Plant Species Diversity in Restored and Created Delmarva Bay Wetlands

Abstract

A primary goal of wetland restoration is to produce biologically diverse and resilient habitat, often to mitigate losses elsewhere. Many factors influence wetland biodiversity including hydrologic regime, soil chemistry, texture, and microtopographic variation. A better understanding of these relationships can provide valuable information to practitioners. This study sampled plant communities of eight created or restored Delmarva Bay wetlands a decade after project completion to identify drivers of plant diversity at multiple scales. Study wetlands varied in terms of size, hydroperiod, soil fertility, coarse woody debris application, and straw mulch type. Wetlands with shorter hydroperiods had higher herbaceous plant diversity, but both herbaceous and woody diversity declined as soil fertility increased. Coarse woody debris density was not related to any of the diversity variables measured. There was no difference in species richness, soil carbon, total N, C:N or exotic species cover between wetlands treated with wheat or barley straw. We found that alpha and beta diversity were significantly correlated with different independent variables in our study and were not intercorrelated, suggesting that beta diversity may be an additional tool to assess diversity in heterogeneous habitats like depression wetlands.

Appendices

Appendix A

Table 3 Species encountered in created and restored wetlands in June and August 2013

Appendix B

Table 4 Soil chemistry and texture of the eight wetlands studied at the Nature Conservancy’s Jackson Lane Preserve