The eastern redcedar Juniperus virginiana is the most widespread conifer in the eastern United States. J. virginiana is a range-expanding (encroaching) species that is native to the United States. This species contributes to the decline of plant biodiversity because it competes with native species for nutrients and other resources and changes the landscape of the areas where it encroaches. J. virginiana abundance is increasing in terms of area occupied, number of locations, and tree size. This encroachment can be related to climate change and the ability of this species to tolerate a wide range of climatic conditions. We tested the effect of a climate gradient on encroachment by J. virginiana in northeast Ohio. Lake-effect snow is a unique weather pattern that occurs on the east side of the Great Lakes, with regions closer to the Great Lakes being colder and receiving more snowfall. We are interested in investigating the effect of temperature and decreasing snowfall with increasing distance from Lake Erie. We conducted a field experiment in three different sites (Geauga, Portage, and Tuscarawas) at increasing distances from Lake Erie. We tested the effects of temperature and intra-specific competition (competition with one, two or four other J. virginiana) on the growth and survival of J. virginiana seedlings. We measured J. virginiana height and trunk diameter as an estimate of seedling quality and performance. In addition, we recorded water potential as an estimate of plant water stress.
Results/Conclusions
Our results suggest that there is no effect of temperature gradient on J. virginiana growth rate or on plant water stress. Moreover, there is no significant effect of intraspecific competition across our climate gradient. However, there appears to be facilitation between neighboring J. virginiana only at the Tuscarawas (warmest) site (p<0.001). Future efforts will determine if climatic conditions and competition are the main factors affecting the encroachment of J. virginiana into new habitats and areas.