Photosynthesis and respiration of feather mosses fumigated at different hydration levels with SO₂

Abstract

WINNER, W. E., and J. D. BEWLEY. 1983. Photosynthesis and respiration of feather mosses fumigated at different hydration levels with SO2. Can. J. Bot. 61: 1456-1461. Fumigation with SO2 of the three feather mosses Pleuroziurn schreberi, Hylocomirtm splendens, and Ptilium crista-castrensis results in an immediate decline in their rate of photosynthesis but has no effect upon respiration. Pleuroziurn schreberi is the most sensitive of the three species, even though they all take up the same amount of SOz. Thus, the feather moss species appear to have similar degrees of SOz avoidance (uptake) but dissimilar degrees of SO2 tolerance. With increasing desiccation, respiration declines equally in all three species, but photosynthesis declines most rapidly for P. schreberi. The immediate effects of SO2 upon photosynthesis of water-limited and of fully hydrated feather mosses are similar, but after a 24-h recovery period in an SO2-free environment photosynthesis remains impaired only in those mosses fumigated in the fully hydrated state. This probably is related to the larger amounts of SO2 absorbed by hydrated mosses.WINNER, W. E., et J. D. BEWLEY. 1983. Photosynthesis and respirationof feather mosses fumigated at different hydration levels with SO2. Can. J. Bot. 61: 1456-1461. La fumigation par du SO2 de trois mousses hypnacCes, Pleurozirtm schreberi, Hylocomium splendens et Ptiliitm crista-castrensis, provoque une diminution immCdiate de leur taux de photosynthkse, mais n'a aucun effet sur leur respiration. P. schreberi est la plus sensible des trois espkces, m&me si elles absorbent toutes la m&me quantitC de SO?. ParconsCquent, il semble que les espkces Cvitent (absorbent) le SO2 i des degrCs semblables, mais qu'elles prksentent des degrCs diffkrents de tolkrance au SO2. Avec une augmentation de la dessication, la respiration diminue au m&me taux chez les trois espkces, mais la photosynthkse diminue le plus rapidement chez P. schreberi. Les effets immkdiats du SO2 sur la photosynthkse sont semblables chez les mousses carencies en eau et chez les mousses complktement hydratCes mais, aprks une pCriode de rCtablissement de 24 h dans un environnement sans SO2, la photosynthkse demeure affectke seulement chez les mousses fumigCes lorsqu'elles Ctaient complktement hydratCes. Ce phknomkne s'explique probablement par les plus fortes quantitCs de SOz absorbCes par les mousses hydraties.[Traduit par le journal]

<p><strong>Evaluación briológica de los efectos de la contaminación atmosférica en la Ciudad de México</strong></p>

“…En la Ciudad de México podría esperarse que la lluvia ácida tuviera un efecto negativo en ese fenómeno. Al respecto existen diversos estudios que sugieren que la lluvia ácida puede causar daño a las plantas y cambiar la estructura de las comunidades, pero bajo ciertas condiciones puede actuar como factor estimulante (Rochefort & Dale 1988, Ferguson et al 1988, Woodin & Lee 1987, Winner & Bewley 1983, Kennedy et al 1985.…”

“…Se ha detectado plasmólisis, destrucción celular, disminución en la fijación de carbono y clorofila y decremento en las tasas de respiración y fotosíntesis (Eversman 1978, Winner & Bewley 1983.…”

Field methods used for air pollution research with plants

“…Comparison of the coverage of each species on a stand-by-stand basis allowed determination of species tolerant of 502, species sensitive to 502, and weedy species which invaded the disturbed community. Species differing in 502 tolerance were then selected for physiological studies designed to determine why such differences occurred (Winner and Bewley, 1983). Similar approaches can be used by physiological ecologists to exploit further plant species found along air pollution concentration gradients.…”

Sulphur dioxide effects on cell structure and photosynthetic performance in the liverwort Frullania dilatata

“…The physiological responses of bryophytes to gaseous SO 2 have been summarized in a number of works (Nash and Nash 1974;Winner and Koch 1982;Winner and Bewley 1983). In most of these, the decline of photosynthesis following exposure to this pollutant has been one of the most frequently used response variables (Türk and Wirth 1975;Takaoki and Mitani 1986).…”