Grasses are spendthrifts, forests are budgeters, in a nuanced account of plant water use

Even a toddler knows that plants need water. It's perhaps the first thing we learn about these green life-forms. But how plants budget this resource varies considerably. The kapok trees of the Amazon have adopted vastly different strategies than the switchgrass of the American plains. Unfortunately, it's hard to directly measure which ones prevail in different ecosystem types and how they shift under changing conditions.