The effect of Pinus sylvestriformis seedlings density on net photosynthetic rate was studied under elevated CO 2. Atmospheric CO 2 concentration was controlled in OTC (Open Top Chamber). The results showed that elevat...The effect of Pinus sylvestriformis seedlings density on net photosynthetic rate was studied under elevated CO 2. Atmospheric CO 2 concentration was controlled in OTC (Open Top Chamber). The results showed that elevated CO 2 not only made net photosynthetic rates (NPRs) of two Pinus sylvestriformis seedlings densities increased,but also mitigated their intra-specific competition. Meanwhile,the difference of seedling NPRs between 100 and 400 plant·m -2 under 500 μmol·mol -1 air CO 2 concentration was less than that under 350 μmol·mol -1 with the same PAR levels. When air CO 2 concentration reached 700 μmol·mol -1 , the NPRs of seedlings under both planting densities were close to each other with the same PAR levels. The intra-specific competition was minimized under air CO 2 concentration of 700 μmol·mol -1 .展开更多
文摘The effect of Pinus sylvestriformis seedlings density on net photosynthetic rate was studied under elevated CO 2. Atmospheric CO 2 concentration was controlled in OTC (Open Top Chamber). The results showed that elevated CO 2 not only made net photosynthetic rates (NPRs) of two Pinus sylvestriformis seedlings densities increased,but also mitigated their intra-specific competition. Meanwhile,the difference of seedling NPRs between 100 and 400 plant·m -2 under 500 μmol·mol -1 air CO 2 concentration was less than that under 350 μmol·mol -1 with the same PAR levels. When air CO 2 concentration reached 700 μmol·mol -1 , the NPRs of seedlings under both planting densities were close to each other with the same PAR levels. The intra-specific competition was minimized under air CO 2 concentration of 700 μmol·mol -1 .