Effects of flood inundation, invasion by Phalaris arundinacea, and nitrogen enrichment on extracellular enzyme activity in an Upper Mississippi River floodplain forest

Nathan R. De Jager; Whitney Swanson; Daniel L. Hernandez; Julia Reich; Richard A. Erickson; Eric A. Strauss

doi:10.1007/s11273-018-09651-2

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Effects of flood inundation, invasion by Phalaris arundinacea, and nitrogen enrichment on extracellular enzyme activity in an Upper Mississippi River floodplain forest

Nathan R. De Jager·Whitney Swanson·Daniel L. Hernandez·Julia Reich·Richard A. Erickson·Eric A. Strauss

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Abstract

The community structures and ecosystem functions of floodplains are primarily driven by variation in flood inundation. However, global changes, such as invasive species and nutrient enrichment, may alter the effects of flooding in these systems. We added nitrogen (N) to correspond with twice the annual atmospheric deposition rate of the south-west Wisconsin, USA region within mature floodplain forest plots and patches of an invasive grass (reed canarygrass, Phalaris arundinacea ) along a floodplain elevation gradient in an Upper Mississippi River floodplain forest. We measured soil physicochemical properties and the activity of six extracellular enzymes during 3 months that varied in flooding conditions. Multivariate analyses (distance-based redundancy analysis) revealed that floodplain elevation, month of sampling, and vegetation type were all significant predictors of variation in soil physicochemical properties, while elevation and month were significant predictors of multivariate extracellular enzyme activity (EEA). The best model for predicting EEA consisted of nitrogen availability, soil porosity, and water filled pore space. Although the categorical fertilization and invasion treatments were not significant predictors of EEA, our results suggest that their effects depend on the degree to which they modify N availability and soil moisture. In this system, spatial and temporal patterns in flooding appear to be the main driver of these properties, but N enrichment and invasion may have the potential to further modify them.

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Wetlands Ecology and Management Article

Source-reported bounding extent: 43.69071491326582° to 43.90778718292443° latitude; -91.40556335449219° to -91.11717224121094° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

Nathan R. De Jager, Whitney Swanson, Daniel L. Hernandez, Julia Reich, Richard A. Erickson, Eric A. Strauss. 2019-01-07. Effects of flood inundation, invasion by Phalaris arundinacea, and nitrogen enrichment on extracellular enzyme activity in an Upper Mississippi River floodplain forest. https://doi.org/10.1007/s11273-018-09651-2

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