CO(sub 2) exchange, environmental productivity indices, and productivity of Opuntia ficus-indica under current and elevated CO(sub 2) concentrations. Carbon Dioxide Research Program

摘要

This project involved placing mature cladodes (flattened stem segments) of Opuntia ficus-indica in growth chambers containing 360 or 720 ppM CO(sub 2). After nine weeks, the new daughter cladodes initiated on the planted cladodes averaged 7% higher in biomass but 8% less is area, leading to a specific stem mass for this Crassulacean acid metabolism (CAM) species that was 16% higher under the elevated CO(sub 2) condition. This is similar to be less dramatic than the increase in specific leaf mass for C(sub 3) and C(sub 4) plants under elevated CO(sub 2), which generally ranges from 28% to 40%. Another contrast with C(sub 3) and C(sub 4) Plants was the reliance of the new organs of the CAM plant on biomass translocated from existing organs instead of derived directly from current photosynthate. In this regard, 18% less dry weight was translocated from basal cladodes into daughter cladodes of Q. ficus-indica at 720 ppM CO(sub 2) compared with 360 ppM.