Analyses on Introduction Results of 4 Tree Species in Genus Larix and Diurnal Photosynthetic Changes

The 4 tree species in genus Larix introduced into the Loess Hilly Region in northwest China grew normally though the growth rate was small because of water deficiency.The growth rate of these 4 tree species was ordered as: Larix principis-rupprechtii > Larix kaempferi > Larix gmelini > Larix olgensis.The mean of the diurnal photosynthetic rate was in order: Larix kaempferi > Larix principis-rupprechtii > Larix gmelini > Larix olgensis, whereas the transpiration rate of the 4 was ordered as: Larix principis-rupprechtii > Larix gmelini > Larix kaempferi > Larix olgensis.It was demonstrated by the results that Larix principis-rupprechtii might be extensively planted in the Loess Hilly Region in the future.