The effects of ecological rehabilitation projects on the resilience of an extremely drought-prone desert riparian forest ecosystem in the Tarim River Basin, Xinjiang, China

Abstract

The Tarim River Basin in Xinjiang, China, has a typical desert riparian forest ecosystem. Analysis of the resilience of this type of ecosystem under extreme drought conditions and ecological rehabilitation projects could provide a theoretical basis for understanding ecosystem stability and resistance, and provide new ecological rehabilitation measures to improve ecosystem resilience. We employed a quantitative framework to assess net primary productivity (NPP) resilience, emphasizing four aspects of NPP dynamics: NPP, NPP stability, NPP resistance, and maximum NPP potential. We compared ecosystem resilience across four time periods: before the implementation of ecological rehabilitation projects (1990–2000), during construction and partial implementation of ecological rehabilitation projects (2001–2012), during the initial project stage of ecological rehabilitation (2013–2015), and during the late project stage of ecological rehabilitation (2016–2018). There are three main finding of this research. (1) Mean NPP was increased significantly from 2013 and was decreased from 2016, especially in the main stream of the Tarim River and in the basins of eight of its nine tributary rivers. (2) Ecosystem resilience in 2013–2018 was greater than in 1990–2012, with the greatest NPP stability, mean NPP and NPP resistance, especially in part one of the river basin (the Aksu River, the Weigan-Kuche River, the Dina River, the Kaidu-Konqi River, and the main stream of the Tarim River). Ecosystem resilience in 2001–2012 was lowest when compared to 1990–2000 and 2013–2018, with lowest mean NPP, NPP stability, NPP resistance and maximum NPP potential, particularly in part two of the river basin (the Kashigr River, the Yarkand River and the Hotan River basins). Therefore, part one was most affected by ecological restoration projects. When 2013–2018 was divided into two distinct stages, 2013–2015 and 2016–2018, resilience in the latter stage was the lowest, with lowest mean NPP, NPP resistance and maximum NPP potential, especially in the main stream of the Tarim River. This may be due to unreasonable water conveyance in 2014–2015. (3) Ecological resilience has increased significantly in 2013–2015 after the implementation of ecological water transfer projects, river regulation, and natural vegetation enclosure projects. Ecosystem resilience could continue to increase even more in the future with the continued implementation of reasonable ecological water transfer projects.

Decoupling Relationship between Urbanization and Carbon Sequestration in the Pearl River Delta from 2000 to 2020

“…Human activities, such as overgrazing and land reclamation, occupy ecological space [8,[16][17][18], and changes in land cover type, such as the conversion of greenbelt forest to construction land, directly lead to the deterioration of NPP [19][20][21]. However, ecological protection measures, such as carbon sequestration, afforestation, and conversion of farmland to forest, increase vegetation coverage, contribute to increasing NPP, and enhance the ability of an ecosystem to resist disturbance [22][23][24]. In the early stage of reform and opening up, China's awareness of ecological protection was low, and urban expansion depended on reduced vegetation coverage, leading to the continuous deterioration of NPP.…”

The effects of landscape change on habitat quality in arid desert areas based on future scenarios: Tarim River Basin as a case study

“…The Tarim River is the China’s largest inland river ( Wang et al., 2021 ). However, recent anthropogenic impacts and climate variability have caused some serious ecological and environmental issues, such as the drying of tributaries, dramatic declines in groundwater level, degradation of habitat and natural vegetation, desertification, and salinization of soil ( Fu et al., 2021 ; Wang et al., 2021 ). In addition, plant species are relatively poor in this region.…”

Resistance and Resilience of Desert Riparian Communities to Extreme Droughts

“…Water management has also affected vegetation growth [30]. See Fu et al [31] for additional information on the hydrology and climate of the Tarim River Basin as well as a schematic diagram of the study area.…”

“…Ecological management, including water-saving transformations, groundwater utilization, ecological water conveyance projects, ecological restoration, and ecological conservation as well as basin water resources regulation and management have changed water demand and supply in desert riparian forests ter management has also affected vegetation growth [30]. See Fu et al [31] for addi information on the hydrology and climate of the Tarim River Basin as well as a sche diagram of the study area.…”