Temperature drives spatial scaling of soil microbial community
Understanding the responses and the underlying mechanisms of ecological communities to environmental changes is a central issue in ecology. Mean temperature rising on Earth surface represents a pervasive environmental change that is predicted to alter global biodiversity, yet our understanding of the emergent biodiversity impacts is very limited, particularly on taxa-area relationships (TARs) (or spatial scaling of biodiversity), which is one of the few fundamental laws in ecology. Although TARs have been intensively examined, how temperature affects TARs remain elusive remains elusive, particularly in microbial communities. Our main objectives of this study are to understand: (i) Are TARs universally applicable to soil microbial communities at a continental scale? (ii) What are the typical spatial turnover rates for in soil microbial communities? (iii) Whether and how do spatial turnover rates of microbial communities change with temperature as well as plants? To address these questions, we used high throughput sequencing technology to analyze 126 soil samples from six LTER (long-term ecological research) forest locations of different latitudes in North America, whose temperature ranges from -4 to 27°C.
Our results revealed that the microbial communities in forest soils of six locations across North America exhibited flatter taxa-area relationships (Pearson correlation coefficient r = 0.999) and the slopes (z values) were from 0.068 to 0.085 across six different sites. Although z values from microbial community were relative smaller than the corresponding aboveground plant communities (z = 0.10-0.31), a strong positive correlation was observed between microbial and plant z values (r = 0.782, p = 0.033). Furthermore, both microbial and plant z values significantly increase with the mean annual temperatures across six sampling sites (r = 0.928 for plant community, r = 0.783 for microbial community), indicating that the z values are not constant and the spatial scaling of both plant and microbial communities is temperature dependent. Elucidating temperature-dependent spatial scaling of microbial biodiversity is fundamental to biodiversity preservation, ecosystem restoration and environmental management.