Studies on the dynamic properties of terrestrial ecosystems based on a simulation model I. Critical light conditions for stability of a tropical rainforest ecosystem
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By employing a microcomputer model developed in a previous study (Oikawa, 1985), the stability of a tropical rainforest ecosystem composed of three strata was analyzed in relation to incident light flux density. Surplus production (P s ), calculated as a function of the leaf area index and light attenuation coefficient, was remarkably affected by the maximum illuminance at noon (I0, max).
Simulation experiments for a period of 100 years demonstrated that the upper stratum was able to reach a steady state at about 50 years and thereafter, when a value ofI 0, max equal to or greater than 80 klux was assigned to the upper stratum, where the higher the value ofI 0, max , the greater the biomasses and the carbon fluxes at the steady state as a result of enhanced productivity. WhenI 0, max was assigned a value of 70 klux, on the other hand, this experiment predicted a failure of the upper stratum to maintain stability due to deficiency of surplus productivity.
Moreover, it was also suggested that excessive luxuriance of the upper stratum due toI 0, max elevation may have a detrimental effect upon the survival of the middle stratum, since increasingI 0, max decreases the light energy available for the middle stratum even in absolute terms, resulting in disappearance of this stratum whenI 0, max is equal to or greater than 120 klux.
These simulation experiments suggested that a tropical rainforest ecosystem composed of three strata is able to exist within a narrow range ofI 0, max between 80 and 110 klux, light conditions which are much higher than the light compensation point for canopy photosynthesis
Key wordsCritical light condition Dry-matter production Forest stability Minimum illuminance requirement Statified structure Tropical rainforest
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- Black, J. N. (1963) The interrelationship of solar radiation and leaf area index in determining the rate of dry matter production of swards of subterranean clover (Trifolium pratense L.). Aust. J. agric. Res.11: 26–42.Google Scholar
- Blackman, G. E. &Black, J. N. (1959) Physiological and ecological studies in the analysis of plant environment. XI. Further assessment of the influence of shading on the growth of different species in the vegetative phase. Ann. Bot. N.S.23: 51–63.Google Scholar
- — (1951a) Physiological and ecological studies in the analysis of plant environment. VI. The constancy for different species of a logarithmic relationship between net assimilation rate and light intensity and its ecological significance. Ann. Bot. N.S.15: 63–94.Google Scholar
- —— (1951b) Physiological and ecological studies in the analysis of plant environment. VII. An analysis of the differential effects of light intensity on the net assimilation rate, leafarea. ratio, and relative growth rate of different species. Ann Bot. N.S.14: 373–408.Google Scholar
- Boysen Jensen, P. (1932) Die Stoffproducktion der Pflanzen. pp. 108 Fishcer, Jena.Google Scholar
- Hiroi, T. &Monsi, M. (1966) Dry-matter economy ofHelianthus annuus communities grown at varying densities and light intensitics. J. Fac. Sci. Univ. of Tokyo9: 241–285.Google Scholar
- Kira, T. (1987) Primary production and carbon cycling in a primeval lowland raiforest of peninsular Malaysia. “Tree Crop Physiology” (ed. Sethuraj M. R. & Raghavendra, A. S.), 99–119. Elsevier Science Publishers. Amsterdam. Paper originally presented at the Internat. Workshop on Special Problems in Physiol. Invest. of Tree Crops, 26–28 August 1982, Kottayam, India.Google Scholar
- Kuroiwa, S. (1966) Dry-matter production of plantsIn: Modern Biology Series Vol. 9, Ecology and Evolution pp. 71–100. Iwanami Shoten, Tokyo (In Japanese)Google Scholar
- Monst, M. (1960) Dry-matter reproduction in plants I. Schemata of dry-matter reproduction. Bot. Mag. Tokyo73: 81–90.Google Scholar
- — (1968) Mathematical models of plant communities. “Functioning of Terrestrial Ecosystems at The Primary Production Level” (ed. Eckardt, F. E.), pp. 131–149, UNESCO, Paris.Google Scholar
- Monsi, M. &Saeki, T. (1953) Über den Lichtfaktor in den Pflanzengesel Ischaften und seine Bedeutung für die Stoffproduktion. Jap. J. Bot.14: 22–52.Google Scholar
- Oikawa, T. (1985) Simulation of forest carbon dynamics based on a dry-matter production model. I. Fundamental model structure of a tropical rainforest ecosystem. Bot. Mag. Tokyo98: 225–238.Google Scholar
- —. (1986a) Simulation of forest carbon dynamics based on a dry-matter production model. II. Effects of dry season upon a tropical rainforest ecosystem. Bot. Mag. Tokyo99: 213–223.Google Scholar
- —. (1986b) Simulation of forest carbon dynamics based on a dry-matter production model. III. Effects of increasing CO2 upon a tropical rainforest ecosystem. Bot. Mat. Tokyo99: 419–430.Google Scholar
- —. (1986c) A simulation study of surplus productivity as influenced by the photosynthesis and respiration rates of a single leaf. J. Agr. Met.42: 207–216.Google Scholar
- Takeda, T. (1961) Studies on the photosynthesis and production of dry matter in the community of rice plants. Jap. J. Bot.17: 402–437.Google Scholar