荆条灌丛下不同林木幼苗根周土壤颗粒分形特征

摘要

Field investigation and lab experiment were conducted to study the different trees seedling rhizospheres' soil particles fractal features under Vitex negundo shrubs' crown at the Taihang mountain area.The results showed that the soil of the study site were mainly silt loam,less soil clay content;the clay and silt content of rhizosphere under the vitex negundos' crown width were greater than that of the external areas,and the percentage of soil sand was less than that of the external areas.Soil fractal dimension of different tree seedlings were Quercus variabilis>Platycladus orientalis,and that of different tree seedlings under Vitex negundo's scrown between inside and outside were significant difference.Soil fractal dimension has significant negative relation with soil sand content(50~2 000μm),significant positive relation with soil silt(<2μm) and clay(2~50μm) content.Soil fractal dimension has significant positive relation with contents of soil organic matter,total N,and there was no obvious relation with available phosphorus content.%通过野外调查取样与室内分析相结合的方法,研究了太行山地区荆条灌丛下,不同林木幼苗根周土壤颗粒分形特征.结果表明,试验地土壤以粉砂壤土为主,土壤粘粒含量较少;荆条灌丛冠幅内林木幼苗根周土壤粘粒与粉粒体积百分比高于冠幅外,砂粒体积百分比则低于冠幅外.栓皮栎幼苗根周土壤分形维数值>侧柏幼苗根周土壤分形维数值,荆条灌丛冠幅内外不同林木幼苗土壤的分形维数差异显著.土壤颗粒分形维数与砂粒(50~2 000μm)显著负相关,与粘粒(<2μm)和粉粒(2~50μm)显著正相关,与土壤有机质、全氮含量为显著的线性正相关关系,与速效磷含量相关性不明显.