关键词: 侧根生物量, 不均衡偏极增长, 节水型, 农田防护林, 新疆杨

Abstract: In order to understand the ecological characteristics of the oasis shelterbelt root system formed in adapting drought climate; verify the lateral root biomass distribution structure of the farmland shelterbelt in arid region, this paper measured the lateral root biomass of different soil layers of Populus alba var. pyramidalis shelterbelt of farm-channel-forest-road type in Dengkou oasis of Ulan Buh Desert by the method of space instead of time. The results showed that with the increase of diameter at breast height (DBH), the lateral root biomass of each diameter grade had an increasing trend, the biomass of rough and large lateral roots accounted for over 81.55% of the lateral root biomass, being the main part of the lateral root biomass. The rest parts were the biomass of medium, small and thin lateral roots. The proportion of rough root biomass increased with the increase of DBH, while the biomass of roots of large, middle, small and fine roots decreased. Through survey, 17 lateral root biomass growth models were established. Their significance were all outstanding proofed by regression model test. The growth of lateral root biomass in 5 grades of shelterbelt in oasis farmland were unbalanced and biased. Along with the increased of DBH, the biomass growth of lateral roots tended to be polarity, and this was the result of evolution when the artificial forest adapted to the drought environment.

Key words: lateral root biomass, inbalance and polarity growth, water saving type, farmland shelter, Populus bolleana