Assessing the responses of ecosystem patterns, structures and functions to drought under climate change in the Yellow River Basin, China

Li Zhang; Caiyun Deng; Ran Kang; Huiying Yin; Tianhe Xu; Hermann Josef Kaufmann

doi:10.1016/j.scitotenv.2024.172603

Assessing the responses of ecosystem patterns, structures and functions to drought under climate change in the Yellow River Basin, China

Sci Total Environ. 2024 Jun 15:929:172603. doi: 10.1016/j.scitotenv.2024.172603. Epub 2024 Apr 21.

Authors

Li Zhang¹, Caiyun Deng², Ran Kang³, Huiying Yin⁴, Tianhe Xu⁵, Hermann Josef Kaufmann⁶

Affiliations

¹ School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China; Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China. Electronic address: zhangli_2000@mail.sdu.edu.cn.
² School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China; Institute of Space Sciences, Shandong University, Shandong 264209, China; Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China. Electronic address: Dengcaiyun@sdu.edu.cn.
³ School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China; Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China. Electronic address: ran_kang@sdu.edu.cn.
⁴ School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China; Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China. Electronic address: yhyingbsd@163.com.
⁵ School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China; Institute of Space Sciences, Shandong University, Shandong 264209, China; Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China. Electronic address: thxu@sdu.edu.cn.
⁶ Institute of Space Sciences, Shandong University, Shandong 264209, China. Electronic address: kofmich@t-online.de.

PMID: 38653405
DOI: 10.1016/j.scitotenv.2024.172603

Abstract

Understanding how ecosystems respond and adapt to drought has become an urgent issue as drought stress intensifies under climate change, yet this topic is not fully understood. Currently, conclusions on the response of ecosystems in different regions to drought disturbance are inconsistent. Based on long MODIS data and observed data, this study systematically explored the relationships between ecosystem patterns, structures and functions and drought, taking a typical climate change-sensitive area and an ecologically fragile area-the Yellow River Basin-as a case study. Drought assessment results revealed that the Yellow River Basin has experienced meteorological and hydrological drought during most of the last two decades, predominantly characterized by medium and slight droughts. The ecosystem patterns and structures changed dramatically as the grassland decreased and the landscape fragmentation index (F) increased with increasing wetness. The annual gross primary productivity (GPP) increased, the water use efficiency (WUE) declined and ecosystem service value (ESV) exhibited a W-shaped increase at the watershed scale, but there were significant regional differences. There were positive correlations between F, GPP, ESV and drought indices, while there was a negative correlation between WUE and drought indices at the watershed scale. Under drought stress, the ecosystem structure in the basin was disrupted, the GPP and ESV decreased, but the WUE increased. Notably, approximately 106 %, 20 %, and 1 % of the maximum reductions in F, GPP, and ESV, respectively, were caused by drought, while the maximum 4 % of WUE increased. Responses of some functions in the wetland and grassland to drought vary from those in other ecosystems. The mechanisms underlying ecosystem responses to drought were further investigated. This study enhances the understanding of these responses and will help stakeholders formulate drought mitigation policies and protect ecosystem health.

Keywords: Drought; Ecosystem pattern-structure-function; Response; Yellow River Basin.