Optimizing conservation planning for multiple cohabiting species

Abstract

Conservation planning often involves multiple species occupying large areas including habitat sites with varying characteristics. For a given amount of financial resources, designing a spatially coherent nature reserve system that provides the best possible protection to targeted species is an important ecological and economic problem. In this paper, we address this problem using optimization methods. Incorporating spatial criteria in an optimization framework considering spatial habitat needs of multiple species poses serious challenges because of modeling and computational complexities. We present a novel linear integer programming model to address this issue considering spatial contiguity and compactness of the reserved area. The model uses the concept of path in graph theory to ensure contiguity and minimizes the sum of distances between selected sites and a central site in individual reserves to promote compactness. We test the computational efficiency of the model using randomly generated data sets. The results show that the model can be solved quite efficiently in most cases. We also present an empirical application of the model to simultaneous protection of two cohabiting species, Gopher Tortoise and Gopher Frogs, in a military installation in Georgia, USA.

Delineating Conservation Areas for Cohabiting Species: An Example of Vernal Pond Conservation From Fort Stewart in Georgia, United States

“…In our previous work where the same area and species were used in the empirical application (Dissanayake et al, 2014;Wang et al, 2020), we incorporated the dependency of the GFs on GT burrows when targeting to conserve these two species. In this paper, we emphasized the importance of considering this interspecies dependency and showed that the results could be dramatically different if this dependency was ignored (compare panel A with panels B and C in Figure 2).…”

“…We note, however, that spatial contiguity is a difficult issue to address in an optimization framework. Although a few alternative modeling approaches have been presented in the literature (see, e.g., Wang et al, 2020), those approaches suffer from computational inefficiency. In general, MIP models become difficult to solve to exact optimality as the model size becomes larger.…”

“…In those studies, species are usually considered collectively but independently, that is they are treated as a whole with the dependency between them being largely ignored. Recently Wang et al (2020) presented an optimization method to design conservation areas for these two species in Fort Stewart. In their model they required that a selected GF site must also be a selected GT site, that is, the conservation areas for the GFs must be completely located within the conservation areas for the GTs.…”

Climate warming threatens the persistence of a community of disturbance‐adapted native annual plants

“…Although many conservation and restoration plans attempt to optimize benefits for a suite of native species (Wang et al. 2020), doing so successfully requires an understanding of the extent to which demographic responses are generalizable.…”

“…It is critical to identify what factors have similar effects on co-occurring species to inform community-wide management in the face of climate change. Although many conservation and restoration plans attempt to optimize benefits for a suite of native species (Wang et al 2020), doing so successfully requires an understanding of the extent to which demographic responses are generalizable.…”