A Preliminary Studies on Photosynthetic Characteristics of Chlorenchyma in Several Tree Barks

Chlorophyll content,photosynthetic rate and respiration rate were investigated in tree barks of three-year-old twigs within tree species.The results showed that the chlorophyll contents and Chl a/b in bark chlorenchyma were 0.0649-0.3460 mg·g-1(FW) and 1.05-1.91 respectively,which were lower than in leaves or needles of the same twigs.Net photosynthetic rate of chlorenchyma and respiration rate of stem were 0.21(Pinus koraiensis)-2.06(Fraxinus mandshurica) μmol(O2)·m-2·s-1 and 1.76(Pinus koraiensis)-3.21(Larix gmelini) μmol(O2)·min-1·g-1(FW) respectively.Light compensation point(LCP) and light saturation point(LSP) of chlorenchyma photosynthesis in barks were lower than those in leaves of the same twigs,while apparent quantum yield(AQY) of chlorenchyma photosynthesis in barks was higher than that in leaves or needles of the same twigs.It suggested that chlorenchyma in tree barks was adapted to shade environment,and was tolerant to shade light.