[Effects of selective cutting disturbance on soil phosphorus adsorption and desorption in a Korean pine and broad-leaved mixed forest in the Xiaoxing'an Mountains, China.]

This study examined the characteristics of phosphorus (P) adsorption and desorption in surface soil (0-10 cm) of a secondary forest after selective cutting disturbance at three levels of intensity (low, medium, high) in order to reveal the effects of different disturbance intensities on soil P adsorption and desorption. Maximum adsorption amount (Qm), adsorption intensity factor, maximum buffer capacity, maximum desorption amount, average desorption rate and readily desorptable phosphorus were measured. Qm in the focal forests was 1383.93-1833.34 mg·kg-1, and Qmin forests with middle and high disturbance intensities was significantly higher than that in forests with low disturbance intensity and in primary forests. P adsorption intensity was 0.024-0.059 L·mg-1, and forests with high and low disturbance intensities increased the P adsorption intensity significantly. The maximum buffer capacity varied from 35.68 to 97.97 L·kg-1, with the highest value found in the forest with the highest disturbance intensity. Selective cutting significantly reduced the potential for phosphorus supply in the forest soils. The maximum desorption amount, average desorption rate and readily desorptable phosphorus content in the focal forests were 526.32-797.54 mg·kg-1, 14.7%-25.5% and 1.79-5.41 mg·kg-1, respectively, indicating that the ability of soil to release phosphorus significantly decreased with increasing disturbance intensity. Selective cutting changed the phosphorus adsorption and desorption characteristics by reducing the supply and release of soil phosphorus.以小兴安岭地区阔叶红松林经过轻度、中度和强度择伐干扰后形成的天然林以及未经干扰的原始林(对照)林地表层(0～10 cm)土壤为对象,对土壤磷素的最大吸附量、吸附强度、最大缓冲容量、最大解吸量、平均解吸率和易解吸磷量等指标进行测定,研究不同干扰强度导致土壤磷吸附解吸的规律性变化,分析择伐干扰对阔叶红松林土壤磷吸附解吸特征的影响.结果表明: 各林地土壤磷最大吸附量为1383.93～1833.34 mg·kg-1,中度和强度干扰林地显著高于轻度干扰林地和原始林地;磷吸附强度为0.024～0.059 L·mg-1,强度和轻度干扰显著增加了林地土壤磷吸附强度;最大缓冲容量为35.68～97.97 L·kg-1,强度干扰林地土壤的最大缓冲容量最高.择伐干扰显著降低了林地土壤的供磷潜力.各样地土壤磷最大解吸量、平均解吸率和易解吸磷量分别为526.32～797.54 mg·kg-1、14.7%～25.5%和1.79～5.41 mg·kg-1,林地土壤磷素释放能力随干扰强度的增加显著降低.择伐干扰通过降低林地土壤磷的供应及释放能力改变了阔叶红松林土壤磷吸附与解吸特征.