Air humidity and stomata in aspen

Corrigendum: Does increased air humidity affect stomatal morphology and functioning in hybrid aspen?

by Niglas A., Alber M., Suur K., Jasin´ ska A. K., Kupper P., Sellin A. (2015)

in Botany, 93(4): 243–250.

doi.10.1139/cjb-2015-0004.

In the above paper, the first sentence in the Results should read as “From June to August, daily average RH was 3%–4% higher in H plots compared with the control.”

Furthermore, the axis labels of Fig. 3 were transposed in error and should be as in the corrected figure below. Received 28 August 2015. Accepted 28 August 2015.

A. Niglas, M. Alber, K. Suur, P. Kupper, and A. Sellin. Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia. A.K. Jasin´ ska. Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia; Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland. Corresponding author: Aigar Niglas (e-mail: aigar.niglas@ut.ee). Fig. 3. Stomatal conductance (gS) versus leaf-to-air vapour pressure difference (VPDL) in leaves showing increasing response (IR) of stomatal conductance with rising VPDL. The IR data were divided into seven groups by VPDL; the data points represent means of the groups.

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ORIGINAL PAPER

ABSTRACT

The study investigated the effects of exposure to increased relative air humidity (RH) on stomatal morphology and sensitivity to stomata closure inducing stimulus (low RH) in hybrid aspen (Populus tremula L. × P. tremuloides Michx.) coppice growing in field conditions. Artificially elevated RH reduced air vapour pressure deficit by 5%–10% and altered stomatal sensitivity; trees grown under high RH exhibited stronger stomatal response to decreasing air humidity. We found no difference in mean stomatal pore length between treatments and a small decline in stomatal density under humidification. The lack of correlation between stomatal sensitivity and morphological traits suggests that stomatal sensitivity was unaffected by stomatal morphology. In light of rising atmospheric humidity predicted for high latitudes, strict stomatal control over water loss might be beneficial for trees if drought events become more frequent in the future. However, our experiment revealed that about two-thirds of the leaf-to-air vapour pressure difference (VPD_L) response curves demonstrated the opposite pattern, i.e., stomatal opening in response to increasing VPD_L. Strict stomatal regulation is probably not beneficial to fast-growing aspen coppice under low RH, as this trait may restrict their carbon gain and growth rate.