Canopy transpiration (E_c) of a 150-year-old Pinus sylvestris L. stand in an inner Alpine dry valley, Tyrol, Austria was estimated throughout two growing seasons 2011 and 2012 by means of xylem sap flow measurements. Although there were prolonged periods of limited soil water availability, E_c did not show a clear trend with respect to soil water availability and averaged 0.4 ± 0.19 mm day⁻¹ under conditions of non-limiting soil water availability and 0.37 ± 0.17 mm day⁻¹ when soil water availability was limited. This is because canopy conductance declined significantly with increasing evaporative demand and thus significantly reduced tree water loss. The growing season total of E_c was 74 mm and 88 mm in 2011 and 2012, respectively, which is significantly below the values estimated for other P. sylvestris forest ecosystems in Central Europe, and thus reflecting a strong adaptation to soil drought during periods of high evaporative demands.

© 2014 Elsevier GmbH

通过木质部液流测量，对奥地利蒂罗尔州内高山干旱山谷中一棵 150 年树龄的樟子松林的冠层蒸腾作用 ( E _c ) 进行了评估，该树在 2011 年和 2012 年的两个生长季节中。尽管存在长期的有限土壤水可用性，但E _c并未表现出土壤水可用性的明显趋势，在非限制土壤水可用性和 0.37 ± 0.17 mm day ^-1的条件下，平均为 0.4 ± 0.19 mm day ^{-1 - 1}当土壤水分有限时。这是因为随着蒸发需求的增加，冠层导度显着下降，从而显着减少了树木的水分流失。 2011年和2012年生长季E _c总量分别为74毫米和88毫米，明显低于中欧其他樟子松森林生态系统的估计值，从而反映了对土壤干旱的强烈适应。高蒸发要求。

 © 2014 爱思唯尔有限公司