The state of biodiversity

Many years of hard work and collaborative effort culminated in a State of Biodiversity report for the Western Cape being made available from Cape Nature Conservation (CNC) at the end of November. The report will serve as a benchmark for subsequent five-yearly updates, and can be obtained on CD, at no charge.

The study of the condition of our province’s natural heritage was given impetus by the introduction of information age tools that helped to collate and capture data on the conservation status and vulnerability of vertebrate animals. Databases linked to Geographical Information Systems (GIS) have enabled CNC to generate valuable spatial information on the distribution of biodiversity in the Western Cape.

The biodiversity review has gathered much of the existing distributional and status data accumulated by museums and universities, collated this, and made it available electronically at one location. The gathering of this data has been characterised by excellent cooperation by all the organisations and institutions involved. So far the assessment of the animal life has been completed – with the exception of invertebrates – and the assessment of the plant biodiversity is underway. ”It is far from complete but we’ve made substantial progress. The spirit of collaboration that has emerged is very heartening” says Guy Palmer, of CNC’s Scientific Services.

The data, housed in CNC’s Conservation Planning Unit (CPU), allows CNC to make informed management and planning decisions such as the configuration of its reserves. It can therefore be guided by the distribution and location of species, home in on species that need special attention, and identify gaps in knowledge about any particular species.

The CPU was established thanks to the funding support of WWF-SA’s Table Mountain Fund and WWF-USA. The unit forms part of the broader conservation strategy of C.A.P.E. (Cape Action for People and the Environment) and will guide regional planning.

An additional R2 million was recently received from the international funding group, Critical Ecosystems Partnership Fund (CEPF) to further expand the service to provide updated maps and information about sensitive nature areas – in and outside official reserves – to the public, urban and regional planners, and other decision makers. The maps and information can be downloaded from http://cpu.uwc.ac.za, or may be requested on CD, or as printouts at a charge. The CPU will also handle enquiries and provide training on using the maps for planning and land use.

Of course, stresses Palmer ”sensitive information about the precise location of threatened species is not made generally known, as this would increase the risk of environmental crime and smuggling.”

The degree to which the Western Cape is able to maintain optimal levels of biodiversity is proportional to the region’s ability to support life. Biodiversity represents the cornerstones of natural productivity, and sustains life by providing most of the key elements in the ecological processes in soils, forests, wetlands and oceans. The greatest part of the Cape Floral Kingdom (CFK) and the Succulent Karoo biome falls within the Western Province’s borders. The CFK is unrivalled for its diversity of plant life and is ranked as one of world’s six floristic kingdoms. It is the only plant kingdom found entirely within one country, and half of the 9 000 plant species that occur in the CFK, occur nowhere else on earth. The Succulent Karoo is the only global biodiversity hotspot that falls entirely within an arid region and its unique flora attracts a specialised and highly adapted animal life. Almost 40% of the 6300 plant species that occur here are endemic to his region.

Such statistics place an enormous responsibility on CNC as the custodian of a significant portion of the country’s biodiversity. Palmer is confident that South Africa ranks amongst the world’s best in its record of species preservation and conservation of its natural heritage. This success won’t make Western Cape conservationists rest on their laurels though. The imperatives for increasing conservation efforts are just too stark as many species are rare, endangered, or close to extinction. The fate of the highly endangered Twee River redfin (see below) or the Riverine Rabbit – one of the world’s rarest mammals – depends on sustained and focussed management of their environments.

Many of these environments are highly sensitive to change and human impact. For example, natural freshwater ecosystems in the Western Cape have special characteristics. Inhabitants of these systems have adapted over millions of years resulting in a suite of highly endemic forms, some of which are confined to a single tributary, river or wetland and each of these unique systems deserves protection.

The establishment of an effective reserve network and the enhancement of off-reserve conservation can contribute significantly to the conservation of the biodiversity of the Western Cape. Co-operative management models and incentive mechanisms will promote community involvement and increase the land under conservation management.

Over the years farmers and landowners have become increasingly cooperative as their knowledge about the need for biodiversity conservation increased. Wicus Leeuwner, who farms near Caledon, is passionate about the blue crane, and the thousands of slides he’s taken of them attests to this. Along with other farmers in the area, he unfailingly assists during the annual blue crane count, as these birds occur mostly on agricultural land.

The general public too has shown its willingness to become involved in conservation, as in the case of the Brenton blue butterfly. Once the alert was raised that development would harm the only known breeding place of this endangered butterfly, it was the outcry from the local community that stopped the housing project. The larvae of the Brenton blue only eat the leaves of the Indigofera erecta, on which the adult butterfly also lays its eggs, and so protecting this plant is crucial to the butterfly’s continued survival. It is delicate arrangements like this between plant and animal, that makes knowledge about their habitats so important, as impacts on the one directly affect the other.

Enhanced biodiversity is, of course, also a source of revenue. Eco-tourism brings much needed money into our country and province, and maintaining the diversity of our heritage will make it an attractive option for eco- tourists. Flyfishing is becoming an increasingly popular sport. Local farmers need to be encouraged to stock indigenous fish species since they offer a superior experience to flyfishermen. Indigenous fish are more challenging to catch as their fighting abilities are superior to the alien trout and bass. If flyfishermen are made aware of this and seek out these species, local farmers will put more effort into preserving indigenous fish and so tourism and conservation can work hand in glove to ensure that the Western Cape remains the prime conservation and tourism destination it is.

The State of Biodiversity Programme’s assessment of faunal vertebrate biodiversity found the following:

Status of Mammals 2002

The Western Cape supports 57% of South Africa’s mammal species. Of the 160 species that occur here, six are endemic. Fifty species are regarded as threatened according to the World Conservation Union (IUCN).

An estimated eleven species have become extinct in the Western Cape. Six species have yet to be re-established in formal conservation areas – the lion, spotted hyena, African wild dog, black rhinoceros, hippopotamus and African buffalo.

Status of Birds 2002

The Western Cape supports 50% of South Africa’s bird life. The South African Bird Atlas Project has listed 344 of the country’s total 686 species in the Western Cape. The majority were recorded in protected areas. Of these, 53 species are listed in the Red Data Book for Birds. Eight species, including the wattled crane, lappetfaced vulture and Cape parrot, are already extinct in the region.

Status of Amphibians and Reptiles 2002

Two out of every five species of amphibians known to occur in southern Africa are found in the province. At least 22 species (50%) are endemic to the region, occurring in habitats that are highly susceptible to change. Six species are listed as threatened, of which the micro frog and the Table Mountain ghost frog are regarded as critically endangered.

South Africa hosts 350 reptile species, more than 5% of the world total. The Western Cape contains 41% of this total, and boasts the highest diversity of terrestrial tortoises in the world. Not only can one find here one of the world’s largest tortoises – the mountain tortoise – but also the smallest – the southern speckled padloper – and one of the rarest – the geometric tortoise. Of the 92 lizard species, seven are threatened and 17 endemic, while of the 41 snake species, three are threatened and two species are endemic.

Status of Fish 2002

Of the 18 species of freshwater fish found in the Western Cape, an alarming 15 are listed as threatened. Of these, 50% are endemic and thus reliant on effective conservation of river systems and aquatic habitats. Unfortunately the Western Cape has many alien invasive fish species, posing a major threat to indigenous fish and other aquatic life. A genetic variety of the Berg River redfin was exterminated from the Eerste River in the 1940s due to the introduction of rainbow trout. If the situation is allowed to deteriorate even further, species such as the highly threatened Twee River redfin may become extinct within the next 20 years.