新植短叶松和白云杉的种植胁迫。2. 组织水势组分的变化。

Faculty of Forestry, University of Toronto, Toronto, Ontario, Canada MSS 1A1.

Tree Physiol. 1988 Mar;4(1):85-97. doi: 10.1093/treephys/4.1.85.

Water relations of bare-root jack pine (Pinus banksiana Lamb.) and white spruce (Picea glauca (Moench) Voss) planted in a greenhouse and on a boreal cut-over site were examined during the first growing season. In field-planted trees, maximum stomatal conductances (g(wv)) were initially low (< 0.10 cm s(-1)). Base and minimum xylem pressure potentials (Psi(x(base)) and Psi(x(min))) were less than -1.5 and -1.7 MPa for jack pine and -2.0 and -2.6 MPa for white spruce, respectively. During the growing season, maximum g(wv) increased in both species to around 0.2 cm s(-1). Base and minimum xylem pressure potentials also increased in both species to around -0.5 and -1.0 MPa in jack pine and -1.0 and -1.5 MPa in white spruce, respectively. Minimum xylem pressure potentials in white spruce fell below the turgor loss point during the first half of the growing season. Osmotic potential at the turgor loss point Psi(pi(TLP)) decreased after field planting to around -2.7 and -2.3 MPa in jack pine and white spruce, respectively. In the greenhouse, minimum values of Psi(pi(TLP)) were -2.2 and -2.3 MPa in jack pine and white spruce, respectively. Maximum bulk modulus of elasticity was greater in white spruce and underwent greater seasonal change than in jack pine. Relative water content (RWC) at turgor loss ranged between 71 and 74% in jack pine and 80 and 87% in white spruce. Available turgor (T(avail)), defined as the integral of turgor over the range of RWC between Psi(x(base)) and xylem pressure potential at the turgor loss point, was similar in jack pine and white spruce just after field planting. For the rest of the growing season, however, T(avail) in jack pine was two to three times that in white spruce. Diurnal turgor (T(diurnal)), defined as the integral of turgor over the range of RWC between Psi(x(base)) and Psi(x(min)), as a percent of T(avail) was higher in field-planted white spruce than jack pine until the end of the season. Dynamics of tissue water potential components are discussed in relation to plantation establishment.

在第一个生长季节，对种植在温室和北方采伐迹地上的裸根短叶松（Pinus banksiana Lamb.）和白云杉（Picea glauca (Moench) Voss）的水分关系进行了研究。在田间种植的树木中，最初最大气孔导度（g(wv)）较低（< 0.10 cm s(-1)）。短叶松的基部和最小木质部压力势（Psi(x(base))和Psi(x(min))）分别小于-1.5和-1.7 MPa，白云杉的分别为-2.0和-2.6 MPa。在生长季节，两个物种的最大g(wv)均增加到约0.2 cm s(-1)。两个物种的基部和最小木质部压力势也分别增加到短叶松约-0.5和-1.0 MPa，白云杉约-1.0和-1.5 MPa。在生长季节的前半期，白云杉的最小木质部压力势降至膨压丧失点以下。田间种植后，膨压丧失点的渗透势Psi(pi(TLP))在短叶松和白云杉中分别降至约-2.7和-2.3 MPa。在温室中，短叶松和白云杉的Psi(pi(TLP))最小值分别为-2.2和-2.3 MPa。白云杉的最大弹性模量更大，且季节性变化比短叶松更大。膨压丧失时的相对含水量（RWC）在短叶松中为71%至74%，在白云杉中为80%至87%。有效膨压（T(avail)）定义为膨压在Psi(x(base))和膨压丧失点处的木质部压力势之间的RWC范围内的积分，田间种植后短叶松和白云杉的有效膨压相似。然而，在生长季节的其余时间里，短叶松的T(avail)是白云杉的两到三倍。直到季节结束，田间种植的白云杉中，定义为膨压在Psi(x(base))和Psi(x(min))之间的RWC范围内的积分的日膨压（T(diurnal)）占T(avail)的百分比高于短叶松。本文讨论了组织水势成分的动态变化与造林的关系。