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Visar resultat 1 - 5 av 142 avhandlingar som matchar ovanstående sökkriterier.
1. Drivers of carbon sink function in tropical seagrass beds : influence of carbon import, plant composition, seascape configuration and human activities
Sammanfattning : Seagrass meadows are effective carbon sinks, sequestering atmospheric CO2 and capturing allochthonous organic material, storing organic carbon (Corg) in their sediments, so called Blue Carbon. In tropical areas, seagrass meadows have a high number of calcareous organisms, which can offset carbon sequestration by releasing CO2 through their calcification. LÄS MER
2. Temporal and spatial dynamics in subarctic peat plateaus and thermokarst lakes
Sammanfattning : Permafrost peatlands are widespread at high northern latitudes and are important soil organic carbon reservoirs. A future warming in these areas, as suggested by global climate models, can cause thawing and increased ground subsidence (thermokarst), resulting in changes in surface hydrology and ecosystem functioning. LÄS MER
3. Holocene dynamics in subarctic peat plateaus of west-central Canada : Vegetation succession, peat accumulation and permafrost history
Sammanfattning : Dynamics in vegetation, permafrost and peat and net carbon accumulation rates throughout the Holocene have been studied in two subarctic peat plateaus of west-central Canada through plant macrofossil analysis, geochemical analyses and AMS radiocarbon dating. Peatland formation at the studied sites began around 6600-5900 cal yr BP as a result of paludification of upland forests. LÄS MER
4. Northern peatland carbon biogeochemistry : the influence of vascular plants and edaphic factors on carbon dioxide and methane exchange
Sammanfattning : The interest in carbon dynamics and the interactions between ecosystems and the atmosphere has increased during the last decade due to the postulated threat of anthropgenically induced global and climate change. Northern peatlands, with their large stores of organic carbon and long-term net accumulation of atmospheric carbon dioxide are key ecosystems in these interactions. LÄS MER
5. Remobilization of terrestrial carbon across temporal and spatial scales deduced from the Arctic Ocean sediment record
Sammanfattning : Arctic warming is expected to trigger large-scale environmental change including remobilization of terrestrial organic carbon (terrOC). Permafrost and peatland systems contain more than twice as much carbon as the atmosphere, and may upon destabilization expose large amounts of their carbon to microbial decomposition and release climate-forcing greenhouse gases (GHG). LÄS MER