English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

We monitored sap flow and estimated diurnal changes in transpiration rates of two trembling aspen ( Populus tremuloides  Michx.) stands, located in the southern boreal forest and aspen parkland of Saskatchewan, Canada. In both stands during the peak growing season (June and July), sap flow during the day (0700–1700 h local time) increased linearly with vapor pressure deficit (VPD) from 0 to about 1 kPa, but then remained remarkably constant at VPD &gt; 1 kPa (up to 4.8 kPa in the aspen parkland stand). The results imply an inverse relationship between stomatal conductance and VPD under well mixed conditions, for VPD &gt; 1 kPa. We postulate that the stomata are operating to maintain leaf water potentials above a critical minimum value, which in turn places a maximum value on the rate of sap flow that can be sustained.

Sap flow in trembling aspen: implications for stomatal responses to vapor pressure deficit