna were significantly higher in October than in other months (P < 0.01). The Evenness and Richness indices of meso-micro soil fauna were significantly higher in August than in other months (P < 0.05). The Simpson Dominance index was significantly lower in August than in other months (P < 0.05). (3) Number of individuals and groups of soil fauna gradually decreased with depth. In addition, in different areas there were differences in the stability of the vertical distribution of soil fauna among seasons. There were not distinct differences in the number of individuals of meso-micro soil fauna in different soil layers in May, but there were significant differences in August and October. The number of individuals was much greater in the 0-5 cm layer than in other layers, and an obvious aggregation on the surface occurred in August and October. (4) Concerning the relationship of soil fauna and the soil environment, the values of pH, total nitrogen, and total phosphorus in cultivated black soil were strongly correlated with the community structure of soil fauna (P < 0.05). The number of individuals, Evenness index, Richness index, and density of soil fauna were closely related to soil physicochemical properties (P < 0.05), whereas the numbers of dominant and common groups were closely associated with total phosphorus, the carbon-nitrogen ratio, and total organic carbon in the soil.