文章基本信息

标题：Satellite-observed decrease in the sensitivity of spring phenology to climate change under high nitrogen deposition
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作者：Xiaoyue Wang ; Chaoyang Wu ; Xiaoyang Zhang 等
期刊名称：Environmental Research Letters
印刷版ISSN：1748-9326
电子版ISSN：1748-9326
出版年度：2020
卷号：15
期号：9
页码：94055
DOI：10.1088/1748-9326/aba57f
出版社：IOP Publishing Ltd
摘要：Spring phenology is a sensitive indicator of climate change and has substantial impacts on the carbon cycle. The global N cycle has been greatly disturbed by anthropogenic activities resulting in altered atmospheric N deposition worldwide. Research has been focused on the changes in the spring phenology and its covariations with climatic factors. However, the influences of N deposition on spring phenology have not been well documented to date. Herein, we investigated the effects of N deposition on the start of growing season (SOS) in continental United States (CONUS) during the years 1986-2015 using the normalized difference vegetation index (NDVI) datasets derived from both the third generation NDVI dataset and the Moderate Resolution Imaging Spectroradiometer (MODIS). We observed that N deposition could only explain approximately 5% of temporal variation in SOS in CONUS. However, the sensitivities of SOS in response to unit change in both temperature (ST) and precipitation (SP) showed clear decreasing spatial patterns with increasing N deposition. The ST generally decreased from-6 d/°C in low N deposition regions (4 kg ha-1. Furthermore, the positive SP also showed a continuously decreasing pattern with the increase in N deposition, but the negative SP was gradually weakened when N deposition was >1.0 kg ha-1. The results have important implications as it reveals the role of N deposition on spring plant phenology, and strongly suggest the consideration of N deposition effects when analyzing or predicting spring phenology in response to future climate change.
关键词：continental United States; nitrogen deposition; precipitation sensitivity; start of growing season; temperature sensitivity