不同坡位红皮云杉林木生长与土壤理化性质比较

Comparison of Tree Growth and Soil Physical and Chemical Properties of Picea koraiensis Plantation at Different Slope Positions

以黑龙江省佳木斯市孟家岗林场43 a红皮云杉人工林为研究对象,测定不同坡位红皮云杉的生长状况和林下土壤理化性质,分析不同坡位红皮云杉人工林林木生长状况和土壤肥沃程度的差异,为建立红皮云杉大径材培育技术提供参考依据。分别在人工林南坡的上、中、下3个坡位上设置样地,调查红皮云杉的树高、胸径、冠幅、活枝下高、单株材积、单位面积蓄积量和单位面积胸高断面积,五点法收集样地不同土层的土壤样品,测定土壤pH和土壤养分(全碳、全氮、全磷、全钾、铵态氮、硝态氮、有效磷和速效钾)含量。对林木生长状况调查发现:不同坡位之间,下坡位的林木生长状况最佳,其树高、胸径、冠幅、活枝下高和单株材积均最大。不同坡位之间,树高、冠幅、活枝下高和单株材积的比较由小到大排序为上坡位、中坡位、下坡位;胸径和单株材积的比较由小到大排序为:中坡位、上坡位、下坡位;单位面积蓄积量和单位面积胸高断面积的比较由小到大排列为:上坡位、下坡位、中坡位。对土壤理化性质分析结果表明,土壤pH随着坡位下降呈增加趋势。不同坡位之间,下坡位的土壤养分含量最高。除了全钾和速效钾的养分含量变化趋势由小到大为:中坡位、上坡位、下坡位外,其余养分含量依次由小到大排列为:上坡位、中坡位、下坡位。对相同坡位土壤养分空间分布的比较发现,林下表层(0~20 cm)土壤养分含量高于较深处(>20~40 cm)土壤。下坡位更有利于红皮云杉林木生长和土壤养分积累,是适合红皮云杉大径材林木培育的有利坡位条件。

Taking the 43 a Picea koraiensis plantation in Mengjiagang Forest Farm of Jiamusi of Heilongjiang Province as the research object, tree growth and forest soil physical and chemical properties were measured. The differences of growth shape and soil fertility artificial trees at different slope positions were analyzed to provide reference for the establishment of large-sized round wood cultivation technology of P. koraiensis.The sample plots were set up at the upper, middle and lower slopes on the south slope of plantation to investigate the tree height, diameter in breast high of trees(DBH), crown width and living branch height, and the soil samples from different soil layers were collected at five points to determine the soil pH and soil nutrient content(such as total carbon, total nitrogen, total phosphorus, total potassium, ammonium nitrogen, nitrate nitrogen, available phosphorus and available potassium). According to the survey, the trees growth on the downhill slope position was the best among different slope positions, and the tree height, DBH, crown width, living branch height and individual volume were the highest, respectively. Among the different slope positions, the comparison of tree height, crown width, living branch height and individual volume was ranked from small to large as uphill slope position, mid-slope position and downhill slope position. The comparison of breast diameter and individual volume were ranked from small to large as mid-slope position, uphill slope position, downhill slope position. The comparison of the unit area accumulation and the unit area of the chest height area was ranked from small to larege as uphill slope position, downhill position and middle slope position. The results of soil physical and chemical properties analysis showed that the pH value increased with the decrease of slope positions. The soil nutrient content of the downhill slope position was the highest among different slope positions. In addition to the change trend of nutrient content of total potassium and available potassium was ranked from small to large as mid-slope position,uphill slope position and downhill slope position. The other nutrient contents were ranked from small to large as uphill slope position,mid-slope position and downhill slope position. Comparing the spatial distribution of soil nutrients on the same slopes,it was found that the soil nutrient content in the lower layer( 0-20 cm) was higher than that in the deeper( > 20-40 cm). The downhill slope position is more favorable for the tree growth of P. koraiensis and soil nutrient accumulation,which is suitable for the cultivation of P. koraiensis trees with large-sized round wood cultivation.