Research on the shade tolerance of 4 shrub tree species mixed with Chinese pine
The chlorophyll content and the photosynthetic characteristics parameters of four shrub species mixed with Chinese pine under different levels of light environments have been measured to analyze the shade tolerance of these four shrub species .The results show that no significant difference of leaf chlorophyll a/b value can be observed between different tree species but between different levels of light environments .With the increase of shade inten-sity ,the leaf chlorophyll a/b value curves of 4 tree species are changing like waves with the minimum value under the light environment of 45 percent light transmittance .T he leaf chlo-rophyll a/b values of different tree species under the 100% light environment and 5% light transmittance are nearly the same .Each photosynthetic characteristic parameter of H ip po-phae rhamnoides is higher than anyone of the other three ,followed by Amorpha f ruticosa . The light compensation point ,the apparent quantum yield and the dark respiration rate of Vitex negundo var .heterophyllaare lower than any one of the others .Although its light u-tility efficiency is low ,its dry matter accumulation starts earlier and it has stronger capacity of weak light utility .Therefore ,Vitex negundo var .heterophylla .has the strongest shade tolerance capacity among the four shrub species ,followed by Caragana microphylla ,Amorpha fruticosa and Hippophae rhamnoides .
Chinese pine mixed forest ,shrub tree specieschlorophyll contentphotosyn-thetic characteristics
NETL
NSTL
万方数据
维普
