Getting to the root of plant form and function

The remarkable diversity of plant shapes and sizes found around the world can explain how some of the most complex plant communities are assembled.

Two separate papers published this month in Nature analyze plant form and function on a global scale. FIU’s Christopher Baraloto co-authored the studies and is one of only a small group of researchers who contributed to both. Baraloto is the director of the International Center for Tropical Botany, a collaboration between FIU and the National Tropical Botanical Garden.

“The common denominator is that we are considering biodiversity in terms of its functionality — what do plants looks like and why, and what are the consequences for how the natural world functions the way it does,” Baraloto said.

Christopher Baraloto, director of the International Center for Tropical Botany, a collaboration between FIU and the National Tropical Botanical Garden.

Baraloto’s lab provided some of the largest data sets used in both studies, including measures of form, function and growth collected over the past decade for hundreds of species of tropical trees.

The first study, The global spectrum of plant form and function, analyzed variation in six major traits essential to plant growth, survival and reproduction — including seed mass, plant height and leaf area. Led by the Universidad Nacional de Cordoba in Argentina, the researchers examined more than 46,000 species of plants from across the globe, yielding the most comprehensive picture of how plant functional diversity has evolved to represent a limited number of combinations of these traits. These findings will help to improve modeling to predict how natural communities will respond to climate change..

In a related study, Plant functional traits have globally consistent effects on competition, researchers examined how wood density, plant height and leaf area influence competition amongst trees across the world’s forests. Led by the IRSTEA (Institut national de recherche en sciences et technologies pour l’environment et l’agriculture in France), an international collaboration of researchers examined data spanning 3 million trees in more than 140,000 plots. The study revealed different combinations of traits either allow for high tolerance of competition or allow plants to grow rapidly in the absence of competition. This study is the most extensive on tree competition to date and could enable researchers to predict plant competition, dynamics and interactions across thousands of different species across the globe.

“Compiling these datasets allows us an unprecedented vision of general patterns of plant diversity across the globe,” Baraloto said. “Anyone can now map a plant from their garden or neighborhood onto the global trait map and appreciate how the form of that plant has contributed to where we find it and why and how it grows, relative to the tens of thousands of plants found around the world.”