东北地区农田防护林结构对林网内积雪分布格局的影响

东北地区冬季降雪是农田土壤水分的重要来源．探索农田防护林结构对林网内积雪分布格局的影响，是经营实践中如何依据疏透度指标来指导农田防护林结构调控的关键问题．通过由3个不同疏透度林带组成的林网内积雪深度的测定，对农田积雪分布格局进行了研究．结果表明，林网的结构对农田积雪分布产生较大影响．疏透度不同的林网内积雪分布的空间格局有明显差别。而且疏透度差异越大。分布格局的差异越显著．其中，在疏透度为φ2w=0．579、φ2s=0．268的林网内，农田积雪分布比较均匀，总体上整个农田积雪深度较为一致．这样，可依据疏透度与积雪分布格局的这种关系。指导冬季防护林带的结构调控与优化经营．

Influence of shelterbelts structure on snow distribution pattern in shelternets in Northeast China

The amount of snow that falls in farmland during winter in Northeast China is the important source of soil water in farmland, so the influence of shelterbelt structure on snow distribution pattern is the key problem in order to adjust structure of shelterbelts according to porosity in management practice. Based on snow depths in shelternets composed of shelterbelts with three levels of porosity, which were shelternet No. 1, shelternet No. 2, and shelternet No. 3, the snow distribution patterns in farmland were studied. The results showed that the structure of shelternet had great influence on snow distribution in farmland. With different levels of porosities, spatial pattern of snow distribution were obviously different in three shelternets. The more variant in porosity, the more obvious difference in snow distribution pattern, and the best uniformity of snow distribution appeared in shelternet with porosity of phi 2w = 0.579, phi 2s = 0.268, in which snow depth in farmland was relative even and the variability of snow depth was the least. Consequently, the relationship of porosity of shelterbelt with snow distribution pattern could be used to guide structure adjustment and optimization management of shelterbelts.