Veld management in the semi‐arid bush‐grass communities of the eastern cape

Abstract

Ecologically and economically the most acceptable way of using the vegetation in these ecosystems is to stock with grazers and browsers to utilize both the herbaceous and the woody plants. The major factor limiting primary production is a low and erratic moisture supply. Management to ensure the most efficient use of the incoming precipitation is outlined. The highly variable rainfall emphasises the need to provide a fodder reserve to combat drought and the need to stock the grazers and browsers within the grazing and browsing capacities. For the herbaceous component, resting a third of the total area is advocated to provide adequate rest and the drought fodder reserve. The resting requirements of the woody component are given. The calculation of the grazing capacity and the browsing capacity is outlined. They are computed according to the botanical composition of the herbaceous component and the botanical composition and availability of the woody component. Optimum periods of stay and absence are given for both rotational grazing and browsing. It is important that cattle be the predominant grazer and that a ratio of 1 beast to 3 sheep not be exceeded. Multi-camp systems are advised. However, the layout must ensure that the minimum adverse effect on the environment due to animal concentration occurs and that fence lines must be aligned along vegetation boundaries to minimise area selective grazing and browsing. UITTREKSELDie mees ekologiese en ekonomiese wyse waarop die plantegroei binne hierdie ekosisteem benut kan word is deur grasbenutters en struikvreters aan beide die gras en struik komponent te benut. Die lae en wissel-vallige reënval is die hooffaktor wat primêre produksie beperk. Bestuurmaatreêls om die beste gebruik van die beskikbare vog te maak word bespreek. Die groot variasie in reenval beklemtoon die feit dat voerreserwes opgebou moet word ten einde droogteperiodes te oorbring, asook om die getalle van struikvreters en grasvreters aan te pas by die hoeveelheid beskikbare gras en struik-weiding. Dit is belangrik dat 'n derde van die totale oppervlakte 'n groeiseisoen moet rus om die graskomponent in die geleentheid te stel om reserwes op te bou vir gebruik gedurende 'n droogte. Die reisvereistes vir die struik-komponent word ook bespreek. Die berekening van weikapasiteit en struikkapasiteit word ook bespreek. Dit word bereken volgens die botanese samestelling van beide die gras-en struikkomponent. Optimale periodes van besetting en periodes van afwesigheid vir beide die gras-en struikkomponent word weergegee. Dit is belangrik dat beeste die primêre benutter van die graskomponent moet wees en dat 'n verhanding van een bees tot drie shape nie oorskry moet word nie. Meer-kamp-stelsels word aanbeveel. Die uitleg moet egter sodanig wees dat topografie en plantegroeitipes geskei moet wees.

Seasonal changes in pasture biomass, production and offtake under the transhumance system in northern Pakistan

“…Thus, the findings of this study indicate that better use could be made of some of the dry temperate pastures in spring before moving to the alpine pastures, allowing greater spring growth in the alpine areas before the animals are moved up to graze them. Bearing in mind that spring 2000 and 2001 were slightly drier and warmer than the 10-year mean, we would expect dry temperate pasture growth on average to be similar to or greater than that recorded in the years of our study, so we are confident that this proposal for greater spring use of these pastures should be robust as a general rule across years (acknowledging that, in this highly variable rainfall area, decisions on stocking have to be fine-tuned year-by-year, as is normally the case in systems like this (Teague et al, 1981;Tainton et al, 1999)). The success of such a change would also depend on wild herbivore densities-if densities are high in an alpine area then later movement of livestock up to the alpine pastures could simply result in greater offtake by wild herbivores in early spring (Albon and Langvatn, 1992).…”

Long-term impacts of goat browsing on bush-clump dynamics in a semi-arid subtropical savanna

“…Individual bush-clumps varied greatly in size, structure and species composition, both within and between plots, and there were clear differences between unbrowsed and browsed plots in many variables measured (Table 1). Examination of frequency distributions (Figure 1a) revealed larger numbers of bush-clumps below 50 cm height in browsed plots (both seedlings and heavily browsed saplings) as compared to unbrowsed (normally distributed), with a greatly reduced frequency of clumps between 50 and 150 cm, which is the normal browse range of goats (Teague et al 1981;Gothesen 1997). As well as mean bush-clump height, mean canopy diameter (and area) and ground diameter (and area) were also significantly smaller for browsed clumps than unbrowsed (p<0.001, p<0.001, p<0.01 respectively; F 1,12 =60.6, 29.0 and 17.1).…”

The effects of exclosures in restoring degraded semi-arid vegetation in communal grazing lands in northern Ethiopia

“…These data were used to compute browsing unit (BU), browsing capacity (BC), and tree equivalent (TE). One BU is a tree or shrub that is consumed by goats and is either 1.5 m tall or has browse within 1.5 m of ground level (Teague et al, 1981). BC refers to the productivity of a homogenous vegetation unit that is grazed or browsed and it is expressed as the area of land required to maintain a single animal unit over time without causing deterioration to the vegetation and soils (Booysen, 1967).…”

“…BC refers to the productivity of a homogenous vegetation unit that is grazed or browsed and it is expressed as the area of land required to maintain a single animal unit over time without causing deterioration to the vegetation and soils (Booysen, 1967). TE is a term used in relation to a tree or shrub that is 1.5 m tall (Teague et al, 1981). BU, BC, and TE were computed according to Beckerling et al (1995).…”