02232nas a2200169   4500008004100000245007000041210006900111300001500180490000700195520167100202100002201873700002201895700001701917700001701934700001701951856009401968       1997                        eng d00aSpatial variability of nitrogen mineralization at the field scale0 aSpatial variability of nitrogen mineralization at the field scal  a1214 -12210 v613 aSpatial variability of N mineralization represents a potential problem in predicting the quantity of N mineralized under field conditions. An understanding of mineralization variability is needed if prediction of potential mineralization is to be incorporated into fertilizer recommendation models. The objective of this study was to characterize spatial variability of N mineralization in a Kansas agricultural field. Intact undisturbed soil cores were collected at 108 locations within a 1.7-ha field following wheat (Triticum aestivum L.) harvest. The undisturbed cores were incubated aerobically, and NO−3 was leached periodically as a measure of mineralization. Variability was characterized by examining the spatially distributed values of mineralization potential, N0, and mineralization rate constant, k, parameters of the classical first-order mineralization rate model. Values of N0 were distributed normally with low variability (coefficient of variation [CV] = 15%) and weak autocorrelation. Values of k also followed a normal distribution with low variability (CV = 14%) but were spatially independent. Both N0 and k determined the spatial pattern of Nm, the quantity of N mineralized at a particular time. Variability in k controlled the spatial pattern of Nm earlier in the incubation period, and variability in N0 controlled the spatial pattern late in the incubation period. The incubation approach used in this study allowed characterization of the spatial patterns in N0, but the spatial variability of k observed in this study may not adequately represent field conditions because conditions of constant temperature and water content were used.1 aMahmoudjafari, M.1 aKluitenberg, G.J.1 aHavlin, J.L.1 aSisson, J.B.1 aSchwab, A.P.  uhttp://lter.konza.ksu.edu/content/spatial-variability-nitrogen-mineralization-field-scale02108nas a2200193   4500008004100000245007500041210006900116300001300185490000700198520154100205653001601746653001501762653002201777100001901799700001901818700002001837700001701857856004001874       1996                        eng d00aInterspecific nutrient transfer in a tallgrass prairie plant community0 aInterspecific nutrient transfer in a tallgrass prairie plant com  a180 -1840 v833 aInterplant nutrient transfer may be an important ecological process in grasslands, and may significantly influence plant neighborhood interactions. We investigated the potential for phosphorus transfer between the dominant grass Andropogon gerardii and several neighboring plant species in tallgrass prairie via a field 32PO4 labelling experiment. The mean amount of 32P received from donor shoots differed significantly among neighboring species and decreased with increasing distance from the donor. In general, forbs and cool-season C3 grasses received more labelled 32P than warm-season C4 grasses. Phosphorus transfer occurred over distances up to 0.5 m. The effects of species and distance on movement of phosphorus changed with increasing time after labelling. The relative mass of receiver and donor shoots did not affect amounts of 32P transfer. A benomyl fungicide treatment, applied to suppress mycorrhizal activity, likely did not affect existing vegetative hyphae and did not affect the amount of 32P transferred. These studies demonstrate that: (1) phosphorus is transferred among neighboring species in tallgrass prairie plant communities, (2) phosphorus may be transferred over significantly greater distances than reported in other grasslands, and (3) there is differential transfer among co-occurring species. Hypothesized mechanisms accounting for these patterns in tallgrass prairie include mycorrhizal hyphal interconnections and/or extensive and differential root and rhizosphere overlap among neighboring species.10amycorrhizae10aPhosphorus10atallgrass prairie1 aWalter, L.E.F.1 aHartnett, D.C.1 aHetrick, B.A.D.1 aSchwab, A.P.  uhttp://www.jstor.org/stable/244593603478nas a2200193   4500008004100000245009800041210006900139300001500208490000700223520277800230653001703008653002703025653003103052653002203083100002003105700001703125700001703142856012503159       1994                        eng d00aMycorrhizal activity in warm-and cool-season grasses: variation in nutrient uptake strategies0 aMycorrhizal activity in warmand coolseason grasses variation in   a1002 -10080 v723 aBecause cool-season grasses display little or no mycorrhizal responsiveness in prairie soil, it is unclear whether the high levels of mycorrhizal activity observed previously in these grasses represent nutrient uptake by external hyphae or simply metabolism of stored fungal reserves in roots. To distinguish between these hypotheses, a warm-season grass, Andropogon gerardii, or a cool-season grass, Bromus inermis, were grown at two temperatures on one side of a pot divided by a 43-μm nylon root barrier. Mycorrhizal function was assessed by measuring the amount of 32P translocated from one side of the pot to plants on the other side. As a control, mycorrhizal hyphae crossing the barrier were severed manually. Approximately 100 times more 32P was observed in mycorrhizal B. inermis grown at 18 °C versus 29 °C, and in B. inermis with intact versus severed hyphae at the cooler temperature. In contrast, A. gerardii accumulated approximately 4 times more 32P at 29 °C than at 18 °C, and approximately 100 times more with intact versus severed hyphae at the warmer temperature. Thus, it appears that mycorrhizal hyphae are highly active in both plant species regardless of the host's mycorrhizal responsiveness. Furthermore, mycorrhizal activity is highest at the temperature that favors growth of each species. The considerable activity of mycorrhizae in B. inermis is enigmatic since it usually has no biomass response. To further clarify the relationship between nutrient uptake and biomass response, both plant species were fertilized with a range of P levels and grown at a neutral temperature that supported the growth of both species. Although the concentration of P in B. inermis plant tissue increased in response to fertilization, there was no corresponding increase in biomass. In contrast, for A. gerardii, there was a direct and positive relationship between P fertilization and biomass produced, but tissue P concentrations remained relatively stable. Mycorrhizal symbiosis had no overall effect on biomass of B. inermis but significantly improved the growth of A. gerardii. These experiments showed clear differences in the growth strategies used by these two plant species. It is unclear whether these are differences that can be attributed to warm- and cool-season grasses in general. Short-term biomass responses as a measure of a plant's reliance on the symbiosis may not entirely reflect the contribution of the symbiosis if plants store nutrients with subsequent and perhaps delayed effects on fecundity, offspring performance, or even biomass. However, if the stored nutrient merely represents luxury consumption, this could still affect competitive ability because luxury consumption preempts the availability of nutrients for competitors. 10abig bluestem10amycorrhizal dependence10amycorrhizal responsiveness10asmooth bromegrass1 aHetrick, B.A.D.1 aWilson, G.T.1 aSchwab, A.P.  uhttp://lter.konza.ksu.edu/content/mycorrhizal-activity-warm-and-cool-season-grasses-variation-nutrient-uptake-strategies00516nas a2200133   4500008004100000245008300041210006900124300001300193490000700206100002100213700001700234700002000251856011100271       1992                        eng d00aMineralization of organic phosphorus by vesicular-arbuscular mycorrhizal fungi0 aMineralization of organic phosphorus by vesiculararbuscular myco  a897 -9030 v241 aJayachandran, K.1 aSchwab, A.P.1 aHetrick, B.A.D.  uhttp://lter.konza.ksu.edu/content/mineralization-organic-phosphorus-vesicular-arbuscular-mycorrhizal-fungi00548nas a2200133   4500008004100000245010300041210006900144300001300213490000700226100002100233700001700254700002000271856012300291       1992                        eng d00aPartitioning of dissolved inorganic or organic phosphorus using acidified molybdate and isobutanol0 aPartitioning of dissolved inorganic or organic phosphorus using   a762 -7650 v561 aJayachandran, K.1 aSchwab, A.P.1 aHetrick, B.A.D.  uhttp://lter.konza.ksu.edu/content/partitioning-dissolved-inorganic-or-organic-phosphorus-using-acidified-molybdate-and02201nas a2200241   4500008004100000245010800041210006900149300001100218490000700229520139600236653002201632100002001654700001901674700001701693700001901710700002001729700001601749700001801765700001701783700001901800700001601819856012401835       1990                        eng d00aField bioassessment for selecting test systems to evaluate military training lands in tallgrass prairie0 aField bioassessment for selecting test systems to evaluate milit  a81 -930 v143 a<p>Ecosystems responses to physical or chemical stress may vary from changes in single organisms to alteration of the structure and function of the ecosystem. These responses to stress cannot be predicted exactly. Ecosystems repeatedly exposed to physical and/or chemical stress can be used to study the separate and combined environmental effects of stress. Such studies also allow the development of procedures to select test systems for the analysis of stress in ecosystems. A preliminary field survey of six military training sites at Fort Riley, Kansas, USA, was conducted to identify and verify ecological test systems for evaluating ecosystem responses to physical and/or chemical stress. Comparisons of these data with data collected concurrently from Konza Prairie Research Natural Area reference sites showed that soil microarthropods, some species of macroarthropods, small mammals, and native earthworm species were negatively affected by stress. In contrast, plant species diversity, plant foliage biomass, soil mycorrhizae, and many soil characteristics were within the boundaries of nominal variations observed on &quot;pristine&quot; Konza Prairie. Introduced European earthworms appeared to be positively affected by training activities. This study provided a test of systematic procedures to support impact analysis, ecological toxicology, and ecosystem risk assessment</p>10atallgrass prairie1 aSchaeffer, D.J.1 aSeastedt, T.R.1 aGibson, D.J.1 aHartnett, D.C.1 aHetrick, B.A.D.1 aJames, S.W.1 aKaufman, D.W.1 aSchwab, A.P.1 aHerricks, E.E.1 aNovak, E.W.  uhttp://lter.konza.ksu.edu/content/field-bioassessment-selecting-test-systems-evaluate-military-training-lands-tallgrass00564nas a2200133   4500008004100000245011400041210006900155300001500224490000700239100002100246700001700267700002000284856012600304       1989                        eng d00aMycorrhizal mediation of phosphorus availability: synthetic iron chelate effects on phosphorus solubilization0 aMycorrhizal mediation of phosphorus availability synthetic iron   a1701 -17060 v531 aJayachandran, K.1 aSchwab, A.P.1 aHetrick, B.A.D.  uhttp://lter.konza.ksu.edu/content/mycorrhizal-mediation-phosphorus-availability-synthetic-iron-chelate-effects-phosphorus02118nas a2200157   4500008004100000245011400041210006900155300001300224490000700237520151900244100002001763700001701783700001501800700001701815856012801832       1988                        eng d00aEffects of soil microorganisms on mycorrhizal contribution to growth of big bluestem grass in nonsterile soil0 aEffects of soil microorganisms on mycorrhizal contribution to gr  a501 -5070 v203 a<p>Plant dry weight and mycorrhizal root colonization of big bluestem (Andropogon gerardii Vitman) inoculated with Glomus etunicatum Becker and Gerd. were suppressed if non-sterile prairie soil sievings were added to pasteurized soil. Addition of prairie soil microorganisms, isolated onto peptone yeast extract, King&#39;s B, or starch casein agar media, to pasteurized soil also reduced dry weight and mycorrhizal root colonization of big bluesteam inoculated with G. etunicatum. In contrast, addition of non- sterile soil sievings or filtrate or organisms isolated onto potato dextrose or pseudomonas isolation agar to pasteurized soil improved growth of non-mycorrhizal big bluestem. These effects of soil microorganisms on plant growth were further quantified by comparing 32P uptake by fungicide treated and untreated mycorrhizal plants and by non-mycorrhizal plants in pasteurized and non-sterile soil. Mycorrhizal plants grown in pasteurized soil absorbed approximately 10 times more 32P than mycorrhizal plants grown in non-sterile soil. Application of propiconazole (Tilt) or fenarimol (Rubigan), fungicides which inhibit non-sterile soil, respectively. Thus, more 32P is absorbed in pasteurized than in non-sterile soil, probably because soil microorganisms limit mycorrhizal activity in non-sterile soil. Assessments of mycorrhizal contribution to plant growth conducted in sterilized soil may significantly overestimate the effects of VAM fungi because other soil microorganisms are not considered</p>1 aHetrick, B.A.D.1 aWilson, G.T.1 aKitt, D.G.1 aSchwab, A.P.  uhttp://lter.konza.ksu.edu/content/effects-soil-microorganisms-mycorrhizal-contribution-growth-big-bluestem-grass-nonsterile