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Tropical tree seedling dynamics: recruitment patterns and their population consequences for three canopy species in Panama

Published online by Cambridge University Press:  10 July 2009

Diane de Steven
Affiliation:
Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA.

Abstract

A study of seedling demography of three shade-tolerant canopy tree species (Quararibea asterolepis, Trichilia tuberculata, and Tetragastris panamensis) was initiated to integrate with long-term studies of tree fruit production and of tree population dynamics on Barro Colorado Island, Panama. Over a five-year period, all seedlings (height <50 cm) and small saplings (height ≥50 cm to dbh 1 cm) were measured and monitored in permanent tree-centred transects (N = 10–11 trees per species). Survival rates increased with plant size class and were similar among species. Maximum height growth rates increased with increasing plant size, but average growth rates did not; this disparity suggests the importance of release from understorey suppression for long-term recruitment success. Among the three species, Quararibea had the lowest standing seedling densities and almost no sapling recruitment, whereas Tetragastris had the highest densities of both seedlings and saplings; Trichilia seedling and sapling densities were intermediate. In all three species, a few trees produced very high seedling and sapling densities in comparison with the sample average. All three species exhibited a year of exceptionally high new seedling recruitment during the study period; these good years were not coincident among the species but instead reflected the species' phenological differences. Since seedling survival becomes relatively constant and high after the first few years of life (c. 80% y−1), such large new cohorts persist as a year-class effect in the seedling population and thus maintain seedling numbers over time. The interspecific differences in seedling and sapling dynamics were consistent with overall 10-year trends of a declining Quararibea population, a stable Trichilia population, and an increasing Tetragastris population.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

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References

LITERATURE CITED

Augspurger, C. K. 1984. Seedling survival of tropical tree species: interactions of dispersal distance, light gaps, and pathogens. Ecology 65:17051712.CrossRefGoogle Scholar
Becker, P. 1983. Effects of insect herbivory and artificial defoliation on survival of Shorea seedlings. Pp. 241–52 in Sutton, S. L., Whitmore, T. C. & Chadwick, A. C. (eds). Tropical rainforest: ecology and management. Blackwell Scientific Publications, London.Google Scholar
Becker, P., Rabenold, P. E., Idol, J. R. & Smith, A. P. 1988. Water potential gradients for gaps and slopes in a Panamanian tropical moist forest's dry season. Journal of Tropical Ecology 4:175184.CrossRefGoogle Scholar
Bonaccorso, F. J. & Humphrey, S. R. 1984. Fruit bat niche dynamics: their role in maintaining tropical forest diversity. Pp. 169183 in Chadwick, A. C. & Sutton, S. L. (eds). Tropical rain-forest: the Leeds symposium. Leeds Philosophical and Literary Society, Leeds, England.Google Scholar
Chan, H. T. 1980. Reproductive biology of some Malaysian dipterocarps. II. Fruiting biology and seedling studies. Malaysian Forester 43:438451.Google Scholar
Chesson, R. & Warner, R. R. 1981. Environmental variability promotes coexistence in lottery competitive systems. American Naturalist 117:923943.CrossRefGoogle Scholar
Clark, D. A. 1986. Regeneration of canopy trees in tropical wet forests. Trends in Ecology and Evolution 1(6): 150154.CrossRefGoogle ScholarPubMed
Clark, D. A. & Clark, D. B. 1981. Effects of seed dispersal by animals on the regeneration of Bursera graveolens (Burseraceae) on Sante Fe Island, Galapagos. Oecologia 49:7375.CrossRefGoogle Scholar
Clark, D. B. & Clark, D. A. 1987. Population ecology and microhabitat distribution of Dipteryx panamensis, a neotropical rain forest emergent tree. Biotropica 19:236244.CrossRefGoogle Scholar
Clark, D. B. & Clark, D. A. 1991. The impact of physical damage on canopy tree regeneration in tropical rain forest. Journal of Ecology 79:447457.CrossRefGoogle Scholar
Condit, R., Hubbell, S. P. & Foster, R. B. 1992. Short-term dynamics of a neotropical forest: change within limits. BioScience 42:822828.CrossRefGoogle Scholar
Cruz, A. 1981. Bird activity and seed dispersal of a montane forest tree (Dunalia arborescens) in Jamaica. Biotropica 13 (Suppl.):3444.CrossRefGoogle Scholar
Croat, T. 1978. The flora of Barro Colorado Island. Stanford University Press, Palo Alto, California.Google Scholar
Denslow, J. S. 1980. Notes on the seedling ecology of a large-seeded species of Bombacaceae. Biotropica 12:220222.CrossRefGoogle Scholar
De Steven, D. 1989. Genet and ramet demography of Oenocarpus mapora spp. mapora, a clonal palm of Panamanian tropical moist forest. Journal of Ecology 77:579596.CrossRefGoogle Scholar
Fleming, T. H. & Heithaus, E. R. 1981. Frugivorous bats, seed shadows, and the structure of tropical forests. Biotropica 13 (Suppl.):4553.CrossRefGoogle Scholar
Forget, P-M. 1990. Seed dispersal of Vouacapoua amiricana (Caesalpiniaceae) by cavimorph rodents in French Guiana. Journal of Tropical Ecology 6:459468.CrossRefGoogle Scholar
Garwood, N. C. 1983. Seed germination in a tropical forest in Panama: a community study. Ecological Monographs 53:159181.CrossRefGoogle Scholar
Howe, H. F. 1980. Monkey dispersal and waste of a neotropical fruit. Ecology 61:944–59.CrossRefGoogle Scholar
Howe, H. F. 1990a. Seed dispersal by birds and mammals: implications for seedling demography. Pp. 191218 in Bawa, K. S. & Hadley, M. (eds). Reproductive ecology of tropical forest plants. Man and the Biosphere Parthenon/UNESCO.Google Scholar
Howe, H. F. 1990b. Survival and growth of juvenile Virola surinamensis in Panama: effects of herbivory and canopy closure. Journal of Tropical Ecology 6:259280.CrossRefGoogle Scholar
Hubbell, S. P. & Foster, R. B. 1983. Diversity of canopy trees in a neotropical forest and implications for conservation. Pp. 2541 in Sutton, S. L., Whitmore, T. C. & Chadwick, A. C. (eds). Tropical rain forest: ecology and management. Blackwell Scientific Publications, Oxford.Google Scholar
Hubbell, S. P. & Foster, R. B. 1987. The spatial context of regeneration in a neotropical forest. Pp. 395412 in Gray, A. J., Crawley, M. J. & Edwards, P. J. (eds). Colonization, succession and stability. Blackwell Scientific Publications, Oxford.Google Scholar
Hubbell, S. P. & Foster, R. B. 1990. Structure, dynamics, and equilibrium status of old-growth forest on Barro Colorado Island. Pp. 522541 in Gentry, A. H. (ed.). Four neotropical rainforests. Yale University Press, New Haven, Connecticut.Google Scholar
Hubbell, S. P., Condit, R. & Foster, R. B. 1990. Presence and absence of density dependence in a neotropical tree community. Philosophical Transactions of the Royal Society of London, Ser. B, 330:269281.Google Scholar
Kiew, R. 1982. Germination and seedling survival in kemenyan, Styrax benzoin. Malaysian Forester 45:6980.Google Scholar
Leigh, E. G., Rand, A. S. & Windsor, D. M. 1982. The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, DC.Google Scholar
Leighton, M. & Leighton, D. R. 1982. The relationship of size of feeding aggregate to size of food patch: howler monkeys (Alouatta palliata) feeding in Trichilia cipo fruit trees on Barro Colorado Island. Biotropica 14:8190.CrossRefGoogle Scholar
Li, M. 1991. The ecology of neotropical forest tree seedlings. PhD dissertation, University of North Dakota, Grand Forks, ND, USA.Google Scholar
Lieberman, D. & Lieberman, M. 1987. Forest growth and dynamics at La Selva, Costa Rica (1969–1982). Journal of Tropical Ecology 3, 4 (Special Issue):347358.CrossRefGoogle Scholar
Nuñez-Farfan, J. & Dirzo, R. 1988. Within-gap spatial heterogeneity and seedling performance in a Mexican tropical forest. Oikos 51:274284.CrossRefGoogle Scholar
Piñero, D., Martinez-Ramos, M. & Sarukhan, J. 1984. A population model of Astrocaryum mexicanum and a sensitivity analysis of its finite rate of increase. Journal of Ecology 72:977991.CrossRefGoogle Scholar
Schupp, E. W. 1990. Annual variation in seedfall, postdispersal predation, and recruitment of a neotropical tree. Ecology 71:504515.CrossRefGoogle Scholar
Sork, V. L. 1987. Effects of predation and light on seedling establishment in Gustavia superba. Ecology 68:13411350.CrossRefGoogle Scholar
Thomas, D. W., Cloutier, D., Provencher, M. & Houle, C. 1988. The shape of birdand bat-generated seed shadows around a tropical fruiting tree. Biotropica 20:347348.CrossRefGoogle Scholar
Turner, I. M. 1990. The seedling survivorship and growth of three Shorea species in Malaysian tropical rain forest. Journal of Tropical Ecology 6:469478.CrossRefGoogle Scholar
Welden, C. W., Hewett, S. W., Hubbell, S. P. & Foster, R. B. 1991. Sapling survival, growth, and recruitment: relationship to canopy height in a neotropical forest. Ecology 72:3550.CrossRefGoogle Scholar
Windsor, D. M. 1990. Climate and moisture variability in a tropical forest: long-term records from Bam Colorado Island, Panama. Smithsonian Contributions to the Earth Sciences, No. 29. Smithsonian Institute Press, Washington, DC.Google Scholar
Wong, M., Wright, S. J., Hubbell, S. P. & Foster, R. B. 1990. The spatial pattern and reproductive consequences of outbreak defoliation in Quararibea asterolepis, a tropical tree. Journal of Ecology 78:579588.CrossRefGoogle Scholar