Spatiotemporal Changes in Vegetation Cover and Its Influencing Factors in the Loess Plateau of China Based on the Geographically Weighted Regression Model

Chen Yang,Yiyu Sun,Meichen Fu,Guohui Zhai,Dingrao Feng

doi:10.3390/f12060673

Abstract

Vegetation plays a key role in ecosystem regulation and influences our capacity for sustainable development. Global vegetation cover has changed dramatically over the past decades in response to both natural and anthropogenic factors; therefore, it is necessary to analyze the spatiotemporal changes in vegetation cover and its influencing factors. Moreover, ecological engineering projects, such as the “Grain for Green” project implemented in 1999, have been introduced to improve the ecological environment by enhancing forest coverage. In our study, we analyzed the changes in vegetation cover across the Loess Plateau of China and the impacts of influencing factors. First, we analyzed the latitudinal and longitudinal changes in vegetation coverage. Second, we displayed the spatiotemporal changes in vegetation cover based on Theil-Sen slope analysis and the Mann-Kendall test. Third, the Hurst exponent was used to predict future changes in vegetation coverage. Fourth, we assessed the relationship between vegetation cover and the influence of individual factors. Finally, ordinary least squares regression and the geographically weighted regression model were used to investigate the influence of various factors on vegetation cover. We found that the Loess Plateau showed large-scale greening from 2000 to 2015, though some regions showed decreasing vegetation cover. Latitudinal and longitudinal changes in vegetation coverage presented a net increase. Moreover, some areas of the Loess Plateau are at risk of degradation in the future, but most areas showed a sustainable increase in vegetation cover. Temperature, precipitation, gross domestic product (GDP), slope, cropland percentage, forest percentage, and built-up land percentage displayed different relationships with vegetation cover. Geographically weighted regression model revealed that GDP, temperature, precipitation, forest percentage, cropland percentage, built-up land percentage, and slope significantly influenced (p < 0.05) vegetation cover in 2000. In comparison, precipitation, forest percentage, cropland percentage, and built-up land percentage significantly affected (p < 0.05) vegetation cover in 2015. Our results enhance our understanding of the ecological and environmental changes in the Loess Plateau.

Highlights

Licensee MDPI, Basel, Switzerland.Over the past decades, research has increasingly focused on vegetation change, as it significantly influences the ecological environment and the capacity for sustainable development [1,2,3]
Vegetation cover changes in the latitudinal and longitudinal profiles are shown in Figures 4 and 5, respectively
All latitudes in the study area displayed a positive net change in vegetation cover, indicating that the increase in vegetation cover exceeded the decrease in vegetation cover

Summary

Introduction

Research has increasingly focused on vegetation change, as it significantly influences the ecological environment and the capacity for sustainable development [1,2,3]. Vegetation plays a key role in ecosystem regulation, surface evaporation, soil erosion, and surface temperature [4,5,6,7]. The distribution of vegetation determines ecosystem patterns that form various ecological landscapes. Vegetation change alters the original ecological regulation, creating an ecological imbalance or forming. Neo-ecosystems that may be influenced by natural or anthropogenic factors [8,9]. It is necessary for researchers to monitor vegetation change and determine the dominant vegetation patterns

Objectives

Methods

Results

Discussion

Conclusion