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作 者 ：石松利,王迎春*,周健华

期 刊 ：生态学报 2008年 28卷 12期 页码：6079~6089

关键词：四合木；PV 技术；水分参数；季节变化；不同生境 耐旱性；

Keywords:Tetraena mongolica, press-volume technique, water parameters, seasonal change, different habitats, drought tolerance,

摘 要 ：运用PV技术对5个不同生境四合木水分参数(Ψsats、Ψtlps、ROWCtlp、RWCtlp、AWC、Va/V0和εmax)的季节动态(5、7、9月份)及生境间差异性进行研究。结果表明：(1)四合木水分参数Ψsats、Ψttlps 值较低， AWC、Va/V0值较高，体现荒漠灌木四合木较强的干旱适应性特点。(2)四合木主要水分参数Ψsats、Ψtlps 值及εmax表现为5月份＞7月份＞9月份，AWC、Va/V0表现为5月份＜7月份＜9月份，四合木耐旱性随5月份、7月份、9月份递增，这种季节变化规律与植物生长发育的节律相吻合，即与物候的进程一致。(3)对5个生境四合木(低山、台地、丘陵、高平原、倾斜平原)耐旱性排序，得出倾斜平原、高平原＞丘陵＞台地＞低山，将3个月份5个不同生境四合木水分参数进行聚类。结果低山、台地、丘陵四合木为一类，高平原、倾斜平原四合木为一类。方差分析表明：3个月份Ψtlps值、Ψsats值和AWC值均表现为高平原、倾斜平原四合木显著低于低山、台地、丘陵四合木。不同生境四合木的渗透调节机制不同，倾斜平原和高平原的四合木其体内通过增加细胞质浓度进行渗透调节能力较强(较低的Ψtlps值和Ψsats值)；而生境为低山、台地和丘陵四合木抗脱水能力较强(较大的AWC值)。

Abstract:The change of water parameters (Ψsats, Ψtlps, ROWCtlp, RWCtlp,AWC,Va/V0 and εmax ) in Tetraena mongolica with season and habitat was studied by means of press-volume technique. The results showed as follows：(1) Tetraena mongolica is of low Ψsats, low Ψtlps, high AWC and high Va/V0, which shows that Tetraena mongolica is of strong ability of drought tolerance. (2) The seasonal change of Ψsats,Ψtlps and εmax showed May＞July＞September. And the AWC,Va/V0 showed May＜July＜September. The drought tolerance of Tetraena mongolica continuously enhanced with season. This seasonal change is response to the phonological rhythm of plant. (3) The ordination analysis for drought tolerance of Tetraena mongolica in upland, hill,tableland, high plain, terrace was finished. The level of drought-tolerance among the five habitats above decreased in the following order: high plain and terrace＞upland＞tableland＞hill. Based on three measurements of water parameters of Tetraena mongolica in five habitats in P-V curves, the cluster analysis of drought tolerance of Tetraena mongolica was finished. Tetraena mongolica in five habitats can be classified into two groups: upland, hill and tableland is one group, high plain and terrace is the other group. The variance analysis showed that three measurements of Ψsats,Ψtlps and AWC of Tetraena mongolica in high plain and terrace is lower than that of upland, hill and tableland. There are difference in osmotic adjustment mechanism among five different habitats. Tetraena mongolica in high plain and terrace is of stronger ability of osmosis adjustment by improving the concentration of cellular solute, but Tetraena mongolica in upland, hill and tableland is of stronger ability of holding water (high AWC).

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