We had our first undergraduate student research presentations in our lab meeting this week. Three of our students shared their summer work under the mentorship of postdoc Dr. Luiza Aparecido – it was wonderful to see how much they have progressed in a few short months.

The summer’s projects have all focused on the ecophysiology of desert plants. For two months in the peak of the Sonoran Desert’s summer heat, our students were outdoors at the Desert Botanical Garden, investigating how leaves cope with extreme heat.

Here you can see photosynthesis measurements on a jojoba (Simmondsia chinensis) shrub.

And here, leaf temperature measurements on a desert willow (Chilopsis linearis).

We are going to save a full update on the science for a coming publication – but for now, one of the most intriguing set of findings from our students’ work is about the thermal extremes that some of these plants can tolerate. With our thermal camera we have measured plant stem and leaf temperatures sometimes in excess of 50°C, with no apparent mortality or loss of function.

You can see that these agaves and saguaros are reaching some very extreme temperatures – classically thought to be high enough to cause tissue mortality – under average afternoon conditions.

How do they survive, and how do they allocate their resources? More analyses are coming, and the puzzle is going to be a fun one. I’m proud of all the hard work (and sweat!) our students have put in, and am excited to see where their analyses take them next!