The term “problem tree” refers to a conceptual model used as a diagnostic tool to analyse a sequence of events that leads to a problem (such as bush encroachment in rangelands). A problem tree is useful because the consequences of different interventions can be visualised and understood more easily in diagrammatic form, thereby guiding management decisions regarding the problem. A problem tree ...

Bush encroachment is an increase in woody plant density typically resulting in impenetrable thickets, suppressing palatable grasses and herbs. Moreover, bush encroachment is a globally observed phenomenon. Besides, increasing the density of unpalatable shrubs and trees has reduced the carrying capacity and threatens the sustainability of grazing animal production, especially in arid and semi-ar...

It is widely accepted that land degradation and desertification (LDD) are serious global threats to humans and the environment. Around a third of savannahs in Africa are affected by LDD processes that may lead to substantial declines in ecosystem functioning and services. Indirectly, LDD can be monitored using relevant indicators. The encroachment of woody plants into grasslands, and the subseq...

Woody plant encroachment in savannas may alter carbon (C) and nitrogen (N) pools over the longterm, which could have regional or global biogeochemical implications given the widespread encroachment observed in the vast savanna biome. Soil and litter %C and %N were surveyed across four soil types in two encroached, semiarid savanna landscapes in northern South Africa. Litter at sampling points w...

Various factors lead to increased woody species density, biomass and cover (so-called ‘bush encroachment’) that influence ecosystem functioning services in semi-arid rangelands. Ultimately, bush encroachment has adverse effects on human livelihoods. An understanding of bush-encroached rangelands could contribute improved management, conservation restoration. This study, therefore, aimed determi...

We study the role of bush encroachment control for a farmer's income and income risk in a stochastic ecological-economic model of grazing management in semi-arid rangelands. In particular, we study debushing as an instrument of risk management that complements the choice of an adaptive grazing management strategy for that sake. We show that debushing, while being a good practice for increasing ...

Background: Much of the Grassland Biome in South Africa is prone to shrub encroachment, leading loss ecosystem services, habitat heterogeneity and species diversity. Burrowing mammals are an important component grasslands as these animals create microhabitats for other taxa, including smaller mammal species, birds, reptiles invertebrates. However, our understanding how encroachment affects burr...