The Effects Of Tourism Disturbance On Habitat Quality And Population Of Chinese Giant Salamander(Andrias Davidianus)in Zhangjiajie City

Tourism is becoming one of the fastest growing and largest industries in many countries,however,tourism may have certain pressures and negative impacts on biodiversity and the ecological environment while driving regionally economic development.Studying the effects of tourism on wildlife can provide an important scientific basis for the coordinated development of tourism and wildlife conservation.The Zhangjiajie City in Hunan Province is not only a world-famous tourist destination,but also the place of the Chinese giant salamander national nature reserve,which was aiming to protect the national second-class protected wild animal,the Chinese giant salamander(CGS,Andrias davidianus).To find out the effects of tourism disturbances on the habitat quality and population of CGS in Zhangjiajie City,we classified the degree of disturbances according to the different tourism factors,such as the number of tourists and facilities.To further specify these effects,we employed both field survey and observation of simulated interference experiments.Firstly,we collected data from field surveies to study the effects of tourism disturbances on main habitat factors such as habitat space,water quality,bait fish,and especially,the population number of CGS.Then,by constructing the simulated observation system to represent both high and low simulated disturbances conditions,we observed or calculated the differences of nocturnal activity rhythm in the early breeding stage,spawning and egg protection behaviors,and the breed fertility(egg production,fertilizing rate and hatching rate)during the breeding season of CGS.Finally,we summarized the process and mechanism of tourism disturbances on the reproductive behaviors,beed fertility and population size of CGS from the way of changing the habitat quality of CGS.The process and mechanism of tourism disturbance affecting the reproductive behavior,fecundity and population number of CGS by changing the habitat of CGSr were comprehensively discussed.The main results and conclusions in this study were as follows.(1)Relative to low tourism disturbances,the high disturbances from tourist activities and the construction of tourist facilities in Zhangjiajie City have increased the environmental noise and reduced the dens number,which lowered the space quality of CGS.Moreover,these higher disturbances have increased the number of bacteria,fungi and actinomycetes,the concentrations of total nitrogen(TN)and total phosphorus(TP),and decreased the content of dissolved oxygen(DO).The water quality in the habitat of CGS has general degenerated.The change of space and water quality has given rise to a significant decline to the population of CGS,with coliform group being the most sensitive factor to tourism disturbances.Relatively speaking,the effects of moderate tourism disturbance on the habitat and population of CGS is not comparatively significant.(2)A total of 23 species of bait fish were found in the habitat of CGS in Zhangjiajie City.Among them,Parasinilabeo longiventralis was a new recorded native fish in Hunan Province.The effect of tourism development in the Zhangjiajie City has been reflected by the decline of native fish and the increase of non-native fish,which have resulted in an increasing number of current bait fishes relative to these before tourism development.Tourist activities have risen the degree of water nutrition by risen the content of nutrients(TN and TP)in the water,which increased the resources of bait fish of CGS indirectly,and resulted in a significant increase of the catch of bait fish from the high tourism disturbed area relative to these of low tourism disturbed area.From this perspective,the high tourism disturbance has no distinct negative effects to the bait fish of CGS.Based on the data on the tourism factors,habitat elements and the population of GCS from those field investigation and the impact analyses between them,the strategies of preventing the resources CGS from tourism interferences have also been put forward.(3)In the waters of simulated high and low tourism disturbances,for the females,the dens exit time was 19:10±0:22 and 18:53±0:24,and the dens entry time was 24:10±0:13 and 24:18±0:17,respectively.For the males,the dens exit time was 18:29±0:20 and 18:13±0:18,and the dens entry time was 6:44±0:23 and 6.40±0:29,respectively.Paired T-test has shown that the dens exit time of both female and male CGS in the simulated high tourism disturbance waters were significantly later than in the low tourist disturbance waters,but these differences of the dens entry time were not significant.It indicated that the effects of high tourism disturbance through decreasing the water quality have mainly been reflected by the dens exit time of the CGS in the early breeding stage.(4)The courtship of CGS included a series of processes as follows:entry to the dens,rolling,chasing,belly colliding,mouth-to-mouth posturing,spermiation,shaking,spawning,and resting,and they spawned several times.Some spawned at daytime which corrected the traditional idea that CGS only spawned at night.There were four kinds of egg protection behaviors of male CGS including tail fanning,agitation,shaking,and eggs eating.The water of high simulated tourism disturbance did not significantly affect the spawning behavior and breed fertility including egg-producting quantity,fertilization rate and hatching rate,but it prolonged the time of the tail fanning,agitation,and the overall hatching time of the male CGS.This behavior would be an active response of male CGS to the disturbed environment.When the DO content declined under high tourism disturbance,the male CGS could prolonged the fan tail and agitation time to increase the DO content to meet the needs of embryo development for higher DO,and they also prolonged the hatching time to maintained the hatching rate?The above results indicated that the high tourism disturbance in Zhangjiajie City has reduced the habitat space and water quality,thus decreased the observed population number of CGS.The simulated interference experiments also indicated that high disturbance had varied the dens exit time in the early breeding stage,affected some reproductive behaviors such as prolonged the frequencies of tail fanning and agitation,and prolonged the hatching time,etc.This study has inferred that the adjustions of dens exit time and the egg-protectiong behavior would be active responses of CGS to the disturbed environment,which had guaranteed the overall reproductive effort was not significantly affected.This paper has also suggested that the pollution risks of tourism would be decreased by controlling the number and enhancing the educational guide to the tourists.In combining with a reasonable construction of tourism facilities,the degree of tourism interference in the habitats of CGS could be reduced substantially.It would protect the habitats and populations of the CGS effectively,and promote the coordinated development of tourism development and protection of CGS pratically.