02188nas a2200217   4500008004100000245015900041210006900200260001600269300001100285490000700296520142400303653002601727653002301753653002701776653002201803653002301825100001601848700001801864700001801882856007001900       2015                        eng d00aWoody plant encroachment, and its removal, impact bacterial and fungal communities across stream and terrestrial habitats in a tallgrass prairie ecosystem0 aWoody plant encroachment and its removal impact bacterial and fu  cDec-10-2015  afiv1090 v913 aWoody plant encroachment has become a global threat to grasslands and has caused declines in aboveground richness and changes in ecosystem function; yet we have a limited understanding on the effects of these phenomena on belowground microbial communities. We completed riparian woody plant removals at Konza Prairie Biological Station, Kansas and collected soils spanning land–water interfaces in removal and woody vegetation impacted areas. We measured stream sediments and soils for edaphic variables (C and N pools, soil water content, pH) and bacterial (16S rRNA genes) and fungal (ITS2 rRNA gene repeat) communities using Illumina MiSeq metabarcoding. Bacterial richness and diversity decreased with distance from streams. Fungal richness decreased with distance from the stream in wooded areas, but was similar across landscape position while Planctomycetes and Basidiomycota relative abundance was lower in removal areas. Cyanobacteria, Ascomycota, Chytridiomycota and Glomeromycota relative abundance was greater in removal areas. Ordination analyses indicated that bacterial community composition shifted more across land–water interfaces than fungi yet both were marginally influenced by treatment. This study highlights the impacts of woody encroachment restoration on grassland bacterial and fungal communities which likely subsequently affects belowground processes and plant health in this ecosystem.10abacterial communities10afungal communities10aland–water interface10atallgrass prairie10awoody encroachment1 aVeach, A.M.1 aDodds, W., K.1 aJumpponen, A.  uhttp://femsec.oxfordjournals.org/lookup/doi/10.1093/femsec/fiv10902680nas 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<p>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 &minus;. 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.</p>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%2Fs10021-012-9630-302328nas a2200217   4500008004100000245011200041210006900153300001000222490000700232520159700239653001001836653001201846653000901858653001801867653002201885653002201907653002101929100001801950700001801968856012401986       2002                        eng d00aWater velocity attenuation by stream periphyton and macrophytes in relation to growth form and architecture0 aWater velocity attenuation by stream periphyton and macrophytes   a2 -150 v213 aPeriphyton and macrophytes alter water velocity in streams, influencing movement of solutes and providing microhabitat for other organisms. How assemblages with different growth form and architecture influence water velocity attenuation across mm to dm scales is not well described. A thermistor microprobe was used to measure water velocity through 4 morphologically distinct stream periphyton assemblages and 4 distinct stream macrophyte assemblages in flumes. All assemblages resulted in an exponential decay in velocity with depth. A dense assemblage of diatoms (primarily Cymbella) attenuated velocity more than filamentous green algae, filamentous green algae with interspersed diatoms, or a red alga (ANOVA, p < 0.05). External water velocity had no significant influence on the coefficient of attenuation in a filamentous green alga (ANOVA, p = 0.76). Macrophytes also attenuated water velocity, but attenuation was more variable and, in all cases, attenuation coefficients were less for macrophytes than for periphyton. A model unifying attenuation by periphyton and macrophytes was developed using biomass density (g ash-free dry mass/m<sup>3</sup>) as the independent variable and it explained 80% of the variation in attenuation. The relative variance of attenuation coefficients increased sharply as Reynolds number increased above ∼500 to 700, suggesting that variance in water velocity was dependent upon the spatial scale of the primary producer through which water is flowing, and that the distinction btween periphyton and macrophytes may have real physical ramifications.10aAlgae10aCurrent10aFlow10aHydrodynamics10amicrophytobenthos10aPrimary producers10aSubmerged plants1 aDodds, W., K.1 aBiggs, B.J.F.  uhttp://lter.konza.ksu.edu/content/water-velocity-attenuation-stream-periphyton-and-macrophytes-relation-growth-form-and