Thursday, August 9, 2007
Exhibit Halls 1 and 2, San Jose McEnery Convention Center
Municipal restoration projects offer ecologists an opportunity to study the effectiveness of a variety of restoration techniques. The New York City Parks Department carried out a project to restore native vegetation on the floodplain of an urban park in 2004. Park managers used two techniques to prevent the re-establishment of invasive Fallopia japonica (formerly Polygonum cuspidatum) in restored areas: the installation of weed-control fabric and high-density seeding of Elymus virginicus. The purpose of this study was to evaluate (i) whether the treatments were effective at controlling Fallopia; (ii) whether the recovery of native vegetation varied between the restoration treatments; and (iii), whether planted woody materials grew faster in either of the restoration treatments. Both treatments successfully controlled Fallopia, with cover in unrestored reference plots= 0.99 ± 0.002, cover in the fabric treated plots= 0.16 ± 0.026 and cover in Elymus treated plots= 0.04 ±0.27. Species richness was lowest in unrestored reference plots (1.44 ±0.15), and was lower in Elymus (5.44 ±0.56) than in fabric treated (7.83 ±0.77) plots. Within the restored plots, there was significantly lower percent native cover in the Elymus treatments (0.27 ±0.030) than in fabric treatments (0.59 ±0.030). Mean height and crown spread of Cornus spp., Platanus occidentalis, and Quercus palustris were significantly greater for individuals planted in the fabric treated plots than in Elymus treated plots. In the critical early years of a restoration project, weed control fabric appears to be a superior restoration treatment to seeding with Elymus in degraded urban floodplains.
