PRUNING HEIGHT AND ITS EFFECT ON QUANTITATIVE AND QUALITATIVE SEED PRODUCTION IN OLD SAXUAL (Haloxylon aphyllum) FORESTS OF YAZD, IRAN

The high quality and quantity seed production in old saxual shrubs are essential for regeneration and sustainable development of saxual forests in desert areas. The objective of this study was to determine the effects of different pruning height on saxual seed production. The study was carried out in an obviously wilted saxual forest located in Ashkezar desert in Yazd in 1994. The experiment was carried out in a split-plot design with 3 replications, with saxual density (250 and 125 shrubs/ha) as the main plots, and pruning height (10, 35, 70 cm, and a no-cut check) as the sub-plots. Pruning was done on autumn 1994. The forest was protected completely and the quality and quantity of seed production of marked shrubs were investigated on autumn 1999 and 2000. The 2-year results showed that saxual density did not have any significant effect on quality and quantity of saxual seed production (P