[Effects of naphthalene on soil respiration, nutrients and enzyme activities in the subalpine forest of western Sichuan, China]

As a biocide to reduce soil and litter faunal populations in field experiments, naphthalene has been widely used in the study of ecological functions of soil fauna, but the non-target effects of naphthalene bring about enormous uncertainty to its application. In order to understand whether there were non-target effects of naphthalene in subalpine forest soil, soil in the subalpine forests of west Qinghai-Tibet Plateau was taken as study object. The short-term responses of soil respiration rate, nutrient content and enzyme activity to naphthalene were studied in microcosms. The results showed that soil respiration rate was significantly suppressed by application of naphthalene within 0-10 days, and then showed a significant promotion effect. Naphthalene significantly affected the dynamics of soil NH萘作为土壤动物化学抑制剂已在土壤动物生态功能的研究中广泛使用,但其非目标效应使其应用仍存在很大的不确定性.为了了解在亚高山森林土壤应用萘抑制土壤动物群落是否存在非目标效应,以青藏高原东缘的川西亚高山森林土壤为研究对象,采用微缩试验研究了萘对土壤呼吸速率、养分含量和酶活性的短期影响.结果表明: 萘处理显著抑制了培养0～10 d的土壤呼吸速率,随后(24～52 d)表现出明显的促进作用.萘处理显著影响了土壤铵态氮和硝态氮含量的动态变化,萘处理铵态氮和硝态氮含量分别以培养的3和17 d最高,对照则以培养的45 d和结束时的52 d最高.萘处理土壤可溶性碳含量在培养3 d急剧增加后迅速降低,对照则略有升高后降低,而萘处理和对照的可溶性氮含量均表现为先升高后降低.萘处理和对照的土壤酶活性均具相似的动态规律,两者的脲酶、硝酸还原酶和亚硝酸还原酶活性分别在培养45、38和10 d至最高.萘处理和采样时间的交互作用显著影响了土壤呼吸速率,以及土壤铵态氮、硝态氮和可溶性氮含量,但对可溶性碳含量、蔗糖酶、硝酸还原酶和亚硝酸还原酶活性的影响不显著.萘作为驱虫剂的非目标效应可能在短期内对川西亚高山森林土壤的氮循环过程产生强烈的影响.