Pižl Václav, Sterzyńska Maria, Tajovský Karel, Starý Josef, Nicia Paweł, Zadrożny Paweł, Bejger Romualda
Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, Na Sádkách 7, 370 05 České Budějovice, Czech Republic.
Museum and Institute of Zoology PAS, Wilcza 64, 00-679 Warsaw, Poland.
Biology (Basel). 2023 Mar 21;12(3):482. doi: 10.3390/biology12030482.
Disturbances, both natural and anthropogenic, influence the patterning of species and species traits. The shift in species composition and distribution pattern of functional traits can demonstrate if the community is resistant, sensitive or resilient to the disturbance. Based on species- and trait-based approaches, we examined the response of the earthworm community to changing hydrologic conditions caused by the artificial drainage of mountain fens, in which cumulative effects of disturbance events over space and time are much less dynamic than in riverine wetlands. We hypothesized that the drainage-related changes of mountain fen peat soils have an effect on the earthworm community composition and its functional structure. We assume that the shift in species composition and value of community-weighted functional traits reflect changes in the resilience or resistance of the earthworm community to environmental change. Our results demonstrate that the total density of earthworms was almost three times lower under drained conditions compared to natural ones. Artificial drainage of fens had a neutral effect on the species-based diversity indices. However, there were species-specific traits that responded to hydrologic changes and which led to the species' replacements and to the co-occurrence of eurytopic, surface-browsing and more drought- and low-pH-resistant earthworm species in the drained fens. Based on these results, we conclude that abiotic-based environmental filtering was the main process responsible for sorting earthworms according to species and traits in the disturbed hydrologic conditions. The greater earthworm functional trait variations in semi-natural hydrologic conditions emphasizes the impact of transient dynamics in an altered disturbance regime on the earthworm assembly. Results also showed that in the changing hydrologic conditions of mountain fens, the functional trait approach revealed only slightly more predictive power than the taxonomic one, but it proved better with processes responsible for earthworm species filtering.
自然和人为干扰都会影响物种及其性状的格局。功能性状的物种组成和分布模式的变化可以表明群落对干扰是具有抗性、敏感性还是恢复力。基于物种和性状的方法，我们研究了蚯蚓群落对山地泥炭沼泽人工排水导致的水文条件变化的响应，其中干扰事件在空间和时间上的累积效应比河流湿地的动态性要小得多。我们假设山地泥炭沼泽泥炭土与排水相关的变化会对蚯蚓群落组成及其功能结构产生影响。我们认为物种组成的变化以及群落加权功能性状的值反映了蚯蚓群落对环境变化的恢复力或抗性变化。我们的结果表明，与自然条件相比，排水条件下蚯蚓的总密度几乎低了三倍。泥炭沼泽的人工排水对基于物种的多样性指数具有中性影响。然而，有一些物种特异性性状对水文变化做出了响应，这导致了物种替代，并使得广适性、地表取食以及更耐旱和耐低pH值的蚯蚓物种在排水后的泥炭沼泽中共存。基于这些结果，我们得出结论，基于非生物的环境过滤是在受干扰的水文条件下根据物种和性状对蚯蚓进行筛选的主要过程。在半自然水文条件下蚯蚓功能性状的更大变化强调了干扰 regime 改变中的瞬态动态对蚯蚓组装的影响。结果还表明，在山地泥炭沼泽不断变化的水文条件下，功能性状方法的预测能力仅比分类学方法略强，但在蚯蚓物种筛选过程方面表现更好。
