Development of Sustainable Protection of Biodiversity using Modeling Corridors of the Landscape Based on Circuit Theory

Modeling habitat network connections in biodiversity conservation planning is one of the global priorities of landscape ecology and ecological security. Destruction of landscape structure by creating disjointed habitats and disconnection in landscape patches leads to disturbance in ecological functions. This research aimed to model the landscape corridors of South Khorasan Province to link habitats together to increase habitat network connections. This, in spite of avoiding island management of conserved areas, causes sustainable protection of ecological security. First, the habitat quality map of the study area was modeled, and then it was converted into a habitat resistance map. Habitat hotspots were also extracted from the habitat quality map using the Getis-Ord G approach. Finally, Habitat corridors and the most significant connecting regions were modeled using the habitat quality and resistance maps in Circuitscape software based on circuit theory. The findings indicated that several regions are capable of producing flow with intensities ranging from 0 to 114.5 Ampere. These areas include about 4,944,200 ha (33%) of the entire study area, of which 900 ha are hot corridors, which can be thought of as corridors that facilitate species movement and can mitigate the negative effects of habitat fragmentation. Therefore, for efficient protection of habitat network security, it is necessary for planners to pay attention to the important corridors for connecting the habitats. The results of this study in the South Khorasan Province can pave the way for operational measures to be taken to construct and plan the protection of corridors and improve the habitat performance of the landscape.

Habitat fragmentation, interruption of the movement of organisms, and gene flow between them are considered a threat to the supply of habitat services in the landscape. It can lead species populations to extinction. Landscape connection is defined as the ability of landscape structure and composition to facilitate the movement of people and populations among habitat patches, and it is considered an important feature of the landscape. Establishing and maintaining gene flow between habitats and populations of species to prevent the fragmentation of habitats in the medium term and to prevent the extinction of species in the long term is one of the main goals of designing ecological corridors and connections. It is considered and causes preservation and supply of habitat services. Modeling habitat network connections in biodiversity conservation planning is one of the global priorities of landscape ecology and ecological security. Destruction of landscape structure by creating disjointed habitats and disconnection in landscape patches leads to disturbance in ecologic functions. This research aimed to model the landscape corridors of South Khorasan Province to link habitats together to increase habitat network connections. In spite of avoiding island management of conserved areas, this matter causes sustainable protection of ecological security.

The province of South Khorasan is a study area that has seven protected areas, three wildlife refuges, and six no-hunting areas. The province's diverse ecosystems and habitats have resulted in an abundance of species in arid land areas. In the first step, habitat quality was modeled using InVEST software. Then, based on the modeled map of the habitat obtained in the previous step, the habitat resistance map was considered as the inverse of the habitat quality. Then, a habitat resistance map and habitat hotspots were prepared as input in Circuitscape software. Also, habitat hotspots were extracted through spatial data mining using the Getis-Ord Gi method. In the third step, by implementing Circuitscape software, habitat corridors were designed in the South Khorasan province based on the circuit theory.

Modeling the status of habitat quality has a vital impact on biodiversity conservation strategies. Threats affect landscape fragmentation and functions and processes and lead the ecosystem to decrease the supply of habitat services. Therefore, building ecological networks by identifying and facilitating the connections of habitats and planning to improve their performance is considered a solution to deal with this crisis and sustainable conservation of habitats. The research method was applied according to the mentioned framework. For this purpose, the status of threat sources, their location, and distribution were determined by reviewing extensive studies. We identified ten types of threats and modeled the habitat quality. Habitat corridors and the most important communication areas were modeled based on the circuit theory using Circuitscape software. Finally, habitat corridors and the most significant connecting regions were modeled using the habitat quality and resistance maps in Circuitscape software based on circuit theory.  Results indicated that several regions are capable of producing flow with intensities ranging from 0 to 114.5. These areas include about 4,944,200 ha (33%) of the entire study area, of which 900 ha are hot corridors, which can be thought of as corridors that facilitate species movement. Another important result of this research was the identification of important connection areas called pinch points. The ease of movement along important connection areas (subject to their protection) can partially compensate for the negative effects of habitat fragmentation by connecting isolated populations and help to identify and review gaps in conservation planning.

In this research, sustainable conservation of biodiversity was done with a method based on habitat corridor modeling and circuit theory. The importance of conducting this research to identify corridors between habitat patches is because the circuit theory provides the possibility to evaluate the strength and intensity of the connection. The application of results of this research can be used to guide the conservation planning development of the province's ecological network based on the supply of habitat services to ensure the survival of wildlife and biodiversity with great benefit and the least cost. Also, as an effective conservation strategy, it causes integration and maximum supply of this service, which enables territorial managers to achieve ecological security and ultimately sustainable development. The results of this study in the South Khorasan Province can pave the way for operational measures to be taken to construct and plan the protection of corridors and improve the habitat performance of the landscape.