AOAC (Association of Official Agricultural Chemists). 1965. Official Methods of Analysis of the Association of Official Agricultural Chemists, 10th ed. Washington DC: Association of Official Agricultural Chemists.
Briske D D, Richards J H. 1995. Plant responses to defoliation: a physiological, morphological and demographic evaluation. In: Bedunah D J, Sosebee R E. Wildland Plants: Physiological Ecology and Developmental Morphology, Denver: Society for Range Management, 635–710.
Busso C A. 1997. Towards an increased and sustainable production in semiarid rangelands of Central Argentina: two decades of research. Journal of Arid Environments, 36: 197–210.
Cabrera A L. 1976. Phytogeographical regions of Argentina. In: Ferreira Sobral E F. Argentinian Encyclopedia of Agriculture and Gargening. Buenos Aires: ACME.
Caldwell M M, Richards J H. 1986. Competing root systems: morphology and models of absorption. In: Givnish T J. On the Economy of Plant Form and Function. Cambridge: Cambridge University Press, 251–273.
Caldwell M M, Manwaring J H, Durham S L. 1991a. The microscale distribution of neighboring plant roots in fertile soil microsites. Functional Ecology, 5: 765–772.
Caldwell M M, Manwaring J H, Jackson R B, 1991b. Exploitation of phosphate from fertile soil microsites by three Great Basin perennial when in competition. Functional Ecology, 5: 757–764.
Casper B B, Jackson R B. 1997. Plant competition underground. Annual Review of Ecology and Systematics, 28: 545–570.
Crick J C, Grime J P. 1987. Morphological plasticity and mineral nutrient capture in two herbaceous species of contrasted ecology. New Phytologist, 107: 403–414.
Di Rienzo J A, Casanoves F, Balzarini M G, et al. 2009. InfoStat. INFOSTAT Group. Argentina: National University of Córdoba.
Distel R A, Bóo R M. 1996. Vegetation states and transitions in temperate semiarid rangelands of Argentina. In: West E N. Proceeding of Vth International Rangeland Congress. Rangelands in a Sustainable Biosphere Society for Range Management, Salt Lake City, 117–118.
Dunn J P, Frommelt K. 1998. Effects of belowground herbivory by Diabrotica virgofera (Coleoptera) on biomass allocation and carbohydrate storage of mayze. Applied Soil Ecology, 7: 213–218.
Eissenstat D M, Caldwell M M. 1989. Invasive root growth into disturbed soil of two tussock grasses that differ in competitive effectiveness. Functional Ecology, 3: 345–353.
Evans G R, Tisdale E W. 1972. Ecological characteristics of Aristida longiseta and Agropyron spicatum in west-central Idaho. Ecology, 53: 37–142.
Fiala K, Tůma I, Holub P. 2012. Interannual variation in root production in grasslands affected by artificially modified amount of rainfall. The Scientific World Journal, doi: 10.1100/2012/805298.
Fitter A H. 1976. Effects of nutrient supply and competition from other species on root growth of Lolium perenne in soil. Plant and Soil, 45: 177–189.
Fowler N L. 1986. The role of competition in plant communities in arid and semiarid regions. Annual Review of Ecology and Systematics, 17: 89–110.
Giorgetti H D. 1995. Conference on cattle raising in shrublands. Chacra Experimental de Patagones, Viedma, Argentina. 56.
Giorgetti H D, Montenegro O A, Rodríguez G D, et al. 1997. The comparative influence of past management and rainfall on range herbaceous standing crop in east-central Argentina: 14 years of observations. Journal of Arid Environments, 36: 623–637.
Giorgetti H D, Montenegro O A, Rodríguez G D, et al. 1998. Effects of previous managements in the Phytogeographical Province of the Monte: plant density. In: 22nd Argentinian Congress of Animal Production, Córdoba, Argentina, 101.
Giorgetti H D, Montenegro O A, Rodríguez G D, et al. 1999. Effects of previous managements in the Phytogeographical province of the Monte: percentage cover. In: 19th Meeting of the Argentinian Association of Ecology. Tucumán, Argentina, 100.
Giorgetti H D, Montenegro O A, Rodríguez G D, et al. 2000a. Frequency of herbaceous and woody species in rangelands of Central Argentina recovering from disturbances. In: 23rd Argentinian Congress of Animal Production, Corrientes, Argentina, 138–139.
Giorgetti H D, Manuel Z, Montenegro O A, et al. 2000b. Phenology of some herbaceous and woody species in central, semiarid Argentina. Phyton, International Journal of Experimental Botany, 69: 91–108.
Giorgetti H D, Busso C A, Montenegro O A, et al. 2006. Cattle raising in central, semiarid Argentina. Rangelands, 28: 32–36.
Gittins C, Busso C A, Becker G, et al. 2010. Defoliation frequency affects morphophysiological traits in the bunchgrass Poa ligularis. Phyton, International Journal of Experimental Botany, 79: 55–69.
Hodgkinson K C, Ludlow M M, Mott J J, et al. 1989. Comparative responses of the savanna grasses Cenchrus ciliaris and Themeda triandra to defoliation. Oecologia, 79: 45–52.
Ivans C Y, Leffler A J, Spaulding U, et al. 2003. Root responses and nitrogen acquisition by Artemisia tridentata and Agropyron desertorum following small summer rainfall events. Oecologia, 134: 317–324.
Jackson R B, Caldwell M M. 1993. The scale of nutrient heterogeneity around individual plants and its quantification with geostatistics. Ecology, 74: 612–614.
Kaspar T C, Ewing R P. 1997. ROOTEDGE: software for measuring root length from desktop scanner images. Agronomy Journal, 89: 932–940.
Kilcher M R, Looman J. 1983. Comparative performance of some native and introduced grasses in southern Saskatchewan, Canada. Journal of Range Management, 36: 654–657.
Páez A, Busso C A, Montenegro O A, et al. 2005. Seed weight variation and its effects on germination in Stipa species. Phyton, International Journal of Experimental Botany, 1–14.
Quinn J A, Ward R T. 1969. Ecological differentiation in sand dropseed (Sporobolus cryptandrus). Ecological Monographs, 39: 61–78.
Saint Pierre C, Busso C A. 2006. Competitive ability and defoliation tolerance in Stipa clarazii, Stipa tenuis and S. ambigua. Phyton, International Journal of Experimental Botany, 75: 21–30.
Saint Pierre C, Busso C A, Montenegro O A, et al. 2002. Root proliferation in perennial grasses of low and high palatability. Plant Ecology, 165: 161–169.
Schacht W H, Smart A J, Anderson B E, et al. 1998. Growth responses of warm-season tallgrasses to dormant-season management. Journal of Range Management, 51: 442–446.
Shinoda M, Nachinshonhor G U, Nemoto M. 2010. Impact of drought on vegetation dynamics of the Mongolian steppe: a field experiment. Journal of Arid Environments, 74: 63–69.
Silver W L, Miya R K. 2001. Global patterns in root decomposition: comparisons of climate and litter quality effects. Oecologia, 129: 407–419.
Sokal R R, Rohlf F J. 1987. Introduction to Biostatistics. 2nd ed. New York: Freeman.
St John T V, Coleman D C, Reid C P P. 1983. Growth and spatial distribution of nutrient-absorbing organs: selective exploitation of soil heterogeneity. Plant and Soil, 71: 487–493.
Svejcar T, Angell R, Bradford J A, et al. 2008. Carbon fluxes on North American rangelands. Rangeland Ecology and Management 61: 465–474.
Torres Y A. 2011. Morphophysiological characteristics and forage production in native, introduced and naturalized warm-season perennial grasses of the center of Argentina. Ph.D. Thesis, Bahía Blanca: Universidad Nacional del Sur.
Valentine J F. 1990. Grazing Management. San Diego: Academic Press, 533.
Wilks S S. 1932. Certain generalizations in the analysis of the variance. Biometrika, 24: 471–494.
Williams T E, Baker H K. 1957. Studies on the root development of herbage plants. I. Techniques of herbage root investigations. Journal of the British Grassland Society, 12: 49–55.