Photosynthetic temperature acclimation in two coexisting seagrasses, Zostera marina L. and Ruppia maritima L.

摘要: Abstract The physiological responses to temperature were investigated in two coexisting seagrasses, Zostera marina L. and Ruppia maritima sensu lato from the lower Chesapeake Bay, Virginia. Seven plant collections made March July, 1983 at ambient temperatures of 8–30°C. Both species maintained relatively constant fresh: dry weight ratios chlorophyll a : b over five-month period. Total content remained Z. while that R. doubled July. P max values for both increased with increasing declined above 19 23°C ( , respectively). significantly higher compared 19°C. short-term (laboratory) long-term (in situ) regimes affected estimates photosynthetic capacity species. Thus, histories experimental material should be carefully considered when interpreting effects on photosynthesis. This study provides support hypothesis seasonal community dynamics Bay are regulated part by different light temperature.