Phenological control on the high Arctic ecosystem CO2 exchange
Abstract
The growing season of the high Arctic ecosystem has been profoundly lengthened by warming temperatures over the last four decades, resulting in extensive greening over most of the region. Yet, there are an increasing number of recent studies showing that this warming-driven phenological change may be limited by other conditions, such as daylength. In this study, we examined the significance of the phenological control on the carbon exchange of the high Arctic ecosystem over the last four decades using an individual-based process model, the Ecosystem Demography model (ED2). We modified the phenology module to use three meteorological variables (temperature, photoperiod, and vapor pressure deficit) and a snow-fraction variable, so that ED2 can now simulate the seasonally-varying climate-driven phenological timing of leaf area index. We initialized vegetation composition and density (of each plant function type) using the Ent Global Vegetation Structure Dataset v1.0 (Ent-GVSD) , and then optimized key parameters using in-situ CO2 exchange measurements at 6 sites over Alaska (5 Ameriflux towers and 1 Korea Polar Research Institute site). We separated the vegetation phenological control from the meteorological control on carbon exchange by simulating different phenological timings of LAI with the same meteorological drivers. The phenology scenarios differ in thresholds of the longest and shortest growing season length. We found that the phenological control may be as important as the meteorological control on the high Arctic ecosystem. This study highlights the importance of improving our understanding of the mechanism of the phenological change in the high Arctic vegetation as it responds to climate change. This study was supported by Korea Environment Industry & Technology Institute(KEITI) through Climate Change program funded by Korea Ministry of Environment(MOE)(2018001310001), National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2018R1A1A3A04079419), and National Research Foundation of Korea Grant from the Korean Government (MSIT ; the Ministry of Science and ICT) (NRF-2016M1A5A1901769) (KOPRI-PN19081) (Title: Circum. Arctic Permafrost Environment Change Monitoring, Future Prediction and development Techniques of useful biomaterials (CAPEC Project)).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B14D..06K
- Keywords:
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- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCES