Data_Sheet_1_Significant Impacts of Both Total Amount and Availability of Heavy Metals on the Functions and Assembly of Soil Microbial Communities in Different Land Use Patterns.docx

Land use change alters the accumulation of heavy metals (HMs) in soils and might have significant influence on the assembly and functions of soil microbial community. Although numerous studies have discussed the impacts of either total amounts or availability of metals on soil microbes in land change, there is still limited understanding on which one is more critical. In the present study, soils from three land use types (forest, mining field, and operating factory) located in Shaoguan city (Guangdong Province, China) were collected to investigate the impacts of soil HMs on soil enzyme activities and bacterial community structures. Mining activities remarkably increased the concentrations of HMs in soils, and land use patterns changed soil properties and nutrition level. Soil pH, total and available HMs (Cu, Pb, Zn, and Cd) and organic matters (SOM) were identified as the key influential factors shaping soil ecological functions (soil enzyme activities) and community assembly (bacterial community composition), explained by HMs accumulation and soil acidification caused by human activities. In addition, total amount and availability of some metals (Zn, Pb, Cu, and Cd) showed similar and significant effects on soil bacterial communities. Our findings provide new clues for reassessing the environmental risks of HMs in soils with different land use.

土地利用变化对土壤中重金属（HMs）的积累产生影响，并可能对土壤微生物群落的组成与功能产生显著影响。尽管众多研究已探讨土地利用变化中金属总量或可用性对土壤微生物的影响，但对哪一种因素更为关键的理解仍显不足。在本研究中，收集了位于广东省韶关市（三种土地利用类型：森林、采矿场和运营工厂）的土壤样本，以研究土壤重金属对土壤酶活性和细菌群落结构的影响。采矿活动显著增加了土壤中重金属的浓度，土地利用模式的变化改变了土壤的性质和营养水平。土壤pH值、总重金属和可利用重金属（Cu、Pb、Zn和Cd）以及有机质（SOM）被确认为塑造土壤生态功能（土壤酶活性）和群落组装（细菌群落组成）的关键影响因素，这些因素的解释归因于重金属的积累和由人类活动引起的土壤酸化。此外，某些金属（Zn、Pb、Cu和Cd）的总量和可用性对土壤细菌群落表现出相似且显著的影响。我们的研究结果为重新评估不同土地利用条件下土壤重金属的环境风险提供了新的线索。