造林密度是保证人工林达到速生、丰产、优质的一项重要措施,笔者多年研究黑龙江省西部半干旱地区营造杨树大径用材林的密度问题,现阐述如下。一、密度与立地条件的关系黑龙江西部地区属北温带大陆性季风气候。冬季寒冷、干燥、少雪,春季短暂,季风交替、气温变化急剧,多沙尘暴天气,全年平均降水量不足440毫米。该地区土壤瘠薄,大部分为沙土,保水保肥力很差,养分含量少。 Afforestation density is an important measure to ensure plantation to achieve fast growth, high yield and good quality. The author studies the density of poplar large-diameter timber in semi-arid areas of western Heilongjiang Province for many years. First, the relationship between density and site conditions The western region of Heilongjiang is a north temperate continental monsoon climate. Winter is cold, dry, snow-less, spring is short, alternation of monsoons, rapid temperature changes, dusty weather, the annual average rainfall of less than 440 mm. The soil in the area is barren, mostly sandy soil, with poor water and fertility and low nutrient content.