Terrestrial Ecology Research Group, Technical University of Munich, Freising, Germany.
Ecosystem Dynamics and Forest Management Research Group, Technical University of Munich, Freising, Germany.
J Anim Ecol. 2023 May;92(5):965-978. doi: 10.1111/1365-2656.13843. Epub 2022 Nov 24.
The patterns of successional change of decomposer communities is unique in that resource availability predictably decreases as decomposition proceeds. Saproxylic (i.e. deadwood-dependent) beetles are a highly diverse and functionally important decomposer group, and their community composition is affected by both deadwood characteristics and other environmental factors. Understanding how communities change with faunal succession through the decomposition process is important as this process influences terrestrial carbon dynamics. Here, we evaluate how beta-diversity of saproxylic beetle communities change with succession, as well as the effects of different major drivers of beta-diversity, such as deadwood tree species, spatial distance between locations, climate and forest structure. We studied spatial beta-diversity (i.e. dissimilarity of species composition between deadwood logs in the same year) of saproxylic beetle communities over 8 years of wood decomposition. Our study included 379 experimental deadwood logs comprising 13 different tree species in 30 forest stands in Germany. We hypothesized that the effects of tree species dissimilarity, measured by phylogenetic distance, and climate on beta-diversity decrease over time, while the effects of spatial distance between logs and forest structure increase. Observed beta-diversity of saproxylic beetle communities increased over time, whereas standardized effects sizes (SES; based on null models) of beta-diversity decreased indicating higher beta-diversity than expected during early years. Beta-diversity increased with increasing phylogenetic distance between tree species and spatial distance among regions, and to a lesser extent with spatial distance within regions and differences in climate and forest structure. Whereas effects of space, climate and forest structure were constant over time, the effect of phylogenetic distance decreased. Our results show that the strength of the different drivers of saproxylic beetle community beta-diversity changes along deadwood succession. Beta-diversity of early decay communities was strongly associated with differences among tree species. Although this effect decreased over time, beta-diversity remained high throughout succession. Possible explanations for this pattern include differences in decomposition rates and fungal communities between logs or the priority effect of early successional communities. Our results suggest that saproxylic beetle diversity can be enhanced by promoting forests with diverse tree communities and structures.
分解者群落演替变化的模式是独特的，因为随着分解的进行，资源的可利用性可预测地降低。木质腐朽（即依赖枯木）甲虫是高度多样化和功能重要的分解者群体，它们的群落组成受到枯木特征和其他环境因素的影响。了解随着分解过程中动物区系演替，群落如何变化对于陆地碳动态很重要。在这里，我们评估了木质腐朽甲虫群落的β多样性如何随演替而变化，以及不同主要驱动β多样性的因素（如枯木树种、地点之间的空间距离、气候和森林结构）的影响。我们研究了木质腐朽甲虫群落的空间β多样性（即同一年内枯木原木之间物种组成的差异），历时 8 年的木质分解。我们的研究包括德国 30 个森林样地的 379 个实验性枯木原木，由 13 个不同树种组成。我们假设，通过系统发育距离测量的树种差异和气候对β多样性的影响随着时间的推移而降低，而原木之间的空间距离和森林结构的影响随着时间的推移而增加。木质腐朽甲虫群落的观察到的β多样性随着时间的推移而增加，而标准化的β多样性效应大小（基于 null 模型）降低，表明早期的β多样性高于预期。β多样性随树种间系统发育距离和区域间空间距离的增加而增加，随区域内空间距离和气候及森林结构差异的增加而增加。虽然空间、气候和森林结构的影响随时间保持不变，但系统发育距离的影响减小。研究结果表明，木质腐朽甲虫群落β多样性的不同驱动因素的强度沿枯木演替而变化。早期腐烂群落的β多样性与树种之间的差异密切相关。尽管这种影响随着时间的推移而降低，但整个演替过程中的β多样性仍然很高。这种模式的可能解释包括原木之间分解率和真菌群落的差异或早期演替群落的优先效应。研究结果表明，通过促进具有多样化树种和结构的森林，可以提高木质腐朽甲虫的多样性。
