Soil biodiversity and the structure of soil animal communities are important foundations for forest ecosystem functions. Forest gap formation is an important forest management practice used to transform monocultures into mixed forests. However, whether and how gap size and age affect soil biodiversity and modify nematode communities remains limited. We manipulated gap size (100, 200, and 400 m2) in Pinus massoniana plantations and studied the communities of soil nematodes, bacteria, fungi, and understory plants two and four years after gap formation. Compared to the no-gap treatment, soil nematode abundance across forest gaps increased by a factor of 1.40, which was largely attributed to the increase in herbivorous nematodes as the abundance and diversity of understory plants increased. The increased abundance of soil nematodes in forest gaps was also associated with increased soil pH presumably related to reduced input of pine needles. Furthermore, the abundance (−5.3 %) and diversity (−25.1 %) of soil nematodes decreased with gap age, presumably because of increased soil temperature and decreased soil moisture in the four- compared to the two-year-old gaps. In contrast to nematodes, the abundance and diversity of soil bacteria (21.8 % and 7.1 %) and fungi (10.5 % and 10.0 %) increased significantly with gap age. Overall, forest gaps increased the diversity of understory plants and soil biota, and changed the community and functional group structure of soil nematodes. These results provide guidelines for fostering soil biodiversity and maintaining soil functioning when transforming coniferous forests into mixed forests.

中文翻译：

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林窗通过林下植物多样性和土壤 pH 值调节土壤线虫群落


土壤生物多样性和土壤动物群落的结构是森林生态系统功能的重要基础。林窗形成是一种重要的森林管理实践，用于将单一栽培转变为混交林。然而，间隙大小和年龄是否以及如何影响土壤生物多样性和改变线虫群落仍然有限。我们操纵了马尾松人工林的林窗大小（100、200 和 400 m2），并在林窗形成 2 年和 4 年后研究了土壤线虫、细菌、真菌和林下植物的群落。与无间隙处理相比，森林间隙的土壤线虫丰度增加了 1.40 倍，这在很大程度上归因于随着林下植物丰度和多样性的增加，食草线虫的增加。森林间隙中土壤线虫丰度的增加也与土壤 pH 值升高有关，这可能与松针输入减少有关。此外，土壤线虫的丰度 （-5.3 %） 和多样性 （-25.1 %） 随着间隔年龄的增加而降低，这可能是因为与两年生的间隙相比，四年生的间隙中的土壤温度升高和土壤水分减少。与线虫相比，土壤细菌 （21.8 % 和 7.1 %） 和真菌 （10.5 % 和 10.0 %） 的丰度和多样性随着间隔年龄的增加而显著增加。总体而言，林窗增加了林下植物和土壤生物群落的多样性，并改变了土壤线虫的群落和功能群结构。这些结果为在将针叶林转变为混交林时促进土壤生物多样性和维持土壤功能提供了指导。