Artificially decreased vapour pressure deficit in field conditions modifies foliar metabolite profiles in birch and aspen

Abstract

HighlightMetabolite profiling and mineral nutrient analysis revealed that long-term exposure to decreased vapour pressure deficit (VPD) promotes production of starch, phenolic compounds, and antioxidants, and affects nutrient status in tree leaves.

Geographical Distribution and Environmental Correlates of Eleutherosides and Isofraxidin in Eleutherococcus senticosus from Natural Populations in Forests at Northeast China

“…This part of results contradicted those in Guo et al, where RH was negatively correlated with betulin and lupeol concentrations in B. platyphylla trees [26]. However, our results concur with those findings about forest crops in the understory [23,33]. Two possible explanations may be responsible for our results.…”

“…Two possible explanations may be responsible for our results. The increase of RH can induce the synthesis of secondary metabolites through depressing vapor pressure deficit [23]. Otherwise, higher RH may induce the synthesis of eleutheroside B concentration as a response to the stimulated disease explosion [33].…”

“…The aim of the study was to map the special distribution of these bioactive compounds in forests of Northeast China and further detect the environmental correlates. With regard to the experimental results that eleutherosides accumulate in cooler temperature [3,23], it was hypothesized that metabolite content was higher in the northern part of the research region or in montane areas at higher elevations.…”

The competitive status of trees determines their responsiveness to increasing atmospheric humidity – a climate trend predicted for northern latitudes

“…This suggests that the initially expected positive growth effect of elevated humidity (Tullus et al ., ) by means of enhanced stomatal conductance and carbon sequestration under lower evaporative demand occurs predominately in a well‐illuminated (and apparently more changed) environment. In addition, enhanced photosynthesis due to a more favourable canopy position probably compensates for the negative growth effects of constrained nutrient uptake caused by reduced transpiration and consequent foliar metabolic changes (Lihavainen et al ., ,b). Morphological and functional responses of humidified tree foliage have been detected in FAHM stands, which were more eminent in B. pendula .…”

“…Elevated relative air humidity (by 6-7%) causes~20% reduction in the leaf-to-air water vapour pressure difference (VPD L ), thereby reducing transpiration through the canopies (Kupper et al, 2011). While a lower evaporative demand maintains higher soil water potential (Hansen et al, 2013;Niglas et al, 2014) and probably leads to oxygen depletion due to prolonged soil wetness (Hansen et al, 2013;Sellin et al, 2016), lower VPD L also decreases transpirationdriven mass flow of nutrients in soil (Tullus et al, 2012;Sellin et al, 2013) and modifies foliar metabolites (Lihavainen et al, 2016a). Altogether these findings refer to altered resource availability (enhanced water and diminished nutrient and oxygen availability) for trees.…”