The impact of roadside ditches on juvenile and sub-adult Bufo melanostictus migration

The amphibian species play an important role in much ecosystem functioning. However, it is severely impacted by civil engineering, which causes a high level of amphibian mortality. This is partly because roads isolate the amphibians’ habitats, causing the amphibians to cross them, during which time they can be killed by vehicles. However, secondly, roadside ditches can also have a fatal impact on the amphibians when they fall into them. This study focuses on this second issue and comprises two parts: field experiments and control experiments in the laboratory. In the field experiments, research into the roadside ditch impact on juvenile/sub-adult Bufo melanostictus migration was carried out by looking at different combinations of the ditch's angle, construction material and depth, and amount of plant growth. In the control experiments in the laboratory, the main focus of the study was the relationship between the body length of the juvenile/sub-adult Bufo melanostictus and its maximum jumping distance and jumping height, and the maximum gradient that Bufo melanostictus could climb.This research indicates that amphibian migration should be taken into account when roadside ditches are being planned. Civil engineering should consider the needs of the amphibians’ living space and thereby reduce its impact on the amphibians’ original habitat, so that human beings live in harmony with nature.