大兴安岭北部森林生态系统 大型土壤动物群落特征

对大兴安岭北部7个代表性森林群落进行了系统调查,总共获取大型土壤动物67类、6729只,隶属于4门7纲18目51科。其中,优势类群1类,常见类群10类,稀有类群56类。寒温带森林土壤动物生物量最大的类群为线蚓和蚯蚓,而温带森林土壤动物生物量最大的类群以蚯蚓为主。不同群落土壤动物的种类组成差异很大,通常群落的生境条件越优越,土壤动物的个体数量、种类越多。不同群落间个体数量、种类及生物量三者总的分布规律不完全一致,表现出生物群落组成特征的复杂性。各群落土壤动物多样性指数排序为:Ⅰ＞Ⅳ＞Ⅶ＞Ⅴ＞Ⅱ＞Ⅲ＞Ⅵ。土壤动物的个体数量、种类、生物量及多样性指数具有较明显的季节变化。

Characteristics of macro-soil fauna in forest ecosystem of northern Da Hinggan Mountains

Investigation of seven soil faunas of forest ecosystem in northern Da Hinggan Mountains respectively in June, August and October of 2004 revealed that their total number was 6729, that is, 67 categories, which belonged to 51 families, 18 orders, 7 classes and 4 phyla. The dominant group is Enchytraeidae, and its individual number takes up 58.5%. The total number of common types is about 10 categories, they are Formicidae, Lithobiomorpha etc. , accounting for 35.9%, and the number of rare groups is 56 categories. The categories of soil animals in different forest communities differ greatly, the more favorable condition the habitats is, the greater the number of individuals is, and the more abundant the categories are. The distribution law of individual, group quantity and biomass is not entirely consistent, which showed complexity of community composition, that is, the distribution of individual number is Ⅲ＞Ⅱ＞Ⅴ＞Ⅵ＞Ⅳ＞Ⅰ＞Ⅶ, the distribution of categories is Ⅳ＞Ⅲ＞Ⅱ＞Ⅴ＞Ⅵ,Ⅶ＞Ⅰ, and the distribution of biomass is Ⅲ＞Ⅱ＞Ⅳ＞Ⅶ＞Ⅴ＞Ⅰ＞Ⅵ. Furthermore, the proportion of each category of soil animals in total biomass differs greatly, and the biomass of Enchytraeidae and Lumbricidae is in absolute dominant position, accounting for 34.8% and 34.4% respectively, then the insect and its larva account for 22.8%, and the proportion of other categories is less than 8%. However, the dominant group of biomass is Lumbricidae in the forest of temperate zone, about 60% to 70% of the total biomass, which differs apparently from the biomass of soil animals in the forest of cool temperate zone; The vertical distribution of individuals and types is in the order of: 0~5cm＞litter layer＞5~10cm. The order of soil animals’ diversity index isⅠ＞Ⅳ＞Ⅶ＞Ⅴ＞Ⅱ＞Ⅲ＞Ⅵ. Evenness and richness index is positively correlated with diversity index, and is negatively correlated with the dominance index. What’s more, individual number, category, biomass and diversity index of soil animals vary with season, in other words, the dynamic change of the total number and category with season is in the order of October > August> June. The dynamic change of the total biomass with season is October> June> August. In addition, the dynamic change of diversity index with season is August > June >October.