Objective Haloxylon ammodendron is a key tree species for afforestation in arid zones of China, but since wind and sand hazards are frequent in sandy areas, it is important to explore a reasonable planting site configuration to enhance the windbreak effect of forest strips.
Method In this study, Haloxylon ammodendron was used as a prototype, and the flow field and wind-proof effect were studied when the planting point disposing changed through wind tunnel simulation test. 4 kinds of forest belts with different disposing, namely AⅠ, AⅡ, BⅠ and BⅡ, were designed (A: triangle; B: rectangular; Ⅰ: plant spacing = 34 cm, row spacing = 17 cm; Ⅱ: plant spacing = 17 cm, row spacing = 34 cm).
Result (1) The spacing and arrangement of planting points had different effects on the protective effect. For the same arrangement, the area of wind speed deceleration zone of small plant spacing and large row spacing forest belt was larger than that of large plant spacing and small row spacing forest belt, namely AⅡ > AⅠ, BⅡ > BⅠ; for the same spacing, the area of wind speed deceleration zone in zigzag forest belt was larger than that in rectangular forest belt, namely AⅠ > BⅠ, AⅡ > BⅡ. (2) The effect of spacing on windbreak effect was more obvious than that of arrangement, and the order of windbreak effect from big to small was as follows: AⅡ > BⅡ > AⅠ > BⅠ. (3) The windbreak effect of AII forest belt was the best, but the wind speed recovery rate after the belt was the largest.
Conclusion The vertical and horizontal flow fields, wind speed variation and wind protection benefits of pokeweed forests with different planting point configurations differ significantly. In production practice, when the planting density is certain, it is recommended to give priority to the “small spacing, large row spacing” “品” shape configuration.
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