• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Antarctic Peninsula; Anvers; Anvers Island; Arctic; Biscoe; Biscoe Point; Palmer Station; Palmer-Station; The Antarctic; Antarc*; Antarctica; Climate change; Tundra
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.459.3690; http://knuforest.net/data/pdf/Paper9.pdf

Abstract There is limited information regarding bio-geochemical pools and fluxes in maritime tundra eco-systems along the Antarctic Peninsula. To collect baseline information on biogeochemical processes in a tundra ecosystem dominated by two vascular plant species (Colobanthus quitensis and Deschampsia ant-arctica) at Biscoe Point off the coast of Anvers Island, we measured pools and fluxes of C and N in trans-planted tundra microcosm cores, complemented with sampling of precipitation and surface runoff. Snow and snowmelt from the tundra collection site and soil leachates from the cores were enriched with N and dissolved organic carbon compared to precipitation and snowmelt samples collected at Palmer Station, indicating high loading of N and organic matter from the penguin colonies adjacent to the tundra site. Rel-atively high values of d15N in the live and dead biomass of D. antarctica and C. quitensis (5.6–25.1&) indicated an enrichment of N in this tundra ecosystem, possibly through N inputs from adjacent penguin colonies. Stepwise multiple linear regressions found that eco-system respiration and gross primary production were best predicted by live biomass of D. antarctica, sug-gesting a disproportionately high contribution of D. antarctica to CO2 fluxes. The cores with higher d 15N and lower d13C in the soil organic horizon exhibited higher CO2 fluxes. The results suggest that abundant N inputs from penguin colonies and the competitive balance between plant species might play a critical role in the response of tundra ecosystems along the Ant-arctic Peninsula to projected climate change.