Model Sizes Up Plant GrowthGAMBIER, Ohio (September 18, 2007) Estimating how fast plants grow may seem a simple, somewhat trivial task. But achieving that goal is anything but easy, and has profound implications, said Andrew Kerkhoff, an assistant professor of biology and mathematics at Kenyon.
Kerkhoff and his colleagues developed a mathematical model that accurately predicts how various plant traits, such as leaf size and wood density, are related to each other and to how fast a plant grows.
The results, published this month in the journal Nature, are of interest to more than just plant biologists.
"Plant growth is the basis for all life on earth," Kerkhoff said. "It's where humans and all other animals get most of their energy.
"Understanding plant growth could be important for crop production, forestry, and managing carbon sequestration, a key component in global climate change."
Kerkhoff said he and his co-authors drew on the work of many scientists to find a small combination of plant traits that would still accurately predict plant growth. Their model included four general trait categories: overall plant size, architecture (how leaves and branches are arranged), leaf qualities, and tissue density.
In the course of the study, the researchers uncovered several traits previously overlooked as significant to plant growth. One example is how efficiently plants used carbon from the atmosphere. Their results suggest that lowland tropical forests are less carbon efficient than forests having cold, short growing seasons.
Of course, a model's success depends on how accurately it describes the way things really work. The researchers compared their model's predictions to actual growth rates of 79 plants found in various parts of the world. They found the model matched up well with reality.
"A model is always going to be a bit of a caricature of the real world," Kerkhoff said. "But our caricature is capturing something meaningful about the relationship between plant traits and plant growth."
Find out more about this article in Nature:
A general integrative model for scaling plant growth, carbon flux, and functional trait spectra.
Brian J. Enquist, Andrew J. Kerkhoff, Scott C. Stark, Nathan G. Swenson, Megan C. McCarthy & Charles A. Price