Research On Carbon Fixation And Oxygen Production And Temperature Decrease And Humidity Increase Effect Of Familiar Shrub Species

The13common kinds shrub species were chosen as research object. LI-6400XT photosynthesis system was used to determine the photosynthesis and transpiration rate of shrub species. Combined with leaf area index and cluster analysis, this article makes a primary assessment and evaluation on carbon fixation and oxygen production, temperature decrease and humidity increase. By fitting the light response curves of photosynthesis and determining other physiological parameters of shrub species. The main results were as follows:(1) Osmanthus fragrans var. Semperflorens is highly shade-tolerant and the use of strong power is relatively weak. Hibiscus syriacus can adapt to a wider range of light intensities and has a relatively wide range of suiTable le. The suiTable le range of Camellia japomica is relatively narrow. Photinia serrulata is fond of strong illumination and has a strong lightfastness. It has high lighter utilization capacity.(2) Over the course of a year, shrub species of carbon fixation and oxygen production, temperature decrease and humidity increase effect is best in August. The second is in June and October and the weakest is in December. Carbon fixation and oxygen production, temperature decrease and humidity increase effect in June of Cercis chinensis is best in13kinds of shrub species. But in general, deciduous shrub species of carbon fixation and oxygen production, temperature decrease and humidity increase effect is weaker than evergreen shrub species.(3) Net photosynthetic rate and transpiration rate change rule shall be classified into two types, a single-peak type and double-peak type. Net photosynthetic rate and transpiration rate show double-peak type includes six kinds and three kinds separately in February. Double-peak type respectively has eight kinds and six kinds in April. Double-peak type respectively has nine kinds and six kinds in June. Double-peak type respectively has ten kinds and seven kinds in August. Double-peak type respectively both has five kinds in October. Double-peak type respectively has one kinds and two kinds in December.(4) Among shrub species, Pyracantha fortuneana, Photinia serrulata, Ligustrum quihoui Carr get the best of average annual carbon fixing and oxygen producing amounts per leaf area and Photinia serrulata, Pittosporum tobira, Ligustrum quihoui Carr get the best of average annual carbon fixing and oxygen releasing amounts per land area.(5) According to cluster analysis, a comprehensive evaluation is made to give a ranking list. Among shrub species, Pyracantha fortuneana, Pittosporum tobira, Cercis chinensis, Ligustrum quihoui Carr, Lorpetalum chinense var.rubrum, Photinia serrulata get the best of carbon fixation and oxygen production effect and temperature decrease and humidity increase effect,while Camellia japomica, Hibiscus syriacus, Osmanthus fragrans var. semperflorens, Rhododendron simsii, Punica granatum, Euonymus japonicus get a medium of it, and Chimonanthus praecox get minimum of it.