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Use of hemispherical photographs in forest ecology: measurement of gap size and radiation totals in a Bornean tropical rain forest

Published online by Cambridge University Press:  10 July 2009

T. C. Whitmore
Affiliation:
Department of Plant Sciences, Oxford University, 0X1 3RB, UK
N. D. Brown
Affiliation:
Department of Plant Sciences, Oxford University, 0X1 3RB, UK
M. D. Swaine
Affiliation:
Department of Plant and Soil Science, Aberdeen University, AB9 2UD, UK
D. Kennedy
Affiliation:
Department of Plant and Soil Science, Aberdeen University, AB9 2UD, UK
C. I. Goodwin-Bailey
Affiliation:
Department of Plant Sciences, Oxford University, 0X1 3RB, UK
W.-K. Gong
Affiliation:
Department of Plant Sciences, Oxford University, 0X1 3RB, UK

Abstract

Study of forest dynamics commonly requires measurement of canopy gap size. Hemispherical photographs can be analysed to provide various measures whereby gaps can be ranked in order of size. For ten artificial gaps in a Bornean tropical rain forest these measures were better correlated with gap microclimate than gap area measured physically on the ground. All these measures are however relative. For detailed (e.g. ecophysiological) studies the greater detail provided by absolute measures of photosynthetically active radiation (PAR) are required. Long term PAR values can be computed from hemiphots so long as measurements in the open nearby are available. Correction for cloudy weather is essential. Computed and measured PAR are compared for the test gaps. Both have inherent limits which means that below c. 15% canopy openness, differences in PAR between gaps cannot be assessed accurately.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

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References

LITERATURE CITED

Anderson, M. C. 1964a. Light relations of terrestrial plant communities and their measurement. Biological Reviews 39:425486.CrossRefGoogle Scholar
Anderson, M. C. 1964b. Studies of the woodland light climate 1. The photographic computation of light conditions. Journal of Ecology 52:2741.CrossRefGoogle Scholar
Becker, P., Erhart, D. W. & Smith, A. P. 1989. Analysis of forest light environments 1. Computerised estimation of solar radiation from hemispherical canopy photographs. Agricultural & Forest Meteorology 44:217232.CrossRefGoogle Scholar
Biggs, W. 1986. Radiation measurement. Pp. 320 in Gensler, W. G. (ed.). Advanced agricultural instrumentation. Nijhoff, Dordrecht, The Netherlands.CrossRefGoogle Scholar
Brokaw, N. V. L. 1982. The definition of treefall gaps and its effect on measures of forest dynamics. Biotropica 11:158160.CrossRefGoogle Scholar
Brokaw, N. V. L. 1985. Treefalls, regrowth and community structure in tropical forests. Pp. 5369 in Pickett, S. T. A. & White, P. S. (eds). The ecology of natural disturbance and patch dynamics. Academic Press, New York.Google Scholar
Brown, N. D. 1990. Dipterocarp regeneration in tropical rain forest gaps of different sizes. DPhil thesis, Oxford University.Google Scholar
Brown, N. D. 1993. The implications of climate and gap microclimate for seedling growth in a Bornean lowland rain forest. Journal of Tropical Ecology 9:153168.CrossRefGoogle Scholar
Brown, N. D. & Whitmore, T. C. 1992. Do dipterocarp seedlings really partition rain forest gaps? Philosophical Transactions of the Royal Society of London B 335:369–78.Google Scholar
Canham, C. D. 1988. An index fors understory light levels in and around canopy gaps. Ecology 69:16341638.CrossRefGoogle Scholar
Chazdon, R. L. & Field, C. B. 1987a. Determinants of photosynthetic capacity in six rain forest Piper species. Oecologia (Berlin) 73:222230.CrossRefGoogle ScholarPubMed
Chazdon, R. L. & Field, C. B. 1987b. Photographic estimation of photosynthetically active radiation: evaluation of a computerized technique. Oecologia (Berlin) 73:525532.CrossRefGoogle ScholarPubMed
Clark, D. A. & Clark, D. B. In press. Life history diversity of canopy and emergent trees in a neotropical rain forest. Ecological Monographs.Google Scholar
Denslow, J. S. 1987. Tropical rain forest gaps and tree species diversity. Annual Review of Ecology and Systematics 18:431451.CrossRefGoogle Scholar
Evans, G. C. 1956. An area survey method of investigating the distribution of light intensity in woodlands with particular reference to sunflecks. Journal of Ecology 44:391428.CrossRefGoogle Scholar
Gates, D. M. 1980. Biophysical ecology. Springer, New York. 611 pp.CrossRefGoogle Scholar
Kennedy, D. 1991. The role of colonising species in the regeneration of dipterocarp rain forest. PhD thesis, Aberdeen University.Google Scholar
Kennedy, D. N. & Swaine, M. D. 1992. Germination and growth of colonizing species in artificial gaps of different sizes in dipterocarp rain forest. Philosophical Transactions of the Royal Society of London B 335:357–68.Google Scholar
Lieberman, M., Lieberman, D. & Peralta, R. 1989. Forests are not just Swiss cheese: canopy stereogeometry of non-gaps in tropical forests. Ecology 70:550552.CrossRefGoogle Scholar
Marshall, A. G. & Swaine, M. D. (eds). 1992. Tropical rain forest: disturbance and recovery. Philosophical Transactions of the Royal Society of London B 335:327457.Google Scholar
Mitchell, P. L. & Whitmore, T. C. 1993. Use of hemispherical photographs in forest ecology: calculation of absolute amount of radiation beneath the canopy. OFI Occasional Papers 44, Oxford Forestry Institute.Google Scholar
Platt, W. J. & Strong, D. R. (eds). 1989. Special feature: treefall gaps and forest dynamics. Ecology 70:535576.CrossRefGoogle Scholar
Rich, P. M. 1989. A manual for analysis of hemispherical canopy photography. Los Alamos National Laboratory Technical Report LA-M733-M. 80 pp.CrossRefGoogle Scholar
Rich, P. M. 1990. Characterizing plant canopies with hemispherical photographs. Remote Sensing Reviews 5:1329.CrossRefGoogle Scholar
Sokal, R. R. & Rohlf, F. J. 1981. Biometry. (2nd edition). W.H. Freeman, New York. 859 pp.Google Scholar
Turner, I. M. 1990. Tree seedling growth and survival in a Malaysian rain forest. Biotropica 22:146154.CrossRefGoogle Scholar
Walters, M. B. & Field, C. B. 1987. Photosynthetic light acclimation in two rain forest Piper species with different ecological amplitudes. Oecologia (Berlin) 72:449456.CrossRefGoogle ScholarPubMed
Whitmore, T. C. 1984. Tropical rain forests of the Far East. (2nd edition). Clarendon, Oxford. 352 pp.Google Scholar
Whitmore, T. C. 1988. The influence of tree population dynamics on forest species composition. Pp. 271292 in Davy, A. J., Hutchings, M. J. & Watkinson, A. R. (eds). Population biology of plants. Blackwell, Oxford.Google Scholar
Whitmore, T. C. 1990. An introduction to tropical rain forests. Clarendon, Oxford. 226 pp.Google Scholar
Whitmore, T. C. & Wong, Y. K. 1959. Patterns of sunlight and shade in tropical rain forest. Malayan Forester 21:5062.Google Scholar