Forest ecosystem services are integral to human activity and forest-dependent organisms. However, the arrival of the hemlock woolly adelgid (HWA; Adelges tsugae), an aphid-like insect, to New England in the 1980s has led to the mortality of hemlock trees of all size classes and could alter ecosystem services in hemlock-dominated forests, necessitating research on how these forests will change. The tree seedling stage is a critical bottleneck stage for tree populations, but their role in forest responses to disturbance is understudied. To understand how hemlock-dominated forests will change, it is necessary to consider factors of current seedling survival. Studies have found that when some seedlings of the same species are closer together, they are more susceptible to host-specific pathogens and predators, negatively impacting their survival. This pattern is known as conspecific negative density dependence (CNDD). To investigate how conspecific density and heterospecific density relate to the seedling survival of different tree species in New England, we collected and analyzed data on seedling survival and species type within 1m2 plots in the Harvard Forest MegaPlot, a 35-hectare plot in which every stem over 1cm in diameter is identified and mapped. We predicted seedling survival to be greater with lower seedling density but that the effect size of conspecific density on survival would be greater than for heterospecific density. Surprisingly, we found a significant positive correlation between Betula spp. survival and conspecific density and a significant negative correlation between Pinus strobus survival and heterospecific density. Understanding the relative impact of CNDD on different seedling species can set a foundation for more research to model future tree populations and provide insight into which species will dominate current hemlock stands.