Future land cover change scenarios in South African grasslands – implications of altered biophysical drivers on land management

Lesley Gibson,Zahn Münch,Anthony Palmer,Sukhmani Mantel

doi:10.1016/j.heliyon.2018.e00693

Lesley Gibson, Zahn Münch + Show 2 more

Open Access

https://doi.org/10.1016/j.heliyon.2018.e00693

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Abstract

Future land cover changes may result in adjustments to biophysical drivers impacting on net ecosystem carbon exchange (NEE), catchment water use through evapotranspiration (ET), and the surface energy balance through a change in albedo. The Land Change Modeller (Idrisi Terrset 18.08) and land cover for 2000 and 2014 are used to create a future scenario of land cover for two catchment with different land management systems in the Eastern Cape Province for the year 2030. In the S50E catchment, a dualistic farming system, the trend shows that grasslands represented 57% of the total catchment area in 2014 decreasing to 52% by 2030 with losses likely to favour a gain in woody plants and cultivated land. In T35B, a commercial system, persistence of grasslands is modelled with approximately 80% coverage in both years, representing a more stable system. Finally, for S50E, NEE and ET will increase under this land cover change scenario leading to increased carbon sequestration but less water availability and corresponding surface temperature increases. This implies that rehabilitation and land management initiatives should be targeted in catchments under a dualistic farming system, rather than those which are predominantly commercial systems.

Highlights

Land use and land cover change (LULCC) has been suggested to be the most important anthropogenic disturbance to the environment at a local level, causing various microclimatic changes (Mishra and Rai, 2016)
Land Change Modeller (LCM) was developed by Clark Labs in conjunction with Conservation International to provide a suite of tools to address the problems of accelerated land conversion and the analytical needs required in biodiversity conservation (Eastman, 2016)
The Land Change Modeller (Idrisi Terrset 18.08) was used, together with land cover mapped for the years 2000 and 2014 (M€unch et al, 2017), to model land cover for the grassland dominated S50E and T35B catchments in the Eastern Cape Province for the year 2030

Summary

Introduction

Land use and land cover change (LULCC) has been suggested to be the most important anthropogenic disturbance to the environment at a local level, causing various microclimatic changes (Mishra and Rai, 2016). Land Change Modeller (LCM), an inductive model integrated into IDRISI Terrset 18.08, provides tools for the assessment and projection of land cover change. The approach used in LCM is to analyse changes in land cover between two past time steps (T1 and T2) and use Multi-layer Perceptron (MLP) with explanatory spatial variables to create transition potential maps. Markov Chain Analysis assigns the probability of change determined by projecting the historic change to the future, which together with transition potential maps, present a land cover scenario for some future data (T3). The individual transition potential maps are aggregated to create a map indicating the propensity of the landscape to experience change

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