Using a Bottom-Up Approach to Scale Leaf Photosynthetic Traits of Oil Palm, Rubber, and Two Coexisting Tropical Woody Species

Rainforest conversion to woody croplands impacts the carbon cycle via ecophysiological processes such as photosynthesis and autotrophic respiration. Changes in associated with land-use change can be estimated through Land Surface Models (LSMs). The accuracy of flux estimation fluxes has been attributed uncertainties model parameters affecting photosynthetic activity, which is a function both carboxylation capacity (Vcmax) electron transport (Jmax). In order reduce for common tropical crops trees, this study we measured Vcmax25 (Vcmax standardized 25 °C), Jmax25 (Jmax °C) light-saturated (Amax) Elaeis guineensis Jacq. (oil palm), Hevea brasiliensis (rubber tree), two native tree species, Eusideroxylon zwageri Alstonia scholaris, converted landscape Jambi province (Sumatra, Indonesia) at smallholder plantations. We considered three plantations; monoculture rubber, oil palm, an agroforestry system (jungle rubber plantation), where trees coexist some trees. performed measurements on leaves lower part canopy, used scaling method based exponential scale up related traits top canopy. At found (i) high values H. from plantation jungle that was linked area-based leaf nitrogen content, (ii) low value Amax E. palm due dark varied much more than among different types. declined fastest canopy demonstrate successfully scaled thus provide helpful new data constrain LSMs simulate expansion.