Ecological connectivity and ecosystem plasticity in a transformed corridor habitat – case study of A4 motorway in Southern Poland

Corridor habitats are proven to be highly vulnerable to creation of artificial barriers, such as public transport infrastructure, which in most cases negatively affects their connectivity functions. This effect is especially high in places, where long road lines cross multiple neighboring ecological corridors, connecting important habitats of large area and great ecological value. An example of such case is the A4 motorway in Southern Poland, which interferes with both main ecological corridors and important habitats situated in its close proximity. The aim of this presentation is to report main results of a medium-scale environmental assessment and monitoring conducted since 2014, at a newly built section of the motorway, in the context of ecological corridor functions sustainability and the change of habitat use by different animal taxa. The performed monitoring includes systematic assessment of the general animal mortality at the roadway and within the area of associated infrastructure, together with the assessment of underpass utilization by animals and amphibian habitat quality in surrounding water reservoirs. Results of the monitoring show unusually low mammal mortality, which indicates the important role of using effective well designed fences and other collision preventing systems. The relatively high bird mortality, especially concerning the predatory birds, shows an important negative effect of the habitat change. Increased prey availability resulting in the accumulation of carcasses of animals killed in road collisions at the roadway, seems to induce the additional increase of raptor collision mortality risk. All of the obtained results give a valuable overview on the environmental changes which occure in a fragmented habitat influenced by an intensively used motorway and support the state of knowledge about the ecological connectivity functions of habitats transformed by  traffic infrastructure. It also allows to evaluate the effectiveness of specific  solutions used in order to prevent excessively large negative impact of motorways on wildlife, e.g.: the data obtained from different types of underpasses reveal the effectiveness of the used designs, contributing the diversity of good practices used for mitigation of environment-infrastructure conflicts.

animal mortality, passage use, habitat fragmentation, corridor barriers, mitigation measures