Understory vegetation mediates permafrost active layer dynamics and carbon dioxide fluxes in open-canopy larch forests of northeastern Siberia
| Autor: | Logan T. Berner, Eric D. Taber, Nikita Zimov, Heather D. Alexander, Michael M. Loranty, Susan M. Natali, S. P. Davydov, Heather Kropp |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences Permafrost lcsh:Medicine Plant Science Forests Atmospheric sciences 01 natural sciences Soil Surface Energy Nonvascular Plants lcsh:Science Autotrophic Processes Multidisciplinary biology Ecology Arctic Regions Physics Eukaryota 04 agricultural and veterinary sciences Vegetation Understory Plants Condensed Matter Physics Terrestrial Environments Chemistry Lichenology Physical Sciences Ecosystem respiration Research Article Forest Ecology Ecosystems Carbon cycle Carbon Cycle Greenhouse Gases Forest ecology Mosses Environmental Chemistry Ecosystem 0105 earth and related environmental sciences Ecology and Environmental Sciences lcsh:R Organisms Chemical Compounds Biology and Life Sciences 15. Life on land Carbon Dioxide biology.organism_classification Carbon Siberia 13. Climate action Atmospheric Chemistry 040103 agronomy & agriculture Earth Sciences 0401 agriculture forestry and fisheries Environmental science lcsh:Q Shrubs Larch |
| Zdroj: | PLoS ONE, Vol 13, Iss 3, p e0194014 (2018) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | Arctic ecosystems are characterized by a broad range of plant functional types that are highly heterogeneous at small (~1–2 m) spatial scales. Climatic changes can impact vegetation distribution directly, and also indirectly via impacts on disturbance regimes. Consequent changes in vegetation structure and function have implications for surface energy dynamics that may alter permafrost thermal dynamics, and are therefore of interest in the context of permafrost related climate feedbacks. In this study we examine small-scale heterogeneity in soil thermal properties and ecosystem carbon and water fluxes associated with varying understory vegetation in open-canopy larch forests in northeastern Siberia. We found that lichen mats comprise 16% of understory vegetation cover on average in open canopy larch forests, and lichen abundance was inversely related to canopy cover. Relative to adjacent areas dominated by shrubs and moss, lichen mats had 2–3 times deeper permafrost thaw depths and surface soils warmer by 1–2°C in summer and less than 1°C in autumn. Despite deeper thaw depths, ecosystem respiration did not differ across vegetation types, indicating that autotrophic respiration likely dominates areas with shrubs and moss. Summertime net ecosystem exchange of CO2 was negative (i.e. net uptake) in areas with high shrub cover, while positive (i.e. net loss) in lichen mats and areas with less shrub cover. Our results highlight relationships between vegetation and soil thermal dynamics in permafrost ecosystems, and underscore the necessity of considering both vegetation and permafrost dynamics in shaping carbon cycling in permafrost ecosystems. |
| Databáze: | OpenAIRE |
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