Early Growing Season Anomalies in Vegetation Activity Determine the Large‐Scale Climate‐Vegetation Coupling in Europe. Issue 5 (7th May 2021)

• Record Type: Journal Article
• Authors: Wu, Minchao; Vico, Giulia; Manzoni, Stefano; Cai, Zhanzhang; Bassiouni, Maoya; Tian, Feng; Zhang, Jie; Ye, Kunhui; Messori, Gabriele
• Is Part Of: Journal of geophysical research. Volume 126:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-07
• Subjects: carbon cycle -- climate‐vegetation coupling -- early growing season -- Europe -- greenness anomalies -- vegetation index; Geobiology -- Periodicals; Biogeochemistry -- Periodicals; Biotic communities -- Periodicals; Geophysics -- Periodicals; 577.14
• DOI: 10.1029/2020JG006167
• Languages: English
• ISSNs: 2169-8953

Abstract

Abstract: The climate‐vegetation coupling exerts a strong control on terrestrial carbon budgets and will affect the future evolution of global climate under continued anthropogenic forcing. Nonetheless, the effects of climatic conditions on such coupling at specific times in the growing season remain poorly understood. We quantify the climate‐vegetation coupling in Europe over 1982–2014 at multiple spatial and temporal scales, by decomposing sub‐seasonal anomalies of vegetation greenness using a grid‐wise definition of the growing season. We base our analysis on long‐term vegetation indices (Normalized Difference Vegetation Index and two‐band Enhanced Vegetation Index), growing conditions (including 2m temperature, downwards surface solar radiation, and root‐zone soil moisture), and multiple teleconnection indices that reflect the large‐scale climatic conditions over Europe. We find that the large‐scale climate‐vegetation coupling during the first two months of the growing season largely determines the full‐year coupling. The North Atlantic Oscillation and Scandinavian Pattern phases one‐to‐two months before the start of the growing season are the dominant and contrasting drivers of the early growing season climate‐vegetation coupling over large parts of boreal and temperate Europe. The East Atlantic Pattern several months in advance of the growing season exerts a strong control on the temperate belt and the Mediterranean region. The strong role of early growing season anomalies in vegetative activity within the growing season emphasizes the importance of a grid‐wise definition of the growing season when studying the large‐scale climate‐vegetation coupling in Europe. Plain Language Summary: Climate and terrestrial ecosystems interact and affect the global climate. Such a climate‐vegetation relationship can be effectively quantified by using satellites to measure how leafy and active the vegetation is, and numerical indices reflecting large‐scale climate patterns over a given region. Previous studies generally focused on changes in mean vegetation indices over the full growing season, which is usually defined by a fixed range of astronomical months for large geographical regions. This overlooks the fact that growing seasons differ in space and vegetation responds differently to the climate in different growing season periods. In this study, we explore how vegetation and climate interact within a growing season, here defined specifically for the local conditions. We find that there are strong relationships between the large‐scale climate patterns and vegetation indices during the first two months of the growing season. Our findings highlight the important role of the vegetation activity during the early growing season for the year‐to‐year vegetation changes in Europe. Hence, for a better understanding of the climate‐vegetation relationships, it is necessary to consider the spatial differences in the growing season, in particular for large geographical regions. Key Points: Climate‐vegetation coupling in Europe is quantified by decomposing sub‐seasonal greenness anomalies using grid‐wise defined growing seasons Large‐scale climate‐vegetation coupling during the first two months of the growing season largely determines the full‐year coupling The North Atlantic Oscillation, Scandinavian Pattern, and East Atlantic patterns emerge as the most relevant large‐scale drivers for this coupling