3.9 C
Sunday, April 5, 2020
Home News Ecosystems Drought tolerance strategies of conifer species in the northwestern US

Drought tolerance strategies of conifer species in the northwestern US

As trees photosynthesize, using carbon from the atmosphere to grow and store energy, they also lose water to the air (transpire). During a drought, continuing to photosynthesize and transpire puts trees at risk of damaging their hydraulic conductivity and overall health. With growing seasons expected to lengthen with climate change in the northwestern USA, the mixed conifer forests that dominate this region will experience extended seasonal drought conditions and more frequent extreme drought events. Already the effects are beginning to be felt, with 2015 experiencing the most extreme drought for the area on record. 

Pictures of the field site in Idaho on the first week (June 26th, left) and the final week (October 17th, right) of field work after a record-breaking drought in 2015. Image credit: K. Baker.

In a recent article published in AoBP, Baker et al. studied trees during the record-breaking 2015 drought to understand how mixed conifer forests in northern Idaho will fare under future extended seasonal drought conditions. Daily courses of water potential and leaf gas exchange, as well as the hydraulic conductivity and vulnerability to embolism of six dominant native conifer species were measured across 5 months. All six conifer species changed their hydraulic strategies in response to the drought conditions. They regulated their water use in response both to how dry the air was (vapor pressure deficit) and to how dry the leaves themselves became (leaf water potential) after two months without rainfall. Despite the severity of this drought, all species were also able to continue photosynthesis until mid-October, the end of the growing season, likely due to the mediating effects of the meter-deep, ash-capped silty-loam soils with large water storage capacity. The results of this study suggest that the future prospects are good for these forests, with the authors stating that these fertile soiled ecosystems could act as refugia under extreme drought events.

Researcher highlight

Kathryn V. Baker is currently a Visiting Professor in Environmental Science at Marist College in New York, USA. Having been introduced to the world of forest ecology and physiology in the Rocky Mountains as a Biology undergraduate at Colorado College, she received her PhD from the University of Idaho in the summer of 2019 with Professor Daniel M. Johnson.

Kathryn’s research focuses on tree hydraulics in drought and how they can change across seasons. She is interested in what conditions and mechanisms drive dynamic water use behavior and using ecophysiological field data to inform predictions of forest growth, mortality, and resilience under climate change.

William Salterhttps://williamtsalter.com/
William (Tam) Salter is a Postdoctoral Research Associate in the School of Life and Environmental Sciences and Sydney Institute of Agriculture at the University of Sydney. He has a bachelor degree in Ecological Science (Hons) from the University of Edinburgh and a PhD in plant ecophysiology from the University of Sydney. Tam is interested in the identification and elucidation of plant traits that could be useful for ecosystem resilience and future food security under global environmental change. He also has an active interest in effective scientific communication.

Latest Articles

Most Popular

10 Plants Used to Spice up Sex

It's well-known that plants can affect how the brain works. Take the right plant in the right dose and you can have an altered...

Amazing moss and how to identify it

If I told you that during a 200m walk down a suburban London street I saw 13 different species from one group of organisms,...

Why small seeds require light to germinate

The influence of light on germination was much stronger in smaller than in larger seeds.

The cell biology of secondary cell wall biosynthesis

What is it that makes a plant get up and stay up? A new review looks at the creation of secondary cell walls. These microscopic features are the key to understanding the architecture of the plants we see around us.

Recent Comments