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揭示不同砍伐频率对森林土壤养分库和氮周转的影响,对于理解森林养分循环的干扰响应具有重要意义。本研究以浙江天童常绿阔叶林为对象,选择了3个具有不同砍伐频率的群落比对组,分析各组内土壤有机碳和氮磷养分库,以及氮素矿化、硝化速率的变化。结果表明:3组群落中,重复砍伐群落的土壤总氮和总有机碳储量显著减小(P<0.05),而土壤总磷、铵态氮和硝态氮储量、土壤容重显著增加(P<0.05)。土壤氨化速率和氮矿化速率在比对组间无显著差异(P>0.05),但硝化速率在重复砍伐后显著增加(P<0.05)。本研究表明,土壤养分库和氮转化对森林重复砍伐的响应方式不同。森林重复砍伐后,土壤有机碳库和氮库含量降低,磷库和无机氮库含量增加,氮素矿化和氨化速率变化不显著,硝化速率显著提高。
To reveal the effect of different deforestation frequency on forest soil nutrient pool and nitrogen turnover is of great significance for understanding the disturbance response of forest nutrient cycle. In this study, three evergreen broad-leaved forests in Tiantong, Zhejiang Province were selected as the comparison groups with different deforestation frequencies. The changes of soil organic carbon and nitrogen and phosphorus nutrient pools and the rate of nitrogen mineralization and nitrification were analyzed . The results showed that total and total organic carbon storage of the three groups decreased significantly (P <0.05), while total phosphorus, ammonium nitrogen and nitrate nitrogen storage, soil bulk density increased significantly (P < 0.05). There was no significant difference in soil ammonification rate and nitrogen mineralization rate between the two groups (P> 0.05), but the nitrification rate increased significantly after repeated cutting (P <0.05). This study shows that soil nutrient pools and nitrogen transformation respond differently to deforestation. After repeated deforestation, soil organic carbon pool and nitrogen pool decreased, phosphorus pool and inorganic nitrogen pool increased, nitrogen mineralization and ammonification rate changed insignificantly, and nitrification rate increased significantly.