ORIGINAL PAPER An assessment of soil bacterial community structure and physicochemistry in two microtopographic locations of a palustrine forested wetland Changwoo Ahn Æ Patrick M. Gillevet Æ Masoumeh Sikaroodi Æ Kristin L. Wolf Received: 13 December 2007 / Accepted: 3 September 2008 / Published online: 19 September 2008 Ó Springer Science+Business Media B.V. 2008 Abstract We studied redoximorphic features, field indicators and bacterial communities of soils in hummocks and hollows of a palustrine forested wetland in Virginia. We hypothesized that presence of hydric soils, soil physicochemistry and soil bacterial community structure would differ between hummocks and hollows. We fingerprinted soils collected from different microtopographic locations using Length Heterogeneity Polymerase Chain Reac- tion (LH-PCR) to study their bacterial community structures. Two hummocks had silty/sandy loam soils with mean chroma values of [ 4, showing no indication of ‘hydric soils’ (i.e., wetland soils). Two hollows, however, had clay loam soils with mean chroma values of 2 with gleying and redox concen- trations observed, indicative of seasonally inundated wetlands. The soils of hollows also had higher organic matter content and soil moisture compared to the soils of hummocks (P \ 0.05). Multidimen- sional scaling (MDS) and Analysis of similarity (ANOSIM) of the fingerprints revealed differences in soil microbial community structures between hum- mocks and hollows (Global R = 0.30, P \ 0.01). The diversity measures of the fingerprints (Shannon’s H 0 ) were also different by microtopography with higher diversity in hollows relative to hummocks (P \ 0.05). LH-PCR proves to be a useful tool in examining bacterial community composition of wetland soils in this study. However, cloning and sequencing of specific community LH-PCR profiles of interest is necessary to fully characterize the community down to genus/species level. With species identities we should be able to not only better explain differences observed in the community profiles, but study their relations to hydrologic and/or physicochemical con- ditions of wetlands. Keywords Soil bacterial community structure Á LH-PCR Á Forested wetlands Á Microtopography Á Redoximorphic features Á Wetland soils Introduction Palustrine forested wetlands are a common type of non-tidal wetland found in the coastal plain of the southeastern United States (Messina and Conner 1998). Seasonally saturated coastal plain forested wetlands are described as shallow, temporary, inun- dated/saturated systems (Mitsch and Gosselink 2000). This type of wetland has a relatively short hydrope- riod, and is in danger of losing their jurisdictional status as wetlands (National Academy of Sciences 1995). Creation or restoration of forested wetlands is becoming more common since these communities are frequently impacted by development projects, but is C. Ahn (&) Á P. M. Gillevet Á M. Sikaroodi Á K. L. Wolf Department of Environmental Science and Policy, George Mason University, 4400 University Dr., MS 5F2, Fairfax, VA 22030, USA e-mail: cahn@gmu.edu 123 Wetlands Ecol Manage (2009) 17:397–407 DOI 10.1007/s11273-008-9116-4