陕西黄陵油松人工林立地类型划分及评价

Site classification and evaluation of Pinus tabulaeformis plantation in Huangling,Shaanxi

【目的】对陕西黄陵地区油松人工林进行了立地类型划分与立地质量评价,以确定油松(Pinus tabulaeformis)适宜的生长环境,为黄陵地区油松人工林的经营管理及油松林生产潜力提升提供参考。【方法】根据不同林龄、林分密度、海拔、坡向、坡位、坡度等因子,在陕西黄陵地区油松人工林区域设置52个20 m×20 m的样地,调查样地内油松树高、胸径、立地环境因子和林分密度等指标,利用数量化理论Ⅰ模型分析各调查因子对油松生长的影响。【结果】(1)在陕西黄陵的油松人工林中,油松的树高、胸径、单株材积随着林龄的增大而增加,但在其生长的20~50年,每10年间油松的生长速率并不相同,其中以30~40年的生长速度最快,而40~50年的生长速度较慢。(2)海拔对油松人工林生长的影响最大,坡度和坡向次之,坡位的影响最小。(3)以海拔、坡度、坡位和坡向为主要立地因子,将研究区油松人工林划分为36种立地类型, 75%立地类型的立地质量处在中等及中等以上水平;(4)建立人工林质量评价模型并对黄陵地区油松人工林进行立地质量评价。评价结果显示,92.3%样地为中等或者优,说明黄陵地区油松人工林生长良好。【结论】黄陵地区油松最适宜生长的立地条件为中海拔、缓坡、下坡位、半阴坡。

【Objective】This study determined the suitable growth environment of Pinus tabulaeformisand and conducted site classification and evaluation of the P.tabulaeformis plantation in Huangling,Shaanxi to provide basis for establishment and management of P.tabulaeformis plantations and increasing production potential.【Method】According to age,stand density,altitude,aspect,slope position,slope and other factors,52 plots with the size 20 m×20 m were set up in the P.tabulaeformis plantation area in Huangling.The site factors,age,stand density of plots were recorded,and growth traits including height and diameter in breast height of each P.tabulaeformis were measured.The quantitative theoryⅠwas applied to obtain the effects of each factor on growth of P.tabulaeformis.【Result】(1)The tree height,DBH,and volume of P.tabulaeformis increased with age,and growth rate of P.tabulaeformis varied every 10 years from 20 to 50 years.The growth rate of P.tabulaeformis was slower from 40 to 50 years than from 30 to 40 years.(2)Altitude had the largest impact on growth of P.tabulaeformis as analyzed by quantitative theoryⅠ,followed by slope and aspect,and slope position had the least impact.(3)Based on elevation,slope,slope position and aspect as main site factors,the site classification of P.tabulaeformis plantations in the study area was divided into 36 site types,and the site quality of 75%site types was medium.(4)At the same time,the quality evaluation model of plantation forest was established to evaluate the site quality of P.tabulaeformis plantation in Huangling area.The classification and evaluation results of site quality showed that 92.3%of the surveyed plots were medium or excellent,indicating that the P.tabulaeformis plantations in Huangling had good growth status.【Conclusion】In Huangling,the most suitable site conditions for growth of P.tabulaeformis were moderate altitude,gentle slopes,lower slope and half cloudy slope.