Small-scale agricultural grassland management can affect soil fungal community structure as much as continental scale geographic patterns

Abstract

A European transect was established, ranging from Sweden to the Azores, to determine the relative influence of geographic factors and agricultural small-scale management on the grassland soil microbiome. Within each of five countries (factor ‘Country’), which maximized a range of geographic factors, two differing growth condition regions (factor ‘GCR’) were selected: a favorable region with conditions allowing for high plant biomass production and a contrasting less favorable region with a markedly lower potential. Within each region, grasslands of contrasting management intensities (factor ‘MI’) were defined: intensive and extensive, from which soil samples were collected. Across the transect, ‘MI’ was a strong differentiator of fungal community structure, having a comparable effect to continental scale geographic factors (‘Country’). ‘MI’ was also a highly significant driver of bacterial community structure, but ‘Country’ was clearly the stronger driver. For both, ‘GCR’ was the weakest driver. Also at the regional level, strong effects of MI occurred on various measures of the soil microbiome (i.e. OTU richness, management-associated indicator OTUs), though the effects were largely regional-specific. Our results illustrate the decisive influence of grassland MI on soil microbial community structure, over both regional and continental scales, and, thus, highlight the importance of preserving rare extensive grasslands.

Drought soil legacy alters drivers of plant diversity-productivity relationships in oldfield systems

“…Our two-phase experiment, examining direct and indirect (legacy) effects of drought on plant diversity-productivity relationships, resulted in three key findings: (i) drought modifies the relationships between plant species richness and richness of soil microbial groups (bacteria, AMF, and fungal pathogens), (ii) drought soil legacy increases the magnitude of net BEs but not the response patterns of net BEs to increasing plant species richness, and (iii) drought soil legacy interacts with subsequent drought, modifying the relative contribution of complementarity and selection to net diversity effects. Overall, levels of soil fungi and AMF richness were high, although similar fungal and AMF OTU richness has been reported in some other grassland studies ( 41 – 43 ).…”

Soil microbial community structures are shaped by agricultural systems revealing little temporal variation

“…This finding is in agreement with the first hypothesis of this study that sharply contrasting (MC – INT – EXT), slightly differing (EXT_HP – EXT_DP) and quite similar (EXT_HP – EXT_LP and EXT_LP – EXT_DP) agricultural systems would differ in terms of fungal community structure. A strong effect of grassland management on soil microbial community structures has been demonstrated previously ( Sayer et al, 2013 ; Szukics et al, 2019 ), with it even being shown to have a comparable effect on fungal community structure to continental-scale geographic factors ( Barreiro et al, 2022 ; Fox et al, 2021 ). All of these studies, however, utilized only a single sampling event.…”

“…This finding concurs with other studies, for example a Swiss field experiment which included a grassland ley and a crop rotation of conventional and no tillage, where agricultural management system had a stronger effect on fungal community β-diversity (7%) than on bacterial β-diversity (2%, Longepierre et al, 2021 ). Indeed, we also previously reported the stronger influence of grassland agricultural management on soil fungal community structure, compared to bacterial community structure, at both the continental and regional scale, including the Swiss lowlands ( Fox et al, 2021 ). In the present study, this disparity in response is even more apparent, particularly between MC and the differently managed permanent grassland systems.…”

“…The soil microbiome is fundamental in a number of agroecosystem processes such as soil nutrient cycling, organic matter decomposition and plant productivity ( Bertola et al, 2021 ). Agricultural management intensity is a major driver of soil microbiome community structure, with this influence having been observed at the plot ( Hartmann et al, 2014 ), regional ( Felipe-Lucia et al, 2020 ), continental ( Fox et al, 2021 ), and even global scale ( Leff et al, 2015 ). Soil microorganisms can, however, also exhibit temporal variation ( Hannula et al, 2019 ), and the importance of such temporal aspects into soil microbiome studies is being increasingly highlighted in the literature ( Geisen, 2021 ).…”

Integrating Ecological Principles for Addressing Plant Production Security and Move beyond the Dichotomy ‘Good or Bad’ for Nitrogen Inputs Choice

“…Traditional monitoring strategies are often expensive and associated with a delay in problem recognition and accessing data. New ecological approaches are needed to differentiate between the potential interactions between climate and land-use effects [113,114]. Some of these include the use of structural equation models [112], others take advantage of the available technology for time-series monitoring and the so-called 'space-for-time substitution' method to analyze ecosystem dynamics in a more comprehensive manner [115].…”