Fine Spatial Scale Variation of Soil Microbial Communities under European Beech and Norway Spruce

Abstract

The complex interactions between trees and soil microbes in forests as well as their inherent seasonal and spatial variations are poorly understood. In this study, we analyzed the effects of major European tree species (Fagus sylvatica L. and Picea abies (L.) Karst) on soil bacterial and fungal communities. Mineral soil samples were collected from different depths (0–10, 10–20 cm) and at different horizontal distances from beech or spruce trunks (0.5, 1.5, 2.5, 3.5 m) in early summer and autumn. We assessed the composition of soil bacterial and fungal communities based on 16S rRNA gene and ITS DNA sequences. Community composition of bacteria and fungi was most strongly affected by soil pH and tree species. Different ectomycorrhizal fungi (e.g., Tylospora) known to establish mutualistic associations with plant roots showed a tree species preference. Moreover, bacterial and fungal community composition showed spatial and seasonal shifts in soil surrounding beech and spruce. The relative abundance of saprotrophic fungi was higher at a depth of 0–10 vs. 10–20 cm depth. This was presumably a result of changes in nutrient availability, as litter input and organic carbon content decreased with soil depth. Overall bacterial community composition showed strong variations under spruce with increasing distance from the tree trunks, which might be attributed in part to higher fine root biomass near spruce trunks. Furthermore, overall bacterial community composition was strongly affected by season under deciduous trees.

Bacteria inhabiting deadwood of 13 tree species are heterogeneously distributed between sapwood and heartwood

“…and Tilia sp., were clearly separated from logs with low pH values, especially those of conifers. It is well known that the majority of bacteria are strongly affected by this factor, in particular by low and fluctuating pH and generally more affected than fungi (Rousk et al ., ; Nacke et al ., ). However, Hoppe et al .…”

Soil abiotic variables are more important than Salicaceae phylogeny or habitat specialization in determining soil microbial community structure

“…For example, only bacteria communities on Salix candida in wetland treatments differed significantly, while ectomycorrhizal communities differed on multiple willow species in wetland plots. Most studies on soil bacteria and archaea responses to plant identity have examined taxonomically diverse plant species (Angel, Soares, Ungar, & Gillor, ; Nacke et al., ; Scheibe et al., ; Schlatter, Bakker, Bradeen, & Kinkel, ; Uroz et al., ). Many find that tree species identity explains a small proportion of the variation in soil bacterial community composition (Schlatter et al., ; Urbanova et al., ; Uroz et al., ), or that one particular plant species explains the difference in community composition (Schlatter et al., ).…”

Unraveling spatiotemporal variability of arbuscular mycorrhizal fungi in a temperate grassland plot

“…Soil microbial communities exhibit spatial patterns at scales from sub-millimetre to hundreds of metres, determined by heterogeneous environmental conditions at respective scale-dependencies (Grundmann et al, 2001;Ettema and Wardle, 2002;Nunan et al, 2003;Bahram et al, 2015). Simultaneously, dynamic variations in abiotic soil conditions lead to fluctuating soil microbial abundances and functions over time, documented in agricultural (Kandeler and Böhm, 1996;Kandeler et al, 1999), tundra (Björk et al, 2008) and forest ecosystems (Görres et al, 1998;Nacke et al, 2016). Moreover, plant growth and development or changes in vegetation within a year are able to shift soil microbial communities (Chaparro et al, 2014;Nacke et al, 2016).…”