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了解喀斯特山地的土壤环境质量,对其植被恢复和石漠化治理有着重要意义。基于群落土壤肥力分析,采用典范对应分析(CCA)和因子分析相结合的方法,定量评价了广西平果喀斯特山地灌丛、灌木、仪花和蚬木群落的土壤质量。结果表明:土壤物理结构随植被恢复得到改善,土壤容重下降、孔隙增多、持水能力增强。土壤p H值以灌丛最高,仪花和蚬木林的土壤有机质、全氮和碱解氮含量明显高于灌丛和灌木,灌丛、灌木的土壤全磷、全钾和速效钾含量则显著高于次生乔木林;土壤速效磷和交换性钙含量差异不显著。CCA可以有效筛选土壤质量评价指标,土壤质量综合评价分值的大小顺序为:仪花林(0.41)>蚬木林(0.27)>灌丛(-0.20)>灌木林(-0.44)。导致灌丛和灌木林土壤质量较低的原因主要与群落生产力低、土壤有机质等养分积累少有关。
Understanding the quality of soil environment in the karst mountains is of great importance to the restoration of vegetation and the management of rocky desertification. Based on the analysis of soil fertility, the soil quality of shrubs, shrubs, flowers and alder communities in Pingguo Karst mountain was quantitatively evaluated using the method of canonical correspondence analysis (CCA) and factor analysis. The results showed that the physical structure of soil improved with the restoration of vegetation, the soil bulk density decreased, the porosity increased and the water holding capacity increased. The soil p H value was the highest in shrubs. The contents of soil organic matter, total nitrogen and total dissolved nitrogen in Yili and Alnus cremastogyne forests were significantly higher than those in shrubs and shrubs. The content of total phosphorus, total potassium and available potassium in soil of shrubs and shrubs were significantly Higher than the secondary trees; soil available phosphorus and exchangeable calcium content difference was not significant. CCA can effectively screen soil quality evaluation indexes. The order of soil quality comprehensive assessment scores is as follows: Yalihua (0.41)> Xulin (0.27)> shrub (-0.20)> shrub (-0.44). The causes of low soil quality in shrub and shrub land are mainly related to low community productivity and little nutrient accumulation in soil organic matter.