Modeling the Environmental and Anthropogenic Factors Influencing the Spatial Distribution of Acacia Mearnsii in a Protected Mountainous Grassland Ecosystem Using Landsat and Sentinel Il Images

Abstract

Listen

Translate article

With A. mearnsii being one of the most successful invaders globally, its management has become a large part of invasive alien species management programs, especially in South Africa, where a significant investment of about 561.9 million rands has been made to eliminate it. Despite this huge investment, there is still no sign that the spread of this species has diminished. To ensure that the damage caused by A. mearnsii is halted, professionals must understand how it spreads and persists. Accurate data on the spatial distribution of A. mearnsii might help to develop useful and successful management techniques for savannah environments, particularly in protected mountainous grasslands. This study, therefore, developed a GIS model for predicting the potential spatial spread of A. mearnsii in a protected mountainous grassland ecosystem using spatiotemporal data derived from Landsat and Sentinel-2 imageries. The study used environmental factors like slope aspect, elevation, distance from streams, and soil type and rainfall. Other climatic variables like land surface temperature derived from the thermal band of Landsat images were included in the environmental factors. The influence of species interactions with fire severity and animal populations was also included as indicator variables. The species' AUC of 0.83 is estimated, and the model fit is a sign of a successful model. The study showed that the spread of A. mearnsii was influenced primarily by the following factors: The average Land surface temperature, aspect, changes in land surface temperature, and rain from 2000 to the present, and distance to the river. The species increased in areas where there was a reduction in both land surface temperature and rainfall. The predicted circumstances of decreasing temperature and rainfall events may lead to widespread invasion by A. mearnsii while nevertheless changing community structure, composition, hydrological properties, and other essential ecosystem services in the examined region.