Global gross primary productivity and water use efficiency changes under drought stress

Thumbnail Image
Date
2017-01-17
Authors
Yu, Zhen
Wang, Jingxin
Liu, Shirong
Rentch, James
Sun, Pengsen
Lu, Chaoqun
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Research Projects
Organizational Units
Journal Issue
Is Version Of
Versions
Series
Department
Ecology, Evolution and Organismal Biology
Abstract

Drought can affect the structure, composition and function of terrestrial ecosystems, yet drought impacts and post-drought recovery potentials of different land cover types have not been extensively studied at a global scale. We evaluated drought impacts on gross primary productivity (GPP), evapotranspiration (ET), and water use efficiency (WUE) of different global terrestrial ecosystems, as well as the drought-resilience of each ecosystem type during the period of 2000 to 2011. Using GPP as biome vitality indicator against drought stress, we developed a model to examine ecosystem resilience represented by the length of recovery days (LRD). LRD presented an evident gradient of high (>60 days) in mid-latitude region and low (<60 days) in low (tropical area) and high (boreal area) latitude regions. As average GPP increased, the LRD showed a significantly decreasing trend, indicating readiness to recover after drought, across various land cover types (R 2 = 0.68, p < 0.0001). Moreover, zonal analysis revealed that the most dramatic reduction of the drought-induced GPP was found in the mid-latitude region of the Northern Hemisphere (48% reduction), followed by the low-latitude region of the Southern Hemisphere (13% reduction). In contrast, a slightly enhanced GPP (10%) was evident in the tropical region under drought impact. Additionally, the highest drought-induced reduction of ET was found in the Mediterranean area, followed by Africa. Water use efficiency, however, showed a pattern of decreasing in the Northern Hemisphere and increasing in the Southern Hemisphere. Drought induced reductions of WUE ranged from 0.96% to 27.67% in most of the land cover types, while the increases of WUE found in Evergreen Broadleaf Forest and savanna were about 7.09% and 9.88%, respectively. These increases of GPP and WUE detected during drought periods could either be due to water-stress induced responses or data uncertainties, which require further investigation.

Comments

This article is published as Yu, Z.*, J. Wang, S. Liu, J.S. Rentch, P. Sun, and C. Lu. 2017. Global gross primary productivity and water use efficiency changes under drought stress. Environmental Research Letters, 12(1), p.014016. Doi: 10.1088/1748-9326/aa5258.

Description
Keywords
Citation
DOI
Copyright
Sun Jan 01 00:00:00 UTC 2017
Collections