Great Basin Naturalist


Leaf area estimates are required by hydrologic erosion, and growth/yield simulation models and are important to the understanding of transpiration interception, CO2 fixation, and the energy balance for native plant communities. Leaf biomass (g) to leaf area (mm2) linear regression relationships were evaluated for 15 perennial grasses, 12 shrubs, and 1 tree. The slope coefficient (β0) of the linear regression equation is a ratio of leaf area to leaf biomass and is defined as the leaf area ratio [LAR = one-sided leaf area (mm2)/oven-dry leaf weight (g)]. LAR represents β0 in each regression equation, where Y = β0(X). Linear regression relationships for leaf area were computed (r2 = .84–.98) for all 28 native range species after full leaf extension. Within-plant estimates of leaf area for mesquite (Prosopis glandulosae Torr. var. glandulosae [Torr.] Cockll.) or lime prickly ash (Zanthoxylum fagara [L.] Sarg.) were not significantly different (P ≤ .05). LARs for three of the shrubs and the tree were established at four different phenological stages. There were no significant differences (P ≤ .05) in LARs for lime prickly ash, mesquite, and Texas persimmon (Diospyros texana Scheele) after full leaf extension during the growing season. The LAR relationship for Texas persimmon changed significantly after full leaf extension. LAR relationships for Texas colubrina (Colubrina texensis [T. & G.] Gray) changed in response to water stress.