京西山区人工林水分参数的研究（Ⅱ）

应用ＰＶ技术研究了京西山区油松、侧柏、白皮松、栓皮栎、元宝枫、刺槐及火炬树等７个树种人工林水分参数（膨压）、ε（细胞弹性模量）及ＲＣＶ（细胞体积比）的季节变化及其相互关系，研究表明：（１）膨压与叶水势呈良好的线性关系，但参数α（保持最大膨压）和ｂ（渗透调节能力）因树种不同及季节变化有较大的差异；（２）最大体积弹性模量（ε￣（ｍａｘ））没有明显的季节变化规律，但树种之间的差异是比较明显的，其中侧柏的ε￣（ｍａｘ）值最小，白皮松的ε￣（ｍａｘ）值最大；（３）和ε随ＲＣＶ（细胞体积比）的变化因树种和季节不同而异，在与ＲＣＶ的关系中，油松和侧柏呈“直线型”，白皮松和４种阔叶树种则呈“指数型”．ε与ＲＣＶ的关系却有５种类型，即“山峰型”（如油松、侧柏、元宝枫、栓皮栋等），“Ｓ型”（如白皮松、生长初期的元宝枫）、“指数型”（如刺槐、火炬树及生长初期的栓皮栎）、“对数型”（如生长初期和落叶期的火炬树）及“直线型”（如落叶期的栓皮株和元宝枫）．这些类型是反映树木渗透调节能力大小的重要标志。

StudVon Water Parameters of Plantations in the Mountainous Area of West Beijing(Ⅱ)

The relationships and seasonal changes of water parameters,turgor,bulkmodulus of elasticity(ε)and relative cell volume(RCV)in plantation of Pinus tabulaeformis,Platycladus orientalis,Pinus bungeana,Quercus variabilis,Acer truncatum,Robinia pseudoaca-cia and Rhus typhina in the mountainous area of west Beijing were studied using the Pres-sure-Volume method. The results show the following:(1) there is a good linear relationship between turgor and leaf water potential,but the parameters A(maintenance of maximum turgor ) and B(ability of osmotic adjustment)vary with treespecies and seasons;(2) it is not clear in seasonal changes of maximum bulk modulus of elas-ticity(ε￣(max)),but there are clear differences among ε￣(max)of tree species,in which ε￣(max) of P. orien-talis is minimum,ε_(max)of P. bungeana is maximum;(3)the relationships between ,ε and RCVvarv with tree species and seasons. There is a“linear type”relationship in P. orientalis andP, tabulaeformis, but an“exponential type”relationship in P. bungeana and four broad-leavedtree species in the relationcships between and RCV. There are five types in the relation-ships between ε and RCV,that is“peak type”(such as P. tabulaeformis,P. orientalis,A, truncatum and Q. variabilis),“Stype”(such as P. bungeana and A. truncatum in the earlygrowing period),“exponential type”(such as R. pseusoacacia,R. typhina and Q.variabilis inthe early growing period),“logarithinic type”(such as Q.variabilis and A. truncatum in ab-scission period).These types are important indicators which show the ability of osmotic ad-Justment in tree specles.