How do monocultures of fourteen forest tree species affect arbuscular mycorrhizal fungi abundance and species richness and composition in soil?

Katarzyna Rożek,Kaja Rola,Janusz Błaszkowski,Tomasz Leski,Szymon Zubek

doi:10.1016/j.foreco.2020.118091

Abstract

Despite the presence of arbuscular mycorrhizal fungi (AMF) in temperate forests, knowledge concerning their diversity and interactions with plants is still insufficient. Therefore, we studied the impact of overstorey species identity on AMF abundance and species richness and composition in relation to herbaceous plant cover and soil chemical properties. The effects of 14 tree species grown for 48 years in monospecific plots in the Siemianice Experimental Forest (western Poland) were compared, including the following groupings: deciduous vs coniferous; native to Poland/Europe vs alien; forming vs not forming arbuscular mycorrhizas (AM). Coniferous tree plots were characterised by lower pH values, plots with deciduous trees by higher concentrations of total Ca and exchangeable forms of Ca, K and Mg. AMF abundance in soils and roots increased along with increasing soil alkalinity and macronutrient levels. Concentrations of the PLFA 16:1ω5 AMF hyphal biomass marker were higher in the soils of deciduous and AM-type tree species than those of coniferous and non-AM types. In addition, concentrations of the NLFA 16:1ω5 AMF spore biomass marker were higher in the soils of deciduous tree species. No significant differences were found between groups of native and alien tree species. AMF spore and species numbers were low in comparison to other unforested ecosystems, averaging 77.5 and 1.2 per 50 g of soils, respectively. The presence of 8 AMF species, both widespread (e.g. Funneliformis constrictus) and rare (Acaulospora cavernata) was revealed. Significant divergence in AMF species composition was noted between plots of deciduous and coniferous species. Our study showed that tree species identity, considered as a single factor, has only a slight impact on determining AMF community characteristics. The disparity between AMF community characteristics results from the effects of several factors, as pH and element concentrations in soils, acting within tree species groups.

Highlights

Numerous abiotic and biotic factors affect the structure and functioning of soil microbial communities
No complex studies on relationships between arbuscular mycorrhizal fungi (AMF) community characteristics and overstorey species identity in European forests of the temperate climate zone have been conducted to date
We focused on the impact of large numbers of tree species, representing groups of deciduous/coniferous, alien/native to Poland/ Europe, and species forming/not forming arbuscular mycorrhiza (AM), on AMF abundance and species richness and composition in relation to herbaceous plant cover and soil chemical properties

Summary

Introduction

Numerous abiotic and biotic factors affect the structure and functioning of soil microbial communities. Arbuscular mycorrhizal fungi (AMF) constitute one of the most common and widespread groups of soil organisms and are symbionts of a majority of plant species, neither their diversity nor their interaction with plants in certain ecosystems are completely understood (Davison et al, 2015; Stürmer et al, 2018). Among these ecosystems are forests of the temperate climate zone. The aforementioned interactions have not yet been sufficiently explored (Nadrowski et al, 2010), and no comprehensive studies have been conducted on the impact of overstorey species identity on AMF abundance and species richness and composition in relation to herbaceous plant cover and soil chemical properties

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Conclusion