陕北黄土高原油松人工林林分结构及个体生长

Individual Growth and Stand Structure of Pinus tabulaeformis Plantation in Loess Plateau of Northern Shaanxi

为了阐明陕北黄土高原不同县人工油松同龄纯林林分结构特点,为陕北黄土高原油松人工林经营管理提供依据。通过样地调查,对陕北黄土高原神木、绥德、吴起、延川、黄龙、宜川等8个县油松人工林的林分结构和林木个体生长及其影响因素进行了对比研究。结果表明,黄龙和宜川两县的直径和树高分布遵从于正态分布。由北向南,平均胸径、平均树高、平均冠幅和平均冠高逐渐增加;黄龙和宜川两地油松人工林林下有1~10年生的幼苗（树）,数量丰富,生长正常;年均降水量和1月平均最低气温对油松人工林的生长影响显著,纬度和无霜期影响次之;黄龙和宜川两县人工油松林可以自我更新,个体生长发育正常,是人工栽培适宜地区;两县以北年均降水量小于550mm的地区,油松人工林天然更新不良,今后人工林培育需要谨慎选择生境。

The characteristics of stand structure of Pinus tabulaeformis plantations in different counties in Loess Plateau of Northern Shaanxi were probed to provide some scientific basis for reasonable management by field investigation.The distribution of diameter obeyed described normal distribution function in Huanglong and Yichuan.The distribution of height obeyed described normal distribution function in Wuqi,Yanchuan,Huanglong and Yichuan.Average DBH,height,crown width and crown height gradually increased from north to south.Annual precipitation and average temperature in January had the most influential effect on growth,while latitude and frostless period took the second place.Plantations in Huanglong and Yichuan grew better than in the other places.