植物特性和环境因子对阔叶红松林暗多样性的影响

Effects of plant characteristics and environmental factors on the dark diversity in a broadleaved Korean pine forest

可能栖息在局域群落但在局部地区不存在的物种集合构成了暗多样性。为探究物种特性和环境因子对阔叶红松林内暗多样性的影响,该研究利用比尔指数模型估计了黑龙江凉水国家级自然保护区的9 hm2阔叶红松(Pinus koraiensis)林动态监测样地内的主要组成物种的暗多样性概率。基于物种水平,评估了耐阴性指数、重要值和暗多样性概率之间的相关性,并分析了生活型和耐阴性对暗多样性概率的影响;基于样方水平,分析了群落完整性与环境因子、物种多样性的相关性。结果表明:(1)该样地物种的暗多样性概率平均值为77.79%,对于乔木,胡桃楸(Juglans mandshurica)的暗多样性概率最高,为97.21%;对于灌木,暗多样性概率最高的是鸡树条(Viburnum opulus subsp.calvescens)和鼠李(Rhamnus davurica),为98.01%。(2)暗多样性概率与重要值呈显著负相关关系,耐阴性指数与重要值呈显著正相关关系。(3)乔木和灌木的暗多样性概率无显著差异,喜光物种的暗多样性概率显著高于耐阴物种。(4)坡度和地面凹凸度均与群落完整性呈显著正相关关系;土壤有机质含量、土壤速效钾(K)含量、土壤密度、土壤质量含水率、土壤p H、土壤有效氮(N)含量和土壤全N含量均与群落完整性无显著相关关系,土壤体积含水率、土壤速效磷(P)含量、土壤全P含量均与群落完整性呈显著的负相关关系。物种多样性指数与群落完整性呈正相关关系。综上,在阔叶红松林内喜光物种和稀有种的暗多样性概率较高,坡度、地面凹凸度、土壤体积含水率、土壤速效P含量、土壤全P含量是导致群落完整性差异的主要环境因素;群落完整性越高,群落物种多样性越高。

Aims A particular set of species that have the potential to inhabit a local community but are locally absent is called dark diversity.Our aim was to investigate the impacts of plant characteristics and environmental factors on the dark diversity in a broadleaved Korean pine(Pinus koraiensis)forest.Methods The study was conducted based on survey data of a 9-hm^(2) broadleaved Korean pine forest in the Liangshui National Nature Reserve of Heilongjiang Province.We estimated the dark diversity probability of main species by using the Beals index.The correlations between the shade tolerance index,importance value and dark diversity probability were evaluated,and the effects of life form and shade tolerance on dark diversity probability were analyzed at the individual level.The correlations between community completeness and environmental factors,and community completeness and species diversity were investigated at the plot level.Important findings The results showed that:(1)Average dark diversity probability for these species in this plot was 77.79%.For arbors,Juglans mandshurica had the highest dark diversity probability of 97.21%;however,for shrubs,the dark diversity probability of Viburnum opulus subsp.calvescens and Rhamnus davurica were the highest,at 98.01%.(2)The dark diversity probability was negatively correlated with the importance value.However,the shade tolerance index was positively correlated with the importance value.(3)There was no significant difference in the dark diversity probability between arbors and shrubs,but the dark diversity probability of shade-intolerant species was significantly higher than that of shade-tolerant species.(4)Slope and convexity were both significantly positively correlated with community completeness.Soil organic matter,soil available potassium,soil bulk density,mass moisture content,soil p H,soil available nitrogen,and soil total nitrogen were not significantly related to community completeness;however,soil available phosphorus,soil total phosphorus and volumetric moisture content were all significantly negatively correlated with community completeness.The correlations between the species diversity indices and community completeness were significantly positive.In short,the dark diversity probability of shade-intolerant species and rare species in the broadleaved Korean pine forest was relatively high.Slope,convexity,soil available phosphorus,soil total phosphorus and volumetric moisture content were the main environmental factors that significantly influenced community completeness.The higher the community completeness was,the higher the species diversity of the community.