The influence of precipitation regimes and elevated CO2 on photosynthesis and biomass accumulation and partitioning in seedlings of the rhizomatous perennial grass Leymus chinensis.
The influence of precipitation regimes and elevated CO2 on photosynthesis and biomass accumulation and partitioning in seedlings of the rhizomatous perennial grass Leymus chinensis.
复制标题
降水模式和CO2升高对多年生根茎草羊草幼苗光合作用和生物量积累与分配的影响
DOI：
10.1371/journal.pone.0103633
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Mu C
中科院分区：
文献类型：
--
作者：
Li Z;Zhang Y;Yu D;Zhang N;Lin J;Zhang J;Tang J;Wang J;Mu C
羊草是中国北部松嫩平原草原的优势种，多年生根茎C3种，其生产力逐年下降。为了确定该物种的生产力如何响应不同的降水制度、增加的二氧化碳及其未来的相互作用，我们测量了光合作用参数以及生物量的积累和分配。在受控环境箱中，植物受到三个降水梯度(正常降水，与正常降水±40%)和两个二氧化碳水平(380±20µmoL-1,760±20µmoL-1)的组合。净光合速率、地上生物量和总生物量均因CO2浓度升高和降水量增加而增加，但当降水量从正常水平增加到较高水平时，在CO2浓度增加的情况下，增加幅度不显著。水分利用效率和根/总生物量比在降水量较少时显著增加，而在CO2浓度较高时显著降低。此外，高CO2水平下的高降水增加了茎生物量占总生物量的比例。在低降水水平下，CO2浓度升高对光合作用和生物量积累的影响大于正常降水和高降水水平。结果表明，在环境CO2水平下，羊草的净光合速率和生物量随降雨量的增加而增加，但当CO2浓度升高时，这些指标不受额外降雨量的进一步影响。此外，CO2还可以部分补偿低降水对羊草生长发育的负面影响。
Leymus chinensis is a dominant, rhizomatous perennial C3 species in the grasslands of Songnen Plain of Northern China, and its productivity has decreased year by year. To determine how productivity of this species responds to different precipitation regimes, elevated CO2 and their interaction in future, we measured photosynthetic parameters, along with the accumulation and partitioning of biomass. Plants were subjected to combinations of three precipitation gradients (normal precipitation, versus normal ± 40%) and two CO2 levels (380±20 µmol mol-1,760±20 µmol mol-1) in controlled-environment chambers. The net photosynthetic rate, and above-ground and total biomass increased due to both elevated CO2 and increasing precipitation, but not significantly so when precipitation increased from the normal to high level under CO2 enrichment. Water use efficiency and the ratio of root: total biomass increased significantly when precipitation was low, but decreased when it was high under CO2 enrichment. Moreover, high precipitation at the elevated level of CO2 increased the ratio between stem biomass and total biomass. The effect of elevated CO2 on photosynthesis and biomass accumulation was higher at the low level of precipitation than with normal or high precipitation. The results suggest that at ambient CO2 levels, the net photosynthetic rate and biomass of L. chinensis increase with precipitation, but those measures are not further affected by additional precipitation when CO2 is elevated. Furthermore, CO2 may partly compensate for the negative effect of low precipitation on the growth and development of L. chinensis.
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影响因子：
4.2
作者：
Flexas, J;Medrano, H
通讯作者：
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