Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW, Australia.
Environ Microbiol. 2014 Aug;16(8):2408-20. doi: 10.1111/1462-2920.12353. Epub 2014 Jan 15.
Loss of microbial diversity is considered a major threat because of its importance for ecosystem functions, but there is a lack of conclusive evidence that diversity itself is reduced under anthropogenic stress, and about the consequences of diversity loss. Heavy metals are one of the largest, widespread pollutant types globally, and these represent a significant environmental stressor for terrestrial microbial communities. Using combined metagenomics and functional assays, we show that the compositional and functional response of microbial communities to long-term heavy metal stress results in a significant loss of diversity. Our results indicate that even at a moderate loss of diversity, some key specialized functions (carried out by specific groups) may be compromised. Together with previous work, our data suggest disproportionate impact of contamination on microbes that carry out specialized, but essential, ecosystem functions. Based on these findings, we propose a conceptual framework to explicitly consider diversity of functions and microbial functional groups to test the relationship between biodiversity and soil functions.
微生物多样性的丧失被认为是一个主要威胁，因为它对生态系统功能很重要，但目前还没有确凿的证据表明在人为压力下多样性本身会减少，以及多样性丧失的后果。重金属是全球最大、分布最广的污染物类型之一，这些污染物对陆地微生物群落构成了重大的环境胁迫。通过结合宏基因组学和功能测定，我们表明微生物群落对长期重金属胁迫的组成和功能响应导致多样性的显著丧失。我们的研究结果表明，即使在多样性的中度丧失的情况下，一些关键的专业化功能（由特定群体执行）可能也会受到损害。结合之前的研究，我们的数据表明，受到污染的影响在那些执行专业化但必不可少的生态系统功能的微生物中不成比例。基于这些发现，我们提出了一个概念框架，明确考虑功能和微生物功能群的多样性，以检验生物多样性与土壤功能之间的关系。
