Species and environment variables
In the study, we used data on the species catalog, which was obtained
from 14 literatures listed in Table S1 (Huang et al., 2008; Zhang et
al., 2007; Han et al., 2015; Xu et al., 2017; Xu et al., 2020; He, 2018;
Yi, 2005; Li et al., 2004; Yang et al., 1998; Xiong, 2005; Kwon et al.,
2016; Nakamura et al., 1970; Yoshifumi et al., 1994; Chuan et al.,
2003). The 14 sampling sites differed in established time, region, and
researchers (Table 1 and 2). The soil fauna identification may vary
among plots at family levels. Thus, the order names in the samples were
checked based on the Pictorial Keys to Soil Animals of China (Yin
et al., 1998) and Catalogue of Life China (2013). Concurrently,
all species were divided into four functional types based on their
feeding guilds, as follows, saprozoic, omnivores, phytophage, and
predacity (Table S2) (Zhang et al., 2001; Xu et al., 2017).
In each sampling site, soil animals were sampled from litter layer
and/or soil cores in multiple seasons (Table 2). The sampling
superficial area was 0.73 ± 0.58 m2 and the sampling
volume was 0.071 ± 0.061 m3 (Table 2), and the
sampling quantity was 339 ± 153. Furthermore, the minimum number of soil
fauna individuals was 9684 and the maximum was 52673. This way, these
samplings can well reflect the profile of the species composition in
that particular region, because the total sampling areas were designed
to adequately cover both microhabitats and plant species (Basset et al.,
2012). Therefore, the effects of sampling difference on large-scale
species composition among plots were negligible. Not only that, the 14
scientific studies selected in this paper declareed that the sampling
completeness of each study could fully reflect the composition of local
soil fauna community.
The longitude and latitude of the samples, climate factors [mean
annual precipitation (MAP, mm), mean annual temperature (MAT, °C), mean
temperature of the coldest months (MTCM, °C), extreme minimum
temperature (EMT, °C)], and soil factors including soil organic carbon
(SOC, g/kg), soil bulk density (SBD, kg/m3), and pH
value were analyzed and compared among the samples. Longitude and
latitude, climate factors, and soil factors were obtained from National
Earth System Science Data Center (http://www.geodata.cn/), Google Earth
Engine (earthengine.google.com/), or literature (Table 1 and 3).