长白山地典型农田生态系统土壤跳虫群落结构及其生态分布特征

Community structure and ecological distribution of soil Collembola from typical farmland ecosystems in the Changbai Mountains

为了解长白山地不同地貌类型典型农田生态系统土壤跳虫群落结构及其分布,探讨不同地貌类型对土壤跳虫群落结构和分布及其季节动态的影响,于2015年春季(5月)、夏季(7月)、秋季(9月)分别对长白山地玄武岩台地、花岗岩低山、花岗岩丘陵三种地貌类型玉米田土壤跳虫进行了研究。研究表明,3个生境共获土壤跳虫881头,隶属10科16属22种。其中,玄武岩台地土壤跳虫个体密度是1 760头/m^2,17种;花岗岩低山个体密度是2 206.67头/m^2,13种;花岗岩丘陵个体密度是1 906.67头/m^2,18种。地貌及取样时间的差异对土壤跳虫个体密度、物种数、多样性指数均有一定的影响。花岗岩低山与花岗岩丘陵的个体密度和物种数大小为秋季>春季>夏季,而玄武岩台地的个体密度和物种数表现出随季节变化呈递增的趋势(P<0.05)。不同地貌土壤跳虫多样性均在秋季达到最大,夏季玄武岩台地多样性指数显著高于花岗岩低山和花岗岩丘陵,秋季,玄武岩台地丰富度指数和均匀度指数显著高于花岗岩低山,玄武岩台地优势度指数显著低于花岗岩低山(P<0.05)。不同土壤环境因子对跳虫的影响不同,土壤温湿度、有机质、全氮、速效氮和全磷与土壤跳虫的群落结构、生态分布有明显的相关性。综上可知,长白山地农田生态系统土壤跳虫群落结构和生态分布因地貌类型不同而存在差异,季节变化也对其影响明显。

Soil Collembola are an important part of terrestrial ecosystems and play important roles in enhancing soil fertility and other soil properties. Furthermore, soil Collembola are good indicator species for the soil environment. At present, most studies have been concerned with community structure and ecological distribution of soil Collembola, but little research has addressed soil Collembola in the Changbai Mountains. To investigate the community structure and ecological distribution of soil Collembola from typical farmland ecosystems in the Changbai Mountains, three typical geomorphic types, including basalt platform, granite low-mountain, and granite hills, were chosen from the Changbai Mountains. The study was conducted in spring （May）, summer （July）, and autumn （September） of 2015. The results could help to provide a scientific basis for maintaining and managing farmland ecosystems in the Changbai Mountains. The plots （5 m×5 m） were established using permanent signs in each maize field in the three landforms. Within each plot, we randomly selected five subplots, 10 cm×10 cm, where we made collections from the 0-5 cm, 5-10 cm, and 10-15 cm soil layers. Soil Collembola were extracted from each of the soil sample by using a Tullgren funnel extractor. The effects of landforms and seasonal variation on the individual density and species number of soil Collembola were analyzed using a one-way ANOVA. Indexes of diversity were calculated to describe the characteristics of the soil Collembola community. The influence of soil environmental factors on soil Collembola diversity was examined using redundancy analysis （RDA）. We obtained 881 collembolan individuals in the three landforms, belonging to 10 families, 16 genera, and 22 species. Significant differences were observed in individual density and species number of soil Collembola for all three landforms. The order for individual density was as follows：granite low-mountain 〉 granite hills 〉 basalt platform. Furthermore, the order for species number was as follows：granite hills 〉 basalt platform 〉 granite low-mountain. In this study, Protaphorura sp.1, Proisotoma sp.1, and Proisotoma sp.2 were the dominant species, accounting for 56.04%. There were 11 common species, accounting for 41.59%. In addition, eight species were rare, accounting for 2.37%. Landforms and sampling time had a significant effect on individual density, species number, and indexes of diversity of soil Collembola. In granite low-mountain and granite hills, the dynamics of individual density and species number of soil Collembola were autumn 〉 spring 〉 summer. In the basalt platform, the dynamics of species number of soil Collembola was autumn 〉 summer 〉 spring. Regardless of landform, soil Collembola had the highest diversity during autumn. The Shannon-Wiener indexes were significantly different in the three landforms during summer （P 〈 0.05）, and the one-way ANOVA showed that a significantly lower abundance and richness of soil Collembola was evident in the basalt platform compared to that of the other landforms in autumn （P 〈 0.05）. In addition, different environmental factors had various influences on soil Collembola. Redundancy analysis （RDA） showed that the community structure and ecological distribution of soil Collembola had obvious correlations with soil moisture, soil temperature, organic matter, total nitrogen, available nitrogen, and total phosphorus. In this study, geomorphic types and seasonal variations had significant effects on community structure and ecological distribution of soil Collembola.