The applied issues of habitats fragmentation mitigation for the projects of infrastructure development

Abstract

A transport network is an artificial component of the human environment, which causes a range of negative impacts on other living organisms, including violation of animal habitats integrity. Ability to move in search of food, shelter or mating, is negatively limited by obstacles that isolate the habitat. The term "habitat fragmentation" includes breaking habitat into several smaller patches, reduction in the total area of the habitat, decrease of the interior/edge ratio, and isolation of one habitat fragment from others. Consequently, roads divide habitats and create barriers that impede wildlife mobility, increasing instances of wildlife-vehicle collisions, which put both people and non-human animals at risk; landscape fragmentation can also result in genetic isolation, putting some species of wildlife at long term risk of extinction. Secondary effects from infrastructure development are further emergence of human settlements or industrial development, which put people and their activity closer to wildlife. In order to reduce the negative impacts of roads, the measures that directly reduce fragmentation by providing links between habitats, namely wildlife crossing structures or fauna passages should be implemented. The pilot area at the highway M-03 from Poltava to Kharkiv between 341 and 472 km planned for reconstruction under the World Bank project was analyzed based on spatial ecosystem approach to define the points of increased concern for the protection of habitats. Mitigation measures, in particular fauna passages, are necessary as the given road bisects important elements of eco-network: Galytsko-Slobozhansky natural latitudinal corridor and Vorskla regional eco-corridor. Five sites were chosen on the territory to provide wildlife mobility improvement with the help of such crossing structures, as landscape bridge, river crossing, joint-use underpass, underpass for small- and medium-sized animals, and multi-use overpass. The selection of the most appropriate type of fauna passage was based on the analysis of landscape structure, type of habitats affected and target species (their living needs, behaviour and preferred moving media). The suggested scheme of wildlife crossings is provided with recommendations on the design of the offered structures, their dimensions, construction materials and elements, as well as details about model target species and their nature conservation status. The cost of the project is supposed to be acceptable as it basically involves transformation of the existing infrastructure elements.