CLAM age model and biomes of sediment core Mfabeni_Peatland
Marı́a Fernanda Sánchez GoñiStéphanie DespratAnne‐Laure DaniauJudy R M AllenRobert S. AndersonHermann BehlingRaymonde BonnefilleRachid CheddadiNathalie Combourieu‐NeboutLydie M DupontWilliam J. FletcherCatalina GonzálezLaurie D. GriggEric C. GrimmRyoma HayashiKarin F. HelmensInes HeßlerLinda E. HeusserH. HooghiemstraBrian HuntleyYaeko IgarashiTomohisa IrinoBonnie F. JacobsGonzalo Jiménez‐MorenoSayuri KawaiFujio KumonIan T. LawsonJudicaël LebambaMarie‐Pierre LedruAnne‐Marie LézinePing-Mei LiewLaurent LondeixCarlos López-MartínezDonatella MagriJean MaleyVasiliki MargariFabienne MarretUlrich MüllerFilipa NaughtonЕлена НовенкоTadamichi ObaKatherine H. RoucouxHikaru TakaharaPolychronis C. TzedakisAnnie VincensCathy L WhitlockDebra A. WillardMasanobu Yamamoto
0
Citation
0
Reference
20
Related Paper
Keywords:
Biome
Sediment core
This chapter contains section titled: Introduction The Effect of Peatland Dynamics on Long-Term Sediment Budgets Re-Vegetation of Eroding Peatlands Controls and Mechanisms of Natural Re-Vegetation Stratigraphic Evidence of Erosion and Re-Vegetation The Future of Blanket Peat Sediment Systems Changes in Pollution Climate Change Impacts Relative Importance of Peat Erosion in Wider Upland Sediment Budgets Conclusions
Cite
Citations (0)
Cite
Citations (25)
Peatlands, wetlands with > 30 cm of organic sediment, cover more than 3 x 106 km2 of the earth surface and have been accumulating carbon and sediments throughout the Holocene. The location of peatland formation and accumulation has been dynamic over time, as peat formation in areas like Alaska and the West Siberian Lowlands preceded peat formation in Fennoscandia and Eastern North America due to more favorable climate for peat formation. Using the geographic distribution of peatlands in the past can indicate general climatic conditions, including hydroclimate, given that the underlying geology is well understood. Peatlands form under a variety of climatic conditions and landscape positions but do not persist under arid conditions, instead requiring either humid conditions or cold temperatures. However, peatlands may have existed in the past in areas not currently suitable for peatland formation and persistence, but where peats can be found at depth within the sediment column. Here we map the locations of histic paleosols, relict peat, and buried peats since the Last Glacial Maximum using a compilation of sites from previous studies. We compare these records of past peatland distribution to present-day peatland distribution. We evaluate regional differences in timing of peatland development in these buried peatlands to the development of extant peatlands. Finally, we compare the timing of past peatland extent to the to modeled paleoclimate during the Quaternary. In addition to implications for paleoclimate, these past peatlands are not well accounted for in present-day soil carbon stocks but could be an important component of deep soil carbon pools.
Paleoclimatology
Cite
Citations (0)
Sphagnum
Mire
Cite
Citations (23)
Model validation experiments are fundamental to ensure that the peat growth models correspond with the diversity in nature. We evaluated the Holocene Peatland Model (HPM) simulation against the field observations from a chronosequence of peatlands and peat core data. The ongoing primary peatland formation on the isostatically rising coast of Finland offered us an exceptional opportunity to study the peatland succession along a spatial continuum and to compare it with the past succession revealed by vertical peat sequences. The current vegetation assemblages, from the seashore to a 3000 year old bog, formed a continuum from minerotrophic to ombrotrophic plant communities. A similar sequence of plant communities was found in the palaeovegetation. The distribution of plant functional types was related to peat thickness and water-table depth (WTD) supporting the assumptions in HPM, though there were some differences between the field data and HPM. Palaeobotanical evidence from the oldest site showed a rapid fen–bog transition, indicated by a coincidental decrease in minerotrophic plant functional types and an increase in ombrotrophic plant functional types. The long-term mean rate of carbon (C) accumulation varied from 2 to 34 g C/m 2 per yr, being highest in the intermediate age cohorts. Mean nitrogen (N) accumulation varied from 0.1 to 3.9 g N/m 2 per yr being highest in the youngest sites. WTD was the deepest in the oldest sites and its variation there was temporally the least but spatially the highest. Evaluation of the HPM simulations against the field observations indicated that HPM reasonably well simulates peatland development, except for very young peatlands.
Ombrotrophic
Chronosequence
Cite
Citations (75)
Peatlands in northern Ontario, Canada, archive multiple biological indicators, including macrofossils, algae, testate amoebae, and pollen. These proxies can provide insights concerning the timing and nature of long-term climatic and environmental changes. The Hudson Bay Lowlands (HBL) of central Canada contain one of Earth’s largest continuous peatland complexes, and thus comprehensive spatial and temporal studies are needed to understand the implications of climate change on carbon cycling. Diatom assemblages were examined in three cores retrieved from ombrotrophic bogs across two Canadian terrestrial ecozones. Comparisons were made with testate amoebae and macrofossil data previously analyzed from these cores, as well as with regional pollen records from surrounding peatlands. From ~2000 to ~600 cal. BP, changes in diatom composition likely reflect hydrosere succession within the peatland, including fluctuations in connectivity to the water table and pH changes. From ~600 cal. BP to present, the synchronous timing of changes in diatoms and testate amoebae are tracking drying conditions and subsequent microhabitat variations that occur within bogs. It is possible that diatoms are tracking subtle changes in the stability of peat microforms including bog hollows and hummocks, highlighting their sensitivity to small chemical change, whereas testate amoebae are tracking the lowering of a peatland water table and subsequent drying of the peatland. The use of multiple proxies provides a more holistic approach to interpreting past ecological succession and responses to climate within peatlands. When present and well preserved, diatoms can be applied to track drying conditions in bogs, in terms of both hydrosere succession and present climatic change.
Testate amoebae
Macrofossil
Ombrotrophic
Sphagnum
Cite
Citations (18)
Abstract Peatland ecosystems are important carbon sinks, but also release carbon back to the atmosphere as carbon dioxide and methane. Peatlands therefore play an essential role in the global carbon cycle. However, the response of high-latitude peatlands to ongoing climate change is still not fully understood. In this study, we used plant macrofossils and peat property analyses as proxies to document changes in vegetation and peat and carbon accumulation after the Little Ice Age. Results from 12 peat monoliths collected in high-boreal and low-subarctic regions in northwestern Québec, Canada, suggest high carbon accumulation rates for the recent past (post AD 1970s). Successional changes in plant assemblages were asynchronous within the cores in the southernmost region, but more consistent in the northern region. Average apparent recent carbon accumulation rates varied between 50.7 and 149.1 g C m −2 yr −1 with the northernmost study region showing higher values. The variation in vegetation records and peat properties found within samples taken from the same sites and amongst cores taken from different regions highlights the need to investigate multiple records from each peatland, but also from different peatlands within one region.
Subarctic climate
Carbon sink
Carbon fibers
Macrofossil
Ombrotrophic
Cite
Citations (33)
Cite
Citations (51)
Sphagnum
Cite
Citations (4)
Subarctic climate
Landform
Cite
Citations (85)