A Closer Examination of the ‘Abundant-Center’ for Ectomycorrhizal Fungal Community Associated With Picea crassifolia in China

Abstract

A long-standing hypothesis in biogeography predicts that a species’ abundance is highest at the center of its geographical range and decreases toward its edges. In this study, we test the abundant-center hypothesis of ectomycorrhizal (ECM) fungal communities associated with Picea crassifolia, an endemic species widely distributed in northwest China. We analyzed the taxonomic richness and the relative abundance of ECM fungi in four main distribution areas, from center to edges. In total, 234 species of ECM fungi were detected, and of these, 137 species were shared among all four sites. Inocybe, Sebacina, Tomentella, and Cortinarius were the dominant genera. ECM fungal richness and biodiversity were highest at the central and lower at peripheral sites. Our results indicated that ECM fungal species richness was consistent with the abundant-center hypothesis, while the relative abundances of individual fungal genera shifted inconsistently across the plant’s range.

Mixed conifer-broadleaf trees on arbuscular mycorrhizal and ectomycorrhizal communities in rhizosphere soil of different plantation stands in the temperate zone, Northeast China

“…In line with previous studies (Wang et al, 2018;Zeng et al, 2021;Wang and Han, 2022), the Glomus and the Tomentella were the most abundant genera in AMF and EMF communities, respectively. The Glomus was primarily distributed in the upper soil layer, particularly where the available N content was high (Wang et al, 2018;Chen et al, 2021).…”

“…The Tomentella has a strong adaptability to the environment and strong colonization ability ( Nara, 2006 ; ÖPik et al, 2010 ). Meanwhile, more abundance and species of the Tomentella was found in soils with high N than that with low N ( Kranabetter et al, 2015 ; Wang and Han, 2022 ). Besides, EM root tips colonized by Tomentella are capable of producing extracellular enzymes used to break down proteins, polysaccharides, and organic forms of P ( Courty et al, 2005 ; Tedersoo et al, 2012 ) and mobilizing organic N ( Pena et al, 2013 ).…”

“…In contrast, mixed Juglans mandshurica and Larix gmelinii did not change AM fungal richness and diversity, but significantly affected AM fungal community structure and composition ( Ji et al, 2021 ). To date, most of the available studies focus on assessing the effects of tree monoculture on mycorrhizal fungal colonization and communities associated with a single mycorrhiza type ( Aldrich-Wolfe et al, 2020 ; Yang et al, 2021a ; Wang and Han, 2022 ). In contrast to the growing interest in comparing AM and EM in terms of their functions and responses to environmental factors ( Kilpeläinen et al, 2019 ), there is still a great knowledge gap about the potential effects of tree mixture comprising of AM and EM tree species on mycorrhizal fungal community.…”