Table of Contents
What are the effects of bush encroachment?
Consequences for humans, animals and ecosystems In areas affected by bush encroachment, wild animal populations are declining sharply, such as certain antelope species, zebras and also the cheetahs, already threatened with extinction.
Why do you think bush encroachment can negatively affect local biodiversity?
Bush encroachment is bad for the following reasons: When good grass disappears, it negatively affects many animal grazer species as their staple food source is significantly depleted, and results in the decline in grazing carrying capacity, which means the land cannot sustain as many grazers as before.
What causes bush encroachment?
Bush encroachment occurs due to increased tree recruitment caused by reductions in grass standing crop and hence fire intensity. They predict that rainfall-driven variation in recruitment is more important in arid savannas, where fires are less intense and more infrequent.
What happens when shrubs encroach into grasslands?
Some studies have reported that shrub encroachment has increased the carbon (C) and nitrogen (N) concentrations in the soil and reduced soil pH (Knapp et al. 2008; Eldridge et al. 2011), but such changes may strongly depend on shrub traits and ecosystem features.
How does overgrazing cause bush encroachment?
Nevertheless, bush encroachment is often associated with overgrazing [20]. This is because of a positive relationship between grazing pressure and woody vegetation cover [13]. There are other reported drivers of bush encroachment such as increased rainfall [21], fire suppression [22], and soil characteristics [23].
Which part of Namibia is affected by bush encroachment?
savannas
Namibia’s bush encroached areas fall mainly within the semi-arid savannas, with rainfall varying from about 300 mm in the west to over 600 mm in the north-eastern parts. It is typically reported that “26 to 30 million hectares of Namibia are encroached”.
How is bush encroachment controlled?
The most popular methods of controlling bush encroachment mechanically, are chopping, slashing, ring barking and felling. The stumps are then treated immediately with a chemical weed killer. Herbicides can be used effectively to control a range of problem plants.
What economic benefit does clearing of thick bush have in Namibia?
Bush control could generate benefits including for livestock production, tourism, groundwater recharge, biodiversity and employment. It offers economic opportunities for the utilisation and/or local value addition of woody biomass via charcoal and firewood production, electricity generation, and other means.