Riparian community structure and soil properties of restored urban streams

Abstract

AbstractCommunity assembly and the resulting community structure reflect both local and regional processes. The relative importance, however, of each of these scales in most restoration contexts is unknown. Urban stream restoration, which often involves complete remodelling and replanting of the riparian zone, presents an opportunity to investigate the influences of local and regional processes on community assembly and local and regional biodiversity. Additionally, published outcomes of urban riparian restoration projects, particularly pertaining to plant community composition and soil properties, are lacking in the literature. The aim of this study was to compare the vegetation and soils of paired restored and unrestored urban stream reaches near Baltimore, Maryland. We found that the composition of the mature tree and sapling communities at restored sites differed significantly from that of unrestored sites, indicating that priority effects imposed via planting may dominate subsequent assembly of woody vegetation in urban riparian plant communities, at least in the short term. We also found disparate outcomes for both vegetation and soils at urban stream restoration sites in Baltimore as compared with other studies elsewhere in the mid‐Atlantic United States, but lack of long‐term data or information on specific restoration practices makes it difficult to draw connections between particular techniques and outcomes. Notably, both restored and unrestored reaches in the Baltimore area had very low levels of invasion by exotic tree species, and high levels of Pb and Zn in unrestored reaches and Ca in all reaches reflect the influence of the urban matrix on soil properties. Copyright © 2015 John Wiley & Sons, Ltd.