Soil bacterial functional diversity mirrors the loss of plant diversity by the expansion of a native tall-grass in high mountain grasslands

Abstract

Background and Aims In highland ecosystems, global change processes are intense and foster vegetation shifts that may have an impact on soil functioning. Soil bacterial communities may be particularly sensitive to these changing scenarios. The aim of this research is to determine whether the loss of floristic diversity caused by the unusual dominance of a native component -the perennial grass Brachypodium rupestre (L.) Beauv., which is expanding aggressively in natural grasslands of the Western Pyrenees-, parallels a decrease of the soil bacterial functional diversity and their potential for nutrient transformations.Methods. We conducted the study in eight grasslands exposed to different degrees of B. rupestre spreading. Soil community physiological profiles of the heterotrophic bacteria, enzymatic activities related to C, P and N cycles, C and N microbial biomasses, N components and soil physical and chemical properties were determined.Results Soils below low-diversity grasslands had lower bacterial functional richness and diversity but greater urease activity, pH and nitrate than soils in diverse grasslands. Ammonium pools, C and N microbial biomasses and enzymatic activities related to C and P did not differ between grasslands. ConclusionsThe expansion of B. rupestre and the decrease of plant diversity coincided with a significant decline of bacterial functional diversity and an alteration of the N cycle. Not only plant composition but the prevailing disturbance regime may account for the results. Results also suggest that B. rupestre may rely on its capability to use N efficiently rather than on a soil bacteria-mediated N availability.

Plant Biomass and Soil Nutrients Mainly Explain the Variation of Soil Microbial Communities During Secondary Succession on the Loess Plateau

“…And Proteobacteria is commonly used as copiotrophic bacteria, due to its extracellular membrane consists of lipopolysaccharide that was involved in carbon conversion [37]. Metabolism in Actinobacteria was affected by light intensity, and the increase in above-ground biomass from grassland to forestland weakens their metabolic e ciencies (Table 2; [38]). Considering the N 2 -xing capacity of leguminous plants such as Robinia pseudoacacia and Caragana korshinskii, the combination of N 2 -xing microorganisms and mycorrhizas was stronger [22].…”

Effects of organic fertilizer on soil nutrient status, enzyme activity, and bacterial community diversity in Leymus chinensis steppe in Inner Mongolia, China

“…As the most important and active part of the soil ecosystem, they are involved in almost all soil life processes. Because of the sensitivity of soil quality to the soil microbial population, many studies have used soil microbial parameters as a measure of soil quality, especially in the evaluation of soil quality after fertilizer application [ 21 , 22 ]. Soil microbial community composition, microbial diversity, microbial respiration, and soil enzymes that respond to microbial activity can be used to determine changes in soil quality [ 23 ].…”

Microbiome-Inspired Green Infrastructure (MIGI): A Bioscience Roadmap for Urban Ecosystem Health

“…Mills et al (2020) provided evidence that revegetation, particularly with native species, can improve urban soil microbiome functional diversity. Other studies show that diverse vegetation communities promote below-ground functional richness, diversity and resilience (Eisenhauer et al 2018;Canals et al 2019). Promoting diversity of local vegetation communities is considered a robust strategy to maintain multifunctional processes under current and future environmental conditions (Eisenhauer et al 2018).…”