Abstract:

Background & Aim: The SLOSS debate in the field of biodiversity conservation outlines whether single large protected area (SL) or several small protected areas (SS) are preferred for the conservation of species diversity, given equal total area or limited resources. This issue has been of great interest to ecologists and conservation biologists and has important implications for the design of protected areas and biodiversity conservation. As a result of the development of research methods and the rise of interdisciplinarity, the SLOSS debate has made important multi-stage advances in both analytical methods and theoretical mechanisms. The main objective of this paper is to review the rapidly research progress of the SLOSS debate and provide some targeted suggestions for future directions. 

Review results: We begin by describing the origins of the SLOSS debate and then analyzed the SLOSS literature from different aspects, including comparisons of publications between study regions and study times. Secondly, we described the analysis methods of the SLOSS debate and the strengths and limitations of each method. In addition, we reviewed the improved saturation indices proposed by previous researchers as well as the optimized indices developed by us. Thirdly, we explored several theoretical mechanisms that influence the SLOSS pattern, e.g, the theory of extinction-colonization dynamics dominated by extinction, the theory of extinction-colonization dynamics dominated by colonization, and the role of risk resistance. We then described how SLOSS debate can be applied to guide conservation management and protected area design. Lastly, we put forward some targeted suggestions for the future direction of SLOSS debate, including the importance of using flexible analytical methods, interdisciplinary collaborations to test theoretical mechanisms, more functional SLOSS and phylogenetic SLOSS research, and integrating the SLOSS debate with other fields such as restoration ecology.

Conclusions: Our review will be helpful to gain a deeper understanding of the progress of SLOSS debate, which is of great significance for promoting the development of this research field.

Key words: Protected area, Species diversity, SLOSS indices, SLOSS analysis, Species accumulation curve, Ecological models, Theoretical mechanisms