Text

ETD_2684

http://hdl.rutgers.edu/1782.2/rucore10002600001.ETD.000052955

theses

Community evolution is the hypothesis that characterizes the changes that occur in the community structure, genetic make up, and the inherent dynamics of those aforementioned characteristics from community inception to climax. The neighborhood effect is the hypothesis that explains the impact that individuals have upon each other in a community setting. These two hypotheses combined are indicative of the field of theoretical community dynamics. Though the field is still in its infancy, much evidence has been provided suggesting that there are vast effects upon community stability, species associations, and plant soil correlations with time as the major treatment variable. Additionally, a few authors have investigated the effects of neighbor change on individual performance and found significant impacts of neighbor identity. These ideas, however, have never been coupled with the field of invasion biology. Four years ago, I designed an experiment to investigate the relationships among species performance, behavior, ecological origin, evolutionary history, and distance. I essentially, defined distance and time as analogous when looking at the effects of competition past, focused on plant performance and behavior, with a spin to include non-native plants in to the design. The results suggest that plant pairs taken from the same community have the ability to avoid root overlap; this trend broke down in a linear fashion from the closest to the most distant treatments. Moreover, individuals of the differing evolutionary origin did not show any avoidance ability or other trend in their root behaviors. Performance of individuals was also significantly affected by origin. Individual sampled together and, consequently, grown together exhibited more even growth than those that were sampled from greater distances apart. Finally, in a real world setting individual replanted within their own community exhibited suppressed growth compared to those transplanted into new communities. We suggest that these results are evidence for community change and the neighborhood effect where the community acts as a growth control and all species are capable of acting an "invasive" manner; and, that the community building process leads to communities consisting of the most ecologically suited composition of individuals. To obtain a broad perspective of the aforementioned results, an observational study of the community dominance trends of Artemisia vulgaris conducted with time as the major treatment variable. From 2006 to 2009 transects, perpendicular to the border zones of our target species and other community constituents, were evaluated for percent cover. Those data were analyzed using metrics that were develop specifically for this study and the results suggest that mugwort is a highly dominant non-native exhibiting characteristics of range expansion within the Liberty State Park interior. Additionally, in all pairs where the border was mugwort and a U.S. native the trend was that of dominance. However, when the pair was mugwort and its home-range conspecific the border was low in A. vulgaris or that of a declining trend. The other purpose of this study was to assess the necessity for control of A. vulgaris in the Liberty State Park interior. The results suggest that, if the overall project goal is to reclaim the land as a natural wildland, A. vulgaris needs to be controlled.

Ph.D.

Includes abstract

Vita

Includes bibliographical references

by Mark June-Wells

doi:10.7282/T3QN66V4

ETD doctoral

The author owns the copyright to this work.

ETD

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