Graduate Assistantship in Plant Ecology available for 2003-2005. For information contact klarson@uca.edu and to learn more about our MS Graduate Program, click here or my homepage .
Research Interests
Invasive plants are a major threat to biodiversity. My lab examines the ecology of two species of honeysuckle vines, one is a native and the other an exotic invader. The red-flowered native Lonicera sempervirens is often outcompeted by the pale yellow flowered invasive, Lonicera japonica. Although their flowers are distinct (hummingbird and hawkmoth-pollinated), they are similar in their vegetative form. Here are their distinct flowers.
My students and I study the movement of plants, especially the movement of exotic invasive plants like Japanese Honeysuckle in natural areas in the southeast US. Plants move in three distinctly different ways, two of which are so slow that their movement tends to escape our animal-biased perception. Of course, plants move when they disperse pollen or seeds and genes or offspring are moved into new areas. But plants also have two other ways of moving that are much less studied: (1) As plants grow at their tips, they constantly enter new areas; changes in their morphology causes them to move at different rates in different environments. Click here to see a video of Japanese Honeysuckle moving past stationary plants during a 48 hour period (it's a big file so be patient while it loads) (2) All plants circumnutate or rotate around their central axis, but vines show an exaggerated form of circumnutation that allows them to climb supports. Click here to see a video of circumnutation. My students and I have projects investigating each of these types of movement in the exotic invasive, Lonicera japonica, and in the native Coral Honeysuckle, Lonicera sempervirens. Our goal is to learn why one is a serious invader of natural areas, and the other is a prized native vine.
Research Projects
Pollination Biology and Fruit Production in Honeysuckle. A biotically pollinated and dispersed exotic plant must establish new relationships with the animal community found within their new range. For Japanese Honeysuckle, the relationship established with pollinators is especially important, as the plants cannot produce viable seeds without pollen from a genetically distinct plant; in other words they are completely self-incompatible. We are investigating whether the pollinators found in the US are carrying enough Japanese Honeysuckle pollen, and carrying it far enough to find a different individual plant to allow for successful fruit and seed production. The importance of invasion through new colonization by seeds is unknown for Japanese Honeysuckle; through this project we hope to gain insights into the role played by seed dispersal in the overall invasion of natural areas by honeysuckle.
Clonal foraging in a native and introduced Honeysuckle. Because plants move on a much slower time scale than animals, we often fail to see them as mobile organisms. However, the honeysuckle vines we study are in constant motion, and move up to 4 meters per year. One researcher of vines stated that they were like green snakes moving through the more stationary tree canopy--they certainly are if you examine their movement over years rather than seconds and minutes as us animals like to do. Where do these vines go? That is the question we are addressing by examining how changes in their morphology and orientation impact how fast they move and where they move. Our hypothesis is that differences in mobility account for the difference in the invasive Japanese Honeysuckle and its non-invasive native congener Coral Honeysuckle.
