Premium
Comparative Photosynthetic and Respiratory Gas Exchange Characteristics of Atriplex Lentiformis (Torr.) Wats. in Coastal and Desert Habitats
Author(s) -
Pearcy R. W.,
Harrison A. T.
Publication year - 1974
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1940360
Subject(s) - habitat , photosynthesis , atriplex , ecology , desert climate , environmental science , carbon dioxide , grassland , botany , arid , biology
Field measurements of the photosynthetic gas exchange characteristics of Atriplex lentiformis (Torr.) Wats. were conducted in both a coastal and an interior desert habitat. Despite large differences in habitat temperature, the diurnal course of CO 2 exchange of the coastal and desert shrubs were remarkably similar. Maximum CO2 uptake rates and stomatal conductances to water vapor were similar in both habitats and occurred during midday when irradiance was highest. Measurement of the temperature dependence of photosynthesis revealed marked differences between the coastal and desert shrubs. The thermal optima for photosynthesis were 32°C in the coastal and desert shrubs respectively. At temperatures below 36°C rates of CO2 uptake were higher in the coastal shrubs than in desert shrubs, whereas at higher temperatures the reverse was true. These differences in temperature dependence coupled with the differences in leaf temperatures in the coastal and desert habitats result in nearly equal rates of CO2 uptake measured under temperature and light regimes similar to natural conditions in the respective habitats.