Vegetation dynamics across a chronosequence of created wetland sites in Virginia, USA

Abstract

Plant species composition, dominance, richness, and diversity were measured across a 15-year chronosequence of created wetland sites in Virginia, USA. Using an age-class categorization (1–2 years, 3–5 years, 6–10 years, or 11–15 years), all classes had a predominance of herbaceous species with perennial life history strategy, and perennials contributed 68.6 % to the overall dominance measure (importance value; IV) averaged across all sites. There was no significant difference in species richness or diversity among age classes. Analysis of Similarity (ANOSIM) indicated that herbaceous species composition was similar between the youngest and oldest age classes, but not the intermediate classes. For woody shrubs and saplings, planted species were more prevalent in the youngest age classes, and volunteer species predominated in the oldest age classes. These results suggest that perennial herbaceous species are important in early plant development on created wetland sites, and may be influential in observed patterns of species composition over time. In the context of plant development in newly created wetlands, dominance shifts from planted to volunteer woody species suggest that planting early successional species, or species with reproductive strategies attuned to created wetland site management, may favor survivorship and recruitment of other species over time.