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

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.

Keywords

• climatic change
• water-holding plants
• plant economic traits
• elemental content
• environment response policy