Responses of Gmelina arborea, a tropical deciduous tree species, to elevated atmospheric CO₂: Growth, biomass productivity and carbon sequestration efficacy

详细信息    查看全文

• 作者：Girish K.  ; Rasineni ; Anirban  ; Guha ; Attipalli R.  ; Reddy  ; ;   ; ^{arrsl@uohyd.ernet.in}
• 关键词：Biomass yields ; Carbon sequestration ; Elevated CO₂ ; Gmelina arborea ; Productivity
• 刊名：Plant Science
• 出版年：2011
• 出版时间：October 2011
• 年：2011
• 卷：181
• 期：4
• 页码：428-438
• 全文大小：1285 K

文摘

The photosynthetic response of trees to rising CO₂ concentrations largely depends on source¨Csink relations, in addition to differences in responsiveness by species, genotype, and functional group. Previous studies on elevated CO₂ responses in trees have either doubled the gas concentration (>700 ¦Ìmol mol^?) or used single large addition of CO₂ (500?00 ¦Ìmol mol^?). In this study, Gmelina arborea, a fast growing tropical deciduous tree species, was selected to determine the photosynthetic efficiency, growth response and overall source¨Csink relations under near elevated atmospheric CO₂ concentration (460 ¦Ìmol mol^?). Net photosynthetic rate of Gmelina was ?0 % higher in plants grown in elevated CO₂ compared with ambient CO₂-grown plants. The elevated CO₂ concentration also had significant effect on photochemical and biochemical capacities evidenced by changes in F_V/F_M, ABS/CSm, ET₀/CSm and RuBPcase activity. The study also revealed that elevated CO₂ conditions significantly increased absolute growth rate, above ground biomass and carbon sequestration potential in Gmelina which sequestered ?100 g tree^? carbon after 120 days of treatment when compared to ambient CO₂-grown plants. Our data indicate that young Gmelina could accumulate significant biomass and escape acclimatory down-regulation of photosynthesis due to high source-sink capacity even with an increase of 100 ¦Ìmol mol^? CO₂.