Photosynthetic characteristics of Garrya ovata Benth. (Lindheimer's silktassle, Garryaceae) at ambient and elevated levels of light, CO2 and temperature

摘要: Garrya ovata Benth. (Lindheimer’s silktassle) is a shrub or small tree found in woodlands and savannas of the central Texas Edwards Plateau region. Plant communities where G. occurs are mainly Juniperus ashei/Quercus virginiana with intercanopy grassland gaps patches. These stressful environments shallow soils, high summer temperatures, inconsistent low rainfall. Currently, density, woody understory species these communities. Although was only understory, this study suggests it more sun edge not truly shade species. Maximum photosynthetic rate (Amax), dark respiration (Rd), intercellular CO2, light saturation (Lsp) water use efficiency significantly increased when levels CO2 concentrations were elevated but temperatures elevated. Stomatal conductance decreased concentration doubled little affected by temperature. findings suggest that should be common Juniperus/Quercus as well associated grasslands today imply will have higher density future environment. However, they do explain why has today. Published on-line www.phytologia.org Phytologia 97(2): 103-119 (April 1, 2015). ISSN 030319430.