环洞庭湖防护林的土壤理化性状研究

Research on soil physical and chemical properties of protection forest surrounding Dongting Lake

以环洞庭湖12种主要造林模式防护林为研究对象,对其进行土壤取样和分析,研究环洞庭湖防护林土壤理化性状。结果表明:环洞庭湖区防护林土壤养分处于中高水平,但速效磷比较贫乏;不同造林模式防护林的土壤理化性状存在显著差异,特别是速效氮、速效钾、容重和pH值,其差异性均达到了极显著水平,其中杉木+木荷等针阔混交模式防护林的土壤理化性状最好,马尾松+湿地松的针叶混交模式防护林的土壤理化性状最差;土壤理化性状各指标间存在着较为紧密的相关性,有机质与速效氮、速效磷、速效钾呈极显著正相关,与pH值及容重呈极显著负相关;土壤有机质、速效氮、速效磷随土层深度的增加而显著递减;速效钾随土层深度的增加呈递减趋势,但递减不明显;土壤容重随土层深度的增加而显著增加;pH值随土层深度的增加呈增加趋势,但增加不明显。

Through investigating and analyzing the soil in 12 different forestation models of protection forest surrounding Dongting Lake, the soil physical and chemical properties were studied. The results showed that soil nutrient was at a high level, but relatively poor in available phosphorus. The soil physical and chemical properties were significant difference among different forestation models, especial- ly differences in available nitrogen, available K, bulk density and pH were significant at 0. 01 level. The forestation model of Cunning- hamia lanceolata ＋ Schima superba had the best soil physical and chemical properties, but the forestation model of Pinus massoniana ＋ Pinus elliottii had the worst soil physical and chemical properties. The soil organic matter had significant positive correlation with avail- able N, available P and available K, hut had significant negative correlation with pI-I and bulk density. The contents of soil organic matter, available N and available P significantly decreased with the increase of soil depth, while the decrease was not obvious in avail- able K. The soil bulk density significantly increased with the increase of soil depth, while the increase was not obvious in pH.