滩羊生态与选育方法的研究 Ⅱ.滩羊的草原生态特征

本文用草原类型学的方法,对滩羊的草原生态特征进行了分析与研究,结果表明:1.根据草原的综合顺序分类法,滩羊分布在①暖温干旱(淡灰钙土,半荒漠)类、②微温干旱(灰钙土、棕钙土,半荒漠)类、③微温微干(栗钙土、淡黑垆土,典型草原)类和④微温微润(黑垆土,草甸草原)类四个类别的草原上。其中①、②为滩羊的典型产区,③为一般产区,④为过渡产区。2.典型产区中二毛袭皮品质最好的滩羊分布区,其水热生态幅极小,年>0℃积温为3632—3739℃(166℃),草原湿润度为0.49—0.55(0.06),年降水量为183.3—222.9毫米(39.7毫米)。

Studies on the Tan Sheep Ecology and Method of Selection (Ⅱ): The Grassland Ecological Characteristics of the Tan Sheep

Tan sheep is a famous breed of lambfur sheep in China. The grassland ecological characteristics of Tan sheep have been studied and analysed with grassland typal method in this paper. The results obtained are as follows, 1.Tan sheep distrbuted only in Ninxia Hui Autonomous Region and its surrounding districts. 2. According to the comprehensive and sequential classification of grassland, the distribution of the Tan sheep may be grouped into 4 classes, they are: (1) warm temperate-arid ( light sierozem, semidesert ) class, (2) temperate-arid (sierzem, brown soil, semidesert ) class, ( 3 ) temperate -smiarid (chestnut, light heilu soil, typical steppe) class and ( 4 ) temperate-semihumid ( heilu soil, meadow-steppe ) class. Among them both (1) and (2) are the typical placs of distribution of Tan sheep, while, (3) is general and (4) is the interium distribution. 3.The grassland ecological conditions of the typical Tan sheep are: (1)heat->0℃ accumulated temperature of a yeac (>0℃∑θ) is 3555—3979℃(2)humidity-the grassland humidity index(K=r/0.1>0℃∑θ) is 0.42—0.68,(3) precipitation of a year (r)—156—253mm,(4) soil—light sierzem, sierzem and brown soil and (5)vegetation—semidesert (desert-steppe), which consists of bushes, semifrutexes, forbs and annual grasses. 4. In the typical regions of its distribution, the ecological amplitude of humidity and heat is very small, > 0℃∑θ is only 166℃(3632—3739), K is 0.06 (0.49—0.55) and r is 39.7mm (183.3—222.9).