流沙海岸风口地段营建防护林的配套技术

Techniques for constructing protection forest on the quicksand in drought coastal area

以福建省最大的海岛———平潭的龙王头与燕下浦两大风口为试验点,按照森林生态系统研究方法,揭示了流沙海岸大风变化与飞沙规律,探讨了培育木麻黄Casuarinaequisetifolia2年生大苗这一核心技术及其在风口地段建立防护林的关键配套技术。研究结果表明:影响沙荒风口造林成败最主要是每年秋冬季的东北大风、飞沙和干旱三大因子;要在风口地段建立防护林,采用2年生木麻黄大苗营建的防护林,其成活率和保存率分别达到97.8%和92.2%;2a郁闭成林,5a郁闭度达到0.75以上,林分平均树高、胸径分别达到7.2m和6.4cm,可降低风速达87.5%,具有较好的防护效能。试验还表明,应用木麻黄小径材与枝条建造的风障是一种非常实用的防风固沙新技术。同时选择高大的木麻黄苗木密植,建造可升高的生物风障,不仅效果好而且成本低廉。

According to the method of forest-ecosystem, the experiment on cultivating two-year old seedlings of Casuarina equisetifolia and constructing protection forest in drought areas was carried out in Longwantou and Yanxiapu of Pintan County——two biggest sea islands in Fujian Province, which revealed the rules of change of strong wind and sandstorm in the coastal area. The results showed that the main factors affecting the afforestation in the drought area were strong northeast wind in autumn and winter, sandstorm and drought. Two-year old seedlings of C. equisetifolia were suitable for the afforestation in the drought areas. The survival rate and preserving rate reached 97.8% and 92.2% respectively. The plantation formed canopy in two years and its canopy density was more than 0.75 in the fifth year. The average height and DBH of the stand reached 1.2 m and 6.4 cm respectively. The stand could reduce wind speed by 87.5% and was with good shelter effect. The results also indicated that it was a very practical technique to construct wind obstacle with small size C. equisetifolia and its branches. At the same time, densely planting tall seedlings of C. equtsetifolia to form wind obstacle had better effect and lower cost. [Ch, 5 tab. 8 ref.]