Responses Of Small Reptiles To Environmental Change In Desert Areas

In this paper,the Eremias argus and Phrynocephalus przewalskii in Inner Mongolia Siziwang Banner.as the research objects,introduced the response of the Eremias argus and Phrynocephalus przewalskii to environmental change,the response of the nest site selection of the Eremias argus to environmental change,and the habitat comparison of the Eremias argus and Phrynocephalus przewalskii.First,a comparative study on the habitats of the Eremias argus and Phrynocephalus przewalskii,In the field study,the line transect method was used to observe and record lizard species,and the main indicators of habitat characteristics in the sample square were recorded by the line transect method: vegetation fraction,gravel proportion,bare land proportion,vegetation height,egetation species,hardness of soil,temperature of soil and soil moisture of soil.The results have differences in the selection of microhabitats between the two lizards.Most of the Eremias argus habitats were shrub or grass with high vegetation coverage,and the microhabitats with high vegetation height,more vegetation species,low ratio of gravel and high soil hardness.However,the Phrynocephalus przewalskii habitat is mainly the micro-habitat with low vegetation coverage,small vegetation species,high ratio of gravel,low soil hardness,high soil temperature and low soil moisture.In the transition region,the two species are distributed in the joint domain.Principal component analysis also showed that the Eremias argus preferred the habitat with high vegetation coverage,while the Phrynocephalus przewalskii preferred the habitat with high bare land proportion.This study provides basic data for understanding the habitat selection of lizards and further understanding the impact of habitat change on lizards.Second,the response of habitats to environmental change,rainfall,vegetation coverage and vegetation height all affected the population density of the Eremias argus and Phrynocephalus przewalskii.(1)In 2019,the annual rainfall will be 402.9mm,and in 2020 it will be 342.1mm.There is a two-year difference of 60.8mm.Therefore,both the Eremias Argus and the Prynocephalus przewalskii were significantly affected by rainfall during vegetation growth.Rainfall has an effect on lizard population: high rainfall leads to high density of spotted spots;In contrast,the Prynocephalus przewalskii has a low density.(2)The vegetation coverage in 2019 was 54.24±13.38%;The vegetation coverage in 2020 was 46.93±12.27%.There was significant difference between them(P =0.021<0.05).The vegetation with high coverage rate will make the speckle density high.Vegetation coverage in2019,41.41±8.79%;The vegetation coverage in 2020 was38.22±8.92%.There was no significant difference in vegetation coverage between the two years(P = 0.464<0.05).(3)The vegetation height was 12.34±7.25 in the habitats where the lizard was distributed in 2019.In 2020,the vegetation coverage was9.75±5.74,and the difference of vegetation coverage between the two years was significant(P =0.0047<0.05),that is,the higher the vegetation height,the higher the population density of the lizard.The vegetation height of the desert lizard was 8.47±2.90 in 2019.The vegetation coverage in 2020 was 5.83±2.21,and there was significant difference in vegetation height between the two years(P =0.039 <0.05).Third,Nest site selection in the Eremias argus is responsive to environmental change(1)Natural nest,temperature: the surface temperature difference of ovaries during incubation period was 8.5-39?,and the temperature difference was 30.5?;The temperature difference of spawning place was11.5-34?,with a difference of 22.5?.The temperature difference at20 cm is 13.5-27?,with a difference of 13.5?;In other words,the difference result was:surface layer>egg deep>20cm.Soil has a certain thermal insulation effect,and the deeper the soil depth,the better the thermal insulation effect.Humidity: the variation of humidity in different soil layers is as follows: the difference of surface humidity is94.6-106.8%,and the difference of humidity is 12.3%.The humidity difference at the egg site was 93.3-105.2%,and the humidity difference was 11.3%.The moisture difference at 20 cm is 92.0-102.5%,and the moisture difference is 10.5%,that is,the soil moisture difference is:surface layer and >egg depth >20cm.Soil has a certain moisturizing effect,and the deeper the soil is,the better the moisturizing effect is.(2)Simulated nest,temperature: the order of temperature difference under different coverings is: no coverings >brick >stone.Humidity: Surface humidity difference results: surface > brick >stone;The humidity difference between the spawning site and 20 cm site was as follows:no coverings>stone>brick.Different coverings have different insulation effects.