A trembling aspen
canopy at the study site in the La Plata Mountains.
Leander Anderegg
(December 11, 2015) In
the face of adverse conditions, people might feel tempted by two radically
different options — hunker down and wait for conditions to improve, or press on
and hope for the best. It would seem that trees employ similar options when the
climate turns dry and hot.
Two University of Washington researchers have uncovered
details of the radically divergent strategies that two common tree species
employ to cope with drought in southwestern Colorado. As they report in a new
paper in the journal Global Change Biology, one tree species shuts down
production and conserves water, while the other alters its physiology to
continue growing and using water. As the entire western United States becomes
warmer and drier through man-made climate change, these findings shed light on
how woody plants may confront twin scourges of less water and hot weather.
The authors, UW biology graduate student Leander Anderegg
and biology professor Janneke Hille Ris Lambers, wanted to understand if
different tree species employ similar coping strategies for drought, and how
these strategies would affect their future ranges in a warmer and drier climate.
They compared how two common tree species differ in terms of shape, growth rate
and physiology across wet and dry portions of their native ranges.
“We really wanted to identify the entire suite of strategies
that a plant can use to grow in drier environments, as well as which of these
strategies each tree would employ,” said Hille Ris Lambers.