TY - JOUR

T1 - Mineral type and land-use intensity control composition and functions of microorganisms colonizing pristine minerals in grassland soils

AU - Brandt, Luise

AU - Stache, Fabian

AU - Poll, Christian

AU - Bramble, De Shorn

AU - Schöning, Ingo

AU - Schrumpf, Marion

AU - Ulrich, Susanne

AU - Kaiser, Klaus

AU - Mikutta, Robert

AU - Mikutta, Christian

AU - Oelmann, Yvonne

AU - Siemens, Jan

AU - Kandeler, Ellen

AU - Konrad, Alexander

N1 - Funding Information: This work is based on data elaborated by the BEmins project of the Biodiversity Exploratories program (DFG Priority Program 1374). The datasets are publicly available in the Biodiversity Exploratories Information System (BExIS; http://doi.org/10.17616/R32P9Q ). BExIS dataset IDs: 31251 (C and N contents), 31316 (enzyme activities), 31317 (PLFAs), 31318 (WEOM), 31320 (Olsen-P in mineral containers), 19286 (soil Olsen-P), 20826 (elevation, slope, aspect, and coordinates), 14686 (soil texture), 22246 (soil pH), and 19007 (climate data). Funding Information: We thank the managers of the Schwäbische Alb, Kirsten Reichel-Jung, Iris Steitz, Sandra Weithmann, Florian Staub, Julia Bass, Max Müller and all former managers for their work in maintaining the plot and project infrastructure; Christiane Fischer, Jule Mangels, and Victoria Grießmeier for giving support through the central office, Michael Owonibi and Andreas Ostrowski for managing the central data base, and Markus Fischer, Eduard Linsenmair, Dominik Hessenmöller, Daniel Prati, François Buscot, Ernst-Detlef Schulze, Wolfgang W. Weisser and the late Elisabeth Kalko for their role in setting up the Biodiversity Exploratories project. We thank the administration of the UNESCO Biosphere Reserve Schwäbische Alb as well as all landowners for the excellent collaboration. We further thank Heike Haslwimmer, Sabine Rudolph, Gudrun Nemson-von Koch, Christine Krenkewitz, Theresa Klötzing, Steffen Ferber, and Katja Pursche for support during laboratory analyses, Core Project 9 of the Biodiversity Exploratories (DFG project number 193957772) for setting the experiment up in 2015 and all people assisting in the sampling of the mineral containers in 2020. We further thank Caterina Penone for advice with statistical analysis and Kathleen Regan for proofreading of the manuscript. The work has been funded by the DFG Priority Program 1374 “Biodiversity Exploratories” (DFG project number 433273584 ) and by a postgraduate scholarship of the Justus Liebig University Giessen for Alexander Konrad. Field work permits were issued by the responsible state environmental office of Baden-Württemberg.

PY - 2023/7

Y1 - 2023/7

N2 - Mineral surfaces in soil are an important interface for organic matter (OM) and nutrient cycling, with associated microorganisms contributing to the formation and turnover of mineral-associated OM (MAOM). However, the relevance of intrinsic (mineral type) versus extrinsic (land-use intensity) factors on the co-development of MAOM and microorganisms under natural conditions remains poorly understood. Mineral containers filled with mixtures of quartz-sand and pristine secondary minerals (goethite or illite) were exposed to 50 grassland topsoils of the Schwäbische Alb (Germany) along a land-use intensity gradient for five years. Mineral samples and soils were analyzed for organic carbon (OC) and nutrients (N and P), abundance and composition of major microbial groups based on phospholipid fatty acid profiles, as well as enzyme activities (β-glucosidase, β-xylosidase, N-acetylglucosaminidase, and acid phosphatase). Microorganisms colonized both mineral samples to the same extent, with goethite samples exhibiting greater MAOM accumulation and higher enzyme activities than illite samples. Both mineral samples differed from the overlying soils with greater relative abundances of fungi and Gram-negative bacteria and greater microbial acquisition of nutrients (N and P) relative to C as indicated by the stoichiometry of enzyme activities. Increasing land-use intensity was associated with decreasing C:N ratios and microbial abundances for goethite samples and increasing β-glucosidase activity for illite samples while the proportion of fungi was reduced in both mineral samples. We conclude that in the studied temperate grasslands the association of OM and microorganisms with secondary minerals is driven more by mineral type and reactivity than by differences in land-use intensity. The different minerals apparently formed distinct microhabitats with unique characteristics that differed in MAOM accumulation and microbial access to OC and nutrients, thus affecting microbial colonization and functionality.

AB - Mineral surfaces in soil are an important interface for organic matter (OM) and nutrient cycling, with associated microorganisms contributing to the formation and turnover of mineral-associated OM (MAOM). However, the relevance of intrinsic (mineral type) versus extrinsic (land-use intensity) factors on the co-development of MAOM and microorganisms under natural conditions remains poorly understood. Mineral containers filled with mixtures of quartz-sand and pristine secondary minerals (goethite or illite) were exposed to 50 grassland topsoils of the Schwäbische Alb (Germany) along a land-use intensity gradient for five years. Mineral samples and soils were analyzed for organic carbon (OC) and nutrients (N and P), abundance and composition of major microbial groups based on phospholipid fatty acid profiles, as well as enzyme activities (β-glucosidase, β-xylosidase, N-acetylglucosaminidase, and acid phosphatase). Microorganisms colonized both mineral samples to the same extent, with goethite samples exhibiting greater MAOM accumulation and higher enzyme activities than illite samples. Both mineral samples differed from the overlying soils with greater relative abundances of fungi and Gram-negative bacteria and greater microbial acquisition of nutrients (N and P) relative to C as indicated by the stoichiometry of enzyme activities. Increasing land-use intensity was associated with decreasing C:N ratios and microbial abundances for goethite samples and increasing β-glucosidase activity for illite samples while the proportion of fungi was reduced in both mineral samples. We conclude that in the studied temperate grasslands the association of OM and microorganisms with secondary minerals is driven more by mineral type and reactivity than by differences in land-use intensity. The different minerals apparently formed distinct microhabitats with unique characteristics that differed in MAOM accumulation and microbial access to OC and nutrients, thus affecting microbial colonization and functionality.

KW - Enzyme activities

KW - Land use intensity

KW - Mineral-associated microorganisms

KW - Mineral-associated organic matter (MAOM)

KW - Mineralosphere

KW - Phospholipid fatty acids (PLFAs)

UR - http://www.scopus.com/inward/record.url?scp=85158140216&partnerID=8YFLogxK

U2 - 10.1016/j.soilbio.2023.109037

DO - 10.1016/j.soilbio.2023.109037

M3 - Article

AN - SCOPUS:85158140216

VL - 182

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

SN - 0038-0717

M1 - 109037

ER -