The Experts below are selected from a list of 28002 Experts worldwide ranked by ideXlab platform
Alexandre Buttler - One of the best experts on this subject based on the ideXlab platform.
-
Economic and sociological approaches of French Peatlands
2020Co-Authors: C. Maitre, Alexandre Buttler, Daniel Gilbert, Daniel Epron, Fatima Laggoun-défarge, D. Jacques-jouvenotAbstract:French Peatlands have been used mainly for sources of peat for horticulture. 16 sites are still exploited for the production of 400,000 tons/year, representing 46 % of the local peat consumption. Most of these Peatlands will be abandoned and restored in the coming years. The objective of this paper is to present the economic aspects of the French Peatlands and to explore the sociological consequences of this change in Peatland use. Concerning the economic aspects, the French sites of extraction, development of French production, consumption and import of peat, and jobs generated by this activity, are presented. The present tendency is to develop substitutes for peat and to increase imports from other countries. In parallel, alternative uses of Peatlands such as conservation, tourism activities and agricultural development of the borders of the Peatland are developed creating newsocio-economic values of Peatlands in France., These changes in economic uses of the Peatland generate modifications in the sociological perceptions of the Peatlands. We performed a sociological study based on semi-directive interviews carried out with members of nature conservation associations, farmers, hunters, industrialist, conservative manager, residents, and officials concerned with Peatlands. Three sites have been studied: an exploited plain-marsh, in Normandy (Baupte), a site exploited for peat until 1994, then restored and now welcoming the public, in Isere (St Laurent-Du-Pont), and a Peatland in Franche-Comte (Frasne) which was exploited until the Second World War, has been recently restored and now welcomes the public. Analysis of interviews reveals that the individuals residing near the site seem to develop a view of the Peatlands related to their attachment with the uses of Peatlands (extraction of the peat, hunting, gathering of bilberries). The people considered as external observers to the site seem to perceive the peat bog less for its uses than for its existence as a natural environment.
-
vascular plant mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change
Global Change Biology, 2018Co-Authors: Alexandre Buttler, Remy Albrecht, Konstantin Gavazov, Ellen Dorrepaal, Mark H GarnettAbstract:Climate change can alter Peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects Peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular‐plant removal experiment in two Sphagnum‐dominated Peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO2 radiocarbon (bomb‐14C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in Peatlands, especially when assessing the future carbon sink function of Peatlands undergoing a shift in vegetation community composition in association with climate change.
-
Peatland vascular plant functional types affect dissolved organic matter chemistry
Plant and Soil, 2016Co-Authors: Bjorn J. M. Robroek, Alexandre Buttler, Remy Albrecht, Samuel Hamard, Adrian Pulgarin, Luca Bragazza, Vincent E. J. JasseyAbstract:Northern Peatlands are large repositories of carbon. Peatland vascular plant community composition has been functionally associated to a set of biogeochemical processes such as carbon cycling. Yet, we do not fully understand to what extent vascular plant functional types (PFTs) affect the quality of dissolved organic matter, and if there is any feedback on soil microbial activity. Using a longer–term plant removal experiment in a boreo–nemoral Peatland in Southern Sweden, we relate the dominance of different vascular plant functional types (i.e. ericoids and graminoids) to the chemistry of the dissolved organic matter (DOM) and microbial enzymatic activities (fluorescein diacetate hydrolysis, FDA). Our results show that PFTs modifies the composition of DOM moieties, with a decrease of low molecular weight organic compounds after vascular plant removal. The decrease of enzymatic activity by up to 68 % in the plant removal plots suggests a reduction in DOM mineralization in the absence of vascular plants. Our results show that plant–derived low molecular organic compounds enhance Peatland microbial activity, and suggest that an increase of vascular plant cover in response to climate change can potentially destabilize the OM in Peatlands, leading to increased carbon losses.
-
Peatland vascular plant functional types affect dissolved organic matter chemistry
Plant and Soil, 2015Co-Authors: Bjorn J. M. Robroek, Alexandre Buttler, Samuel Hamard, Adrian Pulgarin, Luca Bragazza, Remy J. H. Albrecht, Vincent E. J. JasseyAbstract:Background and aims: Northern Peatlands are large repositories of carbon. Peatland vascular plant community composition has been functionally associated to a set of biogeochemical processes such as carbon cycling. Yet, we do not fully understand to what extent vascular plant functional types (PFTs) affect the quality of dissolved organic matter, and if there is any feedback on soil microbial activity.\ud Methods: Using a longer–term plant removal experiment in a boreo–nemoral Peatland in Southern Sweden, we relate the dominance of different vascular plant functional types (i.e. ericoids and graminoids) to the chemistry of the dissolved organic matter (DOM) and microbial enzymatic activities (fluorescein diacetate hydrolysis, FDA). Results Our results show that PFTs modifies the composition ofDOMmoieties, with a decrease of lowmolecular weight organic compounds after vascular plant removal. The decrease of enzymatic activity by up to 68 % in the plant removal plots suggests a reduction in DOM mineralization in the absence of vascular plants.\ud Conclusions: Our results show that plant–derived low molecular organic compounds enhance Peatland microbial activity, and suggest that an increase of vascular plant cover in response to climate change can potentially destabilize the OM in Peatlands, leading to increased carbon losses
Angela V Gallegosala - One of the best experts on this subject based on the ideXlab platform.
-
latitudinal limits to the predicted increase of the Peatland carbon sink with warming
Nature Climate Change, 2018Co-Authors: Angela V Gallegosala, Dan J. Charman, David W Beilman, Colin I Prentice, Simon Brewer, Susan E Page, Pierre Friedlingstein, Steve Moreton, Matthew J Amesbury, Svante BjorckAbstract:The carbon sink potential of Peatlands depends on the balance of carbon uptake by plants and microbial decomposition. The rates of both these processes will increase with warming but it remains unclear which will dominate the global Peatland response. Here we examine the global relationship between Peatland carbon accumulation rates during the last millennium and planetary-scale climate space. A positive relationship is found between carbon accumulation and cumulative photosynthetically active radiation during the growing season for mid- to high-latitude Peatlands in both hemispheres. However, this relationship reverses at lower latitudes, suggesting that carbon accumulation is lower under the warmest climate regimes. Projections under Representative Concentration Pathway (RCP)2.6 and RCP8.5 scenarios indicate that the present-day global sink will increase slightly until around ad 2100 but decline thereafter. Peatlands will remain a carbon sink in the future, but their response to warming switches from a negative to a positive climate feedback (decreased carbon sink with warming) at the end of the twenty-first century.
-
climate related changes in Peatland carbon accumulation during the last millennium
Biogeosciences, 2012Co-Authors: Dan J. Charman, David W Beilman, Robert K. Booth, Angela V Gallegosala, Maarten Blaauw, Simon Brewer, Frank M Chambers, J A Christen, Sandy P HarrisonAbstract:Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of Peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the global positive carbon cycle feedback. Here we use a new extensive database of peat profiles across northern high latitudes to examine spatial and temporal patterns of carbon accumulation over the past millennium. Opposite to expectations, our results indicate a small negative carbon cycle feedback from past changes in the long-term accumulation rates of northern Peatlands. Total carbon accumulated over the last 1000 yr is linearly related to contemporary growing season length and photosynthetically active radiation, suggesting that variability in net primary productivity is more important than decomposition in determining long-term carbon accumulation. Furthermore, northern Peatland carbon sequestration rate declined over the climate transition from the Medieval Climate Anomaly (MCA) to the Little Ice Age (LIA), probably because of lower LIA temperatures combined with increased cloudiness suppressing net primary productivity. Other factors including changing moisture status, Peatland distribution, fire, nitrogen deposition, permafrost thaw and methane emissions will also influence future Peatland carbon cycle feedbacks, but our data suggest that the carbon sequestration rate could increase over many areas of northern Peatlands in a warmer future.
-
bioclimatic envelope model of climate change impacts on blanket Peatland distribution in great britain
Climate Research, 2010Co-Authors: Angela V Gallegosala, Joanna M Clark, Joanna Isobel House, Colin I Prentice, Pete Smith, Timothy S Farewell, S J ChapmanAbstract:Blanket Peatlands are rain-fed mires that cover the landscape almost regardless of topography. The geographical extent of this type of Peatland is highly sensitive to climate. We applied a global process-based bioclimatic envelope model, PeatStash, to predict the distribution of British blanket Peatlands. The model captures the present areal extent (Kappa = 0.77) and is highly sensitive to both temperature and precipitation changes. When the model is run using the UKCIP02 climate projections for the time periods 2011–2040, 2041–2070 and 2071–2100, the geographical distribution of blanket Peatlands gradually retreats towards the north and the west. In the UKCIP02 high emissions scenario for 2071–2100, the blanket Peatland bioclimatic space is ~84% smaller than contemporary conditions (1961–1990); only parts of the west of Scotland remain inside this space. Increasing summer temperature is the main driver of the projected changes in areal extent. Simulations using 7 climate model outputs resulted in generally similar patterns of declining aereal extent of the bioclimatic space, although differing in degree. The results presented in this study should be viewed as a first step towards understanding the trends likely to affect the blanket Peatland distribution in Great Britain. The eventual fate of existing blanket Peatlands left outside their bioclimatic space remains uncertain.
David W Beilman - One of the best experts on this subject based on the ideXlab platform.
-
latitudinal limits to the predicted increase of the Peatland carbon sink with warming
Nature Climate Change, 2018Co-Authors: Angela V Gallegosala, Dan J. Charman, David W Beilman, Colin I Prentice, Simon Brewer, Susan E Page, Pierre Friedlingstein, Steve Moreton, Matthew J Amesbury, Svante BjorckAbstract:The carbon sink potential of Peatlands depends on the balance of carbon uptake by plants and microbial decomposition. The rates of both these processes will increase with warming but it remains unclear which will dominate the global Peatland response. Here we examine the global relationship between Peatland carbon accumulation rates during the last millennium and planetary-scale climate space. A positive relationship is found between carbon accumulation and cumulative photosynthetically active radiation during the growing season for mid- to high-latitude Peatlands in both hemispheres. However, this relationship reverses at lower latitudes, suggesting that carbon accumulation is lower under the warmest climate regimes. Projections under Representative Concentration Pathway (RCP)2.6 and RCP8.5 scenarios indicate that the present-day global sink will increase slightly until around ad 2100 but decline thereafter. Peatlands will remain a carbon sink in the future, but their response to warming switches from a negative to a positive climate feedback (decreased carbon sink with warming) at the end of the twenty-first century.
-
sensitivity of northern Peatland carbon dynamics to holocene climate change
Geophysical monograph, 2013Co-Authors: Zicheng Yu, David W Beilman, Miriam C JonesAbstract:In this paper, we evaluate the long-term climate sensitivity and global carbon (C) cycle implications of northern Peatland C dynamics by synthesizing available data and providing a conceptual framework for understanding the dominant controls, processes, and interactions of Peatland initiation and C accumulation. Northern Peatlands are distributed throughout the climate domain of the boreal forest/taiga biome, but important differences between Peatland regions are evident in annual temperature vs. precipitation (T-P) space, suggesting complex hydroclimatic controls through various seasonal thermal-moisture associations. Of 2380 available basal peat dates from northern Peatlands, nearly half show initiation before 8000 calendar years (cal years) B.P. Peat-core data from sites spanning Peatland T-P space show large variations in apparent C accumulation rates during the Holocene, ranging from 8.4 in the Arctic to 38.0 g C m -2 a -1 in west Siberia, with an overall time-weighted average rate of 18.6 g C m -2 a -1 . Sites with multiple age determinations show millennial-scale variations, with the highest C accumulation generally at 11,000-8000 cal years B.P. The early Holocene was likely a period of rapid Peatland expansion and C accumulation. For example, maximum peat expansion and accumulation in Alaska occurred at this time when climate was warmest and possibly driest, suggesting the dominant role of productivity over decomposition processes or a difference in precipitation seasonality. Northern Peatland C dynamics contributed to the peak in atmospheric CH 4 and the decrease in CO 2 concentrations in the early Holocene. This synthesis of data, processes, and ideas provides baselines for understanding the sensitivity of these C-rich ecosystems in a changing climate.
-
Carbon Cycling in Northern Peatlands - Sensitivity of Northern Peatland Carbon Dynamics to Holocene Climate Change
Geophysical monograph, 2013Co-Authors: Zicheng Yu, David W Beilman, Miriam C JonesAbstract:In this paper, we evaluate the long-term climate sensitivity and global carbon (C) cycle implications of northern Peatland C dynamics by synthesizing available data and providing a conceptual framework for understanding the dominant controls, processes, and interactions of Peatland initiation and C accumulation. Northern Peatlands are distributed throughout the climate domain of the boreal forest/taiga biome, but important differences between Peatland regions are evident in annual temperature vs. precipitation (T-P) space, suggesting complex hydroclimatic controls through various seasonal thermal-moisture associations. Of 2380 available basal peat dates from northern Peatlands, nearly half show initiation before 8000 calendar years (cal years) B.P. Peat-core data from sites spanning Peatland T-P space show large variations in apparent C accumulation rates during the Holocene, ranging from 8.4 in the Arctic to 38.0 g C m -2 a -1 in west Siberia, with an overall time-weighted average rate of 18.6 g C m -2 a -1 . Sites with multiple age determinations show millennial-scale variations, with the highest C accumulation generally at 11,000-8000 cal years B.P. The early Holocene was likely a period of rapid Peatland expansion and C accumulation. For example, maximum peat expansion and accumulation in Alaska occurred at this time when climate was warmest and possibly driest, suggesting the dominant role of productivity over decomposition processes or a difference in precipitation seasonality. Northern Peatland C dynamics contributed to the peak in atmospheric CH 4 and the decrease in CO 2 concentrations in the early Holocene. This synthesis of data, processes, and ideas provides baselines for understanding the sensitivity of these C-rich ecosystems in a changing climate.
-
climate related changes in Peatland carbon accumulation during the last millennium
Biogeosciences, 2012Co-Authors: Dan J. Charman, David W Beilman, Robert K. Booth, Angela V Gallegosala, Maarten Blaauw, Simon Brewer, Frank M Chambers, J A Christen, Sandy P HarrisonAbstract:Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of Peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the global positive carbon cycle feedback. Here we use a new extensive database of peat profiles across northern high latitudes to examine spatial and temporal patterns of carbon accumulation over the past millennium. Opposite to expectations, our results indicate a small negative carbon cycle feedback from past changes in the long-term accumulation rates of northern Peatlands. Total carbon accumulated over the last 1000 yr is linearly related to contemporary growing season length and photosynthetically active radiation, suggesting that variability in net primary productivity is more important than decomposition in determining long-term carbon accumulation. Furthermore, northern Peatland carbon sequestration rate declined over the climate transition from the Medieval Climate Anomaly (MCA) to the Little Ice Age (LIA), probably because of lower LIA temperatures combined with increased cloudiness suppressing net primary productivity. Other factors including changing moisture status, Peatland distribution, fire, nitrogen deposition, permafrost thaw and methane emissions will also influence future Peatland carbon cycle feedbacks, but our data suggest that the carbon sequestration rate could increase over many areas of northern Peatlands in a warmer future.
-
global Peatland dynamics since the last glacial maximum
Geophysical Research Letters, 2010Co-Authors: Zicheng Yu, Julie Loisel, Daniel P Brosseau, David W Beilman, Stephanie J HuntAbstract:[1] Here we present a new data synthesis of global Peatland ages, area changes, and carbon (C) pool changes since the Last Glacial Maximum, along with a new Peatland map and total C pool estimates. The data show different controls of Peatland expansion and C accumulation in different regions. We estimate that northern Peatlands have accumulated 547 (473–621) GtC, showing maximum accumulation in the early Holocene in response to high summer insolation and strong summer – winter climate seasonality. Tropical Peatlands have accumulated 50 (44–55) GtC, with rapid rates about 8000–4000 years ago affected by a high and more stable sea level, a strong summer monsoon, and before the intensification of El Nino. Southern Peatlands, mostly in Patagonia, South America, have accumulated 15 (13–18) GtC, with rapid accumulation during the Antarctic Thermal Maximum in the late glacial, and during the mid-Holocene thermal maximum. This is the first comparison of Peatland dynamics among these global regions. Our analysis shows that a diversity of drivers at different times have significantly impacted the global C cycle, through the contribution of Peatlands to atmospheric CH4 budgets and the history of Peatland CO2 exchange with the atmosphere.
Zicheng Yu - One of the best experts on this subject based on the ideXlab platform.
-
Holocene Peatland carbon dynamics in Patagonia
Quaternary Science Reviews, 2013Co-Authors: Julie Loisel, Zicheng YuAbstract:Abstract Patagonian Peatland ecosystems have received very little attention in the scientific literature despite their widespread distribution in the regional landscape and the anthropogenic pressure they experience from the peat extraction industry. The functioning of these southern Peatlands is strikingly similar to that of northern Peatlands, but they have developed under very different climate boundary conditions. Therefore, studying these ecosystems provides a unique opportunity to test ideas and hypotheses about the sensitivity of carbon-rich peat accumulating ecosystems to climate change, in addition to filling significant data and knowledge gaps. Here we provide a synthesis of detailed peat accumulation records for southern Patagonia using a combination of new peat-core analysis (from 4 sites) and a data review from previously published studies (from 19 sites). We also present the modern climate space (temperature, precipitation, and seasonality ranges) of Patagonian Peatlands on the basis of modern Peatland distribution and gridded climate data to discuss climate controls of Patagonian Peatlands at the present and in the past by inference. Results indicated that Patagonian Peatlands occupy a distinct climatological niche that corresponds to an end-member of the northern Peatland climate domain, with a mild mean annual temperature (from 3 to 9 °C) and very weak temperature seasonality. We also found that Patagonian Peatlands have been efficient land carbon sinks since their initiation, with a mean soil carbon density of 168 kg C m−2 ± 10%. The total carbon pool for these ecosystems was estimated at 7.6 GtC. Modeled peat addition rates to the catotelm in Patagonian Peatlands were significantly higher than what has been reported for northern Peatlands, but decay coefficients were similar between these two high-latitude regions. These results support the idea that long, mild growing seasons promote peat formation in southern Patagonia. At the regional scale however, the lack of correlation between climatic parameters and peat accumulation indices suggests that autogenic controlling factors might be at play. Overall, southern Peatlands provide a unique opportunity for studying Peatland–carbon–climate linkages under a new set of climatic conditions.
-
quantifying landscape morphology influence on Peatland lateral expansion using ground penetrating radar gpr and peat core analysis
Journal of Geophysical Research, 2013Co-Authors: Julie Loisel, Zicheng Yu, Andrew D Parsekian, J T Nolan, Lee SlaterAbstract:[1] Northern Peatlands contain vast amounts of organic carbon. Large-scale datasets have documented spatial patterns of Peatland initiation as well as vertical peat accumulation rates. However, the rate, pattern, and timing of lateral expansion across the northern landscape remain largely unknown. As Peatland lateral extent is a key boundary condition constraining the dynamics of Peatland systems, understanding this process is essential. Here we use ground penetrating radar (GPR) and peat core analysis to study the effect of local slope and topography on Peatland development at a site in south-central Alaska. The study site is unique in that a thick tephra (volcanic ash) layer, visible in the GPR data, interrupted the Peatland development for about one thousand years during the mid Holocene. In our analysis, this tephra layer serves as a re-initiation point for Peatland development. By comparing the initial mineral basin vs. the post-tephra surfaces, the influence of topography and slope on Peatland expansion rate and peat-carbon sequestration was analyzed. Our results show that (1) Peatland surface slope becomes progressively shallower over the Holocene, (2) slope affects Peatland lateral expansion nonlinearly, (3) the relationship between lateral expansion rate and slope follows a power-law behavior, and (4) Peatland expansion becomes slope-limited above a threshold (0.5°). Furthermore, we propose a conceptual model linking slope to Peatland lateral expansion where slope gradient and basin topography exert deterministic controls on Peatland lateral expansion directly or through hydrology and vertical accumulation rates.
-
sensitivity of northern Peatland carbon dynamics to holocene climate change
Geophysical monograph, 2013Co-Authors: Zicheng Yu, David W Beilman, Miriam C JonesAbstract:In this paper, we evaluate the long-term climate sensitivity and global carbon (C) cycle implications of northern Peatland C dynamics by synthesizing available data and providing a conceptual framework for understanding the dominant controls, processes, and interactions of Peatland initiation and C accumulation. Northern Peatlands are distributed throughout the climate domain of the boreal forest/taiga biome, but important differences between Peatland regions are evident in annual temperature vs. precipitation (T-P) space, suggesting complex hydroclimatic controls through various seasonal thermal-moisture associations. Of 2380 available basal peat dates from northern Peatlands, nearly half show initiation before 8000 calendar years (cal years) B.P. Peat-core data from sites spanning Peatland T-P space show large variations in apparent C accumulation rates during the Holocene, ranging from 8.4 in the Arctic to 38.0 g C m -2 a -1 in west Siberia, with an overall time-weighted average rate of 18.6 g C m -2 a -1 . Sites with multiple age determinations show millennial-scale variations, with the highest C accumulation generally at 11,000-8000 cal years B.P. The early Holocene was likely a period of rapid Peatland expansion and C accumulation. For example, maximum peat expansion and accumulation in Alaska occurred at this time when climate was warmest and possibly driest, suggesting the dominant role of productivity over decomposition processes or a difference in precipitation seasonality. Northern Peatland C dynamics contributed to the peak in atmospheric CH 4 and the decrease in CO 2 concentrations in the early Holocene. This synthesis of data, processes, and ideas provides baselines for understanding the sensitivity of these C-rich ecosystems in a changing climate.
-
Carbon Cycling in Northern Peatlands - Sensitivity of Northern Peatland Carbon Dynamics to Holocene Climate Change
Geophysical monograph, 2013Co-Authors: Zicheng Yu, David W Beilman, Miriam C JonesAbstract:In this paper, we evaluate the long-term climate sensitivity and global carbon (C) cycle implications of northern Peatland C dynamics by synthesizing available data and providing a conceptual framework for understanding the dominant controls, processes, and interactions of Peatland initiation and C accumulation. Northern Peatlands are distributed throughout the climate domain of the boreal forest/taiga biome, but important differences between Peatland regions are evident in annual temperature vs. precipitation (T-P) space, suggesting complex hydroclimatic controls through various seasonal thermal-moisture associations. Of 2380 available basal peat dates from northern Peatlands, nearly half show initiation before 8000 calendar years (cal years) B.P. Peat-core data from sites spanning Peatland T-P space show large variations in apparent C accumulation rates during the Holocene, ranging from 8.4 in the Arctic to 38.0 g C m -2 a -1 in west Siberia, with an overall time-weighted average rate of 18.6 g C m -2 a -1 . Sites with multiple age determinations show millennial-scale variations, with the highest C accumulation generally at 11,000-8000 cal years B.P. The early Holocene was likely a period of rapid Peatland expansion and C accumulation. For example, maximum peat expansion and accumulation in Alaska occurred at this time when climate was warmest and possibly driest, suggesting the dominant role of productivity over decomposition processes or a difference in precipitation seasonality. Northern Peatland C dynamics contributed to the peak in atmospheric CH 4 and the decrease in CO 2 concentrations in the early Holocene. This synthesis of data, processes, and ideas provides baselines for understanding the sensitivity of these C-rich ecosystems in a changing climate.
-
global Peatland dynamics since the last glacial maximum
Geophysical Research Letters, 2010Co-Authors: Zicheng Yu, Julie Loisel, Daniel P Brosseau, David W Beilman, Stephanie J HuntAbstract:[1] Here we present a new data synthesis of global Peatland ages, area changes, and carbon (C) pool changes since the Last Glacial Maximum, along with a new Peatland map and total C pool estimates. The data show different controls of Peatland expansion and C accumulation in different regions. We estimate that northern Peatlands have accumulated 547 (473–621) GtC, showing maximum accumulation in the early Holocene in response to high summer insolation and strong summer – winter climate seasonality. Tropical Peatlands have accumulated 50 (44–55) GtC, with rapid rates about 8000–4000 years ago affected by a high and more stable sea level, a strong summer monsoon, and before the intensification of El Nino. Southern Peatlands, mostly in Patagonia, South America, have accumulated 15 (13–18) GtC, with rapid accumulation during the Antarctic Thermal Maximum in the late glacial, and during the mid-Holocene thermal maximum. This is the first comparison of Peatland dynamics among these global regions. Our analysis shows that a diversity of drivers at different times have significantly impacted the global C cycle, through the contribution of Peatlands to atmospheric CH4 budgets and the history of Peatland CO2 exchange with the atmosphere.
Konstantin Gavazov - One of the best experts on this subject based on the ideXlab platform.
-
vascular plant mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change
Global Change Biology, 2018Co-Authors: Alexandre Buttler, Remy Albrecht, Konstantin Gavazov, Ellen Dorrepaal, Mark H GarnettAbstract:Climate change can alter Peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects Peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular‐plant removal experiment in two Sphagnum‐dominated Peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO2 radiocarbon (bomb‐14C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in Peatlands, especially when assessing the future carbon sink function of Peatlands undergoing a shift in vegetation community composition in association with climate change.
