川中新桥防护林树木相对含水量（RWC）单分子指数模拟测定及其水信号

Simulant Measurements on the Relative water Content of Trees in Protective Forests of the Middle Part of Sichuan Province with a Monomolecular Growth Formula and the Hydraulic Signals of these Trees

本文用单分子指数方程ＲＨ＝ＫＳＷｔ＝Ｗｒ（１－ｅ－ｋｔ）对川中防护林树种叶片的吸水过程进行了模拟。通过推导得到计算防护林树叶饱和鲜重的公式这里，Ｗｒ为吸水饱和鲜重，Ｗ０为样品最初鲜重，Ｗ１是浸水ｔ小时后的叶片重，Ｗ２为再次浸水ｔ小时后的叶片重。试验表明，单分子指数法测定和计算的树叶相对含水量（ＲＷＣ）的误差都在允许范围内，与算术外推法几子相近，比浸水数次称量恒重法快速、准确。单分子指数法对ＲＷＣ的快速测定，结合对水势和土壤含水量的同步测定，进一步探讨了川中防护林的水信号：春旱季节柏木叶弹性模量（ε）为２２．２２ＭＰａ，桤木为２０．１８ＭＰａ，其压缩率（Ｋ）后者是前者的１．１１倍。用单分子—Ｄａｒｃｙ法推测（４柏１桤）桤柏混交林．中午土壤含水量为０．２６７９／ｃｍ３与实测结果的误差为０．０３％，（５柏５桤）机柏混交林中午土壤含水量为０．３４０ｇ／ｃｍ３，与实测值相同。

In order to solve problems mentioned above more accurately, a monomolecular growth formula is adopted for protective forests in the middle pert of Sichuan province in this peper.The formula is described as follows:With mathematic deduction, the formula to count the turgidity fresh weight is obtained:Where, WT i. e. turgidity fresh weight,W0 i. e. primitive fresh weight,W1 i. e. the weight obtained after'to''hours in distilled water,W2 i. ethe weight obtained after'2to'hours in distilled water. A few experiments have been done and the conclusion is expxessed as follows: When the value of RWC which is obtained from WTcalculated with formula as above is compared with the value of RWC obtained from tursidity curve, the relative error is very little and can be neglected. Hence the period of WT measurement is shortened to two hours, and sometimes the results are obtained in an hour for those Plants such as cypress and alder whose tissues take a little time to reach turgidity.