Small Habitat Patches and Conservation Value in Fragmented Protected Areas

Abstract

Habitat fragmentation is a critical issue for biodiversity, especially in conservation areas, where conservation initiatives are usually directed at large, continuous habitats. Nonetheless, small patches of habitat can be seen to be very important in terms of sustaining species diversity, ecological connectivity, and general conservation value in fragmented landscapes. This paper compares the conservation value of small habitat patches, using three metrics, which are species richness, abundance, and habitat quality, in three fragmented protected areas. The field surveys were also performed on 45 patches, and the presence of plant and animal species, habitat structure and level of anthropogenic disturbance were recorded. Data were statistically analyzed using generalized linear models and species accumulation curves to demonstrate that small patches were disproportionately important to the total biodiversity, and that 35-50% of the species in large patches were supported on small patches. Patch size, isolation, and habitat quality interactively had great effect on species richness (p < 0.01), and well-connected patches revealed a richer and more functional habitat. Additionally, there are indicator species that were only present in the small and high-quality patches, therefore emphasizing the special conservation interest. Network analyses revealed these patches to increase the landscape connectivity, in the form of stepping-stones that promote species dispersal and genetic exchange. Based on the findings, it is noted that managing small patches out of management plans may jeopardise the long-term conservation objectives especially to species that are vulnerable to fragmentation. The work comes to a conclusion that the conservation planning and protected area management using small habitat patches can help to maximize the persistence of biodiversity. The future studies are advised to consider time dynamics, species specific reaction and the contribution of small patches in reducing the impacts of climate changes. In general, in this study, the ecological and strategic importance of small pieces of habitat as a means of supporting biodiversity in fragmented areas of protection is highlighted.