Evergreen forests in South Africa – their composition, biogeography, ecological dynamics and sustainable use management

Abstract

South African forests are organized into eight Forest Groups and 26 National Forest Types and have a long history of biogeographical inter-relationships, that drove the ecological adaptation of their plant and animal species to survive diverse disturbance-recovery processes. Such relationships have been assessed in various studies to provide a better understanding of the ecology of their biota, within their assemblages, in widely fragmented species associations. The derived concept is that their biodiversity, productivity and value, for the benefit of current and future generations, can be maintained through active resource use practices that simulate natural, disturbance-recovery processes underlying their ecology. These forests are confined to fire-shadow areas within a larger suitable climatic-edaphic landscape; with large parts of the landscape being fire-prone. These fire-adapted vegetation systems, such as grassland, shrubland (Fynbos), bushland and woodland, with their own species assemblages, biodiversity and functionality, developed in potentially suitable evergreen forest landscapes. Economic development through agriculture, forestry, conservation, and infrastructure has changed to cooler fires or fire exclusion. This has contributed to the widespread establishment of invasive alien plant (IAP) species and the invasion of evergreen forest species (naturalizing) into the broader landscape. These evergreen forest species either expanded directly or became established via the light-demanding IAPs that nurse the more shade-tolerant, indigenous forest species. Forestry plantations in the fire-prone landscapes have also facilitated the expansion of natural forest. This better understanding of the ecology and functionality of the natural forest systems can be used in sustainable forest management practices to benefit from the products, values, and services they provide to society. Bottlenecks to the application of the knowledge gained into diverse sustainable resource use practices exist due to fortress conservation mindsets and strategies, and the national and provincial policies and regulations that are not aligned with the contemporary ecological realities. For example, (i) it is necessary to allow variable harvesting practices of timber and poles based on the ecology and regeneration strategies of targeted species and not insisting on one universal system of minimizing disturbance; (ii) a changed approach is needed towards using IAP stands strategically (selective ringbarking or thinning) to facilitate forest recovery and not simply clearing them, taking account of historic vegetation systems; (iii) participatory management in the sustainable harvesting of non-timber products (such as poles, firewood, timber for wood carving, etc.) and non-wood forest products (bark for traditional medicine and fibre, ferns for florist greenery, fruit and other foods, etc.) should become the norm rather than applying restrictive law enforcement of no use. Guidance is provided towards better resource-use practices for timber, poles, firewood, bark for traditional medicine and other non-wood forest products that could/hopefully can contribute to the development of diverse small businesses related to the interests of all levels of rural and urban societies.

HIGHLIGHTS Highlights of Geldenhuys et al. Review Paper on Evergreen forest ecologt. • The paper challenges the general perception that all natural evergreen forests in South Africa should be protected from disturbance to ensure their presence into the future, with evergreen forests in South Africa having a long history of biogeographical relationships that comprised the adaptation of their plant and animal species to diverse disturbance-recovery processes. • Evergreen forests in South Africa cover about 0.5 % of their potential area of >7 % of South Africa based on rainfall, with the major limitation of their limited presence and major fragmentation being fire flow patterns that sees landscapes potentially suitable for forests being covered by fire-adapted vegetation systems with their own species assemblages, biodiversity and functionality, such as grassland, shrubland (Fynbos), bushland and woodland. • Changing fire regimes and fire exclusion through commercial agriculture and forestry, fire controls in conservation areas, and infrastructure development, contribute to forest expansion via plantation forestry, invader plant stands, and naturalising forest species into former fire zones and fire-adapted vegetation systems. • The derived concept is that evergreen forest biodiversity, productivity and use value for the benefit of current and future generations can be maintained through active resource use practices that simulate the natural disturbance-recovery processes underlying their ecological dynamics, and so guidance is provided towards better resource use practices for timber, poles, firewood, bark for traditional medicine and other non-wood forest products that could contribute to development of diverse small businesses at all levels of rural and urban societies. • It is essential that current national and provincial policies and regulations be adjusted to be aligned with the ecological realities to remove bottlenecks constraining the application of the gained knowledge.