Project

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Effects of climate change on plant-microbe interactions for nutrient acquisition in bogs: implications for carbon and nutrient dynamics (CLIMABOG)

Applicant Bragazza Luca
Number 129981
Funding scheme Project funding (Div. I-III)
Research institution Laboratoire des systèmes écologiques EPFL - ENAC - IIE - ECOS
Institution of higher education Swiss Federal Institute for Forest, Snow and Landscape Research - WSL
Main discipline Pedology
Start/End 01.04.2010 - 30.09.2012
Approved amount 155'910.00
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All Disciplines (3)

Discipline
Pedology
Ecology
Environmental Research

Keywords (12)

Peat bogs; Climate warming; Soil enzymes; Soil organic carbon; Microbial diversity; Plant-microbe interactions; Primary production; peatlands; nitrogen; vegetation biomass; Sphagnum; soil chemistry

Lay Summary (English)

Lead
Lay summary
The research project CLIMABOG aims at assessing the relationships between plants and microbes for nutrient acquisition in peatlands (bogs) and potential feedbacks on soil biogeochemistry along a gradient of increasing peat soil temperature. Peatlands are important sinks of atmospheric carbon dioxide and although they cover about 3% of world land cover, peatlands store about 30% of world soil organic carbon or 60% of the carbon present in the atmosphere. Bogs are peatlands dominated by Sphagnum mosses, a peculiar type of plants producing a litter extremely refractory to decomposition so that the remnants of Sphagnum plants accumulate as "peat". Because Sphagnum productivity is dependent on water surplus, bogs are particularly sensitive to climate change. Some laboratory experiments suggest that increasing peat soil temperature can promote the growth of vascular plants at expense of Sphagnum mosses through an alteration of plant competitive ability for nutrient acquisition with respect to soil microbes. A better understanding of the effects of climate warming on plant-microbe interactions in bogs is then crucial for predicting the potential alteration of peat accumulation rates.In CLIMABOG the increasing peat soil temperature will be obtained by selecting the study bogs along an altitudinal gradient so as to assess the effects of climate warming under conditions of long-term equilibrium between biogeochemistry, vegetation and local climatic conditions. The research project will include both field observations along one entire year (so as to include also the winter season), and a mesocosm experiment where peat monoliths will be transplanted to lower altitude so as to study the biological and physico-chemical reactions of the system to a sudden climate change. By means of information concerning soil enzymatic activity, microbial diversity and abundance, plant biomass and productivity, peat and water chemistry, we want to assess: 1) how microbial biomass nutrients change during the year in relation to vascular plant growth; 2) how soil enzymatic activity changes along the year and along the altitudinal gradient; 3) how standing biomass of vascular plants and Sphagnum growth vary along the altitudinal gradient; 4) if there is any difference in the microbial diversity in relation to increasing peat soil temperature. A better understanding of the aboveground and belowground interactions in peatlands in response to climate change will permit to better forecast the future carbon sinking ability of these ecosystems
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Biogeochemical plant-soil microbe feedback in response to climate warming in peatlands
Bragazza L. Parisod J Buttler A. & Bardgett R. (2013), Biogeochemical plant-soil microbe feedback in response to climate warming in peatlands, in Nature Climate Change, 273-277.
Seasonal patterns of testae amoebae diversity, community structure and species-environment relationships in four Sphganum-dominated peatlands along a 1300 m altitudinal gradient in Switzerland
Lamentowicz M Bragazza L Buttler A Jassey VEJ Mitchell EAD (2013), Seasonal patterns of testae amoebae diversity, community structure and species-environment relationships in four Sphganum-dominated peatlands along a 1300 m altitudinal gradient in Switzerland, in Soil Biology and Biochemistry, 1-11.
Snow cover manipulation effects on microbial community structure and soil chemistry in a mountain bog
Robroek BJM Heijboer A Jassey VEJ Hefting MM Rouwenhorst TG Buttler A Bragazza L (2013), Snow cover manipulation effects on microbial community structure and soil chemistry in a mountain bog, in Plant and Soil, 369, 152-164.
Linking soil microbial communities to vascular plant abundance along a climate gradient
Luca Bragazza Richard D. Bardgett Edward A. D. Mitchell and Alexandre Buttler, Linking soil microbial communities to vascular plant abundance along a climate gradient, in New Phytologist.

Collaboration

Group / person Country
Types of collaboration
School of Biological Sciences, University of Aberdeen Great Britain and Northern Ireland (Europe)
- Publication
Institut des Sciences de la Terre d'Orléans France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Laboratoire SRSN - Université de Poitiers France (Europe)
- in-depth/constructive exchanges on approaches, methods or results

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
MUE13, Mountains under Watch 2013, Observing climate effects in the Alps Talk given at a conference Biogeochemical feedback between plants and soil microbes explain shrub encroachment in peatlands in response to climate change 20.02.2013 Aosta (Italy), Italy Bragazza Luca;
BIOGEOMON 2012: The 7th International Symposium on Ecosystem Behavior Talk given at a conference Aboveground and belowground interactions in peatlands: the influence of climate warming and changes in plant cover on nutrient partitioning between soil microbes and plants 15.07.2012 Northport, Maine (USA), United States of America Bragazza Luca;
International Symposium on Ecohydrology (LATSIS) Poster Aboveground and belowground feedbacks for nutrient acquisition in bogs: responses to climate change 17.10.2010 EPFL-Lausanne, Switzerland Bragazza Luca;


Self-organised

Title Date Place
Wetland Biogeochemistry Symposium 2011 (in association with the annual meeting of the SWS-Society of Wetland Scientists) 03.07.2011 Prague (Czech Republic), Czech Republic

Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Avec le réchauffement, les tourbières se transforment en émetteurs de CO2 Le Monde International 2013
New media (web, blogs, podcasts, news feeds etc.) De puits de carbone à sources de carbone 20 Minutes-on line Western Switzerland 2012
New media (web, blogs, podcasts, news feeds etc.) How shrubs are reducing the positive contribution of peatlands to climate ScienceDaily International 2012
Media relations: print media, online media L’avenir se joue aussi dans une tourbière de la Vallée 24 heures - Nordvaudois-Broye Western Switzerland 2010

Associated projects

Number Title Start Funding scheme
144024 Climate warming and vegetation change in peatlands: spatial and temporal effects on biogeochemistry (VEGANPEAT) 01.02.2014 Project funding (Div. I-III)
141188 The effect of cadavers on soil ecology: biotic and functional responses (CADAVER) 01.08.2012 Project funding (Div. I-III)

Abstract

Peatlands are important long-term carbon (C) sinks, particularly Sphagnum-dominated peatlands (or bogs) where the bulk of living and dead biomass is formed by Sphagnum mosses. This peculiar genus of bryophytes is characterized by physiological and biochemical features that enhance the sequester of C by the production of litter extremely refractory to decomposition and by the presence of microbial inhibitors. Furthermore, Sphagnum productivity is strictly dependent on water surplus so that bogs are expected to be particularly sensitive to climate change. Indeed, any reduction of Sphagnum dominance in favour of vascular plants can jeopardize the C sink function of bogs because the litter of vascular plant is much more easily decomposable. Any increase of vascular plant productivity is necessarily mediated by soil microbes, whose decomposing activity releases nutrients for root absorbance and plant growth. Some laboratory experiments suggest that increasing peat soil temperature can promote the growth of vascular plants at expense of mosses through an alteration of plant competitive ability for nutrient acquisition with respect to soil microbes. In the light of the ongoing climate change, a better understanding of the effects of climate warming on plant-microbe interactions in bogs is then crucial for predicting potential alteration on C sinking mediated by above- and belowground feedbacks. The main aim of the present research project is then to understand the relationships between plants and microbes for nutrient acquisition (C, N and P) and potential feedbacks on bog biogeochemistry along a gradient of increasing peat soil temperature. Increasing peat soil temperature will be obtained by selecting the study bogs along an altitudinal gradient so as to assess the effects of climate warming under conditions of long-term equilibrium between biogeochemistry, vegetation and local climatic conditions. The research project will include both field observations along one entire year (so as to include also the winter season), but it will also include a mesocosm experiment where peat monoliths will be transplanted to lower altitude so as to study the biological and physico-chemical reactions of the system to a sudden climate change. By means of information concerning soil enzymatic activity, microbial diversity and abundance, plant biomass and productivity, peat and water chemistry, we want to test the following main hypotheses and clarify the underlying mechanisms:1) microbial biomass is higher during summer months when the plant growth is higher and it is negatively correlated with the altitude;2) enzymatic activity is higher during summer months to face a higher nutrient request by growing plants and it decreases along the altitudinal gradient as a consequence of a lower peat temperature;3) the standing biomass of vascular plant decreases with altitude, but Sphagnum productivity increases with altitude; in addition, we hypothesize that vascular plant nutrient content is higher at lower altitude;4) higher peat temperature will stimulate a higher rhizodeposition, mirrored in a higher concentration of polyphenols in bog water, with potential lower microbial immobilization of nutrient during summer months.
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