Rates and patterns of habitat loss across South Africa’s vegetation biomes

Andrew L Skowno,Debbie Jewitt,Jasper A Slingsby

doi:10.17159/sajs.2021/8182

Abstract

The loss of natural habitat resulting from human activities is the principal driver of biodiversity loss in terrestrial ecosystems globally. Metrics of habitat loss are monitored at national and global scales using various remote sensing based land-cover change products. The metrics go on to inform reporting processes, biodiversity assessments, land-use decision-making and strategic planning in the environmental and conservation sector. We present key metrics of habitat loss across South Africa at national and biome levels for the first time. We discuss the spatial patterns and trends, and the implications and limitations of the metrics. Approximately 22% of the natural habitat of South Africa has been lost since the arrival of European settlers. The extent and the rate of habitat loss are not uniform across South Africa. The relatively mesic Grassland, Fynbos and Indian Ocean Coastal Belt biomes have lost the most habitat, while the arid Nama-Karoo, Succulent Karoo and Desert have lost the least. Rates of loss increased across all biomes in recent years (2014–2018), indicating that the historical drivers of change (i.e. expansion of croplands, human settlements, plantation forestry and mining) are intensifying overall. We should caution that the losses we report are conservative, because the land-cover change products do not capture degradation within natural ecosystems. Preventing widespread biodiversity losses and securing the benefits we derive from biodiversity requires slowing and preventing further habitat degradation and loss by using existing land-use planning and regulatory tools to their full potential. Significance:  The loss of natural habitat resulting from human activities is the principal driver of biodiversity loss in terrestrial ecosystems in South Africa. Monitoring trends and patterns of habitat loss at a national scale provides a basis for informed environmental decision-making and planning, thus equipping civil society and government to address habitat loss and protect biodiversity while also meeting key development and socio-economic needs.  Open data set: https://doi.org/10.15493/SAEON.FYNBOS.10000011

Highlights

The loss of natural habitat caused by human activities such as crop farming and infrastructure development is the principal driver of biodiversity loss in terrestrial ecosystems, globally and in South Africa.[1,2]
The total extent of habitat loss caused by the expansion of each of the six anthropogenic land-cover classes since European settlement was evident from the 2018 data set, while recent change was calculated by cross tabulating the 1990 and 2018 data sets
The Indian Ocean Coastal Belt, a narrow biome (~20 km wide) stretching from the Eastern Cape through KwaZuluNatal into Mozambique, stands out in terms of high overall habitat loss and rate of loss. In this region in particular, it is crucial that the bioregional plans and biodiversity sector plans are fully considered in land-use and development planning.[19,20,21]

Summary

Introduction

The loss of natural habitat caused by human activities such as crop farming and infrastructure development is the principal driver of biodiversity loss in terrestrial ecosystems, globally and in South Africa.[1,2] These changes are increasingly reliably detected through the use of satellite remote sensing platforms[3], and there is a growing focus on developing tools to automatically detect change in near-real time[4,5]. The land-cover change products that result are widely used as the basis for species and ecosystem risk assessments[3,6], land-use decision-making and strategic planning in the environmental and conservation sector[7,8]. The utility of these products stretches well beyond the environmental sector and forms a key source of intelligence for planning and management across multiple sectors including infrastructure development, agricultural planning, defence, health, mining and energy.[9]. The Biodiversity Intactness Index[17] and South Africa’s national biodiversity assessments[2] used vegetation types as the unit of assessment and clearly illustrated the wide application to biodiversity conservation efforts of land-cover change analysis

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