Larigauderie Anne, Hilbert David W, Oechel Walter C
Systems Ecology Research Group, San Diego State University, 92182, San Diego, CA, USA.
Oecologia. 1988 Dec;77(4):544-549. doi: 10.1007/BF00377272.
The effects of CO enrichment on the growth, biomass partitioning, photosynthetic rates, and leaf nitrogen concentration of a grass, Bromus mollis (C), were investigated at a favorable and a low level of nitrogen availability. Despite increases in root: shoot ratios, leaf nitrogen concentrations were decreased under CO enrichment at both nitrogen levels. For the low-nitrogen treatment, this resulted in lower photosynthetic rates measured at 650 μl/l for the CO-enriched plants, compared to photosynthetic rates measured at 350 μl/l for the non-enriched plants. At higher nitrogen availability, photosynthetic rates of plants grown and measured at 650 μl/l were greater than photosynthetic rates of the non-enriched plants measured at 350 μl/l. Water use efficiency, however, was increased in enriched plants at both nitrogen levels. CO enrichment stimulated vegetative growth at both high and low nitrogen during most of the vegetative growth phase but, at the end of the experiment, total biomass of the high and low CO treatments did not differ for plants grown at low nitrogen availability. While not statistically significant, CO tended to stimulate seed production at high nitrogen and to decrease it at low nitrogen.
在氮素供应充足和供应水平较低的条件下，研究了二氧化碳浓度升高对一种禾本科植物——软雀麦（Bromus mollis (C)）的生长、生物量分配、光合速率和叶片氮浓度的影响。尽管根冠比增加，但在两种氮素水平下，二氧化碳浓度升高均导致叶片氮浓度降低。对于低氮处理，与在350 μl/l下测量的未富集植株的光合速率相比，富集二氧化碳的植株在650 μl/l下测量的光合速率更低。在较高的氮素供应水平下，在650 μl/l下生长和测量的植株的光合速率高于在350 μl/l下测量的未富集植株的光合速率。然而，在两种氮素水平下，富集二氧化碳的植株的水分利用效率均有所提高。在营养生长阶段的大部分时间里，二氧化碳浓度升高在高氮和低氮条件下均刺激了营养生长，但在实验结束时，低氮供应条件下生长的植株，高二氧化碳处理和低二氧化碳处理的总生物量没有差异。虽然没有统计学意义，但二氧化碳倾向于在高氮条件下刺激种子产量，而在低氮条件下降低种子产量。
