城市土壤微生物多样性研究进展
闫冰, 陆晴, 夏嵩, 李俊生

An overview of advances in soil microbial diversity of urban environment
Bing Yan, Qing Lu, Song Xia, Junsheng Li
图1 城市化环境梯度 (改编自网络图片)。
箭头表示城市化梯度方向。
Fig. 1 The environmental gradients of urbanization (adapted from the web images).
Arrow indicates the direction of the urbanization gradient.