CAJ | 학술논문

在黑龙江省帽儿山地区对经过不同强度采伐1 a后的次生林，采用PVC管原位培养法测定土壤净氮矿化速率和净氮硝化速率的变化，结果表明，0～10 cm土层的土壤平均净氮矿化速率和净氮硝化速率从大到小依次为皆伐后造林、皆伐后农作、50％强度采伐、25％强度采伐和对照，各采伐处理的0～12 cm土层土壤质量含水量均显著高于对照（ P＜0?05），净氮矿化速率和净氮硝化速率与土壤质量含水量呈显著正相关（ P＜0?05），同时采伐亦增加了土壤中的有机碳含量，这说明采伐引起土壤含水量和有机碳含量增加是导致净氮矿化速率和净氮硝化速率升高的主要原因。此外，采伐还引起了土壤无机氮含量的变化，在生长季各采伐处理土壤硝态氮平均含量均显著高于对照（ P＜0?05），而土壤铵态氮平均含量则显著低于对照（ P＜0?05），各采伐处理土壤无机氮以硝态氮为主，对照则以铵态氮为主。上述结果表明该地区的森林经过采伐干扰后，可导致土壤硝态氮含量增加，土壤氮素流失风险亦增加。
재흑룡강성모인산지구대경과불동강도채벌1 a후적차생림，채용PVC관원위배양법측정토양정담광화속솔화정담초화속솔적변화，결과표명，0～10 cm토층적토양평균정담광화속솔화정담초화속솔종대도소의차위개벌후조림、개벌후농작、50％강도채벌、25％강도채벌화대조，각채벌처리적0～12 cm토층토양질량함수량균현저고우대조（ P＜0?05），정담광화속솔화정담초화속솔여토양질량함수량정현저정상관（ P＜0?05），동시채벌역증가료토양중적유궤탄함량，저설명채벌인기토양함수량화유궤탄함량증가시도치정담광화속솔화정담초화속솔승고적주요원인。차외，채벌환인기료토양무궤담함량적변화，재생장계각채벌처리토양초태담평균함량균현저고우대조（ P＜0?05），이토양안태담평균함량칙현저저우대조（ P＜0?05），각채벌처리토양무궤담이초태담위주，대조칙이안태담위주。상술결과표명해지구적삼림경과채벌간우후，가도치토양초태담함량증가，토양담소류실풍험역증가。
A field experiment was carried out using a PVC tube in?situ incubation method to explore effect of harvest cut?ting on soil net nitrogen ( N) mineralization rate and net nitrification rate in temperate secondary forests one year after the felling operation varying in intensity in the Maoershan region of Heilongjiang Province. Results show that in terms of means of soil net N mineralization rates and net nitrification rates in the 0-10 cm soil layer, the treatments followed an order of afforestation after clear cutting>farming after clear cutting>50% of the stand volume removed>25% of the stand volume removed > control. Soil water content in the 0-12 cm soil layer was significantly higher in the harvested plots than in the control. Both net N mineralization rate and net nitrification rate were significantly and positively related to soil water con?tent. Harvesting also increased soil organic carbon content. All the findings suggest that the increased soil water and organic carbon are the main causes of the increase in soil net N mineralization rate and net nitrification rate after harvest cutting. In addition, harvest cutting also triggered change in soil inorganic N content. During the growing season, the means of NO3-?N contents in the harvested plots were significantly higher than that in the control, while the means of NH4+?N were quite the contrary. Soil inorganic N was dominated with NO3-?N in the harvested plots, and with NH4+?N in the control. The above findings suggest that harvest cutting may increase NO3-?N content in the soil, and hence, the risk of losing soil nitrogen in this region.