The project, titled “Uncovering the mechanisms driving co-flowering community assembly: Integrating flowering and floral trait distribution patterns via a novel use of network analysis,” has been funded for a three-year grant totaling $699,700.
“The overarching question that we’re trying to get at is, ‘How are plant communities organized in nature?’ ” said Arceo-Gomez, an assistant professor in the ETSU Department of Biological Sciences. “Are there any rules that govern the assembly of these plant communities?”
This new project is an outgrowth of an earlier study funded by ETSU’s Research Development Committee. In that study, Arceo-Gomez and his students measured floral traits that are important to pollinators, including flower color, in close to 50 plant species in California.
Preliminary data from that study, he said, showed a tendency toward non-random assembly of plants within flowering plant communities.
“Plants in those communities tend to be either very similar or very dissimilar, more than you would expect just by chance,” Arceo-Gomez said. “There’s some kind of structure, and color seems to be important. Plants tend to look alike in certain communities, or be very different in terms of flower color in other communities.”
Arceo-Gomez says they know that two of the mechanisms at work in determining the composition of co-flowering plant communities are competition and facilitation for pollinator attraction.
“Plants can compete with each other and exclude each other from any given site, or they can facilitate each other and help each other to coexist in a given place,” he said. “The theory behind that is that if plants tend to look very similar to each other, it’s probably facilitation that operates. If they tend to look very different from each other, it’s probably competition.”
But what governs that?
“There’s some kind of basis to it,” Arceo-Gomez said. “There is some kind of structure, and we really want to understand what the processes and the rules are that determine the assembly of communities.
“If I walk to a prairie or a grassland and see all these plants, why are these plants here and not somewhere else? Why are these plants flowering with each other now and not later with other species?”
In trying to learn what rules determine which species can co-flower and which cannot, Arceo-Gomez and his undergraduate and graduate student researchers, in collaboration with researchers at Cornell University, will create artificial plant communities to observe these governing mechanisms at work.
In these experimental communities, which will be both outdoors in California and in a greenhouse environment on the campus of ETSU, the researchers will combine plants with a specific set of colors; switch plants to different locations; extract and analyze flower scents; and more to see what effects these manipulations have on mediating competitive and facilitative processes.
Another component of the NSF project will involve looking at the timing of flowering. Within a specific community studied over a four-month period, for instance, some flowers will bloom during the first weeks of the study, followed by other plants flowering in the middle and ending weeks.
“The ultimate goal, if we can uncover those rules and really determine how a plant community is organized,” Arceo-Gomez said, “is to get a step closer to being able to predict how plant communities will change when they encounter disturbances – how they’re going to change if invasive species arrive, how they’re going to change if some species go extinct, how they’re going to change with climate change.”