【作者】 张勇；

【导师】 龚大洁；

【作者基本信息】 西北师范大学 ， 生态学， 2021， 硕士

【摘要】 两栖动物具有很高的生态环境价值,不仅能够影响生态平衡,还反映其所处栖息地环境质量,常被视为环境健康的重要指示类群。近年来,受人类活动和全球气候变化的共同影响,两栖动物的栖息地退化、丧失及功能失调问题已日益突出,严重影响了它们的种群结构及所承担的生态功能。全球现已发现雨蛙科Hylidae雨蛙属Hyla物种38种,中国现分布有8种;秦岭雨蛙H.tsinlingensis作为在秦岭山脉不断变迁中存活下来的物种之一,是我国秦岭山区的特有物种。1964年,人们首次记录到在甘肃有秦岭雨蛙分布,但对其种群生态学从未有过系统性研究。基于此,本研究于2020年5月底至9月,在甘肃开展其种群生态学研究。选取秦岭雨蛙在秦岭最西端分布区——康县为研究地,对该物种的种群生态及物种保护等开展了相关调查研究,以期掌握其在甘肃的种群资源现状,为后续研究和保护这一特有种提供基础性生态学资料。研究期间利用样线法结合样方法、直接计数法、相关性检验、方差分析、主成分分析和线性回归分析等处理方法,研究了秦岭雨蛙的种群生态学问题。主要研究结果如下:(1)野外共捕获到成体秦岭雨蛙共203只(146♂,57♀),通过度量其14项形态指标并加以分析,得出康县种群秦岭雨蛙雄性平均体长41.55±0.18mm,雌性46.40±0.26 mm,雌雄头体长比为1.117,异形指数为SDI=0.105,雌雄间存在两性异形现象,且雌雄在头长、鼻间距、眼径、鼓膜径、前臂及手长、前臂宽、胫长和后肢全长上存在显著差异(P<0.05),而在头宽、吻长、眼间距、胫宽和足长上不存在显著差异(P>0.05),生育力假说可解释其两性异形现象。(2)秦岭雨蛙在不同样地和不同月份间的种群数量均有较大变化,种群数量及密度最大是李家沟样地(34.7只/hm~2)、其次是豆坝河样地(29.3只/hm~2),最小的是袁家沟样地(4.0只/hm~2)。秦岭雨蛙的偶见率在6、7月份最高,属于严格的夜行性动物。在繁殖期内,秦岭雨蛙雌性数量小于雄性,雌雄总性比为1:2.56,这也符合多数蛙类性比研究结论。秦岭雨蛙平均头体长和体质量均在7月份最大,肥满度在6月份和8月份存在显著差异(P<0.05),同时雌性的肥满度也高于雄性。(3)通过分析42只雄性秦岭雨蛙录音,发现秦岭雨蛙仅发出单一类型的鸣声,且鸣声的主频分别与头体长、后肢全长、头长呈负相关,鸣声个数与头体长呈负相关,但鸣声时长与头体长呈正相关,鸣声特征可能受到亲缘关系、身体大小以及环境因素影响。秦岭雨蛙雌性平均产卵量为1135.60±26.12粒,平均卵径为1.31±0.01 mm,产卵量主要与头体长、体质量存在正相关,表明雌性可能通过增加自身体型大小来相应地增加腹部容量,以储存更多能量促使产生更多卵。(4)在室温3～4天后,秦岭雨蛙的卵即可孵化完成,此时蝌蚪呈黑色并可自由游动。通过控制密度实验发现,密度对秦岭雨蛙的抑制作用主要发生在变态发育后期,而非前期;其主要原因可能是早期秦岭雨蛙个体小,种内竞争弱,随着个体的生长,对资源需求增加,产生了负密度效应。(5)生境喜好系数分析表明,秦岭雨蛙更偏好栖息于低矮灌木丛、植被盖度较高、大气湿度较高、静水型、距农田较近的生态环境;进一步通过主成分分析表明,秦岭雨蛙对生境的选择主要受到植被因子、温度因子、水源因子、食物因子和人为干扰的影响。更多还原

【Abstract】 Amphibians have high ecological environmental value,which can not only affect the ecological balance,but also reflect the environmental quality of their habitats,and are often regarded as an important indicator group of environmental health.Amphibians have been affected by human activities and global changes in recent years,and their habitat degradation,loss and dysfunction have become increasingly prominent,which has severely affected their population structure and ecological functions.The genus Hyla,which has 38 known species currently.Of the 8 species found in China,tsinling tree toad is endemic to Qinling Mountains.Since it was first recorded in Gansu Province in 1964,there has been a lack of systematic research on population ecology.Accordingly,in this study,a survey on population ecology of tsinling tree toad was conducted from the end of May to September 2020,in Kang County,Gansu Province.The data obtained can also fill the gaps in the life history of tsinling tree toad and provide basic data for subsequent ecological research and the protection of this specie.During the study,the population ecology of the tsinling tree toad was studied by combining the sample method,direct counting method,correlation test,variance analysis,principal component analysis and linear regression analysis.The main results of the study are as follows:(1)A total of 203 adult tsinling tree toad(146 ♂,57 ♀)were captured in the wild.The results showed that the average body length of male was 41.55 mm ± 0.18 mm,while the female’s average body length was 46.40 mm ± 0.26 mm by measuring the14 morphological characteristics.The average body length ratio of female to male was1.117,and the heterosexual index was 0.105.There were significant differences between male and female in diameter of tympanum,diameter of eye,head length,internasal space,diameter of lower arm,tibia length,leg length(P < 0.05).There was no significant difference in head width,snout length,interorbital space,tibia width,foot length(P > 0.05),which is in line with the fertility hypothesis.(2)The population and density of tsinling tree toad varied greatly in different sites and months.The population and density of tsinling tree toad were the largest in Lijiagou plot,followed by Doubahe plot,and the smallest in Yuanjiagou plot.The occurrence rate of tsinling tree toad is highest in June and July.Tsinling tree toad is a strict nocturnal animal.The ratios of females to males were 1:2.56 during the breeding period,which is also in line with the conclusions of the existing research on sex ratio of frogs.The average snout-urostyle length and body mass are the largest in July.The relative fatness was different between June and August and between male and female(P < 0.05).(3)It was the only species with a monosyllabic call by analyzing the recordings of 42 male tsinling tree toads.The relationship between the call dominant frequency and the morphological characteristics was analyzed,and it was found that the call dominant frequency was negatively correlated with head length,leg length and snout-urostyle length.The snout-urostyle length were positively and negatively correlated with call duration and t call numbers,respectively.The brood amount of female tsinling tree toad was mainly positively correlated with snout-urostyle length and body mass.Females may increase their abdominal capacity by increasing their body size to store more energy and promote the production of more eggs.(4)The eggs of the tsinling tree toad could hatch after 3 to 4 days at room temperature.It was found that the inhibitory effect of density on tsinling tree toad tadpoles mainly occurs in the late stage,not the early stage through density control experiments.The main reason may be the early tsinling tree toad tadpoles was small individuals and weak intraspecies competition;as the individuals grow,the demand for resources increases,which produces a negative density effect.(5)It showed that tsinling tree toad preferred to inhabit in low shrubs,vegetation coverage,high atmospheric humidity,hydrostatic type,close to farmland habitat by analysing habitat preference coefficient.It showed that the habitat selection of tsinling tree toad was mainly affected by vegetation factor,temperature factor,water factor,food factor and human disturbance by principal component analysis.更多还原