应用压力室技术和稳态气孔仪,测定了在北京地区8年生人工油松林,7个气候生态型13个种源的水势值季节变化和蒸腾速率的日变化及季节变化。结果表明,油松各种源一年中,水势值最低的是严冬季节(—19.75巴)和高温干旱期(—14.81巴)。从不同生态型水势值来看,差异明显。无论在严寒的一月还是在高温干旱的六月,东北型水势值最高,其次是西北型,南部型最低。西南型略高于南部型。水势值高低还明显表现与越冬死亡率高低的关系。南部型种源水势值最低,越冬死亡率也最高。各种源蒸腾速率日变化和季节变化有明显的规律,与环境因子(光照、气温、大气湿度)密切相关。在日变化中呈现早、晚低,中午高的“凸形峰曲线”。随着春季温度升高。在季节变化中,五月份升至第一高峰,而六月高温干旱期,蒸腾速率明显下降。形成一个低谷。雨季以后的8、9月份升至全年最高值,11月秋末冬初又下降至很低。全年呈现一双峰曲线。从各生态型种源蒸腾速率来看,差异是很明显的。以东北型最高,其次是西北型,中部型,中西型居中,西南型,南部型最小。除上述外,从针叶形态解剖特征上来看,各生态型也差别明显,东北型、西北型的针叶短、窄、薄,表皮和皮下组织则较厚,而南部型种源的针叶长、宽、厚,表皮及皮下组织则较薄.这均反映了不同生态型避旱机制的差异。 The diurnal and seasonal changes of seasonal and transpiration rates of water potentials of 8-year-old artificial Pinus tabulaeformis forests and 13 climate-ecotypes of 13 provenances in Beijing area were measured by using pressure chamber technique and steady-state stomata. The results showed that in the year, the lowest water potential was in the severe winter season (-19.75 bar) and in the high-temperature and drought period (-14.81 bar). From different ecotype water potential point of view, the difference is obvious. Whether in the freezing January or in the high temperature and drought in June, the northeast water potential is the highest, followed by the northwest, the lowest in the southern. Southwest slightly higher than the southern type. The level of water potential also clearly shows the relationship with the level of overwintering mortality. Southern type of source water potential minimum, overwintering mortality rate is also the highest. The diurnal and seasonal variations of transpiration rate of various sources have obvious laws, which are closely related to environmental factors (light, air temperature and atmospheric humidity). In the diurnal changes appear early, late low, noon high “convex peak curve.” As spring temperatures rise. In the seasonal changes, the first peak was reached in May, while the transpiration rate dropped significantly during the hot and dry periods in June. Form a trough. After the rainy season in August and September rose to the highest value of the year, in late autumn and early November fall to very low. A full year peak curve. Differences are obvious from the transpiration rates of all ecotypes. Highest northeast, followed by the northwest, central, central and western, southwest, southern minimum. In addition to the above, from the anatomical features of the conifer morphology, the ecological differences are also obvious, northeast, northwest type of needle short, narrow, thin, epidermis and subcutaneous tissue is thick, and southern provenance conifer The length, width, thickness, epidermis and subcutaneous tissue are thinner, which reflect the difference of different ecological drought-relief mechanisms.