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本文应用PV技术详细研究了兴安落叶松和樟子松三种不同类型苗水和二株幼树的水分参数的季节变化,并讨论了水分参数在耐旱性评价中的可能意义.结果表明:苗木和幼树的水分参数均有季节性变化.这种季节性变化与苗木和幼树的物候进程及生长发育密切相关.水分参数的季节变化表明:苗木和幼树的耐旱能力也有季节性变化.一般生长季苗木和幼树耗水量大,组织比较幼嫩,易受干旱胁迫的影响,因而耐旱能力相对比较弱;生长季末和非生长季,苗木和幼树木质化程度高,积累的营养物质多,因而耐旱能力也随之提高.从水分参数总的评价来看,樟子松耐旱能力显著高于落叶松.值得指出的是:虽然落叶松幼树叶片抗脱水能力显著低于樟子松,但是在整个生长季π_0和π_(100)却低于樟子松,π_0和π_(100)的降低是落叶松幼树对水分亏缺的一种适应.
In this paper, the seasonal variations of water parameters of three different types of seedlings and two saplings of Larix gmelinii and Pinus sylvestris var. Mongolica were studied by using PV technology, and the possible significance of the water parameters in the evaluation of drought tolerance was discussed.The results showed that: The seasonal changes of the water parameters of seedlings and saplings were closely related to the phenological process and growth of seedlings and saplings.The seasonal changes of water parameters showed that the drought tolerance of seedlings and saplings also had seasonal changes The seedlings and saplings had higher waterlogging, younger tissues and more susceptible to drought stress, thus their drought tolerance ability was relatively weaker. During the growth season and the non-growth season, the seedlings and saplings had a high degree of lignification, Accumulated more nutrients, and thus drought tolerance also increased.From the overall evaluation of the water parameters, drought tolerance of Pinus sylvestris was significantly higher than that of larch.It is worth pointing out that although the larch seedling leaf anti-dehydration ability But significantly lower than that of Pinus sylvestris. However, the decrease of π_0 and π_ (100) during the whole growing season was an adaptation of larch seedlings to water deficit.