PARENT SESSION
Poster Session # 16: Invasive Species.

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

The role of plant-soil feedbacks in the persistence of reed canary grass.

Vinton, MaryAnn^*,1, Vigue, Leanne^*,1, ¹ Department of Biology, Omaha, NE, 68178

ABSTRACT- Reed canary grass (Phalaris arundinacea) is a persistent and invasive species of tallgrass prairie lowlands. We performed field experiments to evaluate the role of soil nitrogen and litter decomposition in the growth and persistence of this species relative to native tallgrass species. Soil manipulations involved nitrogen fertilization with ammonium nitrate and lowered soil nitrogen treatments with the addition of high carbon materials, sucrose and sawdust. Litter bags were constructed using recently produced litter of big bluestem and reed canary. Reed canary grass showed a stronger positive response to added nitrogen than did native species. The growth of both reed canary grass and native species seemed to be affected by a preemption of soil nitrogen by weedy dicots that eventually dominated many plots. Soil carbon additions affected plant-available nitrogen in complex ways and may not have the desired effect of lowering nitrogen mineralization. Reed canary grass litter likely persists longer than that of other species and this mechanism may be key to its ability to dominate sites.

Key words: nitrogen mineralization, invasive species, Phalaris arundinacea , litter decomposition