【目的】了解退耕还林后阔叶混交林与毗邻红松(Pinus koraiensis)人工林中步甲科(Carabidae)昆虫群落结构及其多样性差异,确定指示监测物种,揭示研究区边缘效应,明确红松人工林在维护生物多样性中的作用。【方法】于2017与2018年5—9月在吉林市丰满区研究区根据距离梯度划分为红松人工林、交错区以及阔叶混交林,并采用巴氏罐诱捕法,在3种生境内均布设27个诱杯,对步甲进行为期2 a的连续诱集,根据形态学进行分类鉴定。此外,步甲群落结构及α多样性指数差异采用单因素方差分析进行判断,不同α多样性指数间相关性采用Pearson相关系数进行判断,物种数、常见物种数及优势物种数随个体数变化趋势采用Hill多样性内插外推分析判断,β多样性采用非度量多维尺度分析、置换多元方差分析及相似性百分比进行判断,指示物种采用IndVal指示值进行判断。【结果】捕获昆虫中步甲共计9亚科41种3 755头,红松人工林中8亚科34种1 037头,交错区中9亚科38种1 643头,阔叶混交林中9亚科32种1 075头,3种生境共有步甲29种。步甲亚科(Carabinae)个体数在阔叶混交林中显著高于其他2种生境(P<0.05),地甲亚科(Harpalinae)个体数在红松人工林中显著高于阔叶混交林(P<0.05),奇颚步甲亚科(Licininae)个体数在交错区中显著高于阔叶混交林(P<0.05),细胫步甲亚科(Platyninae)个体数在交错区中显著高于其他2种生境(P<0.05);地甲亚科和偏须步甲亚科(Panagaeinae)物种数在阔叶混交林中显著低于其他2种生境(P<0.05),通缘步甲亚科(Pterostichinae)物种数在交错区中显著高于其他2种生境(P<0.05)。Hill多样性内插外推分析表明虽交错区物种数最多,但红松人工林常见物种数与优势物种数均最多。α多样性指数中,个体数在交错区中显著高于其他2种生境(P<0.05),物种数、Chao1指数与ACE指数在交错区中显著高于阔叶混交林(P<0.05),丰富度指数在阔叶混交林中显著低于其他2种生境(P<0.05),众多指数与物种数存在显著相关性(P<0.05)。非度量多维尺度分析与置换多元方差分析显示不同生境间群落结构差异显著(P<0.05),相似性百分比显示奇颚步甲亚科和步甲亚科对群落结构差异贡献较大。指示值显示红松人工林中无指示监测物种,交错区中监测物种有4种,阔叶混交林中指示物种有2种。研究区边缘效应整体呈较弱的正效应。【结论】不同生境步甲群落结构和多样性存在差异说明不同亚科步甲对生境选择各有差异,这与生活习性存在密切关系,但结果表明步甲整体更倾向于在交错区中进行活动,这与步甲在研究区呈正边缘效应相互印证,红松人工林中常见种和优势种最高说明红松人工林在维护生物多样性方面具有一定作用,另外,由于交错区与阔叶混交林中具有多个指示或监测物种,建议进行监测同时选择多个物种。

【Objective】To characterize the community structure and diversity of Carabidae insects in different habitats in broad-leaved mixed forest and adjacent Pinus koraiensis plantation forest following farmland conversion to forests, to identify indicator or monitor species to investigate the edge effect in the study area and to elucidate the role of P. koraiensis plantation forests in the maintenance of diversity.【Method】During May to September in 2017 and 2018, the study area was divided into three habitats—Pinus koraiensis plantation forest, ecotone, and broad-leaved mixed forest-based on distance gradients. Using the pitfall trapping method, 27 pitfall traps were deployed in each habitat to continuously trap and collect Carabidae insects over two years. Collected specimens were subsequently classified and identified based on morphological characteristics. One-way ANOVA was used to assess differences in Carabidae insects community structure and α-diversity indices. Pearson correlation coefficients were employed to examine correlations among these α-diversity indices. Hill diversity rarefaction and extrapolation analyses were conducted to characterize trends in the number of species, common species, and dominant species in relation to the number of individuals. For β-diversity, NMDS, PERMANOVA, and SIMPER were applied. Indicator species were identified using IndVal indices.【Result】A total of 3 755 Carabidae insects of 41 species from nine subfamilies were captured, there were 1 037 Carabidae insects of 34 species from eight subfamilies in the P. koraiensis plantation forest, 1 643 Carabidae insects of 38 species from nine subfamilies in ecotone, 1 075 Carabidae insects of 32 species from nine subfamilies in the broad-leaved mixed forest, there were all 29 species in three habitats. The number of individuals of Carabinae in broad-leaved mixed forest was significantly higher than that the other two habitats (P<0.05), the number of individuals of Harpalinae in the P. koraiensis plantation forest was significantly higher than in that broad-leaved mixed forests (P<0.05), the number of individuals of Licininae in ecotone was significantly higher than that in the broad-leaved mixed forests (P<0.05), the number of individuals of Platyninae in ecotone was significantly higher than that in the other two habitats (P<0.05). The number of species of Harpalinae and Panagaeinae in broad-leaved mixed forests were significantly lower than that in the other two habitats (P<0.05), the number of species of Pterostichinae in ecotone was significantly higher than that in the other two habitats (P<0.05). Rarefaction and extrapolation of Hill diversity showed that although ecotone had the highest number of species, P. koraiensis plantation forest had the highest number of common and dominant species. Among α diversity indices, the number of individuals in ecotone was significantly higher than that in the other two habitats (P<0.05), the number of species, Chao1 index and ACE index in ecotone were significantly higher than those in broad-leaved mixed forests (P<0.05), Margalef index in broad-leaved mixed forests was significantly lower than that in the other two habitats (P<0.05), and many indices were are significantly correlated with the number of species (P<0.05). NMDS and PERMANOVA showed significant differences in community structure in different habitats (P<0.05), SIMPER showed Licininae and Carabinae had large contribution to differences in different community structure. IndVal index showed no indicator and monitor species in P. koraiensis plantation forest,four monitor species in ecotone, and two indicator species in broad-leaved mixed forest. The edge effect was weakly positive overall in the study area.【Conclusion】Differences in the community structure and diversity of Carabidae insects across habitats suggest distinct habitat preferences among different taxa, which are closely linked to their ecological behaviors. Notably, the finding that Carabidae insects exhibited a strong tendency to inhabit ecotones further corroborates with the presence of a positive edge effect for this group in the study area. The highest number of common and dominant species observed in P. koraiensis plantation forests indicates that these plantations play a critical role in maintaining local biodiversity. Additionally, given the multiple indicator and monitoring species identified in both ecotones and broad-leaved mixed forests, a multi-species monitoring approach is recommended to effectively assess habitat conditions.