Variation in Flood-Induced Stomatal and Photosynthetic Responses of Three Bottomland Tree Species

Abstract

Abstract The effects of flooding on plant water status, stomatal conductance, and net photosynthesis in seedlings of three bottomland species, Fraxinus pennsylvanica Marsh., Quercus michauxii Nutt., and Taxodium distichum (L.) Rich. var. distichum were studied under controlled environmental conditions. Flooding for three weeks induced significant stomatal closure in all species. After 24 hours of flooding, stomatal conductance was reduced to 49% of the preflood level in T. distichum, 56% of the preflood level in Q. michauxii, and 53% of preflood level in F. pennsylvanica. Leaf water potential measurements indicated that water deficits did not develop as a result of flooding; therefore, stomatal closure was apparently not caused by water deficits in any of the study species. Limited photosynthesis data indicated that flooding did not substantially reduce net photosynthesis in T. distichum or F. pennsylvanica, even though partial stomatal closure was induced. Net photosynthesis was, however, substantially reduced in flooded Q. michauxii. Forest Sci. 32:914-923.