Forests are important because they benefit the economy, harbor biodiversity, store carbon, and are a valuable conservation mechanism. Unfortunately several trees are dying due to invasive species. One in particular, Tsuga canadensis(eastern hemlock), is being killed by the Adelges tsugae (hemlock wooly adelgid). Tsuga canadensisis a hypothesized foundation species that is prevalent in the eastern United States. This tree casts deep shade over the area it occupies. The pH under T. canadensisis significantly more acidic than other areas in the forest with a pH of four compared to the usual pH of about six. For this reason, T. canadensishas a big effect on understory plant abundance, diversity, and mortality because light limitation and soil acidity can affect how plants grow and survive. How will the absence of T. canadensis affect tree seedling recruitment in the forest? To answer this question data were collected from the hemlock-dominated mega plot where adelgid was first found in 2009. In the megaplot seedlings that reside in meter by meter plots were measured and identified. Hemispherical canopy pictures were taken to measure canopy openness, and soil samples were collected to measure pH.
Results/Conclusions
A total of 4,240 seedlings were measured with the top species found being Acer rubrum(red maple) at 2,557 seedlings, Tsuga canadensis (hemlock)at 604 seedlings, Quercus rubra(red oak) 333 seedlings, and Pinus Strobus(white pine) 218 seedlings. The survivorship rates for A. rubrum, T. canadensis, Q. rubra, and P. Strobuswere 0.71, 0.84, 0.62, and 0.87, respectively. The mortality rates for A. rubrum, T. canadensis, Q. rubra, and P. Strobuswere 0.29, 0.16, 0.38, and 0.13. With the hemlock dying off, the forest could change drastically depending on which trees take its place. It is necessary to study seedlings because they represent the future trees.