PARENT SESSION
Poster Session 7: Invasive Species.
Monday, August 2 Presentations from 5:00 PM to 6:30 PM, Exhibit Hall A 1.
Interactions in the decomposition of native and invasive litter in a northeastern hardwood forest.
Hickman, Jonathan*,1, Howe, Kate1, Ashton, Isabel1, Jessica, Gurevitch1, Lerdau, Manuel1, 1 Stony Brook University, Stony Brook, NY
ABSTRACT- If the litter quality of invasive and native plant species differs, the introduction of invasive litter to an ecosystem can change decomposition rates and alter nutrient cycling. Litter from invasive species may decompose more quickly, but its presence also has the potential to increase rates of decomposition of native litter when litter of different species is mixed if microorganisms colonizing invasive litter are transferred to native litter. We conducted two experiments to examine differences in the decomposition of single species and mixed native and invasive litter within a single site and to determine the role of microbial communities in decomposition of native and invasive litter . Both experiments were conducted in a mesic, harwood forest on Long Island, using litter from congeneric or confamilial pairs of common native and invasive plant species. For the first experiment , mesh bags filled with litter from a single species were placed in the field and collected at six time points over a year to study rates of mass and nutrient loss. Within the invaded sites, litter from single invasive species appears to be losing mass more quickly than native litter, though this may not be significant. Litter of both native and invasive species decreased in C:N ratio up to 25 weeks, and invasive litter had consistently lower C:N. The second experiment examines the decomposition of species combinations using litter from three of the native-invasive pairs used in the first experiment. Mesh bags were filled with each single species and each possible two-species combination; mass and C:N content were measured for bags collected at six time points over the year. We used measures of respiration and an examination of 16s rRNA fragments to characterize differences in the structure of microbial communities associated with each species and species combination at three time points.
Key words: decomposition, Invasive species, microbial communities