摘要
借助P-V曲线,研究了油松主要水分参数(包括饱和含水时的最大渗透势φ_(?)^(sat)、初始质壁分离时的渗透势φ_(?)(tlp)、渗透水相对含量F_(tlp),和相对含水量RWC_(tlp)以及质外体水相对含量AWC)随季节和种源的变化。结果表明,油松P-V曲线主要水分参数是随生长发育阶段和环境条件的改变而发生变化的。其中φ_(?)^(sat)φ_(?)(tlP) F_(tlp),和RWC_(tlp)值在夏季生长高峰期达到最高,以后逐渐降低,到严冬季节达到一年中的最低水平,随春季来临又将升高。而AWC值表现了与此相反的季节变化趋势。油松林木主要水分参数随季节发生的变化,与林木的抗寒锻炼过程表现了很大的一致性。油松不同种源水分参数上的差异亦很明显,表现最典型的是在冬季。根据水分参数所计算的综合指标表明,在油松不同气候生态型中,抗旱性强弱的顺序是,东北型、中部型、东部型、西南型、西北型、中西型、南部型。
The changes of main water parameters (MWP), including ψ_(?)^(sat)(maximum osmotic potential at water saturation point), ψ_8^(tlp) (osmotic potential when a plasmolysis just emerges), F_(tlp) (relative content of osmotic water), RWC_(tlp) (relative water content) and AW (relative water
content in apoplast), in Pinus tablaeformis with season ana provenance
were studied by means of pressure-volume curve. The result sh-
owed that the MWP in P-V curve of P. tablaeformis changed in re-
sponse to the changes of both the growth and development stages
and the environmental conditions. Among these parameters, ψ_(?)^(sat), ψ_(?)^(tlp),
F_(tlp) and RWC_(tlp) were the highest during the stage of a growtn peak
in summer, tnen reduced gradually, and reacned down to the lowest
in cold winter. These parameters increased again when spring co-
mes. However, the change trend of AWC was the opposite. Changes
in MWP of P. tablaeformis with season were rather consistent with
tree′s cold hardening. The difference in MWP of P. tablaeformis fr-
om aiiierent porvenances was remarkable, especially in winter. The
syntnetical index calculated from MWP indicated that of the clima-
tic ecotypes of P. tablaeformis drought resistance had following order
from strong to weak: northeast, central, east, southwest, northwest,
centralwest and south type.
关键词
P-V曲线
水分参数
生态型
油松
Pressure-volume curve
Water parameters
Ecotype
Pinus tablaeformis
