Comparison of hydraulic architecture of woody plants of differing phylogeny and growth form with special reference to freestanding and hemi-epiphytic Ficus species from Panama.

Hydraulic parameters were measured in seven species of Fiats (three free-standing and four hemi-epiphytic) on stem segments of 3-35 mm in wood diameter. Parameters measured included K (water flux per unit pressure gradient), K (leaf specific conductivity =K per unit leaf area), K (specific conductivity =H per unit wood cross section), and H (Huber value = wood cross section per unit leaf area). The hemi-epiphytes tended to have less conductive stems per unit leaf area (lower K and invested less wood cross section per unit leaf area (lower H ) than free-standing species. Hydraulic parameters of Ficus are compared to 21 other temperate and tropical species to see if there is any discernible pattern in hydraulic architecture that correlates with phylogeny, growth form or habitat occupied by diverse species. Figs, as a group, had relatively high h . and relatively low h compared to other tropical trees. A possible correlation between K and transpiration and growth form is discussed.