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Research article - Peer-reviewed, 2021

Woody encroachment in grassland elicits complex changes in the functional structure of above- and belowground biota

Sepp, Siim-Kaarel; Davison, John; Moora, Mari; Neuenkamp, Lena; Oja, Jane; Roslin, Tomas; Vasar, Martti; Opik, Maarja; Zobel, Martin


Woody plant encroachment affects dry grasslands globally. To predict changes in biodiversity and ecosystem processes, it is important to understand how this process affects the functional composition of grassland organism groups. In this context, seminatural wooded meadows represent a form of experimental manipulation-where open grassland and woody patches co-occur in homogeneous environmental conditions due to human management decisions-which provides an opportunity to address the effect of woody plant encroachment on vegetation and soil biota. We used environmental DNA metabarcoding to address variation in plant, soil fungal, and soil animal communities in parallel. We also addressed functional groups of fungi-animal and plant pathogens, saprotrophs, decomposers, arbuscular mycorrhizal, ectomycorrhizal, endophytic, and other symbiotrophic fungi-and of soil animals-fungivores, bacterivores, litter feeders, root feeders, macro plant feeders, algal/lichen feeders, predators, and parasites. Co-variation between communities was detected from aboveground vegetation plots and metabarcoding of soil DNA, in terms of estimated richness and compositional patterns. Differences between open and wooded patches were most pronounced among plants and symbiotic fungi, whereas soil animals exhibited less marked differences. For most organisms, mean richness, as well as total richness per habitat type, was higher in open than wooded patches, but ectomycorrhizal fungi exhibited the opposite pattern. The functional structure of the soil biotic community, as characterized by the proportion of DNA sequences attributed to different functional groups, differed significantly between open and wooded grassland patches, with symbiotic fungi (arbuscular mycorrhizal, ectomycorrhizal, and other symbiotrophic [mostly orchid mycorrhizal] fungi) contributing most to the difference. This study supports the notion that a soil DNA-based metabarcoding approach can provide insights into the diversity and composition of multiple taxonomic groups in natural ecosystems. It also provides a first demonstration of the complex changes to the functional structure of the belowground community that accompany woody plant encroachment in grasslands.


co-variation; ecosystem engineers; environmental DNA; plant-fungal interactions; plant-soil interactions; seminatural ecosystem; soil biota

Published in

2021, volume: 12, number: 5, article number: e03512
Publisher: WILEY

Authors' information

Sepp, Siim-Kaarel
University of Tartu
Davison, John
University of Tartu
Moora, Mari
University of Tartu
Neuenkamp, Lena
University of Tartu
Oja, Jane
University of Tartu
Swedish University of Agricultural Sciences, Department of Ecology
Vasar, Martti
University of Tartu
Opik, Maarja
University of Tartu
Zobel, Martin
University of Tartu

Associated SLU-program

SLU Network Plant Protection

Sustainable Development Goals

SDG15 Life on land

UKÄ Subject classification

Soil Science

Publication Identifiers


URI (permanent link to this page)