Microtopography Alters Hydrology, Phenol Oxidase Activity and Nutrient Availability in Organic Soils of a Coastal Freshwater Forested Wetland
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
2018, Society of Wetland Scientists. Hummock-hollow microtopography is a unique feature of wetland ecosystems, but our understanding of its effects on soil carbon and nutrient cycling is limited. We investigated effects of microtopography on hydrology, phenol oxidase activity (POX) and nutrient availability in a freshwater forested wetland of coastal North Carolina. Water table depth (WTD) was measured from September 2012 to August 2013. Ion exchange probes were used to measure nutrient concentrations prior to soil sample collection in August 2013. WTD fluctuated seasonally with maximum and minimum WTD resulting in 92% (September 2012) to 8% (June 2013) of the site in flooded and non-flooded conditions, respectively. Hummocks had greater POX activity (12 2.8molg1h1) compared to hollows (4 0.7molg1h1) and greater concentrations of potassium and sulfur, but lower concentrations of calcium, iron, zinc, boron, and lead. POX was negatively correlated with soil water content. Higher enzyme activity in hummocks likely drives greater rates of carbon and nutrient cycling compared to hollows, consistent with observations that hummocks are hotspots for CO2 fluxes. Microtopography altered site-level hydrologic conditions, phenol oxidase activity and nutrient availability with important implications for understanding carbon and nutrient cycling in forested wetlands and response to changes in hydrology.
