农牧交错带不同土地类型土壤动物生态特征研究--以内蒙古卓资山为例

Ecological characteristics of soil fauna in different soil types of agro-pasture ecotone:A case of Zhuozi Mountain,Inner Mongolia

对内蒙古中部农牧交错带不同土地类型土壤动物进行研究,发现线虫占绝对优势,个体数占总个体数的64.95%。线虫个体数在不同土地类型的差异显著。线虫、蜱螨类和弹尾类构成研究区中小型土壤动物的优势类群。天然草地各生境土壤动物的类群数和个体数均高于撂荒地、半裸露坡地和裸露坡地。大型和中小型土壤动物的类群数和个体数的垂直分布具有表聚性。根据土壤动物聚类分析的结果,可将采样的6个生境分为3类:天然草地、人类干扰停止后自然恢复的坡地和裸露坡地。CCA排序表明土壤含水量对中小型土壤动物类群分布影响最大。土地利用方式相近的生境,土壤动物种类组成和个体数量相似程度较高。土壤动物组成的差异能够较好地反映土地类型的差异。

Soil fauna community was investigated in the agro-pasture ecotone in the middle of Inner Mongolia. Soil macrofauna was gained by handpicking in the field. In the laboratory, soil meso-microfauna was extracted by Tullgren and Baermann. Nematoda dominated the soil fauna community. The individual numbers accounted for 64.95% of the totals. The difference of their individual numbers in various soil types was significant （P 〈0.05）. Nematoda, Acari and Collembola were dominant groups of soil meso-microfauna. The groups and individuals of soil fauna in grassland were more than those in stopping farming field, semi-bare slope and bare slope. The composition of different habitats in grassland was various. The groups of macrofauna and meso-microfauna were Ⅱ〉 Ⅲ〉 Ⅰ and their individuals were Ⅱ 〉Ⅲ 〉 Ⅰ and Ⅱ 〉 Ⅰ 〉Ⅲ,respectively. Both groups and individuals of soil macrofauna and meso-niicrofauna were gathering at surface in vertical distribution. The result of dendrogram of cluster analysis for soil fauna community showed that 6 habitats were divided into 3 kinds： grassland, slopes of stopping disturbance and bare slope. Soil moisture content was calculated after drying at 105℃. Measured soil factors included total nitrogen （with microKjeldhal method）, organic matter （ with dichromate acid oxidation）, total phosphorus （with a calorimetric method with molybdenum in sulfuric acid）, total potassium （with flame photometry method）, pH in saturation extract （with PHS - 3B meter）. Most of the contents of soil factors of 0 - 5 cm were higher than those of 5 - 10 cm. The average contents of soil moisture, organic matter and total nitrogen were as follows ： grassland 〉 stopping farming field 〉 semi-bare slope 〉 bare slope. The contents of P and K of stopping farming field were higher than those of other habitats. The group of soil fauna was significantly positively correlated with soil moisture. The correlation coefficient of individual numbers of soil meso-microfauna and soil environmental factors was relatively higher than others. It showed that they were influenced by soil environmental factors. CCA two-dimensional scatter ordination diagram indicated that soil moisture had the greatest influence on soil meso-microfauna. The difference of soil factors in various habitats influenced the distribution of soil meso-microfauna. The composition and individuals of soil fauna was more similar in the habitats of similar land use. The difference of composition of soil fauna can reflect the difference of land use. Their characteristics can be served as the biological index of land sustainable use.