TY - JOUR

T1 - Soil fungal networks moderate density-dependent survival and growth of seedlings

AU - Liang, Minxia

AU - Shi, Liuqing

AU - Burslem, David F. R. P.

AU - Johnson, David

AU - Fang, Miao

AU - Zhang, Xinyi

AU - Yu, Shixiao

N1 - Funding Information: We are grateful to Yan Xie, Yongning Li and Weinan Ye for their assistance in the field. We thank the Editor, Prof. Marc‐André Selosse, and three anonymous reviewers for very helpful comments that further improved the manuscript. This research was funded by the National Key Research and Development Program of China (2017YFA0605100) and the National Natural Science Foundation of China (NSFC grants 31870403, 31830010, 32071539), and partly supported by awards from the UK Natural Environment Research Council (NERC NE/M004848/1 and NE/R004986/1) and a Newton Advanced Fellowship from the Royal Society (NAF/R1/201192). DJ is also supported by the N8 AgriFood programme. Publisher Copyright: © 2021 The Authors New Phytologist © 2021 New Phytologist Foundation

PY - 2021/6/30

Y1 - 2021/6/30

N2 - Pathogenic and mutualistic fungi have contrasting effects on seedling establishment, but it remains unclear whether density-dependent survival and growth are regulated by access to different types of mycorrhizal fungal networks supported by neighbouring adult trees. Here, we conducted an extensive field survey to test how mycorrhizal and pathogenic fungal colonization of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) seedlings in a subtropical forest respond to density of neighbouring adult trees. In addition, we undertook a hyphal exclusion experiment to explicitly test the role of soil fungal networks in driving density-dependent effects on seedling growth and survival. Conspecific adult density was a strong predictor for the relative abundance of putative pathogens, which was greater in roots of AM than of ECM seedlings, while mycorrhizal fungal abundance and colonization were not consistently affected by conspecific adult density. Both ECM and AM fungal networks counteracted conspecific density-dependent mortality, but ECM fungi were more effective at weakening the negative effects of high seedling density than AM fungi. Our findings reveal a critical role of common fungal networks in mitigating negative density-dependent effects of pathogenic fungi on seedling establishment, which provides mechanistic insights into how soil fungal diversity shapes plant community structure in subtropical forests.

AB - Pathogenic and mutualistic fungi have contrasting effects on seedling establishment, but it remains unclear whether density-dependent survival and growth are regulated by access to different types of mycorrhizal fungal networks supported by neighbouring adult trees. Here, we conducted an extensive field survey to test how mycorrhizal and pathogenic fungal colonization of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) seedlings in a subtropical forest respond to density of neighbouring adult trees. In addition, we undertook a hyphal exclusion experiment to explicitly test the role of soil fungal networks in driving density-dependent effects on seedling growth and survival. Conspecific adult density was a strong predictor for the relative abundance of putative pathogens, which was greater in roots of AM than of ECM seedlings, while mycorrhizal fungal abundance and colonization were not consistently affected by conspecific adult density. Both ECM and AM fungal networks counteracted conspecific density-dependent mortality, but ECM fungi were more effective at weakening the negative effects of high seedling density than AM fungi. Our findings reveal a critical role of common fungal networks in mitigating negative density-dependent effects of pathogenic fungi on seedling establishment, which provides mechanistic insights into how soil fungal diversity shapes plant community structure in subtropical forests.

KW - arbuscular mycorrhizal (AM) fungi

KW - density dependence

KW - ectomycorrhizal (ECM) fungi

KW - hyphal exclusion experiment

KW - pathogenic fungi

KW - seedling growth

KW - seedling survival

KW - subtropical forest

U2 - 10.1111/nph.17237

DO - 10.1111/nph.17237

M3 - Journal article

VL - 230

SP - 2061

EP - 2071

JO - New Phytologist

JF - New Phytologist

SN - 0028-646X

IS - 5

ER -