不同林型兴安落叶松林土壤理化特征

以不同林型（草类、杜香、杜鹃）兴安落叶松林0~60 cm土壤为研究对象，探讨兴安落叶松林土壤理化性质及其相关性。结果表明:1）0~60 cm土层，兴安落叶松林土壤含水量为17.93%，容重为1.07 g/cm³，随土层深度增加，土壤含水量呈下降趋势，容重呈递增趋势；2）兴安落叶松林土壤为弱酸性（pH=5.59），随土层深度增加，pH呈递增趋势；3）兴安落叶松林土壤铵态氮含量为17.94 mg/kg，速效K含量为89.05 mg/kg，有效P含量为17.85 mg/kg，有机P含量为0.43 g/kg，随土层深度增加，各养分指标含量均呈下降趋势；4）兴安落叶松林土壤各金属氧化物的含量大小依次为Al₂O₃（13.77%）>Fe₂O₃（5.44%）> K₂O（2.33%）>Na₂O（1.80%）>MgO（1.30%）>CaO（1.25%），随土层深度增加，除CaO外，各指标含量整体呈增加趋势，且表层含量与其他土层间差异显著；5）林型对土壤含水量、pH、铵态氮、有效P、MgO、Al₂O₃、CaO、Fe₂O₃的影响显著，而对容重、速效K、有机P、Na₂O和K₂O的影响不明显。表明兴安落叶松3种林型的土壤理化性质存在一定差异，草类-兴安落叶松林的土壤理化特征显著区别于杜香-兴安落叶松林和杜鹃-兴安落叶松林，可为兴安落叶松林的可持续经营提供依据。

Soil Physicochemical Characteristics of Larix gmelinii Forest with Different Forest Types

Taking the soil samples of 0-60 cm layer of Larix gmelinii forest with different forest types (grass,Ledum and Rhododendron) as the research objects,the correlations of soil physicochemical properties were discussed.The results showed that 1) the soil water content (SWC) and bulk density (BD) were 17.93% and 1.07 g/cm³.With the increase of soil depth,the SWC decreased and the BD increased gradually.2) The soil was weakly acidic (pH=5.59),and pH increased with soil depth.3) The contents of ammonium nitrogen (NH₄⁺-N),available potassium (AP),available phosphorus (AP) and organic phosphorus (OP) were 17.94,89.05,17.85 mg/kg and 0.43 g/kg,respectively.The contents of all nutrients decreased with soil depth.4) The contents of metal oxides were in the order of Al₂O₃ (13.77%)>Fe₂O₃ (5.44%)>K₂O (2.33%)>Na₂O (1.80%)>MgO(1.30%)>CaO (1.25%),which decreased with soil depth except for CaO.The contents of metal oxides were significantly different between the surface layer and other layers.5) Forest types had significant effects on SWC,pH,NH₄⁺-N,AP,MgO,Al₂O₃,CaO and Fe₂O₃,but had no significant effects on BD,AK,OP,Na₂O and K₂O.The understory vegetation had certain effects on soil physicochemical properties.There were some differences in soil physicochemical properties among three types of L.gmelinii forest.The soil physicochemical characteristics of grass-L.gmelinii forest were significantly different from those of Ledum-L.gmelinii forest and Rhododendron-Larix forests.The results could provide a basis for the sustainable management of L.gmelinii forest.