The Study On The Design Of Forest Road Crossing Structures For Amphibians And Reptiles

In order to protect the biodiversity and reduce the adverse impact of road to wildlife, wildlife crossing structures have been designed and used abroad, but since the design of crossing structures was not perfect and the ecological habit of the research object was not known enough, a part of crossing cannot fully play effectively. So it is necessary to study the wildlife roadkill research, thereby specific wildlife crossing could be designed and built. The rearch on design technology of amphibians and reptiles crossing is not only can reduce their highway mortality in reserve, but also contribute to the solution of habitat fragmentation that caused amphibian and reptiles diffusive and gene communication obstructed, At the same time the crossing design parameters can be widely used in other reserves which have a similar natural environment. A field survey was carried out that how to design crossing structures for amphibians and reptiles of forest road in Hunan MangShan national nature reserve, respectively from23th of May to10th of July, from27th of August to6th of October in2010, from26th of May to10th of June, from3rd of August to2nd of September in2011. The research choose larger road mortality of amphibians and reptiles species in MangShan reserve as the experimental subject, such as Odorrana schmackeri、Odorrana graminea、Bufo gargarizans gargarizans、Takydromus septentrionalis、Sphenomorphus indicus、Trimeresurus stejnegeri stejnegeri、Protobothrops mucrosquamatus、Dinodon favozonatum and study the crossing design parameters for amphibians and reptiles, which including channel size, substrate type, vegetation cover rate in channel entrance and the fence height.The results of the study show that: Through the chi-square test, O. schmackeri、O. graminea、T. s. stejnegeri、P. mucrosquamatus、D. favozonatum have a significant difference in different sizes of channel choice, Among them frogs choose0.6m the most times, snakes choose0.5m the most times,0.3m is the fewer times they choose; O. schmackeri、O. graminea、T. s. stejnegeri、P. mucrosquamatus、D. favozonatum have a significant difference in different substrate type of channel choice, Among them frogs choose the substrate of river sand the most times, snakes choose the substrate of gravel the most times, the substrate of PVC is the fewer times they choose; O. schmackeri、O. graminea、T. septentrionalis、S. indicus、T. s. stejnegeri、P. mucrosquamatus have a significant difference in different vegetation cover rate in channel entrance, Among them frogs and lizards tend to choos low or medium vegetation cover rate, T. s. stejnegeri tend to choos low vegetation cover rate, P. mucrosquamatus tend to choos medium vegetation cover rate, all kinds of object choose the fewer times of highly cover rate.Through analysis of the simulation experimental data, the author puts forward the crossing design parameters of amphibians and reptiles in Hunan MangShan National Nature Reserve:1. The channel size:The diameter or high wide of amphibians and reptiles channel cannot less than0.3m, not more than0.6m, for larger size animals can be increased the channel size appropriately.2. Channel substrate:The amphibians and reptiles channel substrate should try to avoid single PVC material, it will be better by use the river sand, gravel or mixed sand as substrate.3.Channel vegetation coverage:All kinds of animals rarely chose the higher vegetation coverage, so the lower vegetation coverage habitat will be suggest in the building of amphibians and reptiles channel entrance.4. Channel fence:When the height of fence is0.6m,0.8m,1.0m, the block rate of experimental subject is41%,84%and98%respectively. In considering the cost, the height of fence will be suggested for0.6~0.8m.Through monitoring the10entrance of5culverts,the results have been recorded47amphibians and reptiles. Amphibians have been recorded37, the richest species was Odorrana schmackeri which have been recorded15, besides Odorrana graminea have been recorded9, Vibrissaphora liui yaoshanensis have been recorded6. Reptiles have been recorded10, all were snakes, Trimeresurus stejnegeri stejnegeri was the richest species have been recorded5. Culverts1, culverts2, culverts7have been recorded more species, could transform into the amphibians and reptiles channel.Finally discussed the shortcomings in the experiment and differences in the design of amphibians and reptiles crossing.