Soil nitrogen limitation does not impact nighttime water loss in Populus
Soil nitrogen limitation does not impact nighttime water loss in Populus
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DOI：
10.1093/treephys/tpp100
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发表时间：
2010-01-01
期刊：
影响因子：
4
通讯作者：
Donovan, Lisa A.
中科院分区：
文献类型：
--
作者：
Howard, Ava R.;Donovan, Lisa A.
C（3）树木夜间蒸腾失水没有碳增益，是常见的和实质性的。然而，这种水分损失的程度各不相同，需要更好地了解导致这种变化的环境因素。研究了夜间电导率（g（night））和蒸腾速率（E（night））对土壤氮素限制的响应。在温室研究中，我们采用瞬时气体交换测量法对狭叶棉白杨和香杨进行了研究。spp.黄果藤（Torr. & A. Gray ex Hook.）黑三角叶杨（Black棉白杨）g（夜）的范围为0.045至0.308 mol m（-2）s（-1）的香芹和0.037至0.188 mol m（-2）s（-1）的沙枣，这是远远大于最低叶导（g（min）;高达0.005 mol m（-2）s（-1）在黑暗中）。长期的氮限制足以大幅减少生物量没有影响克（夜）或E（夜）时，潜在的混淆水胁迫的影响被消除。我们的结论是，夜间水分流失从两个杨树品种是大的，虽然它是气孔控制下不调节在夜间响应土壤氮的可用性。
Nighttime transpirational water loss from C(3) trees occurs without carbon gain and is both common and substantial. However, the magnitude of this water loss varies and a better understanding of the environmental factors driving this variation is needed. We investigated the response of nighttime conductance (g(night)) and transpiration (E(night)) to soil nitrogen limitation. We used instantaneous gas exchange measurements in greenhouse studies of Populus angustifolia James (narrowleaf cottonwood) and Populus balsamifera L. spp. trichocarpa (Torr. & A. Gray ex Hook.) Brayshaw (black cottonwood). g(night) for sufficiently watered plants ranged from 0.045 to 0.308 mol m(-2) s(-1) for P. balsamifera and 0.037 to 0.188 mol m(-2) s(-1) for P. angustifolia, which was much larger than minimum leaf conductance (g(min); up to 0.005 mol m(-2) s(-1) in the dark). Long-term nitrogen limitation sufficient to substantially reduce biomass did not affect g(night) or E(night) when potentially confounding water stress effects were eliminated. We conclude that nighttime water loss from two Populus species is large and although it is under stomatal control is not regulated at night in response to soil nitrogen availability.