摘要:
哺乳类几大区系在川渝地区交汇,物种非常丰富,特有成分多。以生态亚区为单位,考虑空间容纳、遗传潜力系数,在分布、特有、种型和经济方面选择五项指标,拟订濒危程度定量评价的指标体系,给四川全部223野生种打分。结果显示四川毛尾睡鼠0.9分最高,VC值其次为大熊猫。评分最低的大多是啮齿目鼠类、翼手目蝙蝠类。随后运用严格数学方法,将濒危系数按7个目各自进行聚类分析,得到各目5项指标的最高、最低值种。聚类反映出,许多濒危系数高的兽种在本目不居首要位置,即优先保护的急切性不强。F检验看出兽种的出现各不相关,区界成分不以地域划断。认为全球7个动物区系交错存活于川渝,并按照兽种的系数评分推导出隶属函数公式,评判它们属于哪一界。古北界诞生于三叠系下统(T1),东洋界诞生于侏罗系中统(J2),渝川这两界种数最大。冈瓦纳古陆分解后,各区系由早到晚依次产生。新北界产生在中新统(N1)之后新仙女木期,新热带界在Q以后。还提出第四系断代动物为果子狸、香猫等。统计出兔形目的第四系新种比例最高,其次为食虫目。大熊猫、小熊猫的歧途演化证明,盆周山地尚未发生过更新统冰盖,新北界产生于小熊猫先祖出现以后。新仙女木气候渐变是真兽亚纲进化为新兽类的分水岭,东洋种按四个区分化、演进得到映射。
Abstract:
Mammal species under several realms are confluent in Sichuan and Chongqing,with very affluent biodiversity,and large amont of endemic components. On ecological sub-region as units, indices were chosen from coefficients of space accommodation and genetic potential, and the five indices were about distribution,indigenousness,specific model and economic value. The system was drawn up for quantitative evaluation of vulnerability degree (value VC),and 223 ferine species in Sichuan were marked according to grades. The results showed that Sichuan hairy-tailed dormouse bore the highest VC of 0.9,and the next was the giant panda. Mammals with the lowest VC by grading were mostly murines of Rodentia and bats of Chiroptera. Afterward,coefficients under threat were classified by cluster analysis through strict mathematic method for 7 orders separately,so as to obtain species with the maximum and minimum values of 5 indexes among each order. It was found that a number of species bearing highest VC in order were not necessarily primary in sequence made by the clustering, so they didnot occupy extremely urgent location in preferential conservation. It was testified by F test that the occurrence of species was not correlated, and ingredients of realms were not divided in terrain clearly. It was discovered that 7 realms survived and coexisted in Sichuan intricately, and formulas about membership function were deduced according to scores of each mammal, so as to judge which realm they belonged to, i. e. Palaearctic, Oriental, Palaeotropical or etc. Palaearctic was formed during lower series of Triassic System, Oriental in medium series of Jurassic System, and species quantity in these two realms were the most. After splitting of the Gondwana, realms came into being in turn. Neoarctic had emerged at Younger Dryas posterior to Miocene Series (N1), whereas Neotropical within Q. It was put forward that mammals for decision of Quaternary period were palm civet, civet cat and etc. Ratio of Quaternary species was the largest in Lagomorpha, and Insectivora was secondary. Differentiation evolution of giant pandas and lesser pandas had proved that icecap of Pleistocene glacier had not occurred in mountain areas around the Sichuan Basin during Quaternary, and Neoarctic happened later than ancestors of red pandas were born. Gradual oscillation of climate in Younger Dryas was watershed of evolvement from Eutherian species to Cainotheres. Oriental species differentiated, processed among 4 sections and were reflected in Sichuan.
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