成都市城市森林冬季大型土壤动物群落特征

Characteristics of soil macrofauna community under urban forests in Chengdu in winter

大型土壤动物作为森林生态系统的重要组成部分,对森林物质循环有着重要的作用.为探究亚热带地区不同林型冬季大型土壤动物群落的差异及其对环境因子的响应机制,2018年12月-2019年2月,对成都龙泉山城市森林公园常绿阔叶天然林及柏木人工林大型土壤动物进行了3次采样调查.捕获大型土壤动物个体5434只,包括72科,鉴定到属36属,共计75个类群.常绿阔叶天然林下的大型土壤动物个体密度和类群数显著高于柏木人工林(P<0.05);从功能群结构来看,植食性功能群占据主导,常绿阔叶天然林下植食性、捕食性、杂食性、腐食性功能群个体密度均显著高于柏木人工林(P<0.05);柏木人工林下大型土壤动物Margalef丰富度指数和Pielou均匀度指数分别显著低于和高于常绿阔叶天然林(P<0.05);大型土壤动物个体密度和类群数与土壤含水率、有机C、全N显著正相关(P<0.05),与土壤容重和pH显著负相关(P<0.05).本研究结果表明冬季土壤温度对大型土壤动物的个体密度和类群数均影响不显著(P>0.05),常绿阔叶天然林因其更丰富的营养来源和更复杂、适宜的栖息环境使其大型土壤动物多样性较之柏木人工林更高.(图8表1参63附表1)

As an essential part of the forest ecosystem, the soil macrofauna community plays a vital role in the forest material cycle. To explore differences in soil macrofauna communities and their response to environmental factors of different forest types in a subtropical forest in winter, we investigated soil macrofauna richness of different forest types and provided a theoretical basis for urban forest optimization in Longquan Mountain Urban Forest Park, Chengdu. From December 2018 to February 2019, the hand-squatting method was used to sample the soil macrofauna of the evergreen broad-leaved natural forest and the cypress planted forest in the Longquan Mountain Urban Forest Park. A total of 5 434 soil macrofauna individuals were collected, including 72 families. Altogether, 75 groups of taxa with 36 genera were identified. The number of large soil macrofauna individuals and the number of taxa under the evergreen broad-leaved natural forest were significantly higher than those under the cypress planted forest(P < 0.05). In terms of the structure of the functional groups, the phytophage group dominated. Moreover, the number of individuals of the phytophage, predator, omnivore, and saprozoic functional groups under the evergreen broad-leaved natural forests were significantly higher than those under the cypress planted forest(P < 0.05). The Margalef’s richness index of large soil macrofauna under the cypress planted forest was significantly lower than that of the evergreen broad-leaved natural forests. By contrast, the Pielou evenness index was significantly higher(P < 0.05). The number of soil macrofauna individuals and the number of taxa were significantly positively correlated with soil moisture content, organic carbon, and total nitrogen(P < 0.05), and significantly negatively correlated with soil bulk density and pH(P < 0.05). The research shows that the soil temperature in the three winter months had no significant effect on the large soil macrofauna individuals and the number of taxa(P > 0.05). Owing to the richer nutrient sources and a more complex and suitable habitat, there is a higher diversity of soil macrofauna in the broad-leaved natural forest than in the cypress planted forest.