# Study on the Extraction Method for Ecological Corridors under the Cumulative Effect of Road Traffic
## 1 Introduction  
\"Ecological corridor\" is a term in landscape ecology that refers to a type of ecosystem that is laid out in a linear or ribbon-like fashion in an ecological setting, capable of connecting spatially isolated and dispersed ecological units [1]. Ecological corridors can prevent soil erosion, increase carbon storage, and promote biodiversity conservation and ecosystem stability [2]. Within a certain period of time, humans have carried out a series of development activities on the earth to create a better life, which have disturbed the regional ecological environment to different degrees, directly leading to the fragmentation of ecological sources and the fracture of ecological corridors. Urbanized areas, agricultural lands, and roads are the three most common anthropogenic features that influence the intensity of human footprints in ecological regions [3]. Anthropogenic disturbances have been pointed out as among the main causes of the world biodiversity crisis [4]. In terms of future world population trends, urbanization is irreversible. Urban expansion and road construction directly lead to fragmentation of many wildlife habitats, scattered in different locations in cities (e.g., new roads into forested landscapes often lead to economic development, as well as deforestation and habitat fragmentation). There are indications that some species are less active during the day and avoid more developed areas [5]. On the one hand, these disturbances directly alter the ground cover; e.g., the construction of roads inevitably alters the original land cover, produces edge effects, and exacerbates landscape fragmentation [6]. On the other hand, they indirectlyaffect biological habitats in the form of noise, artificial light, and dust, and they ultimately have far-reaching effects on the whole ecosystem. For example, in general, some species seem to abandon the area when noise occurs and return once the noise dissipates. Of all these disturbances, urbanization and road construction cause the fastest and most radical changes to regional ecosystems, with extremely high costs of recovery at a later stage. In particular, the presence of a large number of hardened surfaces has, to a certain extent, hindered the exchange of plants and animals across the hardened surfaces and isolated the material and energy exchange between the surface and the subsurface. Based on the data on land cover, land use, and topography, a series of methods of ecological corridor extraction have been studied, with relatively good results. For example, many scholars in landscape ecology have tried to construct ecological networks at different spatial scales. The minimum cumulative resistance (MCR) model is a practical method for identifying the most efficient movement paths in landscape ecology [7; 8]. The study [9] combined MCR with DO indices (Duranton and Overman indices) to construct an ecological safety network for the urban cluster around Poyang Lake in China. Different from the MCR model, which represents ecological corridors by finding the path of least cumulative resistance, the study [10] proposed the circuit theory, which considers that species have multiple alternative paths in the migration process and do not necessarily choose the optimal path. It considers the landscape surface as a conducting surface and uses the random movement of electrons in a circuit to simulate the migration process of species while considering all possible paths in the landscape [11]. It distinguishes ecological sources and ecological corridors according to their importance to the ecological network. As a key aspect of ecological corridor construction, ecological source identification has often been performed by subjective methods in previous studies, and new methods are needed to objectively identify ecological sources.