by 
“I went into science because I thought nature was really cool.” When he was nine, physiological ecologist Manuel Lerdau volunteered at a nature center near his Maryland home, cleaning out the cages of injured animals that couldn’t be released back into the wild. A few years later, he got a job catching and banding migratory birds after school. Moving further afield, he took a year off from college to study birds and primates in the tropical forests of Borneo.
For a while, Lerdau thought that he would “go into science policy and save the world.” But after working as a technician in graduate school, helping other scientists with their projects, he realized that doing science and hanging out with other scientists was really fun and the way he wanted to spend his career.
With climate change putting extra pressure on the people who feed and provide energy for growing populations, Lerdau’s work might just help “save the world” after all. How can we grow enough food to feed everyone without running out of water, land, and the other resources farmers need to provide us with food? What roles might plants play in providing energy for 21st-century societies? Lerdau studies the ways that plants grow, identifying ways to reduce the amount of water and fertilizer they need and potentially helping provide food and produce energy.
Ecologists like Lerdau use models similar to those used by economists to understand how plants grow, looking closely at what’s abundantly available and what becomes a limiting factor. If nutrients like nitrogren and phosphorous are easy to come by, carbon dioxide might become the limiting factor of growth, making it useful to plants to increase the size of their leaves. But if they have access to plenty of carbon dioxide, nitrogen might become the limiting factor and they might grow larger and longer roots. Lerdau has looked at the ways plants metabolize copper, which they all need but which tends to be available in most soil. He aims to determine how plants make more productive use of copper and grow larger without needing additional water or fertilizers. This might help farmers grow more corn, wheat, tomatoes, and other forms of food.
Arapidopsis thaliana, the “fruit fly of plant biology,” belongs to the mustard family. Lerdau tested its metabolism of copper first because scientists have mapped out its genes. Then he moved on to switch grass, a potential biofuel. In each case, he looked at the ways the plants used copper for photosynthesis, measuring the rates at which their leaves exchanged carbon dioxide with the atmosphere. He also looked at the rate at which electrons move down the electron tranport chain, making ATP and NADPH as they capture energy. The plants he modified genetically (to make better use of the copper available in the soil) increased in size by 30%.
What math does Lerdau wish he knew better? “I just wish that I had taken more linear algebra and I wish that I had a better understanding of probability theory.” Advances in statistics have been “revolutionary” for the kind of science he does.
Math4Scence was surprised to hear that some of the work Lerdau has done was funded by NASA. After getting his doctorate in biology, he did postdoctoral studies in analytical chemistry at NASA’s Ames Research Center. Not just for astronauts, and astrophysicists, NASA supports regional and global ecology. Like Lerdau they recognize that the work of all sorts of scientists can help improve life here on Earth.
