Abstract:

Combining with engineering and biological measures, the construction of Caragana korshinskii vegetation and excessive depletion and resumption of soil water were studied. The results showed that the whole growing stages could be divided into three phases—young-age period for the first six years, middle-age period from the seventh year to the fourteenth year and old-age period after fourteen years. In young-age period, dry layer of 0～800 cm soils did not formed, while in middle-age and old-age period, dry layer reached 240～260 cm and 700 cm,respectively. By level-step measures, soil water had a surplus of 44.82 mm in abundant precipitation year, deficiency of 53.91 mm in equal precipitation year and 102.87 mm in dry year, and its compensated depth of soil water in different precipitation year was 80～180 cm, while that of CK was deficiency of 51.5～79.6 mm, 103.64 mm and 153.32 mm respectively in different kinds of years and the compensated depth was 21～45 cm. According to the distributed proportion of the main root, the lateral roots and hair roots, it took 13 years for soil water of C. korshinskii vegetation by measures to resume natural situation in abundant precipitation year and over 16 years in equal precipitation year and over 20 years in dry year, while it took over 20 years for that of CK in any kinds of years.

Key words: Caragana korshinskii, growth, soil water, depletion process, soil dry layer, semi-arid region