阿波罗绢蝶种群数量和垂直分布变化及其对气候变暖的响应

Abstract

Global climate change and its effects on organisms has caused great concern.This is particularly true for those species in high-altitude and high-latitude environments due to their specialized ecology.Butterflies are one of the most susceptible species to global climate change and good indicators of an ecosystem′s response to climate variation.The present study used a mountain specialized butterfly Parnassius apollo,only found in Xinjiang,China,as a model system to investigate how its population numbers and vertical distribution changed and how the mountain species responded to the rising temperature during the last forty years(1970—2010).At a 10-year interval from 1980(i.e.1981,1991,2001,2010),butterfly count data(numbers and vertical distribution) were collected along the same 6 fixed transect routes(800—3200m asl.) during suitable weather conditions from July to August in Guozigou,Yili area,which is a part of western Tianshan Mountains.The meteorological data(1970—2010) were obtained from Huocheng weather station. Results showed that the population of P.apollo has decreased sharply since 1980.The number in 2010(133 individuals) was less than the half of that in 1981(289 individuals),and there was a significant difference among elevations(P0.01).Most of P.apollo collected(80.40%) were found at the vertical distribution from 1600m to 2100 m,followed by the range from 2100 m to 2900 m(11.36%).Only 8.24% of butterflies were found at the range from 1200—1600 m.No P.apollo was found at more than 3000 m or less than 1200 m during the field investigations.There was a trend that P.apollo shifted to higher elevation over the last three decades.The percentages of P.apollo numbers at higher elevations(2100-2700 m) are 7.17%,8.04%,8.62%,12.70% for the year of 1981,1991,2001,2010,respectively.Whereas at lower elevations(1100—1600 m),P.apollo numbers decreased during the four periods,the percentages being 10.0%,8.3%,4.4%,3.7% for the year of 1981,1991,2001,2010,respectively. Since 1970,the annual temperature has significantly increased by the rate of 0.199℃per decade.The winter temperature had the fastest rate of 0.350℃per decade,followed by spring by at the rate of 0.219℃per decade.Correlation analysis on P.apollo population numbers and annual temperature,seasonal temperatures,and monthly temperatures showed that P.apollo was significantly negative correlated to all three groups of temperatures(P0.05),with the highest correlation coefficient to the winter(-0.79) and to February temperatures(-0.76).The sliding window correlation analyses between 5-year moving average temperatures in winter and Feburary and P.apollo population numbers showed when the temperature rose in winter and February,the correlation coefficient increased.This study revealed the mountain specialized butterfly P.apollo is facing both a decline in abundance and a shift to higher elevation with the rapid climate warming.