琵琶柴（Reaumuria soongorica）地上植物量的估测模型

本文选择和利用在野外能够实地简单测定的高度、冠幅、基生枝条数、枝条直径、当年生枝条长度等数量特征对琵琶柴的地上植物量进行估测和模拟，从而能够动态监测其植物量变化。统计分析表明，琵琶柴的重量（Ｆ，Ｄ）与其植株高度、当年生枝条长度（１）相关不明显，而与冠幅直径（ｅ，ｓ）、枝条数（ｔ）、枝条直径总和（ｒ）相关明显，这一点与灌木有明显的差异。琵琶柴平均每丛枝条数为１０．６７，枝条的平均直径为０．８４ｃｍ。与其它变量的相关分析结果表明：琵琶柴的枝条数（ｔ）与重量、冠幅、高度均相关显著，但对于地上植物量的估测意义不大。各种变量中冠幅与植物量有十分密切的关系，东西直径与南北直径的乘积（ｅｓ）与干重的相关系数高达０．９５１，在多元回归中的偏回归系数也很高。故利用冠幅（ｅｓ）作为变量对琵琶柴的植物量进行估测是简便、易行的。估测模型如下：Ｆ（鲜重）＝－３１．０７５＋０．０７２ｅｓ（冠幅）ｒ＝０．９６４５ｒ２＝０．９３０９ｐ＜０．００１Ｄ（干重）＝－１５．８６６＋０．０２８ｅｓ（冠幅）ｒ＝０．９５０８ｒ２＝０．９０４０ｐ＜０．００１

The Estimating Model of Upper Plant Weight on Reaumuria soongorica Semishrub

Reaumuria soongorica, extreme xerophyte semishrub, widely distribute in Asia centre desert. This study investigated using some quantitative characteristics of Reaumuria soongorica to estimate,simulate and monitor the change of upper plant weight. The studied quantitative characteristics included: uper plant fresh weight (f) and dry weight (d), plant height (h), eastwest diameter (e)and southnorth diameter (s )of canopy, number of hasal twig(t),sum siameter of hasal(r) twig and length of the same year twig(1).The relationships between the all of quantitative characteristics is represented by the correlation coefficients in Table 2-1,The correlation coefficients are not significant between uper plant weight (f,d) and height (h),length (l), This point is different from shrub plant. . After multiple regerssion analyzing,the upper plant weight estimating model was built as following:F(fresh weight)=-31.075+0. 072 e s(diameter of canopy)r=0. 9648 r2-0. 9309 P<0. 001D(dry weight)=-15.866+0.028 e s(diameter of canopy)r=0. 9508 r2=0. 9040 P<0. 001Using these models,we can easily and eonomically predict and monitor upper plant weight of Reaumuria soongorica.