Historic and Simulated Desert-Oasis Ecotone Changes in the Arid Tarim River Basin, China

Fan Sun,Patient Mindje Kayumba,Jingxiu Qin,Qifei Zhang,Yupeng Li,Yi Wang,Yaning Chen

doi:10.3390/rs13040647

Abstract

The desert-oasis ecotone, as a crucial natural barrier, maintains the stability of oasis agricultural production and protects oasis habitat security. This paper investigates the dynamic evolution of the desert-oasis ecotone in the Tarim River Basin and predicts the near-future land-use change in the desert-oasis ecotone using the cellular automata–Markov (CA-Markov) model. Results indicate that the overall area of the desert-oasis ecotone shows a shrinking trend (from 67,642 km2 in 1990 to 46,613 km2 in 2015) and the land-use change within the desert-oasis ecotone is mainly manifested by the conversion of a large amount of forest and grass area into arable land. The increasing demand for arable land for groundwater has led to a decline in the groundwater level, which is an important reason for the habitat deterioration in the desert-oasis ecotone. The rising temperature and drought have further exacerbated this trend. Assuming the current trend in development without intervention, the CA-Markov model predicts that by 2030, there will be an additional 1566 km2 of arable land and a reduction of 1151 km2 in forested area and grassland within the desert-oasis ecotone, which will inevitably further weaken the ecological barrier role of the desert-oasis ecotone and trigger a growing ecological crisis.

Highlights

Published: 11 February 2021The spatial interface between two or more ecological regions and their material, energy, and structural and functional systems is called an ecotone or an ecological ecotone [1]
The desert-oasis ecotone of the Tarim River Basin declined during this period, decreasing from 67,642 km2 in 1990 to
This paper investigated the dynamic evolution of the desert-oasis ecotone in the Tarim

Summary

Introduction

Published: 11 February 2021The spatial interface between two or more ecological regions and their material, energy, and structural and functional systems is called an ecotone or an ecological ecotone [1]. The desert-oasis ecotone is distributed along the periphery of an oasis and is characterized by a zone of desert vegetation that separates the extensive desert from the oasis [2]. A desert-oasis ecotone is a unique ecosystem between a desert and an oasis, usually characterized by low diversity, sparse cover, and dominance by perennial herbaceous grasses and semi-shrubs, such as Phragmites australis, Tamarix ramosissima, Karelinia caspia, and Alhagi sparsifolia. The desert-oasis ecotone is the interface between the oasis ecosystem and the desert ecosystem where energy, material, and information exchange occurs [8], which is highly sensitive to external environmental and human disturbances, affected by human activities, including the expansion of cultivated land

Methods

Results

Discussion

Conclusion