Abstract
The importance of light as a limiting factor for growth and reproductionin tropical understorey plants is well known, but the population-levelconsequences of light limitation remain little explored. Here, I usedemographicmodelling to examine if the effect of canopy gaps on individual-levelperformance in a tropical understorey palm translates into an effect on thepopulation growth rate. The demographic effects of heterogeneity in crownillumination (index of hemispherical canopy openness), forest-phase, and othermicroenvironmental parameters were quantified using data on 2592 individuals ofall sizes in permanent plots followed over a 1.5 year period. Supplementaryexperiments investigating the effects of canopy conditions on seedlingrecruitment were also conducted. Among the microenvironmental parameters onlycrown illumination and forest-phase had strong and consistent demographiceffects. Growth and fecundity generally increased with increasing crownillumination. Under open forest-phase conditions growth tended to increase andsurvival to decrease (due to increased physical damage). Seedlings transplantedinto gap centres were damaged by solarization. The population-level effect ofheterogeneity in crown illumination and forest-phase was investigated usingtransition matrix models. The overall population growth rate was 0.999, and notsignificantly different from 1. Illumination-specific models showed thatG. macrostachys would be unable to persist at permanentlylow illumination, but would increase in density under higher illumination.Forest-phase-specific models gave similar, but weaker results. Thus, inG. macrostachys effects of canopy openness onindividual-level performance strongly limit the population growth rate. Thepresent study thereby shows that fine-scale spatiotemporal variation in canopyopenness in the tropical rain forest understorey can play a central role in thepopulation ecology of shade-tolerant understorey plants.
Similar content being viewed by others
References
Alvarez-Buylla E.R. and Slatkin M. 1991. Finding confidence limits on population growth rates: three real examples revisited. Ecol. 75: 255-260.
Bentley B.L. 1979. Longevity of individual leaves in a tropical rainforest understory. Ann. Bot. 43: 119-121.
Bernal R. 1998. Demography of the vegetable ivory palm Phytelephas seemannii in Colombia, and the impact of seed harvesting. J. Appl. Ecol. 35: 64-74.
Borchsenius F., Pedersen H.B. and Balslev H. 1998. Manual to the palms of Ecuador. AAU Reports, Department of Systematic Botany, University of Aarhus, Aarhus.
Bullock S.H. 1980. Demography of an undergrowth palm in littoral Cameroun. Biotropica 12: 247-255.
Caswell H. 1989. Matrix Population Models. Sinauer Ass., Inc. Publishers, Sunderland, Massachusetts.
Chazdon R.L. 1985. Leaf display, canopy structure, and light interception of two understory palm species. Am. J. Bot. 72: 1493-1502.
Chazdon R.L. 1986a. The costs of leaf support in understory palms: economy versus safety. Am. Nat. 127: 9-30.
Chazdon R.L. 1986b. Light variation and carbon gain in rain forest understorey palms. J. Ecol. 74: 995-1012.
Chazdon R.L. 1986c. Physiological and morphological basis of shade tolerance in rain forest understory palms. Principes 30: 92-99.
Chazdon R.L. 1992. Patterns of growth and reproduction of Geonoma congesta, a clustered understory palm. Biotropica 24: 43-51.
Chazdon R.L. and Fetcher N. 1984. Light environments of tropical forests. In: Medina E., Mooney H.A. and Vásquez-Yánes C. (eds), Physiological Ecology of Plants of the Wet Tropics. Dr W. Junk Publishers, The Hague, pp. 27-36.
Chazdon R.L., Pearcy R.W., Lee D.W. and Fetcher N. 1996. Photosynthetic responses of tropical forest plants to contrasting light environments. In: Mulkey S.S., Chazdon R.L. and Smith A.P. (eds), Tropical Forest Plant Ecophysiology. Chapman & Hall, New York, pp. 5-55.
Cintra R. 1997. A test of the Janzen-Connell model with two common tree species in Amazonian forest. J. Trop. Ecol. 13: 641-658.
Clark D.A. and Clark D.B. 1992. Life history diversity of canopy and emergent trees in a neotropical rain forest. Ecological Monographs 62: 315-344.
Clark D.B., Clark D.A. and Rich P.M. 1993. Comparative analysis of microhabitat utilization by saplings of nine tree species in neotropical rain forest. Biotropica 25: 397-407.
Clark D.B., Clark D.A., Rich P.M., Weiss S. and Oberbauer S.F. 1996. Landscape-scale evaluation of understory light and canopy structure: methods and application in a neotropical lowland rain forest. Can. J. For. Res. 26: 747-757.
Clark J.S., Macklin E. and Wood L. 1998. Stages and spatial scales of recruitment limitation in southern Appalachian forests. Ecol. Monogr. 68: 213-235.
Condit R., Hubbell S.P. and Foster R.B. 1994. Density dependence in two understory tree species in a neotropical forest. Ecology 75: 671-680.
Condit R., Hubbell S.P. and Foster R.B. 1995. Mortality rates of 205 neotropical tree and shrub species and the impact of a severe drought. Ecological Monographs 65: 419-439.
Crawley M.J. 1997a. Life history and environment. In: Crawley M.J. (ed.), Plant Ecology. Blackwell Science Ltd., Oxford, pp. 73-131.
Crawley M.J. (ed.) 1997b. Plant Ecology. Blackwell Science Ltd., Oxford.
Cunningham S.A. 1997. The effect of light environment, leaf area, and stored carbohydrates on inflorescence production by a rain forest understory palm. Oecologia 111: 36-44.
Davies S.J., Palmiotto P.A., Ashton P.S., Lee H.S. and LaFrankie J.V. 1998. Comparative ecology of 11 sympatric species of Macaranga in Borneo: tree distribution in relation to horizontal and vertical resource heterogeneity. J. Ecol. 86: 662-673.
de Granville J.-J. 1992. Life forms and growth strategies of Guianan palms as related to their ecology. Bulletin de l'Institut français d'études andines 21: 533-548.
Denslow J.S. 1987. Tropical rainforest gaps and tree species diversity. Ann. Rev. Ecol. Syst. 18: 431-451.
Denslow J.S., Newell E. and Ellison A.M. 1991. The effect of understory palms and cyclanths on the growth and survival of Inga seedlings. Biotropica 23: 225-234.
Dixon P.M. 1993. The bootstrap and the jackknife: describing the precision of ecological indices. In: Scheiner S.M. and Gurevitch J. (eds), Design and Analysis of Ecological Experiments. Chapman & Hall, New York, pp. 290-318.
Fowler N. 1988. The effects of environmental heterogeneity in space and time on the regulation of populations and communities. In: Davy A.J., Hutchings M.J. and Watkinson A.R. (eds), Plant Population Ecology. Blackwell Scientific Publications, Oxford, pp. 249-269.
Gerwing J.J. 1995. Competitive effects of three tropical tree species on two species of Piper. Biotropica 27: 47-56.
Givnish T.J. 1988. Adaptation to sun and shade: a whole-plant perspective. Aus. J. Plant Phys. 15: 63-92.
Goldberg D.E. and Barton A.M. 1992. Patterns and consequences of interspecific competition in natural communities: a review of field experiments with plants. Am. Natural. 139: 771-801.
Hensher D.A. and Johnson L.W. 1981. Applied Discrete-Choice Modelling. Halsted Press, a Division of John Wiley & Sons, Inc., New York.
Hodel D.R. 1992. Chamaedorea Palms - The Species and Their Cultivation. Allen Press, Lawrence.
Horvitz C.C. and Schemske D.W. 1995. Spatiotemporal variation in demographic transitions of a tropical understory herb: projection matrix analysis. Ecol. Monogr. 65: 155-192.
Hosmer D.W. and Lemeshow S. 1989. Applied Logistic Regression. John Wiley & Sons, Inc., New York.
Hubbell S.P., Condit R. and Foster R. 1990. Presence and absence of density dependence in a neotropical tree community. 330: 269-281 Philosophical Transactions of the Royal Society of London., series B.
Kobe R.K. 1999. Light gradient partitioning among tropical tree species through differential seedling mortality and growth. Ecology 80: 187-201.
Larcher W. 1995. Physiological Plant Ecology: Ecophysiology and Stress Physiology of Functional Groups. Springer Verlag, Berlin.
Lee D.W. 1986. Unusual strategies of light absorption in rain-forest herbs. In: Givnish T.J. (ed.), On the Economy of Plant Form and Function. Cambridge University Press, Cambridge, pp. 105-131.
Mack A.L. 1995. Distance and non-randomness of seed dispersal by the dwarf cassowary Casuarinus bennetti. Ecography 18: 286-295.
Mendoza A., Piñero D. and Sarukhán J. 1987. Effects of experimental defoliation on growth, reproduction and survival of Astrocaryum mexicanum. J. Ecol. 75: 545-554.
Nicotra A.B., Chazdon R.L. and Iriarte S.V.B. 1999. Spatial heterogeneity of light and woody seedling regeneration in tropical wet forests. Ecology 80: 1908-1926.
Niklas K.J. 1988. The role of phyllotactic patterns as a “developmental constraint” on the interception of light by leaf surfaces. Evolution 42: 1-16.
Oyama K. 1990. Variation in growth and reproduction in the neotropical dioecious palm Chamaedorea tepejilote. J. Ecol. 78: 648-663.
Pascarella J.B. and Horvitz C.C. 1998. Hurricane disturbance and the population dynamics of a tropical understory shrub: megamatrix elasticity analysis. Ecology 79: 547-563.
Piñero D. and Sarukhán J. 1982. Reproductive behaviour and its individual variation in a tropical palm, Astrocaryum mexicanum. J. Ecol. 70: 461-472.
Piñero D., Martinez-Ramos M. and Sarukhán J. 1984. A population model of Astrocaryum mexicanum and a sensitivity analysis of its finite rate of increase. J. Ecol. 72: 977-991.
Pulliam H.R. 1996. Sources and sinks: empirical evidence and population consequences. In: Rhodes J.O.E., Chesser R.K. and Smith M.H. (eds), Population Dynamics in Ecological Space and Time. The University of Chicago Press, Chicago, pp. 45-69.
SAS Institute 1994. JMP Statistics and Graphics Guide. Version 3 of JMP. SAS Institute Inc., Cary, North Carolina.
Schupp E.W. and Frost E.J. 1989. Differential predation of Wel fia georgii seeds in treefall gaps and the forest understory. Biotropica 21: 200-203.
Sheil D. 1995. A critique of permanent plot methods and analysis with examples from Budongo Forest, Uganda. For. Ecol. Man. 77: 11-34.
Sherman P.T. 1996. Family Psophiidae (Trumpeters). In: del Hoyo J., Elliott A. and Sargata J. (eds), Handbook of the Birds of the World. Vol. 3. Lynx Ediciones, Barcelona, Spain, pp. 96-107.
Silvertown J., Franco M., Pisanty I. and Mendoza A. 1993. Comparative plant demography - relative importance of life-cycle components to the finite rate of increase in woody and herbaceous perennials. J. Ecol. 81: 465-476.
Smith A.P., Hogan K.P. and Idol J.R. 1992. Spatial and temporal patterns of light and canopy structure in a lowland tropical moist forest. Biotropica 24: 503-511.
Svenning J.-C. 1999. Microhabitat specialization in a species-rich palm community in Amazonian Ecuador. J. Ecol. 87: 55-65.
Vandermeer J. 1994. Effects of hurricane Joan on the palms of the Caribbean coast rainforest of Nicaragua. Principes 38: 182-189.
Vandermeer J.H., Stout J. and Miller G. 1974. Growth rates of Wel fia georgii, Socratea durissima, and Iriartea gigantea under various conditions in a natural rainforest in Costa Rica. Principes 18: 148-154.
Walsh R.P.D. 1996. Microclimate and hydrology. In: Richards P.W. (ed.), The Tropical Rain Forest-An Ecological Study. 2nd edn. Cambridge University Press, Cambridge, pp. 206-236.
Wessels Boer J. 1968. The geonomoid palms. Verhandelingenn der Koninklijke Nederlandse Akademie van Wetenschappen, Afd. Natuurkunde. Tweede Reeks 58: 1-202.
Whitmore T.C. 1998. An Introduction to Tropical Rain Forests. Oxford University Press, Oxford.
Wolfram S. 1996. The Mathematica Book. Wolfram Media/Cambridge University Press, Cambridge.
Wright S.J. 1992. Seasonal drought, soil fertility and the species density of tropical forest plant communities. Trends Ecol. Evol. 7: 260-263.
Zuidema P.A. 2000. Demography of exploited tree species in the Bolivian Amazon, Scientific Series 2. PROMAB, Riberalta, Bolivia.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Svenning, JC. Crown illumination limits the population growth rate of a neotropical understorey palm (Geonoma macrostachys, Arecaceae). Plant Ecology 159, 185–199 (2002). https://doi.org/10.1023/A:1015520116260
Issue Date:
DOI: https://doi.org/10.1023/A:1015520116260