| 1. |
- Loisel, J., et al.
(författare)
-
Expert assessment of future vulnerability of the global peatland carbon sink
- 2021
-
Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 11:1, s. 70-77
-
Tidskriftsartikel (refereegranskat)abstract
- Peatlands are impacted by climate and land-use changes, with feedback to warming by acting as either sources or sinks of carbon. Expert elicitation combined with literature review reveals key drivers of change that alter peatland carbon dynamics, with implications for improving models. The carbon balance of peatlands is predicted to shift from a sink to a source this century. However, peatland ecosystems are still omitted from the main Earth system models that are used for future climate change projections, and they are not considered in integrated assessment models that are used in impact and mitigation studies. By using evidence synthesized from the literature and an expert elicitation, we define and quantify the leading drivers of change that have impacted peatland carbon stocks during the Holocene and predict their effect during this century and in the far future. We also identify uncertainties and knowledge gaps in the scientific community and provide insight towards better integration of peatlands into modelling frameworks. Given the importance of the contribution by peatlands to the global carbon cycle, this study shows that peatland science is a critical research area and that we still have a long way to go to fully understand the peatland-carbon-climate nexus.
|
|
| 2. |
- Charman, D. J., et al.
(författare)
-
Climate-related changes in peatland carbon accumulation during the last millennium
- 2013
-
Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4189. ; 10:2, s. 929-944
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 3. |
- Obst, Matthias, 1974, et al.
(författare)
-
A Marine Biodiversity Observation Network for Genetic Monitoring of Hard-Bottom Communities (ARMS-MBON)
- 2020
-
Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Marine hard-bottom communities are undergoing severe change under the influence of multiple drivers, notably climate change, extraction of natural resources, pollution and eutrophication, habitat degradation, and invasive species. Monitoring marine biodiversity in such habitats is, however, challenging as it typically involves expensive, non-standardized, and often destructive sampling methods that limit its scalability. Differences in monitoring approaches furthermore hinders inter-comparison among monitoring programs. Here, we announce a Marine Biodiversity Observation Network (MBON) consisting of Autonomous Reef Monitoring Structures (ARMS) with the aim to assess the status and changes in benthic fauna with genomic-based methods, notably DNA metabarcoding, in combination with image-based identifications. This article presents the results of a 30-month pilot phase in which we established an operational and geographically expansive ARMS-MBON. The network currently consists of 20 observatories distributed across European coastal waters and the polar regions, in which 134 ARMS have been deployed to date. Sampling takes place annually, either as short-term deployments during the summer or as long-term deployments starting in spring. The pilot phase was used to establish a common set of standards for field sampling, genetic analysis, data management, and legal compliance, which are presented here. We also tested the potential of ARMS for combining genetic and image-based identification methods in comparative studies of benthic diversity, as well as for detecting non-indigenous species. Results show that ARMS are suitable for monitoring hard-bottom environments as they provide genetic data that can be continuously enriched, re-analyzed, and integrated with conventional data to document benthic community composition and detect non-indigenous species. Finally, we provide guidelines to expand the network and present a sustainability plan as part of the European Marine Biological Resource Centre (www.embrc.eu).
|
|
| 4. |
- Gallego-Sala, Angela V., et al.
(författare)
-
Latitudinal limits to the predicted increase of the peatland carbon sink with warming
- 2018
-
Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 8:10, s. 907-
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 5. |
- Loisel, Julie, et al.
(författare)
-
A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation
- 2014
-
Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 24:9, s. 1028-1042
-
Tidskriftsartikel (refereegranskat)abstract
- Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45 degrees N. It encompasses regions within which peat carbon data have only recently become available, such as the West Siberia Lowlands, the Hudson Bay Lowlands, Kamchatka in Far East Russia, and the Tibetan Plateau. For all northern peatlands, carbon content in organic matter was estimated at 42 +/- 3% (standard deviation) for Sphagnum peat, 51 +/- 2% for non-Sphagnum peat, and at 49 +/- 2% overall. Dry bulk density averaged 0.12 +/- 0.07 g/cm(3), organic matter bulk density averaged 0.11 +/- 0.05 g/cm(3), and total carbon content in peat averaged 47 +/- 6%. In general, large differences were found between Sphagnum and non-Sphagnum peat types in terms of peat properties. Time-weighted peat carbon accumulation rates averaged 23 +/- 2 (standard error of mean) g C/m(2)/yr during the Holocene on the basis of 151 peat cores from 127 sites, with the highest rates of carbon accumulation (25-28 g C/m(2)/yr) recorded during the early Holocene when the climate was warmer than the present. Furthermore, we estimate the northern peatland carbon and nitrogen pools at 436 and 10 gigatons, respectively. The database is publicly available at https://peatlands.lehigh.edu.
|
|
| 6. |
- Shaw, William S., et al.
(författare)
-
Early patient screening and intervention to address individual-level occupational factors ("blue flags") in back disability
- 2009
-
Ingår i: Journal of occupational rehabilitation. - Berlin : Springer. - 1053-0487 .- 1573-3688. ; 19:1, s. 64-80
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To develop a consensus plan for research and practice to encourage routine clinician screening of occupational factors associated with long-term back disability.METHODS: A 3-day conference workshop including 21 leading researchers and clinicians (the "Decade of the Flags Working Group") was held to review the scientific evidence concerning clinical, occupational, and policy factors in back disability and the development of feasible assessment and intervention strategies.RESULTS: The Working Group identified seven workplace variables to include in early screening by clinicians: physical job demands, ability to modify work, job stress, workplace social support or dysfunction, job satisfaction, expectation for resuming work, and fear of re-injury. Five evaluation criteria for screening methods were established: reliability, predictive performance, feasibility, acceptability, and congruence with plausible interventions. An optimal screening method might include a stepped combination of questionnaire, interview, and worksite visit. Future research directions include improving available assessment methods, adopting simpler and more uniform conceptual frameworks, and tying screening results to plausible interventions.DISCUSSION:There is a clear indication that occupational factors influence back disability, but to expand clinician practices in this area will require that patient screening methods show greater conceptual clarity, feasibility, and linkages to viable options for intervention.
|
|
| 7. |
- Treat, C. C., et al.
(författare)
-
Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils
- 2016
-
Ingår i: Journal of Geophysical Research - Biogeosciences. - 2169-8953 .- 2169-8961. ; 121:1, s. 78-94
-
Tidskriftsartikel (refereegranskat)abstract
- Permafrost dynamics play an important role in high-latitude peatland carbon balance and are key to understanding the future response of soil carbon stocks. Permafrost aggradation can control the magnitude of the carbon feedback in peatlands through effects on peat properties. We compiled peatland plant macrofossil records for the northern permafrost zone (515 cores from 280 sites) and classified samples by vegetation type and environmental class (fen, bog, tundra and boreal permafrost, and thawed permafrost). We examined differences in peat properties (bulk density, carbon (C), nitrogen (N) and organic matter content, and C/N ratio) and C accumulation rates among vegetation types and environmental classes. Consequences of permafrost aggradation differed between boreal and tundra biomes, including differences in vegetation composition, C/N ratios, and N content. The vegetation composition of tundra permafrost peatlands was similar to permafrost-free fens, while boreal permafrost peatlands more closely resembled permafrost-free bogs. Nitrogen content in boreal permafrost and thawed permafrost peatlands was significantly lower than in permafrost-free bogs despite similar vegetation types (0.9% versus 1.5% N). Median long-term C accumulation rates were higher in fens (23g C m(-2)yr(-1)) than in permafrost-free bogs (18g C m(-2)yr(-1)) and were lowest in boreal permafrost peatlands (14g C m(-2)yr(-1)). The plant macrofossil record demonstrated transitions from fens to bogs to permafrost peatlands, bogs to fens, permafrost aggradation within fens, and permafrost thaw and reaggradation. Using data synthesis, we have identified predominant peatland successional pathways, changes in vegetation type, peat properties, and C accumulation rates associated with permafrost aggradation.
|
|
| 8. |
- Treat, Claire C., et al.
(författare)
-
Widespread global peatland establishment and persistence over the last 130,000 y
- 2019
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:11, s. 4822-4827
-
Tidskriftsartikel (refereegranskat)abstract
- Glacial-interglacial variations in CO2 and methane in polar ice cores have been attributed, in part, to changes in global wetland extent, but the wetland distribution before the Last Glacial Maximum (LGM, 21 ka to 18 ka) remains virtually unknown. We present a study of global peatland extent and carbon (C) stocks through the last glacial cycle (130 ka to present) using a newly compiled database of 1,063 detailed stratigraphic records of peat deposits buried by mineral sediments, as well as a global peatland model. Quantitative agreement between modeling and observations shows extensive peat accumulation before the LGM in northern latitudes (> 40 degrees N), particularly during warmer periods including the last interglacial (130 ka to 116 ka, MIS 5e) and the interstadial (57 ka to 29 ka, MIS 3). During cooling periods of glacial advance and permafrost formation, the burial of northern peatlands by glaciers and mineral sediments decreased active peatland extent, thickness, and modeled C stocks by 70 to 90% from warmer times. Tropical peatland extent and C stocks show little temporal variation throughout the study period. While the increased burial of northern peats was correlated with cooling periods, the burial of tropical peat was predominately driven by changes in sea level and regional hydrology. Peat burial by mineral sediments represents a mechanism for long-term terrestrial C storage in the Earth system. These results show that northern peatlands accumulate significant C stocks during warmer times, indicating their potential for C sequestration during the warming Anthropocene.
|
|
