Exposures to temperature beyond threshold disproportionately reduce vegetation growth in the northern hemisphere

Xiuchen Wu; Weichao Guo; Hongyan Liu; Xiaoyan Li; Changhui Peng; Craig D Allen; Cicheng Zhang; Pei Wang; Tingting Pei; Yujun Ma; Yuhong Tian; Zhaoliang Song; Wenquan Zhu; Yang Wang; Zongshan Li; Deliang Chen

doi:10.1093/nsr/nwy158

Exposures to temperature beyond threshold disproportionately reduce vegetation growth in the northern hemisphere

Natl Sci Rev. 2019 Jul;6(4):786-795. doi: 10.1093/nsr/nwy158. Epub 2018 Dec 22.

Authors

Xiuchen Wu^{1

2}, Weichao Guo³, Hongyan Liu³, Xiaoyan Li^{1

2}, Changhui Peng⁴, Craig D Allen⁵, Cicheng Zhang², Pei Wang^{1

2}, Tingting Pei², Yujun Ma^{1

2}, Yuhong Tian², Zhaoliang Song⁶, Wenquan Zhu², Yang Wang², Zongshan Li⁷, Deliang Chen⁸

Affiliations

¹ State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875.
² Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
³ College of Urban and Environmental Science, Peking University, Beijing 100871, China.
⁴ Institute of Environment Sciences, University of Quebec at Montreal, Quebec G1K 9H7, Canada.
⁵ US Geological Survey, Fort Collins Science Center, Jemez Mountains Field Station, Los Alamos, NM, 87544, USA.
⁶ Institute of the Surface-Earth System Science Research, Tianjin University, Tianjin 300072, China.
⁷ State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
⁸ Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg 460, Sweden.

Abstract

In recent decades, terrestrial vegetation in the northern hemisphere (NH) has been exposed to warming and more extremely high temperatures. However, the consequences of these changes for terrestrial vegetation growth remain poorly quantified and understood. By examining a satellite-based vegetation index, tree-ring measurements and land-surface model simulations, we discovered a consistent convex pattern in the responses of vegetation growth to temperature exposure (TE) for forest, shrub and grass in both the temperate (30°-50° N) and boreal (50°-70° N) NH during the period of 1982-2012. The response of vegetation growth to TE for the three vegetation types in both the temperate and boreal NH increased convergently with increasing temperature, until vegetation type-dependent temperature thresholds were reached. A TE beyond these temperature thresholds resulted in disproportionately weak positive or even strong negative responses. Vegetation growth in the boreal NH was more vulnerable to extremely high-temperature events than vegetation growth in the temporal NH. The non-linear responses discovered here provide new insights into the dynamics of northern terrestrial ecosystems in a warmer world.

Keywords: extremely high temperature; non-linear response; temperate and boreal northern hemisphere; temperature exposure; vegetation growth.