Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest
Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest
复制标题
DOI：
10.1016/j.advwatres.2003.08.001
复制
发表时间：
2003-12
影响因子：
4.7
通讯作者：
D. Pataki;R. Oren
中科院分区：
文献类型：
--
作者：
D. Pataki;R. Oren
为了评价北美6种常见东部落叶树种的蒸腾作用控制因子，根据树干液流通量数据，建立了描述冠层气孔导度(GS)对净辐射(RN)、水汽压亏差(D)和相对可提取土壤水分(REW)响应的模型。在北卡罗来纳州杜克森林的一片河滩橡树-山核桃林中，测定了24株成熟树木的液液通量，这些树种包括毛果山核桃、白栎树、红曲柳、美洲水曲柳、鹅掌木和枫香。在1997年的生长季中，模型系数存在物种差异。与其他树种相比，所有树种都表现出随着树冠上覆被树荫不耐受树冠密度的增加而影响树种GS值的降低。此外，尽管在研究期间发生了严重干旱，但只有郁金香表现出GSS下降，REW下降。干旱对其他树种的主要影响似乎是早秋叶片衰老和脱落。因此，尽管这片习惯于充足供水的滩地森林干旱，但最大日蒸腾量(1.6毫米)和生长季蒸腾(264毫米)与附近旱地森林在高于平均降雨量的一年中测得的相似。这些结果可能有助于评估水利用的差异和滩地落叶物种容忍降水频率或降水量变化的能力。结果还表明，生长在景观不同位置的相似组成和结构的森林之间的用水量几乎没有变化，并且受到供水的较大年际变化的影响。
In order to evaluate factors controlling transpiration of six common eastern deciduous species in North America, a model describing responses of canopy stomatal conductance (GS) to net radiation (RN), vapor pressure deficit (D) and relative extractable soil water (REW) was parameterized from sap flux data. Sap flux was measured in 24 mature trees consisting of the species Carya tomentosa, Quercus alba, Q. rubra, Fraxinus americana, Liriodendron tulipifera, and Liquidambar styraciflua in a bottomland oak-hickory forest in the Duke Forest, NC. Species differences in model coefficients were found during the 1997 growing season. All species showed a reduction in GSwith increasing D. RNinfluenced GSin the overstory shade intolerant L. styraciflua to a larger extent than the other species measured. In addition, despite a severe drought during the study period, only L. tulipifera showed a decline in GSwith decreasing REW. The primary effect of the drought for the other species appeared to be early autumn leaf senescence and abscission. As a result, despite the drought in this bottomland forest accustomed to ample water supply, maximum daily transpiration (1.6 mm) and growing season transpiration (264 mm) were similar to a nearby upland forest measured during a year of above average precipitation. These results may aid in assessing differences in water use and the ability of bottomland deciduous species to tolerate alterations in the frequency or amount of precipitation. Results also suggest little variation in water use among forests of similar composition and structure growing in different positions in the landscape and subjected to large interannual variation in water supply.