PARENT SESSION
Poster Session # 16: Invasive Species.

Wednesday, August 6 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Invasion by Lonicera japonica impacts species turnover in a successional system.

Yurkonis, Kathryn^*,1, Meiners, Scott¹, ¹ Eastern Illinois University, Charleston, IL

ABSTRACT- Invasive plant species are often associated with reductions in species richness within native communities. Reductions in species richness can either occur through changes in species extinction rates or colonization rates within native communities. Documenting species turnover in long-term studies provides an opportunity to identifying the mechanistic basis for reductions in species richness associated with exotic species invasions. One such study that has been documenting exotic species invasions in abandoned agricultural fields is the Buell-Small Succession study. Over the past 44 years, species abundance and coverage has been recorded for 480 plots in 10 fields differing in last crop and type and season of abandonment. During a ten year time window from 5 to 15 years since abandonment, coverage of the exotic species Lonicera japonica increased. Within this time period, increasing Lonicera japonica cover is associated with decreases in species richness. Additional analyses indicate increases in coverage of Lonicera japonica have little effect on community extinction rates, whereas increasing Lonicera coverage results in a reduction in community colonization rates. In association with reduced colonization rates, variation exists in dominant species and lifeform responses to invasion. These findings suggest that species richness declines seen with invasion result from reduced community colonization rates and not competitive species displacement as is often hypothesized.

Key words: invasion, species turnover, exotic species , diversity