I really like trees. When I was coming to the end of my time at NSF, I got interested in the local urban forestry commission. When I see mature trees come down in my neighborhood due to in-fill, I see a distinct loss. Those trees provide shade in the summer and a nice windbreak in the winter. Trees are also extremely important to the health of the planet because they fix carbon. According to this paper in Nature, they account for approximately 45% of the terrestrial carbon stocks. But the paper is worth reading because it reviews how trees respond to the stress of droughts…of which there are likely to be a lot more in the future. What’s interesting to me is how trees respond to stress through a variety of mechanisms that are truly multidimensional. But…eventually they reach a threshold point where the mechanisms of homeostasis break down and mortality ensues. When this happens, it can be a mass-event with thousands of hectares dying at nearly the same time.