Scientists monitor trends, status of biosphere

Posted in Africa | 17-Oct-08 | Source: The Namibia Economist

Colin Stanley (left), a BIOTA Africa fieldworker, demonstrates to a communal farmer the negative effects of overgrazing.

For the first time, scientists are ready to give a full account on the status and trend of the continent’s biosphere. From September 29 to October 3, 2008, more than 300 policy-makers, scientists, land users and other stakeholders from 15 African countries and Germany met to discuss solutions for the challenges to Africa’s basis for survival – biological diversity – in an international congress at Spier, Stellenbosch, South Africa.

The African-German research network, BIOTA Africa, with more than 400 scientists, is the largest, continent-wide joint initiative that investigates into the complex relationships between humans and nature in the continent.
Results from seven years of successful research in more than 75 observatories were presented to the public. Recommendations for further joint initiatives on sustainable land use and the protection of biodiversity were also discussed at the congress.
The conference was funded by the German Federal Ministry of Education and Research (BMBF) and by various African research institutions.
Scientists from Namibia presented their work at the congress:
Dave Joubert and his team presented a web-based decision support system for bush encroachment management that farmers could apply to assist them in decision-making on their farmland.
Bush encroachment – the invasion and thickening of aggressive undesired woody species on grassland – is a large economic problem in Namibia, estimated to reduce revenue from beef production by at least N$700 million per annum.
One of the main species causing the encroachment problem is Acacia mellifera (Black thorn). Results are an imbalance of the grass: bush ratio, a decrease in biodiversity, and a decrease in carrying capacity.
Researchers involved in BIOTA projects in Southern Africa are measuring the change in vegetation on Farm Narais and Farm Duruchaus in Namibia. On these two neighbouring farms, the BIOTA Southern Africa teams have observed something interesting: for more than 20 years, sheep and goats were kept at Duruchaus, while, during the same period, a comparatively small number of cattle grazed on adjacent areas at Narais.
The consequences of differing use show that fewer of the grasses and dwarf shrubs particularly nutritious for the animals grow in the soil of the sheep farm. The quality of grazing on Narais, the cattle farm, is, by contrast, considerably higher.
Long-term observation of this type is an important key to understanding the connection between biodiversity and land use, one of the central concerns of BIOTA.