00555nas a2200157   4500008004100000245009400041210006900135100002100204700002300225700001900248700001800267700001900285700001800304700001800322856005700340       2022                        eng d00aImpacts of riparian and non-riparian woody encroachment on tallgrass prairie ecohydrology0 aImpacts of riparian and nonriparian woody encroachment on tallgr1 aKeen, Rachel, M.1 aNippert, Jesse, B.1 aSullivan, P.L.1 aRatajczak, Z.1 aRitchey, Brynn1 aO’Keefe, K.1 aDodds, W., K.  uhttps://link.springer.com/10.1007/s10021-022-00756-700616nas a2200169   4500008004100000245012100041210006900162300001200231490000700243100001600250700001800266700002300284700001700307700002100324700002200345856007900367       2021                        eng d00aSpatio-temporal differences in leaf physiology are associated with fire, not drought, in a clonally integrated shrub0 aSpatiotemporal differences in leaf physiology are associated wit  aplab0370 v131 aWedel, E.R.1 aO’Keefe, K.1 aNippert, Jesse, B.1 aHoch, Braden1 aO’Connor, R.C.1 aMitchell, Patrick  uhttps://academic.oup.com/aobpla/article/doi/10.1093/aobpla/plab037/629532502066nas a2200205   4500008004100000245009100041210006900132260001600201300001400217490000800231520142400239653001901663653001101682653002201693653001801715653002001733100001801753700002301771856006601794       2017                        eng d00aAn assessment of diurnal water uptake in a mesic prairie: evidence for hydraulic lift?0 aassessment of diurnal water uptake in a mesic prairie evidence f  cFeb-02-2017  a963–9750 v1833 aHydraulic lift, the passive movement of water through plant roots from wet to dry soil, is an important ecohydrological process in a wide range of water-limited ecosystems. This phenomenon may also alter plant functioning, growth, and survival in mesic grasslands, where soil moisture is spatially and temporally variable. Here, we monitored diurnal changes in the isotopic signature of soil and plant xylem water to assess (1) whether hydraulic lift occurs in woody and herbaceous tallgrass prairie species (Rhus glabra, Amorpha canescens, Vernonia baldwinii, and Andropogon gerardii), (2) if nocturnal transpiration or grazing by large ungulates limits hydraulic lift, and (3) if a dominant grass, A. gerardii, utilizes water lifted by other tallgrass prairie species. Broadly, the results shown here suggest that hydraulic lift does not appear to be widespread or common in this system, but isolated instances suggest that this process does occur within tallgrass prairie. The isolated instance of hydraulic lift did not vary by grazing treatment, nor did they result in facilitation for neighboring grasses. We suggest that the topographic complexity of this tallgrass prairie and the high rates of nocturnal transpiration observed in this study likely limit the frequency and occurrence of hydraulic lift. These results suggest that hydraulic lift can be a patchy process, particularly in heterogeneous landscapes.10aHydraulic lift10aStable10atallgrass prairie10aTranspiration10aWater potential1 aO’Keefe, K.1 aNippert, Jesse, B.  uhttps://link.springer.com/article/10.1007%2Fs00442-017-3827-202016nas a2200205   4500008004100000245010300041210006900144300001200213490000800225520137200233653000901605653001401614653002001628653001801648653001701666653002001683100001801703700002301721856006601744       2017                        eng d00aGrazing by bison is a stronger driver of plant ecohydrology in tallgrass prairie than fire history0 aGrazing by bison is a stronger driver of plant ecohydrology in t  a423-4360 v4113 a<p>Background and Aims: Fire and grazing are important disturbances in grasslands, yet we know little about how they impact a variety of plant physiological processes such as plant ecohydrology. Here, we assessed the impact of fire history and grazing by Bison bison on the source of water uptake and niche overlap in common grassland species at the Konza Prairie Biological Station, a temperate mesic grassland located in northeastern Kansas, USA. Methods: We used the stable isotopic signature of soil and xylem water to evaluate water uptake in Andropogo n gerardii, Vernonia baldwinii, Amorpha canescens,and Rhus glabra within varying grazing (grazed, ungrazed), fire (0,1,2 or 3 years since last burn), topography (upland, lowland), and month (July, August) contrasts over 3 years (2013&ndash;2015). Results: The presence of grazers, not fire history, altered water uptake patterns in these common grassland species. Particularly, grazing increased the proportion of shallow water utilized by A. gerardii and R. glabra, reducing niche overlap with other co-occurring species. However, these responses varied intra-annually and were often modulated by topography. Conclusions: These results suggest that grazing can alter aspects of grassland ecohydrology at small scales, which may extend to impact community and ecosystem processes at larger spatial scales.</p>10afire10aHerbivory10aMesic grassland10aNiche overlap10aSource water10aStable isotopes1 aO’Keefe, K.1 aNippert, Jesse, B.  uhttps://link.springer.com/article/10.1007%2Fs11104-016-3048-102048nas a2200157   4500008004100000245011900041210006900160300000900229490000600238520149400244100001801738700001401756700002301770700001901793856007801812       2013                        eng d00aPopulation origin and genome size do not impact Panicum virgatum (switchgrass) responses to variable precipitation0 aPopulation origin and genome size do not impact Panicum virgatum  a37 -0 v43 a<p>Population-level adaptation to broad-scale regional climates or within-population variation in genome size of the genetically and phenotypically diverse C4 grass, Panicum virgatum (switchgrass), may influence the responses of this species to future precipitation variability associated with climate change. Therefore, we investigated P. virgatum responses to water variability between natural populations collected across a latitudinal gradient and among individuals spanning a range of genomes sizes within these populations. P. virgatum plants from natural populations originating from Kansas, Oklahoma, and Texas, U.S.A, received frequent, small precipitation events (&ldquo;ambient&rdquo;) or infrequent, large precipitation events (&ldquo;altered&rdquo;) to simulate contrasting rainfall variability expected for this region. We measured leaf-level physiology, aboveground biomass and genome size for each individual. Gas exchange rates and aboveground biomass varied significantly by population origin but did not differ by genome size. Altered precipitation treatments reduced leaf-level physiological rates; however this result did not vary by population or genome size. Our results suggest that trait variation in P. virgatum is primarily attributed to population-level adaptation across a latitudinal gradient, not genome size, and that neither population-level adaptation nor genome size may be important predictors of P. virgatum responses to future climatic conditions.</p>1 aO’Keefe, K.1 aTomeo, N.1 aNippert, Jesse, B.1 aSpringer, C.J.  uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES12-00339.1