@article {KNZ00599,
	title = {Spatial variability of nitrogen mineralization at the field scale},
	journal = {Soil Science Society of America Journal},
	volume = {61},
	year = {1997},
	pages = {1214 -1221},
	abstract = {Spatial 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.},
	keywords = {LTER-KNZ},
	doi = {10.2136/sssaj1997.03615995006100040029x},
	author = {Mahmoudjafari, M. and Kluitenberg, G.J. and Havlin, J.L. and Sisson, J.B. and Schwab, A.P.}
}
@article {KNZ00541,
	title = {Interspecific nutrient transfer in a tallgrass prairie plant community},
	journal = {American Journal of Botany},
	volume = {83},
	year = {1996},
	pages = {180 -184},
	abstract = {Interplant 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.},
	keywords = {LTER-KNZ, mycorrhizae, Phosphorus, tallgrass prairie},
	url = {http://www.jstor.org/stable/2445936},
	author = {Walter, L.E.F. and D.C. Hartnett and Hetrick, B.A.D. and Schwab, A.P.}
}
@article {KNZ00448,
	title = {Mycorrhizal activity in warm-and cool-season grasses: variation in nutrient uptake strategies},
	journal = {Canadian Journal of Botany},
	volume = {72},
	year = {1994},
	pages = {1002 -1008},
	abstract = {Because 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 {\textdegree}C versus 29 {\textdegree}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 {\textdegree}C than at 18 {\textdegree}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{\textquoteright}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{\textquoteright}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. },
	keywords = {LTER-KNZ, big bluestem, mycorrhizal dependence, mycorrhizal responsiveness, smooth bromegrass},
	doi = {10.1139/b94-126},
	author = {Hetrick, B.A.D. and G.T. Wilson and Schwab, A.P.}
}
@article {KNZ00363,
	title = {Mineralization of organic phosphorus by vesicular-arbuscular mycorrhizal fungi},
	journal = {Soil Biology \&amp; Biochemistry},
	volume = {24},
	year = {1992},
	pages = {897 -903},
	keywords = {LTER-KNZ},
	doi = {10.1016/0038-0717(92)90012-M},
	author = {Jayachandran, K. and Schwab, A.P. and Hetrick, B.A.D.}
}
@article {KNZ00364,
	title = {Partitioning of dissolved inorganic or organic phosphorus using acidified molybdate and isobutanol},
	journal = {Soil Science Society of American Journal},
	volume = {56},
	year = {1992},
	pages = {762 -765},
	keywords = {LTER-KNZ},
	doi = {10.2136/sssaj1992.03615995005600030014x},
	author = {Jayachandran, K. and Schwab, A.P. and Hetrick, B.A.D.}
}
@article {KNZ00294,
	title = {Field bioassessment for selecting test systems to evaluate military training lands in tallgrass prairie},
	journal = {Ecosystem Health.V.1 Environmental Management},
	volume = {14},
	year = {1990},
	pages = {81 -93},
	abstract = {<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>},
	keywords = {LTER-KNZ, tallgrass prairie},
	doi = {10.1007/BF02394022},
	author = {Schaeffer, D.J. and Seastedt, T.R. and D.J. Gibson and D.C. Hartnett and Hetrick, B.A.D. and James, S.W. and D.W. Kaufman and Schwab, A.P. and Herricks, E.E. and Novak, E.W.}
}
@article {KNZ00238,
	title = {Mycorrhizal mediation of phosphorus availability: synthetic iron chelate effects on phosphorus solubilization},
	journal = {Soil Science Society of America Journal},
	volume = {53},
	year = {1989},
	pages = {1701 -1706},
	keywords = {LTER-KNZ},
	doi = {10.2136/sssaj1989.03615995005300060015x},
	author = {Jayachandran, K. and Schwab, A.P. and Hetrick, B.A.D.}
}
@article {KNZ00184,
	title = {Effects of soil microorganisms on mycorrhizal contribution to growth of big bluestem grass in nonsterile soil},
	journal = {Soil Biology \&amp; Biochemistry},
	volume = {20},
	year = {1988},
	pages = {501 -507},
	abstract = {<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>},
	keywords = {LTER-KNZ},
	doi = {10.1016/0038-0717(88)90065-X},
	author = {Hetrick, B.A.D. and G.T. Wilson and Kitt, D.G. and Schwab, A.P.}
}
