地形对阔叶红松林物种多样性的影响

为了更好地了解阔叶红松林(Pinus koraiensis)物种多样性的维持机制,对不同地形下的阔叶红松林乔木和灌木种,进行了物种多样性指数比较、物种多度分布模型拟合及物种多样性指数与环境因子的排序分析。结果表明,乔木在阴坡、半阴坡的丰富度显著高于半阳坡;灌木在坡度25°处的均匀度显著高于坡度6°处,在谷地处的4个多样性指数显著低于其他坡位,在阴坡、半阴坡处的4个多样性指数显著高于平地。统计模型、生态位模型、中性模型在不同地形下均能够通过拟合优度检验,物种多度分布在不同地形间差异不明显;地形对乔木的多样性指数的影响:海拔凹凸度坡度坡向坡位,对灌木的多样性指数的影响:坡位海拔坡向坡度凹凸度,土壤对乔木的物种多样性指数的影响:土壤pH土壤容重土壤有效N含量土壤速效K含量,对灌木的物种多样性指数的影响:土壤pH土壤有机质含量土壤速效P含量土壤全N含量土壤全P含量。总体而言,物种多样性随着坡度的增加而增加,阴坡处最高,谷地处最低。

Effects of topography on species diversity in a typical mixed broadleaved-Korean pine forest

To better understand the mechanism regulating the species diversity of mixed broadleaved-Korean pine (Pinus koraiensis) forest, the species diversity index, goodness-of-fit test of six models for species-abundance distribution, and the significance test between environmental factors and ordination axis of arbor and shrub in the different topographies of mixed broadleaved-Korean pine forest were analyzed. The results showed that the abundance of arbor at the shady and semi-shady slopes is significantly higher than that in the semi-sunny slopes. The shrubs at slope gradient greater than 25 degrees were significantly higher than that at slope gradient less than 6 degrees. The slope position exhibited a significant effect on the four diversity indices of shrub, and valley was significantly lower than those of other slope positions. The four diversity indices of arbor at the shady and semi-shady slopes are significantly higher than those at flats. Statistical models, niche models, and neutral models can be tested by fitting goodness under different topographies, but species distribution in different topographies was not obvious. The effects of topographic factors on species diversity of arbor were in the order:elevation > concavity > slope aspect > slope aspect > slope position. The effects of topographic factors on species diversity of shrub were in the order:slope position > elevation > slope position > slope gradient > concavity. The effects of soil factors on species diversity of arbor were in the order:pH > BD > SHN > SAK. The effects of soil factors on species diversity of shrub were in the order:pH > SOC > SAP > STN > STP. In general, the species diversity increased with the increase in slope, and the species diversity at shady slope was the highest, and that at the valley was the lowest.