01811nas a2200181 4500008004100000245012800041210006900169260003200238300001000270520111500280653002201395100001801417700001501435700001901450700001601469700001701485856012701502 1992 eng d00aEffects of tallgrass prairie vegetation on the concentration and seasonality of nitrate\-nitrogen in soil water and streams0 aEffects of tallgrass prairie vegetation on the concentration and bUniversity of Northern Iowa a9 -123 a
Inorganic nitrogen concentrations in tallgrass prairie soils and streams exhibit a sinusoidal seasonal pattern; nitrate levels are relatively high in winter and low in summer. The pattern is not observed in either rainfall or canopy drip (throughfall). Thus, the pattern is created by plant root-microbial interactions; when roots are not active, nitrates accumulate and can be leached from the soil. We used nitrogen fertilizer and herbicide in a factorial experiment to test the strength of root uptake activities on soil water nitrogen. Soil-water nitrate concentrations were 10 times higher when prairie roots were deactivated by application of a foliar herbicide. Ammonium nitrogen concentrations were unaffected. When fertilizer was added, nitrate levels of soil water beneath herbicide-treated vegetation were double that of untreated prairie. Mineralization of nitragen from herbicide-treated roots was not believed to be the source of the increased nitrate. These and previous studies at Konza Prairie emphasize the importance of plant cover in maintaining low nitrate concentrations of streams
10atallgrass prairie1 aRamundo, R.A.1 aTate, C.M.1 aSeastedt, T.R.1 aSmith, D.A.1 aJacobs, C.A. uhttp://lter.konza.ksu.edu/content/effects-tallgrass-prairie-vegetation-concentration-and-seasonality-nitrate-nitrogen-soil01975nas a2200205 4500008004100000245010800041210006900149260003200218300001100250520124000261653002201501100001601523700001801539700001801557700001601575700001701591700001601608700001701624856012801641 1992 eng d00aPopulation ecology of thirteen-lined ground squirrels in ungrazed tallgrass prairie manipulated by fire0 aPopulation ecology of thirteenlined ground squirrels in ungrazed aUniversity of Northern Iowa a51 -543 aFrom March 1983 to October 1987, thirteen-lined ground squirrels (Spermophilus tridecemlineatus Mitchill) were studied in ungrazed tallgrass prairie manipulated by fire on the Konza Prairie Research Natural Area, Kansas. Overall abundance varied among years (2.6 animals/ha in 1985; 5.6 animals/ha in 1986); however, no significant variation in sex ratio was observed (overall average=52% males for adults, 48% males for juveniles). Fire had a positive effect on ground squirrels; abundance was significantly higher in burned than unburned prairie during the year of a fire and in more recently than less recently burned prairie during years following a fire. Ground squirrels also selected hillsides with exposed rocks (breaks) over upland and lowland prairie sites. Although females and males selected similar habitats, home ranges were significantly larger for adult males (average=0.56 ha) than for adult females (0.36 ha). Both adult females and males caught on the study area typically were residents rather than transients. Further, overwinter survival did not differ between adult females and males. Overwinter survival of juvenile females was similar to adults; however, no juvenile males overwintered on the study area
10atallgrass prairie1 aClark, B.K.1 aKaufman, D.W.1 aKaufman, G.A.1 aGurtz, S.K.1 aBixler, S.H.1 aSmith, D.A.1 aJacobs, C.A. uhttp://lter.konza.ksu.edu/content/population-ecology-thirteen-lined-ground-squirrels-ungrazed-tallgrass-prairie-manipulated