Studies On Physiological Ecology Characteristics Of Caragana Korshinskill In Loess Hill Region

Using Caragana korshinskill kom. which can conserve soil and water widely planting in loess hilly region as material, the paper main studied growth characteristics, physiological ecology characteristics, seeds germination and community dynamic characteristics of the shrub. The experiment included out-doors experiment and indoor experiment; the main results were as follows:1. The growth characteristics of 4 ages Caragana korshinskill under different site conditions was the number and length of branches had a great difference, but the angle of branches no difference. The numbers of branch in sunny site was 82.2, but in shady site only 44, they had significant discrepancy. The average length of primary branch was 27.39cm, the length of secondary branch and tertiary branch were 27.11cm and 25.49cm, the average angle of branches was 40.30°. The height, crown scope of aboveground and the roots depth, roots volume of underground showed that the C. korshinskill growing in sunny site fine than other sites, and they had significant discrepancy. The compositor of 4 ages C. korshinskill biomass under different conditions was sunny (390.82g)> semi-sunny (291.05g)> semi-shady (232.57g)> hilltop (213.93g)> shady hillside (183.02g). There were significant discrepancy between sunny, semi-sunny and shady sites (a=0.05), but between of the semi-shady and hilltop weren't remarkable difference. The phonological periods of C. korshinskill under different site conditions had no difference, the C. korshinskill in sunny site can effloresce and made seeds, but in other sites the plant weren't buds.2. The vertical changes of soil water content in 4 ages C. korshinskill plods showed the tendency of increasing with soil depth, and soil depth in 0～140cm was active layers, 160cm～300cm was sub-active layers, below 300cm was relatively stable layers. The soil water content had great relations to season changes, the soil water content were higher at the initial stages and teminal stages than metaphase of growing. The soil water condition of C. korshinskill under different sites had a great difference, shady site was13.12% and bigger than that of others, and that of shady slope only 9.63%, which was the lowest. The soil water content compositor in different sites was shady>semi-shady>semi-sunny>hilltop>sunny...