Soil Respiration and Photosynthetic Carbon Gain on an Abundant Coastal Land After Plantation of Tamarix chinensis

Abstract

A field experiment was performed to assess the dynamics of soil respiration and its key influencing factors in a coastal saline wasteland along the Bohai Sea at 3 and 10 years after planting Tamarix chinensis. The results showed that the cultivation of T. chinensis, which corresponded to relatively higher root biomass and soil-infiltration ability, can result in a significantly higher rate of soil respiration than that of abandoned saline-alkali bare land as well as regulated net photosynthesis along with other CO 2 /H 2 O gas exchange parameters. The root growth rate was the key factor that affected the soil respiration rate more than the total root biomass of the plants did. The soil surface temperature was also an important factor that affected the soil respiration rate in each land, and the soil salt and water contents were closely related to only root respiration on the lands planted with 3-year-old T. chinensis due to the short-term improvement of the soil by the plant community; long-term cultivation of T. chinensis reduced the soil surface salinity during the period of the highest evaporation and provided an adequate carbon source for the growth of bacteria, fungi, and actinomycetes. This research can offer a reference value for the characteristics of carbon sequestration during the process of vegetation regeneration on coastal saline lands.