Effects of an Invasive Species, Bush Honeysuckle, on Leaf Decomposition in Central Kentucky

The forests of central Kentucky are dynamic ecosystems in which leaf litter decomposition is an important pathway of nutrient recycling. The presence of invasive bush honeysuckle (Lonicera maackii) in the forest understory may alter decomposition in leaf litters of native species. This study was designed to examine the influence of bush honeysuckle on leaf litter decomposition in a forested site at Griffith Woods, located in the Inner Bluegrass Physiographic Region. Using leaf litter of bush honeysuckle and two dominant tree species, white ash (Fraxinus americana), and hickory (Carya spp.), we tested the hypotheses that honeysuckle litter will have the fastest rate of decomposition followed by ash and hickory, and that the presence of bush honeysuckle will increase decomposition rate of all three species. To test these hypotheses, 10 plots were established within a forested area, 5 dominated by bush honeysuckle, 5 without honeysuckle. Eight grams of leaf litter of each of the three species were sealed in mesh bags and placed at the plots and then collected in 0, 1, 3, 6, and 12 month intervals to measure decomposition over time. Results thus far (through 6 months) suggest that honeysuckle litter decomposes much more rapidly than the other species. Contrary to our second hypothesis, bush honeysuckle decreased the decomposition rate of all leaf litters in months 1 and 3, but not at 6 months. Rapid decomposition of honeysuckle litter is likely driven by litter quality, whereas slower decomposition under bush honeysuckle is likely the result of changes to microclimate and soil processes