农田防护林的防护作用是多方面的,复杂的,有时间和空间的变化。目前对此问题的研究还很不够,许多重要的课题有待近一步深入研究,要利用地理学、农业物理学和流体力学等学科的新成就去阐明有关农田防护林的尚未解决的问题。从流体力学的角度可以深入揭示林带防护作用的物理性质。 世界各国均以风速的降低作为评定林带防护作用的重要因素,把其他小气候因 The protective role of farmland shelterbelt is multifaceted, complex and has time and space changes. At present, the research on this issue is still not enough. Many important topics have yet to be further studied. We must make use of the new achievements in disciplines such as geography, agro-physics and fluid dynamics to clarify the unresolved issues concerning farmland shelterbelts. From the perspective of fluid mechanics can reveal the physical properties of the protective effect of forest belt. All countries in the world reduce the wind speed as an important factor in assessing the role of shelterbelt, and other microclimate