Accurate scale-related vegetation assessment is the first step necessary to return abused, overgrazed veld to healthy life-sustaining natural bush
As published in: Peleanuus/News, Official Publication of the East Cape Game Management Association – December 2006
Large numbers of commercial farms, particularly marginal operations and farms bordering on national parks, are being transformed from uneconomical “traditional” farms into game farms aimed at gaining revenue from tourism or lucrative hunting dollars.
However, due to a dynamic and competitive relationship between grasses and trees, over-grazed commercial farmland does not spring back to pristine, diverse life-supporting bush by simply removing livestock and introducing game species, according to Zingela Consulting’s Mike Zingel.
It’s a common assumption that by converting former stock and crop farms to game alone the veld will revert to its former glory all by itself.
The dynamic relationship between grasses, shrubs and trees in diverse environments leads to the establishment of plant communities. The plants within these communities are in constant competition with each other. Grazing and browsing herbivores influence the balance. Africa’s large herbivores assist in keeping the bush in a natural balance – and grass species effectively competing with shrub and tree species. Large commercial farms often have too much grazing stock and as a result place extraordinary pressure on the grass component of plant communities.
The result is that, in most cases, if a former commercial farm is left to its own devices it does not return to a healthy competitive environment. Invariably shrubs and then trees tend to dominate because the grass community has been severely abused – first by stock and then often by erosion. To make matters worse, the lack of large browsing herbivores further tilts competition in favour of tree species which quickly take advantage of these factors and block out valuable sunlight on the ground removing any chance of a fair fight between grasses and trees.
“One would think that there are simple answers to this problem – like introducing browsers and mega-herbivores such as giraffe, rhino or elephant,” he says. “However, nature neither intended, nor designed large African herbivores to be confined to small areas. They want, and need to roam over large areas or they destroy the tree component – especially ‘good’ trees or a whole tree species in an area which specifically support other animal and invertebrate species,” Zingel continues.
Clearly man does need to intervene, but this time in an effort to return bush to its natural state. What is critically important is the accurate assessment of plant species diversity, degree of cover and growth form in order to supply correct information on which a foundation for wildlife management can be laid.
“The trouble is that up until now, most assessments have been little more than educated best guesses,” says Zingel. “Lacking the ability to clearly identify different plant communities has resulted in numerous incorrect assessments and wildlife management plans which are quite simply inaccurate,” says Zingel.
Zingela Consluting uses the latest technology including satellite imagery to produce accurate results in order to determine carrying capacity and sustainable consumptive management of wildlife. The technology facilitates monitoring of the same plant communities year by year, which is essential for adaptive resource management.
“Being able to accurately measure and plot different plant communities with the assistance of satellite imagery essentially revolutionises wildlife management,” says Zingel. “For the first time ecologists who have taken the time and made sufficient effort to learn and understand the process can accurately determine the carrying capacity of a particular area such as a farm or a large game reserve,” he says.
Satellite images produced to reveal different plant communities are far more accurate than previous methods which relied heavily on generalisations.
More importantly, by being able to realistically identify different plant communities we are now able to determine the ideal number of different herbivore species for an area and what actions need to be taken in order to re-establish the natural ideal for a healthy plant and animal community,” he continues.
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Scientific accuracy is needed in order to establish the ideal mix of sustainable plant and animal species regardless of the size of the property. Scale-related vegetation assessment utilises satellite images which have been filtered to reveal plant communities. Knowledgeable ecologists who have been trained to work with these satellite images and relate them to actual sample site data are able to accurately determine the composition and size of plant communities.
“In the past, vegetation assessment has been much more of a haphazard science as it relied heavily on generalisations,” says Zingel. “For the first time we are now able to accurately determine the state of competition between plant species, what human action should be taken and indicate the options for game to stock,” says Zingel. The technology facilitates monitoring of the same plant communities year by year which is essential for adaptive resource management.
“For example, a former cattle ranch which has been converted to a game farm can be assessed to determine precisely how many, of which species of game are sustainable for a healthy balance,” he continues. “Should the grass species be struggling against tree and shrub species then it is likely that human intervention by brush packing to protect grass areas and in the process removal of certain tree species from areas is advisable. Now that the area’s stocking rate has been determined, with the assistance of monitoring one may find in this kind of situation, the area is only able to support a small herd of buffalo but many more giraffe and kudu, and stocking changed accordingly,” says Zingel.
An area’s ecological progress can be analysed and stocking rates scientifically re-calculated on an annual basis in order to maintain an ideal and sustainable balance. With active human intervention it is possible for the veld to return to it’s natural state within a few years – providing a healthier, richer environment for plant and animal species.