水葱和香蒲叶经济性状对模拟增温和CO2浓度倍增的响应

Responses of leaf economic traits of Scirpus validus and Typha orientalis to simulated warming and CO2 concentration multiplication

关键词:  气候变化, 挺水植物, 植物经济性状, 元素含量, 环境响应策略

Key words:  climatic change, water-holding plants, plant economic traits, elemental content, environment response policy

摘要:

气候变化是国际社会共同关注的环境问题,植物对气候变化的响应反映了植物应对气候变化的生长和生存策略。叶经济性状与植物对资源的获取、利用和储存直接相关,并且受到温度条件和CO₂浓度的显著影响。该文采用人工环境控制系统封顶式生长室研究广布湿地植物水葱(Scirpus validus)和香蒲(Typha orientalis)的叶经济性状对模拟增温(现行环境温度+2 ℃)和CO₂浓度倍增(增至850 μmol·mol^-1)的响应。结果表明:(1)增温处理下,水葱净光合速率、氮含量和磷含量显著降低,但其胞间CO₂浓度和比叶重显著增加; CO₂浓度倍增处理下,水葱胞间CO₂浓度和净光合速率均显著降低,但比叶重显著增加。(2)增温处理下香蒲的比叶重显著增加,而氮含量和磷含量显著降低; 香蒲的光合参数、氮含量和磷含量在CO₂浓度倍增处理下均显著降低,而比叶重显著增加。(3)水葱的比叶重、氮含量、磷含量、净光合速率、气孔导度、胞间CO₂浓度与主成分分析的两个环境变量相关; 而香蒲的经济性状均与两个环境变量相关,表明这些经济性状在香蒲响应增温和CO₂浓度变化过程中发挥重要作用。(4)除碳含量外,水葱和香蒲的其他经济性状参数包括净光合速率、气孔导度、蒸腾速率、胞间CO₂浓度、氮含量、磷含量和比叶重均在响应增温和CO₂浓度倍增过程中发挥重要作用。总体而言,该研究结果反映了水葱和香蒲在功能性状上对增温和CO₂浓度倍增的响应策略。两种植物的光合能力和养分含量在两种处理下虽然均受到显著的抑制作用,但是其抗逆能力升高,表明增温和CO₂浓度升高不利于水葱和香蒲的生长。

Abstract:

Climate change is an environmental issue of common concern to the international community. The response of plants to climate change reflects the growth and survival strategies of plants in response to climate change. Leaf economic traits are directly related to the resource acquisition, utilization and storage of plant, and are significantly affected by temperature conditions and CO₂ concentration. A capped growth chamber with an artificial environment control system was used to study the response of the leaf economic traits of the widely spread wetland plants Scirpus validus and Typha orientalis to the simulated warming(current ambient temperature +2 ℃)and doubled CO₂ concentration(increased to 850 μmol·mol^-1). The results were as follows:(1)The net photosynthetic rate, contents of N and P Scirpus validus were significantly reduced, but the intercellular CO₂ concentration and leaf mass per area increased significantly under increased temperature treatment. Both the intercellular CO₂ concentration and net photosynthetic rate of S. validus were significantly reduced, but the leaf mass per area was significantly increased under the treatment of doubled CO₂ concentration.(2)Similar to S. validus, the leaf mass per area of Typha orientalis also increased significantly, while the contents of N and P were significantly reduced under warming treatment; in addition, the photosynthetic parameters, contents of N and P of T. orientalis were significantly reduced, while the leaf mass per area increased significantly under the treatment of doubled CO₂ concentration.(3)The leaf mass per area, contents of N and P, net photosynthetic rate, stomatal conductance, and intercellular CO₂ concentration of Scirpus validus were significantly correlated with the first two axes of the principal component analysis; while all the studied leaf economic traits of Typha orientalis were related to two environment variables, indicating that these traits played an important role in the response of plants to changes in temperature and CO₂ concentration.(4)In addition to C content, other economic trait parameters of Scirpus validus and Typha orientalis including net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO₂ concentration, contents of N and P and leaf mass per area were all played important roles in response to increasing temperature and doubled CO₂ concentration. Overall, these results reflect the response strategies of Scirpus validus and Typha orientalis on functional traits to increasing temperature and doubled CO₂ concentration. The photosynthetic capacity and nutrient contents of the two species are significantly inhibited under the two treatments, but their resistance to stress increased, indicating that the increase in temperature and CO₂ concentration are not conducive to the growth of the two species.