Vernal pools of the northeastern United States: Plant assemblages and environmental conditions of constructed and natural ephemeral pools in New York State

Vernal pools enhance diversity by supporting wetland plant assemblages within terrestrial landscapes, and may provide habitat for plant species of concern (e.g. Scirpus ancistrochaetus). Conservation organizations construct vernal pools to mitigate wetland losses, but often without understanding pool plant assemblages or environmental factors acting on them. This research increases knowledge and understanding of plant assemblages in constructed and natural pools in New York State. I characterized abiotic features and vascular plants in pools of various origins and ecological contexts, and quantified influences of environmental factors on vascular plant richness, cover, and composition. Pools were heterogeneous. Open-canopy pools differed significantly from forested pools, and older pools were more similar to natural pools. Light, drawdown, depth, age, conductivity, and pH were related to plant assemblage characteristics. I recommend an environmental sieve model to frame how environmental factors influence species composition. Pool design and management decisions should consider potential impact on plant assemblages.