Ecological Networks for Biodiversity Conservation Mitigating the impact of changing ecosystems to stem biodiversity loss Overview Globally, natural ecosystems are being rapidly transformed and fragmented. Commercial and subsistence agriculture, commercial forestry and other extensive forms of human development now dominate many landscapes. Even the best network of protected areas cannot ensure the survival of all species and their associated ecosystem services. This means that mitigation measures in production landscapes, especially those containing extensive agriculture and forestry plantations, are required. Ecological networks (ENs) are one mitigation solution, and are proving highly effective. ENs are composed of quality set-aside land, mostly in the form of corridors within production landscapes and are aimed at: 1) extending the size of protected areas, 2) maximizing on biodiversity conservation, and 3) maintenance of ecosystem processes – in short, to stem biodiversity loss. Mondi is working with Professor Michael Samways and his research team at Stellenbosch University in South Africa to identify and manage ENs in their plantation forests. ENs maintain as much high quality habitat heterogeneity as possible. Implementation Putting ENs into practice involves understanding the natural biodiversity and ecosystem processes in an area, and then designing and managing the ENs to optimise wood production as well as biodiversity conservation (components of biodiversity and their interactive whole). This has involved an intensive research programme over the last eight years, with an iterative process between research and implementation leading to more effective implementation. This iterative process rests on a theoretical synthetic approach based on sound conservation principles. There are seven elements to this synthetic approach: 1. Maintain protected areas or reserve areas, preferably adjacent to ENs or as nodes within them 2. Maintain as much undisturbed land outside of reserves as possible, such as ENs or conservancies 3. Maintain as much high quality habitat heterogeneity as possible 4. Implement high quality, wide corridors 5. Simulate natural disturbance, such as fire and grazing 6. Reduce contrast between patches i.e. soften edges 7. Maintain the ‘metapopulation trio’ of large patch size, good patch quality and reduced patch isolation The seven key elements of biodiversity conservation integrated into Ecological Networks: Recent research has highlighted three operational scales in this process: 1. The landscape (tens to hundreds of metres), its quality, its topography and its connectedness. 2. The mesofilter or features of the landscape e.g. rocky patches, rotting logs, ponds, waterfalls and seeps. 3. Species conservation. When the landscape has been taken into account, and that of the natural range of ecosystems (often manifested as a variety of mesofilters), it may then be important to focus on the specific needs of certain species, ranging from rare D = Design premise or element, M = Management premise or element and threatened ones through to keystone species which determine the ecological processes in an EN. Progress to date The research so far has shown categorically that wide corridors combined with nodes of grasslands, wetlands and forest in ENs are equivalent in terms of biodiversity to that in neighbouring protected areas/ reserves. This is a major and positive finding. Furthermore, good quality ENs, such as those being implemented by Mondi, are in effect extensions of protected areas and are therefore functioning as protected area extensions. This adds considerable resilience to the system in terms of maintaining biodiversity and all the processes associated with the complexity of biodiversity evident in South African systems. This also affords resilience in the face of El Niño Southern Oscillation events and global climate change. The research has also provided much insight into the importance of corridor size, especially width. Corridors greater than 60m wide begin to function like reserves, providing refuge for all the rare, specialist species typically found in a reserve. This does not mean that narrower corridors have no value. Instead they tend to act like movement corridors, allowing various organisms to disperse across the landscape. The value of ENs also means maintaining the whole range of natural heterogeneity and topography, which includes hilltops, rocky areas, forest patches, clean streams, and wetlands, among others. Well managed grazing, whether by indigenous game or domestic livestock, is also important in helping create a natural mosaic of habitat types for biodiversity. In summary, the implementation of extensive ENs in South Africa continues to show good results and these ENs are playing a major role in conserving natural resources for future generations. EN maintains ecosystem (hydrological) processes. ENs simulate natural disturbance such as grazing. For further information, please contact: Professor Michael Samways Department of Conservation Ecology and Entomology, Stellenbosch University Tel: +27 21 808 3728 // Email: [email protected] // Website: http://www.cons-ent.com/