不同干扰方式对东北山地沼泽土壤肥力的影响

Effect of disturbances on soil fertility of northeast mountain swamp

为探讨不同人为干扰方式下山地沼泽土壤中主要营养元素含量的变化规律,以小兴安岭北部沼泽湿地分布比较集中的公别拉河流域为研究对象,比较分析5种干扰方式（农扰、筑坝、放牧、造田和采矿）对山地沼泽土壤肥力的影响。结果表明：与对照相比,5种干扰方式下土壤有机质,全N,水解N和10-20 cm、20-40 cm土壤速效P含量降低程度均达极显著水平（P〈0.01）;0-10 cm土壤层全P含量降低程度达显著水平（P〈0.05）,放牧干扰增加了该层土壤速效P含量,其他干扰则使该层土壤速效P含量降低程度达极显著水平（P〈0.01）;10-20 cm土壤层中,除农扰外,其他4种干扰方式下的全P含量均显著降低（P〈0.01）;20-40 cm土壤层中,农扰、筑坝、放牧和造田干扰对全P含量无显著影响（P〉0.05）。总体来看,采矿对沼泽土壤干扰程度相对最强,与对照相比,其土壤有机质含量下降98.90%,全N含量下降96.14%,水解N未检出,全P含量下降89.16%,速效P含量下降97.38%;其次是造田干扰,其土壤有机质、全N、水解N、全P和速效P含量下降幅度分别为90.20%、89.28%、84.41%、56.31%和61.19%;放牧干扰影响相对较小,其土壤有机质、N、P含量下降幅度均在45%以下。从回归分析结果看,不同干扰方式下,各层土壤全N、水解N、全P和速效P与土壤有机质含量呈显著相关关系。

An experiment was conducted to study the changing rule of nitrogen and phosphorus in soil under different types of disturbances （disturbances due to tilling, damming, grazing, cultivating and mining） in Gongbiela River Basin in northeast of Xiaoxing＇ an Mountain through field sampling and investigation. Results indicate that organic matters, total nitrogen, available nitrogen and available phosphorus in 10 - 20 cm and 20 - 40 cm soil layer under different disturbances decrease to an extreme level compared with the control （ P 〈 0.01）. In 0 - 10 cm soil layer, total phosphorus decreased significantly （ P 〈 0.05）, available phosphorus increases under disturbance of gazing, and decreases to an extreme level under the other four types of disturbances （P 〈 0.01）. Except for the disturbance due to tilling, the other four types of disturbances result in total phosphorus in 10- 20 cm soil layer decreasing extremely （P 〈 0.01）, while the disturbances of tilling, damming, grazing and cultivating have no significant effects on total phosphorus in 20 -40 cm soil layer. On the whole, mining produces the most serious disturbance to the swamp soil judging from the fact that organic matters, total nitrogen, total phosphorus and available phosphorus are 98.90%, 96.14%, 89.16% and 97.38 % lower than those of the control, respectively; even available nitrogen is hard to be detected out. Cultivating show a relatively strong disturbance, which results in organic matters, total nitrogen, available nitrogen, total phosphorus and available phosphorus decrease by 90.20%, 89.28%, 84.41%, 56.31% and 61.19%, respectively. Gazing causes a relatively lightest disturbance to swamp soil, which leads to organic matters, nitrogen and phosphorus decreasing by no more than 45 %. We can know from the result of regression that total nitrogen, available nitrogen, total phosphorus and available phosphorus show significant correlation with organic matters of swamp soil under different disturbances.