PARENT SESSION
Oral Session # 9: Invasive Species I: Theory and Modeling.
Presiding: E Rykiel
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 201.

Exotics do NOT always invade: Mechanisms underlying the success and failure of vine invasions.

Ashton, Isabel^*,1, Lerdau, Manuel ¹, ¹ Stony Brook University, Stony Brook, NY

ABSTRACT- Some species of exotic woody vines are aggressive invaders in temperate forests, yet others do not invade these ecosystems. Invasion success in vines may be related to differential growth and response to light environment. To test the hypothesis that invasive vines are better adapted to both low and high light environments than their non-invasive relatives, I performed a greenhouse experiment in Long Island, NY with temperate vines from 3 families (Caprifoliaceae, Celastraceae, and Vitaceae). I grew plants of 3 invasion categories (invasive exotic, non-invasive exotic and native) within each family. Plants were grown under either shade cloth (75% ambient) or ambient light conditions. Invasive species grew significantly faster than either native or exotic non-invasive species under both treatments. These results suggest that invasive vines have the capacity to grow rapidly even in the forest understory. To examine the physiological underpinning of this response, light response curves and maximum photosynthetic rates were measured. The exotic non-invasive vines respond to increases in light availability differently than native or invasive vines. Native and invasive vines respond to increases in light availability with increases in photosynthetic capacity. In contrast, non-invasive vines do not increase their photosynthetic capabilities. These results suggest that exotic vines that have not established in the United States may be limited in part by their physiological properties.

Key words: Temperate vines, Invasions