02680nas a2200229 4500008004100000245009800041210006900139300001300208490000700221520195100228653002002179653002102199653002002220653002402240653002202264653002302286100002002309700002002329700001702349700001802366856006602384 2013 eng d00aWoody vegetation removal stimulates riparian and benthic denitrification in tallgrass prairie0 aWoody vegetation removal stimulates riparian and benthic denitri a547 -5600 v163 a
Expansion of woody vegetation into areas that were historically grass-dominated is a significant contemporary threat to grasslands, including native tallgrass prairie ecosystems of the Midwestern United States. In tallgrass prairie, much of this woody expansion is concentrated in riparian zones with potential impacts on biogeochemical processes there. Although the effects of woody riparian vegetation on denitrification in both riparian soils and streams have been well studied in naturally wooded ecosystems, less is known about the impacts of woody vegetation encroachment in ecosystems that were historically dominated by herbaceous vegetation. Here, we analyze the effect of afforestation and subsequent woody plant removal on riparian and benthic denitrification. Denitrification rates in riparian soil and selected benthic compartments were measured seasonally in naturally grass-dominated riparian zones, woody encroached riparian zones, and riparian zones with woody vegetation removed in two separate watersheds. Riparian soil denitrification was highly seasonal, with the greatest rates in early spring. Benthic denitrification also exhibited high temporal variability, but no seasonality. Soil denitrification rates were greatest in riparian zones where woody vegetation was removed. Additionally, concentrations of nitrate, carbon, and soil moisture (indicative of potential anoxia) were greatest in wood removal soils. Differences in the presence and abundance of benthic compartments reflected riparian vegetation, and may have indirectly affected denitrification in streams. Riparian soil denitrification increased with soil water content and NO3 −. Management of tallgrass prairies that includes removal of woody vegetation encroaching on riparian areas may alter biogeochemical cycling by increasing nitrogen removed via denitrification while the restored riparian zones return to a natural grass-dominated state.
10adenitrification10anitrogen removal10aprairie streams10ariparian vegetation10atallgrass prairie10awoody encroachment1 aReisinger, A.J.1 aBlair, John, M.1 aRice, C., W.1 aDodds, W., K. uhttps://link.springer.com/article/10.1007%2Fs10021-012-9630-3