Dissimilar responses of fungal and bacterial communities to soil transplantation simulating abrupt climate changes

Authors: ZHAO, MENGXIN - Chinese Academy Of Agricultural Sciences; SUN, BO - Chinese Academy Of Sciences; WU, LINWEI - University Of Oklahoma; WANG, FENG - Chinese Academy Of Sciences; WEN, CHONGQING - Guangdong University; WANG, MENGMENG - Tsinghua University; LIANG, YUTING - Chinese Academy Of Sciences; Hale, Lauren; YANG, YUNFENG - Tsinghua University

Submitted to: Molecular Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2019
Publication Date: 2/20/2019
Citation: Zhao, M., Sun, B., Wu, L., Wang, F., Wen, C., Wang, M., Liang, Y., Hale, L.E., Yang, Y. 2019. Dissimilar responses of fungal and bacterial communities to soil transplantation simulating abrupt climate changes. Molecular Ecology. 28(7):1842-1856. https://doi.org/10.1111/mec.15053.
DOI: https://doi.org/10.1111/mec.15053

Interpretive Summary: The responses of bacterial and fungal communities to climate change could have significant impacts on soil carbon stability. To simulate climate variations, soils were transplanted to different latitudes. Six years after soil transplantation, fungi in transplanted soils appeared to acclimate to the destination environment, based on biomass and community composition trends. In contrast, bacterial communities remained largely unchanged. The relative abundances of fungal genes encoding carbon-decomposing enzymes were more influenced by soil transplantation and, in general, larger than those than those from bacteria. Overall fungal community composition was mainly determined by climate factors, whereas bacterial occupancy was more related to soil conditions, which were stable after soil transplantation. Together, these results demonstrate dissimilar response patterns and resource partitioning in fungal and bacterial communities that are important to predicting ecosystem-scale carbon cycling.

Technical Abstract: Both fungi and bacteria play essential roles in regulating soil carbon cycling. To predict future carbon stability, it is imperative to understand their responses to environmental changes, which is subject to large uncertainty. As current global warming causes range shifts toward higher latitudes, we conducted three reciprocal soil transplantation experiments over large transects in 2005 to simulate abrupt climate changes. Six years after soil transplantation, fungal biomass of transplanted soils showed a general pattern of changes from donor sites to destination, which were more obvious in bare fallow soils than maize cropped soils. Strikingly, fungal community compositions were clustered by sites, demonstrating that fungi of transplanted soils acclimated to the destination environment. Several fungal taxa displayed sharp changes in relative abundance, including Podospora, Chaetomium, Mortierella and Phialemonium. In contrast, bacterial communities remained largely unchanged. Consistent with the important role of fungi in affecting soil carbon cycling, 8.1-10.0% of fungal genes encoding carbon-decomposing enzymes were significantly (P < 0.01) increased and larger than those from bacteria (5.7-8.4%). To explain those observations, we found that fungal occupancy across samples was mainly determined by annual average air temperature and rainfall, whereas bacterial occupancy was more related to soil conditions, which remained stable six years after soil transplantation. Together, these results demonstrate dissimilar response patterns and resource partitioning between fungi and bacteria, which may have considerable consequences for ecosystem-scale carbon cycling.