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Shoot dynamics of the giant grass Gynerium sagittatum in Peruvian Amazon floodplains, a clonal plant that does show self-thinning

Abstract

The giant rhizomatous grass Gynerium sagittatum is an early successional species that forms dense monocultures in Peruvian Amazon floodplains. We studied the shoot population structures by recording shoot densities and shoot heights. Leaf areas and stem volumes were allometrically estimated. Stands of two varieties of G. sagittatum were examined that differ in height and in the degree of shoot branching. In stands of increasing age, marked decreases in shoot densities were accompanied with an increase in mean shoot size. Self-thinning was indicated by the negative correlation between log stem volume per unit ground area and log shoot density, significant at least for one of the two varieties. The difference in thinning slope between the varieties could be largely accounted for by their different shoot geometry, as was revealed by calculations based on the allometric model of Weller (1987b). The relationship between log leaf area per shoot and log shoot density was significantly negative with slopes close to −1. Shoot size inequalities decreased with increasing mean stem volume per shoot, probably as a result of density-dependent mortality of the smaller shoots. All of these results accord with expectations for shoot self-thining. Gynerium sagittatum is the first clear example of a clonal plant species that exhibits self-thining in natural monospecific stands. It is argued that self-thinning occurs in this giant tropical grass because its shoots are perennial and do not experience seasonal die-back (periodic density-independent mortality), in contrast to many of the clonal plant species that have been studies so far.

References

  1. Bradbury IK (1981) Dynamics, structure and performance of shoot populations of the rhizomatous herb Solidago canadensis L. in abandoned pastures. Oecologia 48: 271–276

    Google Scholar 

  2. Briske DD, Butler JL (1989) Density-dependent regulation of ramet population within the bunchgrass Schizachyrium scoparium: interclonal versus intraclonal interference. J Ecol 77: 963–974

    Google Scholar 

  3. Cain MJ (1990) Patterns of Solidago altissima ramet growth and mortality: the role of below-ground ramet connections. Oecologia 82: 201–209

    Google Scholar 

  4. Dickerman JA, Wetzel RG (1985) Clonal growth in Typha latifolia: population dynamics and demography of the ramets. J Ecol 73: 535–552

    Google Scholar 

  5. Dixon PM, Weiner J, Mitchell-Olds T, Woodley R (1987) Bootstrapping the Gini coefficient of inequality. Ecology 68: 1548–1551

    Google Scholar 

  6. Ellison AM (1987) Density-dependent dynamics of Salicornia europaea monocultures. Ecology 68: 737–741

    Google Scholar 

  7. Ellison AM (1989) Morphological determinants of self-thinning in plant monocultures and a proposal concerning the role of self-thinning in plant evolution. Oikos 54: 287–293

    Google Scholar 

  8. Ford ED, Newbould PJ (1970) Stand structure and dry weight production through the sweet chestnut (Castanea sativa Mill.) coppice cycle. J Ecol 58: 275–296

    Google Scholar 

  9. Hara T, Kimura M, Kikuzawa K (1991) Growth patterns of tree height and stem diameter in populations of Abies veitchii, A. mariesii and Betula ermanii. J Ecol 79: 1085–1098.

    Google Scholar 

  10. Hara T, Toorn J van der, Mook JH (1993) Growth dynamics and size structure of shoots of Phragmites australis, a clonal plant. J Ecol 81: 47–60

    Google Scholar 

  11. Hartnett DC (1993) Regulation of clonal growth and dynamics of Panicum virgatum (Poaceae) in tallgrass prairie: effects of neighbor removal and nutrient addition. Am J Bot 80: 114–1120

    Google Scholar 

  12. Hutchings MJ (1979) Weight-density relationships in ramet populations of clonal perennial herbs, with special reference to the −3/2 power law. J Ecol 67: 21–33

    Google Scholar 

  13. Hutchings MJ (1983) Shoot performance and population structure in pure stands of Mercurialis perennis L., a rhizomatous perennial herb. Oecologia 58: 260–264

    Google Scholar 

  14. Hutchings MJ, Barkham JP (1976) An investigation of shoot interactions in Mercurialis perennis L., a rhizomatous perennial herb. J Ecol 64: 723–743

    Google Scholar 

  15. Hutchings MJ, Bradbury IK (1986) Ecological perspectives on clonal perennial herbs. BioScience 36: 178–182

    Google Scholar 

  16. Hutchings MJ, Budd CSJ (1981) Plant self-thinning and leaf area dynamics in experimental and natural monocultures. Oikos 36: 319–325

    Google Scholar 

  17. Kalliola R, Renvoize S (1994) One or more species of Gynerium (Poaceae). Kew Bull 49: 305–320

    Google Scholar 

  18. Kalliola R, Salo J, Puhakka M, Rajastilta M (1991) New site formation and colonizing vegetation in primary succession on the western Amazon floodplains. J Ecol 79: 877–901

    Google Scholar 

  19. Kalliola R, Puhakka M, Salo J (1992) Intraspecific variation, distribution and ecology of Gynerium sagittatum (Poaceae) in the western Amazon. Flora 186: 153–167

    Google Scholar 

  20. Knox RG, Peet RK, Christensen NL (1989) Population dynamics in loblolly pine stands: changes in skewness and size inequality. Ecology 70: 1153–1166

    Google Scholar 

  21. Kroon H de (1993) Competition between shoots in stands of clonal plants. Plant Spec Biol 8: 85–94

    Google Scholar 

  22. Kroon H de, Kwant R (1991) Density-dependent growth responses in two clonal herbs: regulation of shoot density. Oecologia 86: 298–304

    Google Scholar 

  23. Kroon H de, Hara T, Kwant R (1992) Size hierarchies of shoots and clones in clonal herb monocultures: Do clonal and non-clonal plants compete differently? Oikos 63: 410–419.

    Google Scholar 

  24. Lamotte S (1992) Essai d'interprétation dynamique des végétations en milieu tropical inondable. PhD thesis, Université des Sciences et Technique du Languedoc, Montpellier

  25. Lapham J, Drennan DSH (1987) Intraspecific regulation of populations of the clonal herb, Cyperus esculentus. J Appl Ecol 24: 1011–1024

    Google Scholar 

  26. Lonsdale WM (1990) The self-thinning rule: dead or alive? Ecology 71: 1373–1388

    Google Scholar 

  27. Lonsdale WM Watkinson AR (1983a) Plant geometry and self-thinning. J Ecol 71: 285–297

    Google Scholar 

  28. Lonsdale WM, Watkinson AR (1983b) Tiller dynamics and self-thinning in grassland habitats. Oecologia 60: 390–395

    Google Scholar 

  29. Makita A (1992) Survivorship of a monocarpic bamboo grass, Sasa kurilensis, during the early regeneration process after mass flowering. Ecol Res 7: 245–254

    Google Scholar 

  30. Makita A, Konno Y, Fujita N, Takada K, Hamabata E (1993) Recovery of a Sasa tsuboiana population after mass flowering and death. Ecol Res 8: 215–224

    Google Scholar 

  31. Miyanishi K, Hoy AR, Cavers PB (1979) A generalized lau of self-thinning in plant populations. J Theor Biol 78: 439–442

    Google Scholar 

  32. Mohler CL, Marks PL, Sprugel DG (1978) Stand structure and allometry of trees during self-thinning of pure stands. J Ecol 66: 599–614

    Google Scholar 

  33. Mook JH, van der Toorn J (1982) The influence of environmental factors and management on stands of Phragmites australis. 2. Effects on yield and its relationships with shoot density. J Appl Ecol 19: 501–517

    Google Scholar 

  34. Norberg RA (1988) Theory of growth geometry of plants and self-thinning of plant populations: geometric similarity elastic similarity, and different growth models of plant parts. Am Nat 131: 220–256

    Google Scholar 

  35. Osawa A, Allen RB (1993) Allometric theory explains self-thinning relationships of mountain beech and red pine. Ecology 74: 1020–1032

    Google Scholar 

  36. Pitelka LF (1984) Application of the −3/2 power law to clonal herbs. Am Nat 123: 442–449

    Google Scholar 

  37. Renvoize SA (1980) The sub-family Arundinodae and its position in relation to a general classification of the Graminae. Kew Bull 36: 85–102

    Google Scholar 

  38. Silvertown JW, Lovett Doust JL (1993) Introduction to plant population biology, 3rd edn. Blackwell, Oxford

    Google Scholar 

  39. Sokal RR, Rohlf FJ (1981) Biometry, 2nd edn. Freeman San Francisco

    Google Scholar 

  40. Thomas SC, Weiner J (1989) Growth, death and size distribution change in an Impatiens pallida population. J Ecol 77: 524–536

    Google Scholar 

  41. Toorn J van der, Mook JH (1982) The influence of environmental factors and management on stands of Phragmites australis. 1. Effects of burning, frost and insect damage on shoot density and shoot size. J Appl Ecol 1982: 477–499

    Google Scholar 

  42. Verwijst T (1989) Self-thinning in even-aged natural stands of Betula pubescens. Oikos 56: 264–268

    Google Scholar 

  43. Weiner J, Solbrig OT (1984) The meaning and measurement of size hierarchies in plants. Oecologia 61: 334–336

    Google Scholar 

  44. Weiner J, Thomas SC (1986) Size variability and competition in plant monocultures. Oikos 47: 211–222

    Google Scholar 

  45. Weiner J, Thomas SC (1992) Competition and allometry in three species of annual plants. Ecology 73: 648–656

    Google Scholar 

  46. Weiner J, Whigham DF (1988) Size variability and self-thinning in wild-rice (Zizania aquatica). Am J Bot 75: 445–448

    Google Scholar 

  47. Weller DE (1987a) A reevaluation of the −3/2 power rule of plant self-thinning. Ecol Monogr 57: 23–43

    Google Scholar 

  48. Weller DE (1987b) Self-thinning exponent correlated with allometric measures of plant geometry. Ecology 68: 813–821

    Google Scholar 

  49. Westoby M (1984) The self-thinning rule. Adv Ecol Res 14: 167–225

    Google Scholar 

  50. White J (1980) Demographic factors in populations of plants. In: Solbrig OT (ed) Demography and evolution in plant populations. University of California Press, Berkeley, pp 21–48

    Google Scholar 

  51. Yokozawa M, Hara T (1992) A canopy photosynthesis model for the dynamics of size structure and self-thinning in plant populations. Ann Bot 70: 305–316

    Google Scholar 

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Correspondence to Hans de Kroon.

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de Kroon, H., Kalliola, R. Shoot dynamics of the giant grass Gynerium sagittatum in Peruvian Amazon floodplains, a clonal plant that does show self-thinning. Oecologia 101, 124–131 (1995). https://doi.org/10.1007/BF00328909

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Key words

  • Clonal plants
  • Self-thining
  • Allometry
  • Shoot dynamics
  • Amazon floodplains