Drivers of contemporary and future changes in Arctic seasonal transition dates for a tundra site in coastal Greenland

作者：Yijing Liu, Peiyan Wang, Bo Elberling, Andreas Westergaard‐Nielsen · 发表于：Global Change Biology · 年份：2023 · DOI：10.1111/gcb.17118 · 被引用次数：10 · 研究领域：Climate change and permafrost、Cryospheric studies and observations、Geology and Paleoclimatology Research

Abstract Climate change has had a significant impact on the seasonal transition dates of Arctic tundra ecosystems, causing diverse variations between distinct land surface classes. However, the combined effect of multiple controls as well as their individual effects on these dates remains unclear at various scales and across diverse land surface classes. Here we quantified spatiotemporal variations of three seasonal transition dates (start of spring, maximum normalized difference vegetation index (NDVI max ) day, end of fall) for five dominating land surface classes in the ice‐free Greenland. Using a distributed snow model, structural equation modeling, and a random forest model, based on ground observations and remote sensing data, we assessed the indirect and direct effects of climate, snow, and terrain on seasonal transition dates. We then presented new projections of likely changes in seasonal transition dates under six future climate scenarios. The coupled climate, snow cover, and terrain conditions explained up to 61% of seasonal transition dates across different land surface classes. Snow ending day played a crucial role in the start of spring and timing of NDVI max . A warmer June and a decline in wind could advance the NDVI max day. Increased precipitation and temperature during July–August are the most important for delaying the end of fall. We projected that a 1–4.5°C increase in temperature and a 5%–20% increase in precipitation would lengthen the spring‐to‐fall p...