| 摘要: |
| [目的]阐明黄土高原森林区油松人工林初植密度对群落更新和持续发育的影响,为当地油松人工林经营管理提供参考.[方法]通过野外调查和室内分析相结合的方法,研究了陕西宜川地区不同初植密度(1 m×1 m(密度Ⅰ),1 m×2 m(密度Ⅱ),2 m×2.5 m(密度Ⅲ))35年生油松人工林的林木个体生长、林地更新、群落物种多样性及土壤养分特征.[结果]油松人工林的死亡率随初植密度的增大呈增加趋势,油松死亡年龄、胸径、树高、冠高和冠幅随初植密度的增加而减小;油松死亡率、胸径、冠高和冠幅与初植密度之间有显著的相关关系,但油松树高与初植密度之间的相关性不显著.油松人工林林下幼苗(树)的更新状况在低密度林地内最好.在各初植密度油松人工林中,各层物种丰富度指数、均匀度指数和多样性指数均表现为灌木层＞草本层.群落总体多样性表现为丰富度指数和多样性指数在3种初植密度间的变化趋势一致,均为Ⅲ＞Ⅱ＞Ⅰ;均匀度指数Jsw和Ea则表现为Ⅰ＞Ⅲ＞Ⅱ,而Jsi表现为Ⅲ＞Ⅰ＞Ⅱ.不同初植密度林地间土壤养分和水分存在显著差异.[结论]根据样地数据和野外实地观察结果认为,宜川地区油松初始造林密度应在2 800～3 000株/hm2,在进入生长高峰期后,适时间伐至1 200～1 500株/hm2比较合适. |
| 关键词: 造林密度 生长状况 更新 物种多样性 油松人工林 |
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| 基金项目:中国科学院西部行动计划项目（KZCX2-XB2-05）；国家“十一五”科技支撑项目（2006BAD09B03） |
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| Growth,regeneration and community structure of Pinus tabulaeformis artificial forest under different densities |
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| Abstract: |
| 【Objective】 To assess the original density impact on community regeneration and development and to provide some scientific basis for reasonable management,Pinus tabulaeformis artificial forest was investigated and studied in Yichuan. 【Method】 Field investigations and inside experiment were conducted to study the growth of Pinus tabulaeformis,saplings and seedlings regeneration,species diversity and soil nutrient under different densities. 【Result】 Death rate increased with the increase of density.The death age,stem diameter,height,crown height and crown width decreased with the increase of density.The death age,stem diameter,crown height and crown width were significantly correlated with density.Height wasn't significantly correlated with density.Saplings and seedlings regeneration was the best in plots of low density.Species richness,evenness index and diversity index in the shrub layer were higher than those in the herb layer in the different density plots.The community species richness and diversity index followed such order as densityⅢ＞densityⅡ＞densityⅠ;evenness index (Jsw,Ea)was densityⅠ＞densityⅢ＞densityⅡ,but Jsiwas density Ⅲ＞densityⅠ＞densityⅡ.There were significant differences in the soil nutrient and soil moisture among different densities. 【Conclusion】 According to the results and field observation,we think that the original density should be controlled under 2 800-3 000 trees/hm2.At the same time,intermediate cutting should be taken into account when growing peak is coming.It is reasonable that the density is about 1 200-1 500 trees per hectare. |
| Key words: density growth regeneration species diversity Pinus tabulaeformis artificial forest |
