What are the effects of nutrient addition and competition on the growth of Juniperus virginiana?
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 grassland biodiversity because it competes with native species for nutrients, resources and changes the landscape of the areas where it encroaches. In Ohio, J. virginiana is particularly abundant on limestone-derived substrates, either because this species prefers to grow on limestone or due to the absence of competition with other species. We are interested in investigating the factors that are most important in facilitating the encroachment of J. virginiana into new areas. We tested the effects of nutrient content, high pH, and interspecific competition with a common invasive grass (Bromus inermis) and a native tree (Quercus stellata) on the growth and survival of J. virginiana seedlings. We recorded J. virginiana and Q. stellata height and trunk diameter weekly as an estimate of seedling quality and performance. We found that J. virginiana seedlings competing with the invasive grass B. inermis grew more slowly than J. virginiana growing without B. inermis or J. virginiana seedlings with the post oak Q. stellata. In addition, there was a negative effect of limestone addition on J. virginiana growth rate. Our results suggest that J. virginiana does not prefer high pH soil, but rather it thrives in these soils to minimize competition. Future efforts will determine if competition is the main factor affecting the encroachment of J. virginiana into new habitats and areas, which in turn will assist efforts to control woody encroachment into grasslands.
Hamati, Samia and Ward, David(2019). What are the effects of nutrient addition and competition on the growth of Juniperus virginiana?. Environmental Science & Design Research Initiative. Paper 25.