Abstract:

The effects of slope position on growth and nutrient status were investigated in the artificial wind-breaking and sand-fixing forest of Hedysarum Laeve (6 a) in semi-mobile dune of Horqin sandy land by comparing with natural abandoned land(the department with 50 m adjaceut in same slope). Results showed that: slope affacted the growth status significantly. The height, numbers, canopy density, coverage density, survival rate in downhill were higher than those in uphill and midslope, and ground diameter in upslope was higer than downslope and midslope. The growth status in downhill and uphill was better than midhill. In the downhill, average height was 79.01 cm, plant density was 64 567 hm^-2, canopy density was 0.253, coverage was 0.314, and survival rate was 82.43 %. Organic matter and hydrolyzable nitrogen in the soil depth of 40~60 cm were influenced obviously the slope and the values were higher in downhill, respectively being 0.38 % and 20.5 mg ·kg^-1. The roots of Hedysarum Laeve mainly distributed in that region. However, the content of available potassium and available phosphorus was lower in the well growth condition. The comprehensive evaluation of the growth and nutrient status of Hedysarum Laeve in different position of slope was that downhill was the best, next came uphill and midhill in sequence.

Key words: Horqin sandy land, Hedysarum Laeve, habitat, plantation, soil nutrient