Provision of ecosystem services by large scale corridors and ecological networks

Abstract

Large scale landscape transformation and contingent habitat loss are among the greatest threats to ecological integrity and ecosystem health. One of the mitigation approaches used to deal with these pressures is to leave interconnected corridors and nodes as remnant ecological networks (ENs) within the transformed landscape. The South African forestry industry has already allocated 500,000 ha, one-third of the plantation holdings, consisting predominantly of natural grassland, as ENs among and within timber plantations. These ENs are intended to maintain structural, compositional and functional biodiversity. However, little scientific research is available on the effectiveness of these huge ENs for biodiversity conservation and maintenance of natural ecosystem function, although initial findings are encouraging. While the local adverse effect of alien plantation trees on functional biodiversity is not in dispute, it is at the scale of the whole landscape where there is much interest in determining how effective these ENs are in maintaining the untransformed portion of the transformed landscape in a close-to-natural state. As these ENs are extensive, species beta diversity is a consideration in addition to alpha diversity. Initial findings reveal diminished ecological integrity in narrow corridors due in part to the adverse edge effect from the alien trees into the margin of the EN. Quality of the ENs is of great importance for maintaining functional diversity, with human disturbance reducing their effectiveness. First findings, and their application to the Framework for Ecosystem Service Provision, suggest that these ENs are significant for biodiversity conservation and for provision of ecosystem services. Nevertheless, still much more research is required on a greater range of taxa, and their interactions, to improve the design of these ENs for ecological and evolutionary processes.

Abundance signals of amphibians and reptiles indicate strong edge effects in Neotropical fragmented forest landscapes

“…This measure can also be used in ecological networks, i.e. large-scale corridors that connect habitat patches for dispersal (Samways et al, 2010): these networks create new edges and it is relevant to know the depth of edge effect on the targeted species in order to design the corridors (Pryke and Samways, 2012). For example, Dixo and Metzger (2009) showed that too narrow corridors may prevent leaf-litter lizards from recolonizing forest fragments.…”

Changing conservation strategies in Europe: a framework integrating ecosystem services and dynamics

“…A specific example of the application of the FESP approach to biodiversity conservation and Ecosystem Service provision is provided by Samways et al (2010). These authors focus on the forestry industry in large-scale ecological networks in South Africa, and provide a model that elaborates on the broad framework of Fig.…”

“…Bennet (1999) and Hannah et al (2007) have pointed out the shortcomings of biodiversity conservation systems based on reserves alone. Now, the policies of isolated site-based conservation that developed over the last century are being replaced by planning and policy with a focus on spatial networking (see Samways et al 2010). Ecological networks that link PAs via habitat corridors, green veining and greenways are together considered a more effective approach to biodiversity conservation as they should reduce species extinction risks by facilitating movement of organisms through the landscape (Jongman and Pungetti 2004).…”

Lifting the Information Barriers to Address Sustainability Challenges with Data from Physical Geography and Earth Observation

“…These changes would severely impact numerous aspects of the natural environment, such as biodiversity and ecosystems, soils, freshwater water, and marine resources as well as human activities, such as agriculture, tourism, transport, and energy production [11]. A second driver of change is land use, which changes and fragmentation are severely impacting the environment, with habitat losses from development that cannot be offset by the creation of protected areas [12], maintenance of connectivity, ecological corridors [13], or extensive agriculture. Finally, the UN's latest projections [14] suggest that the global population will reach between 9.4 and 10 billion by 2050 (key finding 2, p. 8).…”