Abstract
Plants in forest understories are subjected to light environments consisting of a very low background of diffuse light that is punctuated by often much brighter sunflecks lasting from a few seconds to several minutes. These sunflecks, although usually present for less than 10% of the time, typically contribute 10 to 80% of the photosynthetically active photon flux density (PFD) (Chazdon 1988). Therefore much of the photosynthesis of understory plants may occur under transiently changing light conditions that characterize sunflecks. The environmental and physiological controls on photosynthesis during transient light changes are not necessarily the same as those that determine photosynthetic performance under steady-state conditions. The shade-plant syndrome of understory plants has been widely studied but mostly in terms of the controls on steady-state photosynthetic characteristics. Until recently, relatively little attention has been given to the mechanisms regulating the use of sunflecks.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Björkman O, Ludlow M (1972) Characterization of the light climate of a Queensland rainforest. Carnegies Inst Wash Yearb 71: 85–94
Björkman O, Ludlow M, Morrow P (1972) Photosynthetic performance of two rainforest species in their native habitat and analysis of their gas exchange. Carnegie Inst Wash Yearb 71: 94–102
Chazdon RL (1988) Sunflecks and their importance to forest understory plants. Adv Ecol Res 18: 1–63
Chazdon RL, Fetcher N (1984) Photosynthetic light environments in a lowland tropical forest in Costa Rica. J Ecol 72: 553–564
Chazdon RL, Pearcy RW (1986a) Photosynthetic responses to light variation in rain forest species. I. Induction under constant and fluctuating light conditions. Oecologia 69: 517–523
Chazdon RL, Pearcy RW (1986b) Photosynthetic responses to light variation in rain forest species. II. Carbon gain and light utilization during lightflecks. Oecologia 69: 524–531
Farquhar GD, Richards RA (1984) Isotopic composition of plant carbon correlates with water use efficiency of wheat genotypes. Aust J Plant Physiol 11: 539–552
Farquhar GD, O’Leary MH, Berry JA (1982) On the relationship between carbon isotope discrimination and intercellular carbon dioxide concentration in leaves. Aust J Plant Physiol 9: 121–137
Kirschbaum MUF, Pearcy RW (1988) Gas exchange analysis of the relative importance of stomatal and biochemical factors in photosynthetic induction in Alocasia macrorrhiza. Plant Physiol 86: 782–785
Miller E, Norman JM (1971) A sunfleck theory for plant canopies. II. Penumbra effect: intensity distributions along sunfleck segments. Agron J 63: 739–748
Oberbauer SF, Clark DB, Clark DA, Quesada MA (1988) Crown light environments of saplings of two species of rain forest emergent trees. Oecologia 75: 207–212
Oker-Blom P (1984) Penumbral effects of within-plant shading on radiation distribution and leaf photosynthesis: a Monte-Carlo simulation. Photosynthetica 18: 522–528
Pearcy RW (1983) The light environment and growth of C3 and C4 tree species in the understory of a Hawaiian forest. Oecologia 58: 19–25
Pearcy RW (1987) Photosynthetic gas exchange responses of Australian tropical forest trees in canopy, gap and understory micro-environments. Funct Ecol 1: 169–178
Pearcy RW (1990) Sunflecks and photosynthesis in plant canopies. Annu Rev Plant Physiol Plant Mol Biol 41: 421–453
Pearcy RW, Calkin H (1983) Carbon dioxide exchange of C3 and C4 tree species in the understory of a Hawaiian forest. Oecologia 58: 26–32
Pearcy RW, Pfitsch WA (1991) Influence of sunflecks on the δ13C of Adenocaulon bicolor plants occurring in contrasting forest understory microsites. Oecologia 86: 457–462
Pearcy RW, Osteryoung K, Calkin HW (1985) Photosynthetic responses to dynamic light environments by Hawaiian trees. The time course of CO2 uptake and carbon gain during sunflecks. Plant Physiol 79: 896–902
Pearcy RW, Sims DA (1993) Photosynthetic acclimation to changing light environments: scaling from the leaf to the whole plant. In: Caldwell MM, Pearcy RW (eds) Exploitation of environmental heterogeneity by plants: ecophysiological processes above and below ground. Academic Press, San Diego (in press)
Pfitsch WA, Pearcy RW (1989a) Daily carbon gain by Adenocaulon bicolor, a redwood forest understory herb, in relation to its light environment. Oecologia 80: 465–470
Pfitsch WA, Pearcy RW (1989b) Steady-state and dynamic photosynthetic response of Adenocaulon bicolor in its redwood forest habitat. Oecologia 80: 471–476
Pfitsch WA, Pearcy RW (1992) Growth and reproductive allocation of Adenocaulon bicolor following experimental removal of sunflecks. Ecology 73: 2109–2117
Roden JS, Pearcy RW (1993) Effect of leaf flutter on the light environment of poplars. Oecologia 93: 201–207
Sassenrath-Cole GF, Pearcy RW (1992) The role of ribulose-1,5-bisphosphate regeneration in the induction requirement of photosynthetic CO2 exchange under transient light conditions. Plant Physiol 99: 227–234
Schleser GH, Jayasekera R (1985) k13C variation of leaves in forest as an indicator of reassimilated CO2 from soil. Oecologia 65: 536–542
Schulze E-D (1972) Die Wirkung von Licht und Temperatur auf den CO2-Gaswechel verschiedener Lebensformen aus der Krautschicht eines montanen Buchenwaldes. Oecologia 9: 223–234
Seemann JR, Kirschbaum MUF, Sharkey TD, Pearcy RW (1988) Regulation of ribulose 1,5-bisphosphate carboxylase activity in Alocasia macrorrhiza in response to step changes in irradiance. Plant Physiol 88: 148–152
Sternberg LSL, Mulkey SS, Wright SJ (1989) Ecological interpretation of leaf carbon isotope ratios: influence of respired carbon dioxide. Ecology 70: 1317–1324
Tinoco-Ojanguren C, Pearcy RW (1992) Dynamic stomatal behavior and its role in carbon gain during lightflecks of a gap phase and an understory Piper species acclimated to high and low light. Oecologia 92: 222–228
Weber JA, Jurik TW, Tenhumen JD, Gates DM (1985) Analysis of gas exchange in seedlings of Acer saccharum: integration of field and laboratory studies. Oecologia 65: 338–347
Woodrow IE, Mott KA (1989) Rate limitation of non-steady-state photosynthesis by ribulose-1,5-bisphosphate carboxylase in spinach. Aust J Plant Physiol 16: 487–500
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1995 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Pearcy, R.W., Pfitsch, W.A. (1995). The Consequences of Sunflecks for Photosynthesis and Growth of Forest Understory Plants. In: Schulze, ED., Caldwell, M.M. (eds) Ecophysiology of Photosynthesis. Springer Study Edition, vol 100. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-79354-7_17
Download citation
DOI: https://doi.org/10.1007/978-3-642-79354-7_17
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-58571-8
Online ISBN: 978-3-642-79354-7
eBook Packages: Springer Book Archive