我场位于山东半岛南部,黄海岸边的冲积沙滩上。场内土层自地表到地下20多米都是粗细交替的砂砾。建场前仅有几棵散生的赤松,而且病虫害严重,生长不良。建场后曾试种过许多树种,都不够理想,只有黑松生长较好,能抗海风、淑雾,粗粒沙和粉沙地均能生长。目前已形成了一条生长健壮的黑松海防林带。但黑松纯林也还存着一定的缺点。它的抗灾能力差,易着病虫害。近几年来曾先后发生过松毛虫、落针病、松红蜘蛛等成片危害,给管护增加了困难。我场职工遵照毛主席“一切真知都是从直接经验发源的”的教导,搞了几种方式的黑松、棉槐混交造林试验。1973年秋 My field is located in southern Shandong Peninsula, the Yellow Sea shore alluvial sand. Field soil from the surface to more than 20 meters underground are alternating gravel thickness. Before the establishment of only a few planted scattered pine, and pests and diseases, poor growth. Many species of trees have been planted since the establishment of the site. They are not ideal. Only the black pine grows well and can resist sea breeze, mist, coarse sand and powder sand. Has formed a robust growth of black pine shelter belt. However, the pure black pine forest also has some drawbacks. It’s poor resilience, easy to pests and diseases. In recent years, there have been dendrolimus, needle drop disease, pine red spider into pieces such as hazards, to increase the management and protection difficulties. In accordance with the teachings of Chairman Mao, “All true knowledge derives from direct experience,” my field staff engaged in mixed-afforestation trials of Pinus thunbergii and Huai-huai in several ways. Autumn 1973