ABSTRACT Plant secrete density, an...

ABSTRACT

Plant secrete density, and standing crop biomass were measured and compared in a created wetland and an adjacent freshwater marsh (reference wetland) in Charles City shire Virginia. No significant difference was observ between monthly standing first stomach in the created wetland and the allusion wetland. Species composition differed between sites (mean SI

INTRODUCTION

Wetland creation attempts are frequently initiated by the removal of upland surface soil materials exposing mineral subsoil strata (Atkinson et al. 1993) The compass to which the revegetation arrangement may be viewed as primary succession is hanging upon the amount of soil removal and the viability of the pre-existing se bank (Mitsch and Gosselink 2000) The vicinity of wetland species in the se bank following construction will frequently be minimal or lacking based in succession the antecedent upland condition of the site (Kusler and Kentula 1989) Species near during the first few years of vegetation establishment that were not planted or grained are assumed to be offers from offsite sources (Reinhartz and Warne 1993) and therefore show the primary seral stage of vegetation succession. For the final causes of this review, we define "created wetland" in the words immediately preceding [i]or[/i] following of wetland regulation in the United States as the "establishment of a wetland where one did not formerly exist" (Federal Register Vol 60 No. 228 p 58613)

Created wetland sites located in stop proximity to undisturbed, adjacent wetlands have shown greater colonization of wetland species than more far off sites (Brown 1998, Brown and Bedford 1997 Reinhartz and Warne 1993) In these combination of parts to form a wholes vegetation in adjacent wetlands may be a potential se source, particularly from habitats dominated by the agency of herbaceous species that are more likely to colonize a young substrate (Thompson 1992)

Prediction of pioneering species composition can be based onward a working knowledge of the life history strategies and reproductive phenologies of the proffer vegetation (ter Heerdt and Drost 1994 van der Valk 1981) Classifying species according to life history (i.e., annual v perennial) upon created wetland sites may help describe vegetation recruitment patterns in the connection of existing wetland succession originals (van der Valk 1981, Mitsch and Gosselink 2000)

The meaning of this study was to compare vegetative species composition and standing lop in a newly created freshwater wetland with that of an adjacent freshwater emergent relation wetland. From this information, we will determine the prototypes of species that utilize created wetland sites as colonizing substrates, and evaluate composition, standing clip and distance from a se source as indicators of wetland vegetation establishment in young sites.

METHODS

Site Description

The subject of attention site is a created wetland in Charles City shire Virginia, located on a tributary of the Chickahominy River in the James River watershed (37?°20'58'' Lat., 76?°55'30' Long; Figure 1) The area was designed for use as forested wetland mitigation, and construction was complet in mid-summer 1996 The sampling window (April to August, 1998) set forths the second full growing season following final grading in succession the site. Woody species had not been planted at the time of the study

The sample site included a portion of the created wetland and a newly timbered (1996) secondary successional emergent respect wetland that was adjacent to the created wetland. The sum of two units sites were approximately 10 meter apart, and were separated at a broad, flat, shallow upland berm (ca. sum of two units feet high) which prevented the direct result of surface water between the sites (Figure 2) The upland berm was created as a construction access road in 1996 and during this cogitation (1998) was populated with native mean fellow vegetation.

Both sites (created wetland and hint wetland) may be classified as palustrine emergent headwater wetlands (Cowardin et al. 1979) The hint wetland lay adjacent to a larger forested wetland complicate to the east (Figure 2) Principle hydrology sources for the couple sites included precipitation capture and runoff from adjacent forested areas. No soil amendments were incorporated into the created wetland during construction, and the site had been semened with a stabilizing grass se mix of Lolium perenne ssp multiflorum and Panicum virgatum immediately after grading was complet During the reflection (April-August 1998), both sites were inundated with shallow surface water (ca. 5-12 cm) in consequence of June.

Study Design

A baseline was established perpendicular to the created wetland/reference wetland interface, from which sampling transects were placed at 2 m 20 m 40 m 60 m and 80 m parallel to the rim of the created wetland. The use of a stratified random sampling design allowed analysis of distance from the potential se source (reference wetland) as an independent variable of vegetation establishment. In the intimation wetland, a random sampling design was occupyed in which a single baseline was determined and three random transects were established perpendicular from that baseline. Transect position and scheme distance along each transect varied from month to month to accommodate destructive sampling (standing crop) The adequacy of the sample size in the respect wetland was verified by species-area winds at the outset of the consideration (Mueller-Dombois and Ellenburg 1974). Three random points were established in succession each of the five created wetland transects and the three relation wetland transects monthly (mid-month), April [i]or[/i] part of to the other August, 1998, for a total of 75 points in the created wetland and 15 points in the intimation wetland over the five month inquiry period.