Estimating Ecological Responses to Climatic Variability on Reclaimed and Unmined Lands Using Enhanced Vegetation Index

Xiang Fan,Heiko Balzter,Zhongke Bai,Yongze Song,Chuxin Zhu

doi:10.3390/rs13061100

Abstract

Climatic impact on re-established ecosystems at reclaimed mined lands may have changed. However, little knowledge is available about the difference in vegetation–climate relationships between reclaimed and unmined lands. In this study, ecological responses to climatic variability on reclaimed and neighbouring unmined lands were estimated using remote-sensing data at the Pingshuo Mega coal mine, one of the largest coal mines with long-term reclamation history in China. Time-series MODIS enhanced vegetation index (EVI) data and meteorological data from 1997 to 2017 were collected. Results show significantly different vegetation–climate relationships between reclaimed and unmined lands. First, the accumulation periods of all climatic variables were much longer on reclaimed mining lands. Second, vegetation on reclaimed lands responded to variabilities in temperature, rainfall, air humidity, and wind speed, while undisturbed vegetation only responded to variabilities of temperature and air humidity. Third, climatic variability made a much higher contribution to EVI variation on reclaimed land (20.0–46.5%) than on unmined land (0.7–1.7%). These differences were primarily caused by limited ecosystem resilience, and changed site hydrology and microclimate on reclaimed land. Thus, this study demonstrates that the legacy effects of surface mining can critically change on-site vegetation–climate relationships, which impacts the structure, functions, and stability of reclaimed ecosystems. Vegetation–climate relationships of reclaimed ecosystems deserve further research, and remote-sensing vegetation data are an effective source for relevant studies.

Highlights

This article is an open access articleSurface mining is an unstoppable anthropogenic force for global land-use change driven by modern society’s dependence on mineral resources [1]
This study presents quantitative analysis about a reclaimed ecosystem response to climatic variability compared with its adjacent remnant analogue
Reclaimed and unmined ecosystems were subject to different climatic drivers. The former responded to variability in temperature, rainfall, air humidity, and wind speed, while the latter only responded to variability in temperature and air humidity

Summary

Introduction

Surface mining is an unstoppable anthropogenic force for global land-use change driven by modern society’s dependence on mineral resources [1] It destroys or disturbs biotic communities, and soil and rock strata overlying mineral deposits, leaving profound adverse impacts on the local and surrounding ecosystems. 2021, 13, 1100 example, the cumulative area disturbed by mining activities was 3.48 × 104 km by the end of 2016, and this number grew to 3.90 × 104 km by the end of 2017 [2], which was equivalent to 69.4% of all built-up areas in China in the same year [3] To restore these destructed lands, land reclamation or rehabilitation measures are legally compulsory in many countries, and re-establishing or restoring stable and self-sustaining ecosystems on postmining lands is a common requirement [4,5,6]

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