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Assessing the response of vegetation photosynthesis to meteorological drought across northern China
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  • Hao-jie Xu,
  • Xin-Ping Wang,
  • C. Y. Zhao,
  • Xue-mei Yang
Hao-jie Xu
Lanzhou University

Corresponding Author:[email protected]

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Xin-Ping Wang
Chinese Academy of Sciences
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C. Y. Zhao
Lanzhou University
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Xue-mei Yang
Gansu Desert Control Research Institute
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Abstract

Satellite-based solar-induced chlorophyll fluorescence (SIF) has the potential for an early detection and accurate impact assessment of meteorological drought on vegetation photosynthesis. However, how the response of satellite SIF to meteorological drought varies under different climatic conditions and biome types remains poorly understood. In this study, we determined the drought time-scale at which the vegetation photosynthesis response was highest based on the standardized precipitation evapotranspiration index (SPEI) and satellite SIF, and examined how the sensitivity of SIF signals from different ecosystems to drought varied along an aridity gradient in northern China. The results showed that spatial variability of the annual maximum SIF was constrained by wetness conditions and biome types. Annual maximum SIF was positively correlated with SPEI in 57.9% of vegetated lands (P < 0.05). 34.8% of humid ecosystems were characterized by a significant SIF-SPEI correlation (P < 0.05). This percentage reached 44%, 71.4% and 86.2% for arid, sub-humid and semi-arid ecosystems, respectively. The variation of SIF-SPEI correlations was a Gaussian function of the aridity index (AI), with the highest SIF-SPEI correlation appearing in the AI bin of 0.4 (0.37-0.46). The drivers for this pattern were vegetation composition and water availability. The variation of SIF time-scales in response to SPEI was a linear function of the AI, but the slope varied among biomes. To summarize with increasing aridity drought-induced declines in vegetation photosynthesis will be quicker and more significant.
05 Mar 2020Submitted to Land Degradation & Development
06 Mar 2020Submission Checks Completed
06 Mar 2020Assigned to Editor
13 Mar 2020Reviewer(s) Assigned
21 May 2020Review(s) Completed, Editorial Evaluation Pending
23 May 2020Editorial Decision: Revise Minor
02 Jun 20201st Revision Received
02 Jun 2020Assigned to Editor
02 Jun 2020Submission Checks Completed
05 Jun 2020Review(s) Completed, Editorial Evaluation Pending
06 Jun 2020Editorial Decision: Revise Minor
08 Jun 20202nd Revision Received
08 Jun 2020Submission Checks Completed
08 Jun 2020Assigned to Editor
09 Jun 2020Review(s) Completed, Editorial Evaluation Pending
13 Jun 2020Editorial Decision: Revise Minor
14 Jun 20203rd Revision Received
15 Jun 2020Submission Checks Completed
15 Jun 2020Assigned to Editor
17 Jun 2020Review(s) Completed, Editorial Evaluation Pending
20 Jun 2020Editorial Decision: Accept