吉林西部水田防护林对林带内温湿度和水稻产量的影响

Effect of Paddy-field-shelter Forest on the Temperature,Humidity and Rice Yield in Western Jilin

防护林林带结构，尤其是疏透度，对于调整和改善林网内的小气候环境和提高作物产量具有重要作用。采用多点式自记测风仪（GB228），对吉林省西部水田防护林开展了林带结构因子对林带内温湿度影响研究，同时分析了林带结构对水稻产量的影响。结果表明：水田防护林在有叶期和无叶期分别降低和提高了背风面的温度，有叶期林带内外温度差（T有叶期）与树高和冠幅分别呈显著正相关和负相关，无叶期林带内外温度差（T有叶期）与树高、胸径和冠幅呈显著负相关和正相关；水田防护林提高了林带内的空气相对湿度，而且有叶期的空气相对湿度增幅要大于相应的无叶期；不同观测距离处的水稻产量不同，但影响趋势一致，其产量的最大值在观测点7处，且林带3、4、6、8的水稻产量较高，分别为880 g／m2、899 g／m2、916 g／m2和923 g／m2；当有叶期疏透度（β有叶期）和无叶期疏透度（β无叶期）分别在0．31～0．39和0．63～0．75时，林带对其背风面的温湿度调节作用明显，对应的水稻产量较高。适宜林带间距是300 m。

Shelter forest structure, its porosity in particular , play an important role in adjusting and improving the microclimate within the shelter forest and in increasing rice yields. By using multi-point-recording anemometer （ GB-228）, the paddy-field-shelter forest in western of Jilin province were investigated, and the effect of shelter- belt structure on the temperature, humidity and rice yield within shelter forest were analyzed. The result showed that the shelter with leaf period lower the leeward side of the temperature and shelter without leaf stage raise the temperature. In leaf period, the range of interior and external shelterbelt temperature （ T leaf） had significant posi- tive and negative relation with tree height and crown respectively, while in non-leaf period, the range of its tem- perature （Teaf） had significant negative and positive relation with tree height, DBH and crown respectively. Paddy-field-shelter increase the relative humidity within the forest, and the increasing rate during leaf period is greater than that of non-leaf period. Although the rice yield was different at different observation points, the im-pact tendency was the same, and the maximum yield was found at the 7 observation points, and the No 3, 4, 6, 8 had higher rice yield than the others with a productivity of 880 g/m2, 899 g/mE, 916 g/m2and 923 g/m2 re- spectively. When porosity of leaf period （β leaf） and porosity of non-leaf period （β nonlenf stage） were 0. 3 -0. 4 and 0.6 -0.8 respectively, The regulating function of shelter forest on temperature and humidity were obvious, and the rice yield were higher than the other paddy-field-shelter forest. The appropriate distance for paddy shelterbelt should be 300 m.