Bartel Heidi, Gossner Martin M, Petermann Jana S
Department of Environment and Biodiversity, Faculty of Natural and Life Sciences Paris Lodron University of Salzburg Salzburg Austria.
Forest Entomology Swiss Federal Research Institute WSL Birmensdorf Switzerland.
Ecol Evol. 2025 Aug 15;15(8):e71962. doi: 10.1002/ece3.71962. eCollection 2025 Aug.
Human activities in forests lead to alteration or even destruction of habitats for numerous organisms, often resulting in a decline of biodiversity. Insects inhabiting water-filled tree holes may be especially sensitive to human impact as they require these microhabitats for at least part of their life cycle, with larvae mainly feeding on plant and animal debris accumulating in the water until they actively disperse in their adult stage. The processes leading to successful colonization of these microhabitats are not well understood, and it is unclear how forest management could influence them. We used sequential collection and recording of larval communities in artificial tree-hole analogues to study the process of colonization by aquatic tree-hole insects. We focused on the effects of parameters related to forest management as well as microhabitat properties on abundance, species richness, and community composition during colonization of artificial tree holes by aquatic tree-hole insects. We observed complex, and partly species-specific, temporal patterns of colonization of these new microhabitats. We found that the forest management intensity index ForMI, tree composition of forests as well as distance to natural water-filled tree holes and debris type were important in shaping community composition of insect larvae inhabiting tree holes across the entire colonization process. Larval abundance was negatively affected by increased distance to natural microhabitats and by changes in microclimate. Our results suggest that forest management significantly impacts microhabitat colonization dynamics of tree-hole insects, emphasizing the need for less-intensively managed forests to support natural tree-hole communities. We recommend the protection, creation, and maintenance of tree-related microhabitats, for example, through the promotion of habitat trees in managed forests, to sustain higher abundances of tree-hole inhabitants. Our findings underline the ecological value of water-filled tree holes and support their integration into forest conservation strategies as both essential habitats and valuable indicators of environmental change.
森林中的人类活动会导致众多生物的栖息地发生改变甚至遭到破坏，常常致使生物多样性下降。栖息在充满水的树洞中的昆虫可能对人类影响尤为敏感，因为它们在其生命周期的至少一部分时间里需要这些微生境，其幼虫主要以积聚在水中的动植物残骸为食，直到成虫阶段才会主动扩散。导致这些微生境成功定殖的过程尚未得到充分理解，而且森林管理如何影响这些过程也不清楚。我们通过在人工树洞模拟物中对幼虫群落进行连续收集和记录，来研究水生树洞昆虫的定殖过程。我们重点关注了与森林管理相关的参数以及微生境特性对水生树洞昆虫在人工树洞定殖过程中的丰度、物种丰富度和群落组成的影响。我们观察到这些新微生境定殖过程中复杂且部分具有物种特异性的时间模式。我们发现，森林管理强度指数（ForMI）、森林的树木组成以及与天然充满水的树洞的距离和残骸类型，在整个定殖过程中对栖息在树洞中的昆虫幼虫的群落组成塑造方面都很重要。幼虫丰度受到与天然微生境距离增加以及小气候变化的负面影响。我们的结果表明，森林管理对树洞昆虫的微生境定殖动态有显著影响，强调需要对森林进行强度较低的管理，以支持天然树洞群落。我们建议保护、创建和维护与树木相关的微生境，例如，通过在人工林中推广栖息树木，以维持树洞居民的较高丰度。我们的研究结果强调了充满水的树洞的生态价值，并支持将其纳入森林保护策略，因为它们既是重要的栖息地，也是环境变化的宝贵指标。
