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Fanin N, Clemmensen KE, Lindahl BD, Farrell M, Nilsson MC, Gundale MJ, Kardol P, Wardle DA. Ericoid shrubs shape fungal communities and suppress organic matter decomposition in boreal forests. New Phytol 2022; 236:684-697. [PMID: 35779014 DOI: 10.1111/nph.18353] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
Mycorrhizal fungi associated with boreal trees and ericaceous shrubs are central actors in organic matter (OM) accumulation through their belowground carbon allocation, their potential capacity to mine organic matter for nitrogen (N) and their ability to suppress saprotrophs. Yet, interactions between co-occurring ectomycorrhizal fungi (EMF), ericoid mycorrhizal fungi (ERI), and saprotrophs are poorly understood. We used a long-term (19 yr) plant functional group manipulation experiment with removals of tree roots, ericaceous shrubs and mosses and analysed the responses of different fungal guilds (assessed by metabarcoding) and their interactions in relation to OM quality (assessed by mid-infrared spectroscopy and nuclear magnetic resonance) and decomposition (litter mesh-bags) across a 5000-yr post-fire boreal forest chronosequence. We found that the removal of ericaceous shrubs and associated ERI changed the composition of EMF communities, with larger effects occurring at earlier stages of the chronosequence. Removal of shrubs was associated with enhanced N availability, litter decomposition and enrichment of the recalcitrant OM fraction. We conclude that increasing abundance of slow-growing ericaceous shrubs and the associated fungi contributes to increasing nutrient limitation, impaired decomposition and progressive OM accumulation in boreal forests, particularly towards later successional stages. These results are indicative of the contrasting roles of EMF and ERI in regulating belowground OM storage.
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Affiliation(s)
- Nicolas Fanin
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901-83, Umeå, Sweden
- INRAE, Bordeaux Sciences Agro, UMR 1391 ISPA, 71 avenue Edouard Bourlaux, CS 20032, F33882, Villenave-d'Ornon cedex, France
| | - Karina E Clemmensen
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7026, SE-75007, Uppsala, Sweden
| | - Björn D Lindahl
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-75007, Uppsala, Sweden
| | - Mark Farrell
- CSIRO Agriculture & Food, Kaurna Country, Locked Bag 2, Glen Osmond, South Australia, 5064, Australia
| | - Marie-Charlotte Nilsson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901-83, Umeå, Sweden
| | - Michael J Gundale
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901-83, Umeå, Sweden
| | - Paul Kardol
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901-83, Umeå, Sweden
| | - David A Wardle
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901-83, Umeå, Sweden
- Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore City, 639798, Singapore
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Grau-Andrés R, Thieffry S, Tian S, Wardle DA, Kardol P. Responses of bryosphere fauna to drought across a boreal forest chronosequence. Oecologia 2022; 200:231-245. [PMID: 36074302 PMCID: PMC9547781 DOI: 10.1007/s00442-022-05255-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/31/2022] [Indexed: 11/29/2022]
Abstract
Projected changes in precipitation regimes can greatly impact soil biota, which in turn alters key ecosystem functions. In moss-dominated ecosystems, the bryosphere (i.e., the ground moss layer including live and senesced moss) plays a key role in carbon and nutrient cycling, and it hosts high abundances of microfauna (i.e., nematodes and tardigrades) and mesofauna (i.e., mites and springtails). However, we know very little about how bryosphere fauna responds to precipitation, and whether this response changes across environmental gradients. Here, we used a mesocosm experiment to study the effect of volume and frequency of precipitation on the abundance and community composition of functional groups of bryosphere fauna. Hylocomium splendens bryospheres were sampled from a long-term post-fire boreal forest chronosequence in northern Sweden which varies greatly in environmental conditions. We found that reduced precipitation promoted the abundance of total microfauna and of total mesofauna, but impaired predaceous/omnivorous nematodes, and springtails. Generally, bryosphere fauna responded more strongly to precipitation volume than to precipitation frequency. For some faunal functional groups, the effects of precipitation frequency were stronger at reduced precipitation volumes. Context-dependency effects were found for microfauna only: microfauna was more sensitive to precipitation in late-successional forests (i.e., those with lower productivity and soil nutrient availability) than in earlier-successional forests. Our results also suggest that drought-induced changes in trophic interactions and food resources in the bryosphere may increase faunal abundance. Consequently, drier bryospheres that may result from climate change could promote carbon and nutrient turnover from fauna activity, especially in older, less productive forests.
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Affiliation(s)
- Roger Grau-Andrés
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
| | - Sylvia Thieffry
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
| | - Shanyi Tian
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095 China
| | - David A. Wardle
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | - Paul Kardol
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
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Grau‐Andrés R, Wardle DA, Nilsson M, Kardol P. Precipitation regime controls bryosphere carbon cycling similarly across contrasting ecosystems. OIKOS 2021. [DOI: 10.1111/oik.07749] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roger Grau‐Andrés
- Dept of Forest Ecology and Management, Swedish Univ. of Agricultural Sciences (SLU) Umeå Sweden
| | - David A. Wardle
- Dept of Forest Ecology and Management, Swedish Univ. of Agricultural Sciences (SLU) Umeå Sweden
- Asian School of the Environment, Nanyang Technological Univ. Singapore Singapore
| | - Marie‐Charlotte Nilsson
- Dept of Forest Ecology and Management, Swedish Univ. of Agricultural Sciences (SLU) Umeå Sweden
| | - Paul Kardol
- Dept of Forest Ecology and Management, Swedish Univ. of Agricultural Sciences (SLU) Umeå Sweden
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Grau-Andrés R, Wardle DA, Gundale MJ, Foster CN, Kardol P. Effects of plant functional group removal on CO 2 fluxes and belowground C stocks across contrasting ecosystems. Ecology 2020; 101:e03170. [PMID: 32846007 PMCID: PMC7757239 DOI: 10.1002/ecy.3170] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 06/29/2020] [Indexed: 11/17/2022]
Abstract
Changes in plant communities can have large effects on ecosystem carbon (C) dynamics and long‐term C stocks. However, how these effects are mediated by environmental context or vary among ecosystems is not well understood. To study this, we used a long‐term plant removal experiment set up across 30 forested lake islands in northern Sweden that collectively represent a strong gradient of soil fertility and ecosystem productivity. We measured forest floor CO2 exchange and aboveground and belowground C stocks for a 22‐yr experiment involving factorial removal of the two dominant functional groups of the boreal forest understory, namely ericaceous dwarf shrubs and feather mosses, on each of the 30 islands. We found that long‐term shrub and moss removal increased forest floor net CO2 loss and decreased belowground C stocks consistently across the islands irrespective of their productivity or soil fertility. However, we did see context‐dependent responses of respiration to shrub removals because removals only increased respiration on islands of intermediate productivity. Both CO2 exchange and C stocks responded more strongly to shrub removal than to moss removal. Shrub removal reduced gross primary productivity of the forest floor consistently across the island gradient, but it had no effect on respiration, which suggests that loss of belowground C caused by the removals was driven by reduced litter inputs. Across the island gradient, shrub removal consistently depleted C stocks in the soil organic horizon by 0.8 kg C/m2. Our results show that the effect of plant functional group diversity on C dynamics can be relatively consistent across contrasting ecosystems that vary greatly in productivity and soil fertility. These findings underline the key role of understory vegetation in forest C cycling, and suggest that global change leading to changes in the relative abundance of both shrubs and mosses could impact on the capacity of boreal forests to store C.
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Affiliation(s)
- Roger Grau-Andrés
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
| | - David A Wardle
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden.,Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | - Michael J Gundale
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
| | - Claire N Foster
- Fenner School of Environment and Society, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Paul Kardol
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
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