Summary
The annual replacement of tillers of Agropyron desertorum (Fisch. ex Link) Schult., a grazing-tolerant, Eurasian tussock grass, was examined in the field following cattle grazing. Heavy grazing before internode (culm) elongation seldom affected tiller replacement. Heavy grazing during or after internode elongation, which elevates apical meristems, increased overwinter mortality of fall-produced tillers and reduced the number and heights of these replacement tillers. Unexpectedly, tussocks grazed twice within the spring growing season tended to have lower overwinter tiller mortality, greater tiller replacement, and larger replacement tillers than tussocks grazed only once in late spring. These responses of twice-grazed tussocks, however, were still less than those of ungrazed tussocks or tussocks grazed moderately in early spring. The presence of ungrazed tillers on partially grazed tussoks did not increase the replacement of associated grazed tillers relative to tillers on uniformly grazed plants. This result indicates that resource sharing among tillers, if present, is short-lived or ecologically unimportant in this species. Although A. desertorum is considered grazing-tolerant, tiller replacement on heavily grazed tussocks, particularly those grazed during or after internode elongation when apical meristems were removed, was usually inadequate for tussock maintenance. These observations at the tiller (ramet) level of organization in individual tussocks (genet) may explain the often noted reduction in stand (population) longevity with consistent heavy grazing.
Similar content being viewed by others
References
Abrahamson WG, McCrea KD (1986) Nutrient and biomass allocation in Solidago altissima: effects of two stem gallmakers, fertilization, and ramet isolation. Oecologia (Berlin) 68:174–180
Ashmun JW, Pitelka LF (1984) Light-induced variation in the growth and dynamics of transplanted ramets of the understory herb, Aster acuminatus. Oecologia (Berlin) 64:255–262
Barkham JP (1980) Population dynamics of the wild daffodil (Narcissus pseudonarcissus) II. Changes in number of shoots and flowers, and the effect of bulb depth on growth and reproduction. J Ecol 68:635–664
Berube DE, Myers JH (1982) Suppression of knapweed invasion by crested wheatgrass in the dry interior of British Columbia. J Range Manage 35:459–461
Caldwell MM, Richards JH, Johnson DA, Nowak RS, Dzurec RS (1981) Coping with herbivory: photosynthetic capacity and resource allocation in two semiarid Agropyron bunchgrasses. Oecologia (Berlin) 50:14–24
Cook RE (1979) Asexual reproduction: a further consideration. Am Nat 113:769–772
Cook CW, Stoddard LA, Kinsinger FE (1958) Responses of crested wheatgrass to various clipping treatments. Ecol Monogr 28:237–272
Deregibus VA, Trlica MJ, Jameson DA (1982) Organic reserves in herbage plants: their relationship to grassland management. In: Rechcigl M (ed) CRC handbook of agricultural productivity, Vol I Plant productivity. CRC Press, Boca Raton, Florida, pp 315–344
Gifford RM, Marshall C (1973) Photosynthesis and asimilate distribution in Lolium multiflorum Lam. following differential tiller defoliation. Aust J Biol Sci 26:517–526
Gill JL (1981) Evolution of statistical design and analysis of experiments. J Dairy Sci 64:1494–1519
Godfrey EB (1979) Utilization practices and the returns from seeding an area to crested wheatgrass. J Range Manage 32:171–175
Harper JL, Bell AD (1979) The population dynamics of growth form in organisms with modular construction. In: Anderson RM, Turner BD, Taylor LR (eds) Population dynamics. Blackwell Scientific Publishing, Oxford, pp 29–52
Hartnett DC, Bazzaz FA (1983) Physiological integration among intraclonal ramets in Solidago canadensis. Ecology 60:910–917
Huiskes HL, Harper JL (1979) The demography of leaves and tillers of Ammophila arenaria in a dune sere. Oecol Plant 14:435–446
Johnson WM (1969) Life expectancy of a sagebrush control in central Wyoming. J Range Manage 21:209–213
Kays S, Harper JL (1974) The regulation of plant and tiller density in a grass sward. J Ecol 62:97–105
Keller W (1979) Species and methods for seeding in the sagebrush ecosystem. In: The sagebrush ecosystem: a symposium. Utah State Univ, Logan, Utah, pp 129–163
Langer RHM, Pyke SM, Jewiss OR (1964) The changing plant and tiller populations of timothy and meadow fescue swards. 1. Plant survival and the pattern of tillering. J Appl Ecol 1:197–208
Lovett-Doust L (1981) Population dynamics and local specialization in a clonal perennial (Ranunculus repens). I. The dynamics of ramets in contrasting habitats. J Ecol 69:743–755
Mack RN, Thompson JN (1982) Evolution in steppe with few large, hooved mammals. Am Nat 119:757–773
Malechek JC, Dwyer DD (1983) Short duration grazing doubles your livestock? Utah Science 44:32–37
Marlette GM, Anderson JE (1986) Seed banks and propagule dispersal in crested wheatgrass stands. J Appl Ecol 23:161–175
Mueggler WF (1972) Influence of competition on the response of bluebunch wheatgrass to clipping. J Range Manage 25:88–92
Noble JC, Bell AD, Harper JL (1979) The population biology of plants with clonal growth. I. The morphology and structural demography of Carex arenaria. J Ecol 67:983–1008
Norton BE, Johnson PS (1983) Pattern of defoliation by cattle grazing crested wheatgrass pastures. In: Smith JA, Hayes VW (eds) Proceeding of the XIV international grassland congress. Westview Press, Boulder, Colorado, pp 462–464
Olson BE (1986) Tiller dynamics of Agropyron desertorum in response to grazing and resouree manipulation. PhD dissertation, Utah State University, Logan, Utah
Rogler GA, Lorenz RJ (1983) Crested wheatgrass — Early history in the United States. J Range Manage 36:91–93
Salihi DO, Norton BE (1987) Survival of perennial grass seedlings under intensive management in semiarid rangelands. J Appl Ecol 24:145–151
Shaver GR, Chapin F, Gartner BL (1986) Factors limiting seasonal growth and peak biomass accumulation in Eriophorum vaginatum in Alaskan tussock tundra. J Ecol 74:257–278
Stout DG, Brooke B (1987) Tiller production of grazed and clipped pinegrass. Can J Plant Sci 67:503–508
Stout DG, Hall J, Brooke B, Mclean A (1981) Influence of successive years of simulated grazing (clipping) on pinegrass growth. Can J Plant Sci 61:939–943
Tomlinson PB (1974) Vegetative morphology and meristem dependence — the foundation of productivity in seagrasses. Aquaculture 4:107–130
Torstensson P, Telenius A (1986) Plastic morphological response to density in Spergularia marina (L.) Griseb.: leaf demography and meristem activity. Holarctic Ecol 9:13–19
Tuomi J, Salo J, Haukioja E, Niemelae P, Hakala T, Mannila R (1983) The existential game of individual self-maintaining units: selection and defence tactics of trees. Oikos 40:369–376
Welker JM, Rykiel EJ, Briske DD, Goeschl JD (1985) Carbon import among vegetative tillers within two bunchgrasses: assessment with carbon-11 labelling. Oecologia (Berlin) 67:209–212
Wraith JM, Johnson DA, Hanks RJ, Sisson DV (1987) Soil and plant water relations in a crested wheatgrass pasture: response to spring grazing by cattle. Oecologia (Berlin) 73:573–578
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Olson, B.E., Richards, J.H. Annual replacement of the tillers of Agropyron desertorum following grazing. Oecologia 76, 1–6 (1988). https://doi.org/10.1007/BF00379592
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00379592