The Research On Herpetological Roadkill And Wildlife Undercrossing Design In Hunan Mangshan National Nature Reserve

As the development of ecotourism, both the road system of Hunan Mangshan National Nature Reserve is increasing and the tourist amount are increasing year by year. Specially, the period from March to October of each year is a touring climax. Therefore the death of herpetological species caused by traffic is very serious. Under the cooperation of the Administration Bureau of Hunan Mangshan National Nature Reserve, a field survey was carried out that how the road system of Hunan Mangshan National Nature Reserve affected on the local herpetological species, respectively from 25th of March to 1st of June in 2008, from 1st of July to 8th, from 19th of July to 2nd of August, from 3rd of September to 14th and from 10th of October to 23rd.This survey was focused mainly on the species composition, ecological habits and distribution pattern of herpetological species around road; the relationship between influencing factors such as habitat, altitute etc. and herpetological species individual's death caused by traffic; the herpetological species' distribution pattern around water culvert and also doing a simulation experiment on the parameters of undercrossing size and the size of aided fence. The results showed:379 herpetological species (including the species unidentified) were recorded in the field survey on the road in Hunan Mangshan National Nature Reserve.16 species in 265 amphibians were identified, belonging to 5 families,1 order; 22 species in 114 reptiles were identified, belonging to 5 families,2 orders. There were 212 living individuals, while dead ones were 171, which account for 45% of all the herpetological species. The number of individuals, number of species, the probability of appearing on the road, deaths and the mortality rate of herpetological species of 2nd belt transect (Xiangguhang-Pingkeng) were the highest in the eight belt transects. Both of the detection rate and death quantity of herpetological species on Mangshan road declined with the altitude increased. The infection of habitat factors counting in statistics indicates that the emergence and deaths near scrub, forest, hillside and rivulet were higher. The traffic on Mangshan road was busiest in the morning and least at night, but it was random. And the probability of appearing on the road were mainly influenced by the altitude and habitat, so the traffic was one of the determining factor which leads to herpetological species' death. There were no individuals entering in the culverts, when the author kept monitoring around three culverts in the nature reserve.After analysing, the parameters of herpetological species'undercrossing of the road system had given out in Mangshan National Nature Reserve as following:1. The site of herpetological species'undercrossing construction:With the highest detection rate and death rate of herpetological species at the altitude from 600-770m,the undercrossings should be built in this area predicted with high usage rate,and eight spots can be built as the altitude rising at each 20m.2. The inner structure and bottom material of undercrossing:Proposing that the structure should be arch and the bottom is paved by stone blocks, pebbles mixed with soil. For frogs, the undercrossing can be designed with water flowing, but for snakes and lizards, the undercrossing's structure should have two floors for animals' speeling, connecting with branches.3. The size of undercrossing:Via the selection test of amphibians and reptiles on undercrossing size, the inner diameter or height of undercrossing less than 0.4m was fine, but in some specific area where there were some lager animals, the size of undercrossing can be enlarged appropriately.4. The undercrossing's environment and aided fence:On the one hand, digging ditchs or pools near the undercrossing's entrance can attract amphibians and reptiles gathering nearby. According to the statistical analysis to amphibians and reptiles' distribution of each habitat, creating compound habitate around entrance could increase the detection rate of animals. On the other hand, building fence with a height more than lm and length 100m near the entrance, the material could be transparent plastic or organic glass, etc., making the part of 0.1m from above curve into the outside of road to protect snakes from speeling, at the same time, standing caution board in this area calling for speeding down and forbiding from break the fence.5. Existing culverts'reforming and reusing:Reducing the density of plants around culverts to make the entrance apparent, clearing them to increase the passing ratio, digging ditches and building fence at the edge of road.6. The maintenance measures of undercrossing:After undercrossings'buildind, long-term maintenance and monitoring are needed, including evaluating its value, in-time mending and clearing soil and stone in it and some extra plants. And the more need is showing its function to tourist and dweller, forbiding from break, enhancing patrol in case capturing in undercrossing.7. The undercrossing aiming at Zhaormia mangshanensis:For this kind of snake, the undercrossing should be lager including inner diameter and the size of protecting fence and also built in the area where there are has high detection rate, then should pay more attention to monitoring and maintainment.