5种森林类型土壤理化性质分析

[目的]研究临高县5种森林类型土壤理化性质。[方法]以临高县滨海台地5种典型森林植被为研究对象,利用标准地调查法对不同森林类型土壤理化性质进行分析。[结果]土壤总孔隙度木麻黄林最大(46.17%),桉树林最小(39.46%)。土壤毛管孔隙度马占相思林最大(22.57%),次生林最小(18.95%)。土壤含水率木麻黄林最高,平均达27.85%,而次生林含水率最低,平均为4.34%。土壤p H在4.81~6.59,马占相思林、木麻黄林和桉树林均为极强酸性(p H 4.5~5.5)土壤,次生林和椰子林为弱酸性土壤。土壤有机质含量为0.34~28.68 g/kg,有机质含量由高到低依次为马占相思林、木麻黄林、桉树林、次生林、椰子林,且随着土壤深度的增加土壤有机质含量呈递减趋势。全氮含量为0.10~1.63 g/kg,马占相思林土壤全氮含量最高,椰子林最低;全磷含量为0.21~1.74 g/kg,桉树林全磷含量最高;全钾含量为0.16~2.15 g/kg,马占相思林最高。有效磷含量为0.98~132.46 mg/kg,次生林有效磷含量最高;速效钾含量为3.03~27.35 mg/kg,椰子林速效钾含量最高。铵态氮含量为1.38~5.15 mg/kg,硝态氮含量为0.56~3.51 mg/kg,其中马占相思林硝态氮(平均2.29 mg/kg)和铵态氮含量(平均3.93 mg/kg)最高。同一森林类型,随着土壤深度的增加,硝态氮和铵态氮含量总体呈递减趋势。[结论]该研究为准确评估临高县森林土壤肥力的潜力,预测和维护人工林生态系统长期生产力,指导人工林的可持续经营和改造提供参考。

Soil Physical and Chemical Properties of Five Subtropical Forests

[Objective] To study physical and chemical properties of five types of forest soil in Lingao County.[Method] Taking five types of typical forest vegetation as the research object,soil physical and chemical properties of different forest types were analyzed by using standard survey method.[Result] The soil total porosity of Casuarina equisetifolia forest was the largest (46.17％),Eucalyptus robusta forest was the smallest(39.46％).The soil capillary porosity ofAcacia mangium forest was the largest (22.57％),and the secondary forest was the smallest (18.95％).Soil moisture content was the highest in Casuarina equisetifolia forest,with an average of 27.85％,while that of secondary forest was the lowest,with an average of 4.34％.Soil pH was between 4.81 and 6.59.Acacia mangensis forest,Casuarina equisetifolia forest and Eucalyptus robusta forest were highly acidic soil (pH 4.5-5.5),and secondary forest and Cocos nucifera forest were weakly acidic.Soil organic matter content was between 0.34 g/kg and 28.68 g/kg,and the order of organic matter content was Acacia mangensis forest,Casuarina equisetifolia forest,Eucalyptus robusta forest,secondary forest,Cocos nuciferaforest,and the soil organic matter decreased with the increase of soil depth.The total nitrogen content was between 0.10 g/kg and 1.63 g/kg,the total nitrogen conten of Acacia mangium forest was the largest,that of Cocos nucifera forest was the smallest.The total phosphorus content was between 0.21 g/kg and 1.74 g/kg,and the total phosphorus content in Eucalyptus robusta forest was the highest,and the total potassium content was 0.16 ～ 2.15 g/kg and content of Acacia mangium forest wast he highest.The available phosphorus content was between 0.98 mg/kg and 132.46 mg/kg,and the available phosphorus content was the highest in the secondary forest.The available potassium content was between 3.03 mg/kg and 27.35 mg/kg,and the available potassium content of Cocos nucifera was the highest.The content of ammonium nitrogen was between 1.38 mg/kg and 5.15 mg/kg,and the nitrate nitrogen content was between 0.56 mg/kg and 3.51 mg/kg.The contents of nitrate nitrogen (average 2.29 mg/kg) and ammonium nitrogen content (average 3.93 mg/kg) in Acacia mangium forest were the highest.In the same forest type,with the increase of soil depth,nitrate nitrogen and ammonium nitrogen content also showed a decreasing trend.[Conclusion] The study provides reference for accurate assessment of forest soil fertility potential,predicting and maintaining long-term plantation ecosystem productivity,guiding the sustainable management of plantations and transformation.