Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-10T13:02:23.816Z Has data issue: false hasContentIssue false

Water potential gradients for gaps and slopes in a Panamanian tropical moist forest's dry season

Published online by Cambridge University Press:  10 July 2009

Peter Becker
Affiliation:
Smithsonian Tropical Research Institute, Aptdo 2072, Balboa, Republica de Panamá
Peter E. Rabenold
Affiliation:
Smithsonian Tropical Research Institute, Aptdo 2072, Balboa, Republica de Panamá
Jacquelyn R. Idol
Affiliation:
Smithsonian Tropical Research Institute, Aptdo 2072, Balboa, Republica de Panamá
Alan P. Smith
Affiliation:
Smithsonian Tropical Research Institute, Aptdo 2072, Balboa, Republica de Panamá

Abstract

Soil water potentials were measured weekly by psychrometers at 20 cm depth during the dry season in a tropical moist forest on Barro Colorado Island, Panama. There was a persistent gradient of decreasing soil moisture from gap centre to gap edge to adjacent understorey at both a large and a small gap. On both a north-south and an east-west transect, the soil was drier (water potentials were more negative) on an upland surface than on moderate slopes. This trend was reflected in the predawn, total water potentials of shallow-rooted Psychotria horizontalis and deep-rooted Trichilia tuberculata measured in the understorey during the last two months of the dry season. P. horizontalis from the wettest sites on the transects had higher osmotic potentials at full hydration and at zero turgor, indicating less drought resistance than for conspecifics from the driest sites.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

Anonymous. 1979. HR-33T instructional manual. Wescor Inc., Logan, Utah. 38 pp.Google Scholar
Anonymous. 1985. STAGRAPHICS: statistical graphics system. STSC Inc., Rockville, Maryland.Google Scholar
Barnes, P. W. & Harrison, A. T. 1982. Species distribution and community organization in a Nebraska Sandhills mixed prairie as influenced by plant/soil-water relationships. Oecologia (Berlin) 52:192201.CrossRefGoogle Scholar
Bazzaz, F. A. 1984. Dynamics of wet tropical forests and their species strategies. Pp. 233244 in Medina, E., Mooney, H. A. & Vázquez-Yánes, C. (eds). Physiological ecology of plants of the wet tropics. Dr W. Junk Publishers, The Hague.CrossRefGoogle Scholar
Black, C. A. (ed.) 1965. Methods of soil analysis. Part 1: Physical and mineralogical properties, including statistics of measurement and sampling. American Society of Agronomy Inc., Madison, Wisconsin.CrossRefGoogle Scholar
Carson, M. A. & Kirkby, M. J. 1972. Hillslope form and process. Cambridge University Press, Cambridge. 475 pp.Google Scholar
Chazdon, R. L. & Fetcher, N. 1984. Photosynthetic light environments in a lowland tropical rain forest in Costa Rica. Journal of Ecology 72:553564.CrossRefGoogle Scholar
Cheung, Y. N. S., Tyree, M. T. & Dainty, J. 1975. Water relations parameters on single leaves obtained in a pressure bomb and some ecological interpretations. Canadian Journal of Botany 53:13421346.CrossRefGoogle Scholar
Denslow, J. S. 1980. Gap partitioning among tropical rainforest trees. Biotropica 12 (special supplement:4755.CrossRefGoogle Scholar
Dietrich, W. E., Windsor, D. M. & Dunne, T. 1982. Geology, climate, and hydrology of Barro Colorado Island. Pp. 2146 in JrLeigh, E. G., Rand, A. S. & Windsor, D. M. (eds). The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, DC.Google Scholar
Fletcher, P. W. & Lull, H. W. 1963. Soil-moisture depletion by a hardwood forest during drouth years. Soil Science Society of America Proceedings 27:9498.Google Scholar
Foster, R. B. & Brokaw, N. V. L. 1982. Structure and history of the vegetation of Barro Colorado Island. Pp. 6781 in Leigh Jr, E. G., Rand, A. S. & Windsor, D. M. (eds). The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, DC.Google Scholar
Geiger, R. 1965. The climate near the ground. Harvard University Press, Cambridge, Massachusetts.Google Scholar
Helvey, J. D. 1971. Predicting soil moisture in the southern Appalachians. MSc. thesis, University of Georgia, Athens, GA.Google Scholar
Hsiao, T. C., Acevedo, E., Fereres, E. & Henderson, D. W. 1976. Stress metabolism: water stress, growth, and osmotic adjustment. Philosophical Transactions of the Royal Society of London, Series B 273:479500.Google 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
Hunt, J. P. & Delagran, L. 1984. Statpro: the statistics and graphics database workstation. Wadsworth Professional Software, Boston.Google Scholar
Knight, D. H. 1975. A phytosociological analysis of species-rich tropical forest on Barro Colorado Island, Panama. Ecological Monographs 45:259284.CrossRefGoogle Scholar
Lee, R. 1978. Forest microclimatology. Columbia University Press, New York. 276 pp.Google Scholar
Merrill, S. D. & Rawlins, S. L. 1972. Field measurement of soil water potential with thermocouple psychrometers. Soil Science 113:102109.CrossRefGoogle Scholar
Minckler, L. S. & Woerheide, J. D. 1965. Reproduction of hardwoods 10 years after cutting as affected by site and opening size. Journal of Forestry 63:103107.Google Scholar
Moore, M. R. & Vankat, J. L. 1986. Responses of the herb layer to the gap dynamics of a mature beech-maple forest. The American Midland Naturalist 115:336347.CrossRefGoogle Scholar
Morrison, D. F. 1976. Multivariate statistical methods. (2nd edition). McGraw-Hill, New York. 415 pp.Google Scholar
Nelson, D. C. & Anderson, R. C. 1983. Factors related to the distribution of prairie plants along a moisture gradient. The American Midland Naturalist 109:367375.CrossRefGoogle Scholar
Neter, J. & Wasserman, W. 1974. Applied linear statistical models. Richard D. Irwin Inc., Homewood, Illinois. 842 pp.Google Scholar
Orians, G. H. 1982. The influence of tree-falls in tropical forests in [sic] tree species richness. Tropical Ecology 23:255279.Google Scholar
Pearcy, R. W. 1983. The light environment and growth of C3 and C4 tree species in the understory of a Hawaiian forest. Oecologia (Berlin) 58:1925.CrossRefGoogle ScholarPubMed
Roberts, S. W., Strain, B. R. & Knoerr, K. R. 1980. Seasonal patterns of leaf water relations in four co-occurring forest tree species: parameters from pressure-volume curves. Oecologia (Berlin) 46:330337.CrossRefGoogle ScholarPubMed
Robichaux, R. H., Rundel, P. W., Stemmermann, L., Canfield, J. E., Morse, S. R. & Friedman, W. E. 1984. Tissue water deficits and plant growth in wet tropical environments. Pp. 99112 in Medina, E., Mooney, H. A. & Vázquez-Yánes, C. (eds). Physiological ecology of plants of the wet tropics. Dr W. Junk Publishers, The Hague.CrossRefGoogle Scholar
Sanford, R. L. 1985. Belowground processes during the early years of succession following slash and burn agriculture. Bulletin of the Ecological Society of America 66:262 [abstract].Google Scholar
Slavik, B., Slavikova, J. & Jenik, J. 1957. Ökologie der gruppenweisen Verjüngung eines Mischbestandes. Rozpravy Tschechoslowenske Akademie 67:2.Google Scholar
Smith, A. P. 1987. The response of tropical forest understory herbs to treefalls. Revista de Biologia Tropical 35 (Supplement 1): 111118.Google Scholar
JrTrimble, G. R. & Weitzman, S. 1954. Effect of a hardwood forest canopy on rainfall intensities. Transactions, American Geophysical Union 35:226234.Google Scholar
Tyree, M. T. & Hammell, H. T. 1972. The measurement of the turgor pressure and the water relations of plants by the pressure-bomb technique. Journal of Experimental Botany 23:267282.CrossRefGoogle Scholar
Tyree, M. T. & Richter, H. 1981. Alternative methods of analysing water potential isotherms: some cautions and clarifications. I. The impact of non-ideality and of some experimental errors. Journal of Experimental Botany 32:643653.CrossRefGoogle Scholar
Van't Woudt, B. D. 1955. On a hillside moisture gradient in volcanic ash soil, New Zealand. Transactions, American Geophysical Union 36:419424.Google Scholar
Vitousek, P. M. & Denslow, J. S. 1986. Nitrogen and phosphorus availability in treefall gaps of lowland tropical rainforest. Journal of Ecology 74(4):11671178.CrossRefGoogle Scholar
JrWerling, J. A. & Tajchman, S. J. 1983/1984. Soil thermal and moisture regimes on forested slopes of an Appalachian watershed. Forest Ecology and Management 7:297310.CrossRefGoogle Scholar
Wilkinson, L. 1984. SYSTAT: the system for statistics. SYSTAT Inc., Evanston, Illinois.Google Scholar
Wilson, J. R., Ludlow, M. M., Fisher, M. J. & Schulze, E.-D. 1980. Adaptation to water stress of the leaf water relations of four tropical forage species. Australian Journal of Plant Physiology 7:207220.Google Scholar
Young, H. J. & Young, T. P. 1983. Local distribution of C3 and C4 grasses in sites of overlap on Mount Kenya. Oecologia (Berlin) 58:373377.CrossRefGoogle ScholarPubMed