Date of Award




Document Type

Master's Thesis

Degree Name

Master of Science (MS)


Department of Biological Sciences

Content Description

1 online resource (vii, 38 pages) : color illustrations, color maps

Dissertation/Thesis Chair

George Robinson

Committee Members

Jeffrey D Corbin, Tomas Caraco


Celastrus, ecology, invasive, mycorrhizae, plant, soil, Invasive plants, Plant-soil relationships, Celastrus orbiculatus

Subject Categories

Ecology and Evolutionary Biology | Plant Sciences | Soil Science


The Hudson River Estuary has been colonized by numerous terrestrial invasive plant species, due in part to its history of anthropogenic and natural disturbance riparian dynamics. This study investigates the spatial patterns of a widespread invasion by Oriental (or Asiatic) bittersweet (Celastrus orbiculatus Thunb.) in Schodack Island State Park, Rensselaer and Columbia Counties. The Park is home to rare species and communities, several of which are threatened by the encroachment of bittersweet. Bittersweet populations were mapped and surveyed on a fixed grid throughout the island, to determine distribution patterns. Stem densities were approximately 50% higher in sites with dredged material substrate. Local experimental tests were performed at twenty-five locations (five different site types) based on substrate properties (dredged substrate or native forested floodplain) and local bittersweet densities (absent, low, and high). Ten greenhouse-grown seedlings (transplants) and 100 seeds were planted at each site, and then tracked for their survival, growth, and evidence of mycorrhizal inoculation. Transplants survived and grew at similar rates among the five experimental site types, but seed germination varied (p=0.05), with the highest rate in the dredged material zones Higher rates of vesicular-arbuscular mycorrhizal inoculation were seen in the dredged versus native substrate (p<0.01), but rates were comparable among sites with different bittersweet densities. This may be the first field test for mycorrhizal mutualism in C. orbiculatus and the first evidence of widespread inoculation as a potential driver of the invasion process.