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本文详细研究了我国北方部分主要造林树种苗木叶水势与土壤含水量的关系,结果表明:①苗木叶水势Ψ_w与土壤含水量SWC呈明显的“反J型”关系,应用双曲线方程y=a+b/x和指数方程y=ae~(b/x)拟合效果最优.②不同树种Ψ_w随SWC下降的变化差异很大,从而表明不同树种对土壤干旱胁迫的反应和适应不尽相同.依据Levitt和Kramer以及李吉跃等人对植物适应干旱方式的分类方法,应用系统聚类法将21个树种分为两大类4个亚类,即高水势延迟脱水树种(包括油松、樟子松、长白松、白皮松,华山松),亚高水势延迟脱水树种(包括二白杨、火炬树、华北落叶松),亚低水势忍耐脱水树种(包括文冠果、杜仲、沙枣、栾树、花椒、白榆、新疆杨.毛条、胡杨、红柳、侧柏),低水势忍耐脱水树种(包括山杏和山桃).相应于每一类为其建立了Fuzzy模式识别模型.这一模型可以在更为广阔的范围内判别其它树种的耐旱机理及其类型.
In this paper, the relationship between the leaf water potential and the soil water content of some afforestation tree species in northern China was studied in detail. The results showed that: ① The relationship between the leaf water potential Ψ_w and SWC of soil moisture showed obvious “anti-J type” relationship, and the hyperbolic equation y = a + b / x and exponential equation y = ae ~ (b / x) .②The variation of Ψ_w of different tree species with SWC decreased greatly, which indicated that the response and adaptation of different tree species to soil drought stress were different According to Levitt and Kramer and Li Jiyue and others on the classification method of plant adaptation to drought, 21 tree species were divided into two categories and four subtypes, namely high water potential delayed dehydration tree species (including Pinus tabulaeformis, Pinus sylvestris (Including Populus tomentosa, Rhus typhina, and Larix principis-rupprechtii), sub-low water tolerance tree species (including Xanthoceras sorbifolia, Eucommia ulmoides, Radix Scutellariae, Koelreuteria paniculata, Pinus armandii) , Ulmus pumila, Xinjiang poplar, tops, Populus euphratica, Platycladus orientalis, and Platycladus orientalis), and low water potential endurance tree species (including Prunus armeniaca and Prunus armeniaca) were established for each of them.The Fuzzy pattern recognition model was established for each of them Judgment for a wide range Drought Mechanism and other types of trees.