大兴安岭地区兴安落叶松林步甲群落多样性时间动态分析

Abstract

兴安落叶松林是大兴安岭地区代表性的植被类型，其生物多样性具有独特性。步甲是森林生态系统环境和多样性的指示性物种，以及认识环境变化和生物多样性特征的关键物种。为研究大兴安岭地区兴安落叶松林步甲群落多样性的时间动态，分析步甲群落对时间变化的响应规律，于2019年5月下旬-8月下旬步甲活跃期，利用陷阱诱捕法在兴安落叶松林5个样地中采集步甲标本共15属34种1149头，其中大兴安岭地区地理新纪录物种7种，中国地理新纪录物种6种。研究结果表明，通缘步甲属（Pterostichus）和大步甲属（Carabus）物种丰富度最高；通缘步甲属未定种5（Pterostichus eximius）为极优势物种，对时间变化最敏感。兴安落叶松林小生境类型的多样化和步甲休眠期的选择是步甲群落个体数和物种数随时间变化呈双峰模式的主要因素，最高峰均出现在6月下旬；多样性与均匀度指数均在7月上旬达高峰期，8月下旬多样性下降而均匀度上升，各指数之间相关性较低。步甲群落在6月下旬到7月下旬对环境具有较高的适应度；群落结构在环境条件相对稳定的6月下旬到7月下旬和8月上旬到8月下旬均表现为极相似（I>0.75）。物种取食特征和生活史策略的多样化使步甲群落各指数随时间变化具有显著差异，而物种取食特征和生活史策略受环境因子的综合影响较大。稳定的森林环境条件下，步甲活跃期更长，群落结构相似度更高。该结果为步甲群落时间动态研究奠定了一定的理论基础，为大兴安岭地区地下生物多样性的保护和管理策略制定提供了一定的理论和数据依据。;Larix gmelinii forest is the most typical vegetation types with unique biodiversity in the Greater Khingan Mountains, and its biodiversity is unique. The ground beetle is an indicator species for the environment and diversity of forest ecosystems, as well as a key species for understanding the characteristics of environmental change and biodiversity. In order to study the temporal dynamics of ground beetle's diversity in L. gmelinii forest,and analyze the response of ground beetles to changes in time, this paper collected 1149 ground beetles of 34 species and 15 genera from 5 large plots of L. gmelinii forest during the active period from late May to late August in 2019, and the pitfall trapping method was used to collect the ground beetles. Among all of the obtained ground beetles, seven new species were discovered for the first time in the Greater Khingan Mountains, six of which were new geography record species in China. The results show that Pterostichus and Carabus were the most abundant genera; Pterostichus eximius was the most dominant species and was the most sensitive to temporal variation in this study. The main factors that caused the number of individuals and species to show a double peak in times were the diversity of habitat types in the L. gmelinii forest and the selection of the ground beetle's dormant period. The highest peak appeared in late June. The diversity and evenness index reached the peak in early July, while the diversity decreased and the evenness increased slowly in late August. The biodiversity indexes of ground beetles were found to have a low correlation. The ground beetles had extremely significant differences in their adaptability to the environment in different time periods, among which, they had higher adaptability to the environment from late June to late July. The community structure of ground beetles was very similar from late June to late July and early August to late August (I>0.75). The changes of feeding characteristics and life history strategies resulted in significant differences in the indices of ground beetles over time, while the changes of species feeding characteristics and life history strategies were greatly affected by environmental factors. The active time of the ground beetle was longer in a stable forest climate, and the ground beetle community structure was more similar. The results provide a theoretical foundation for ground beetle temporal dynamics, as well as a theoretical and data basis for the formulation of underground biodiversity conservation and management strategies in the Greater Khingan Mountains.