萘对川西亚高山森林土壤呼吸、可溶性有机质和微生物生物量的影响

通过原位控制试验,研究了萘对川西亚高山森林土壤动物抑制效率、土壤呼吸、可溶性有机质和微生物生物量的影响.结果表明:萘施用显著抑制了大型和中小型土壤节肢动物的个体密度和类群数量,个体密度分别下降76.3%~78.5%和83.3%~84.8%,类群数量分别降低48.3%~56.1%和45.8%~58.3%.萘处理与对照的土壤呼吸速率季节动态呈单峰曲线,分别以2月和8月为最低值和最高值,而且未受萘施用的显著影响.与对照相比,萘处理显著降低了8月和10月土壤可溶性碳和可溶性氮含量,以及4月和8月微生物生物量碳,增加了4月的微生物生物量碳氮比.萘处理和采样时间的交互作用显著影响了微生物生物量碳和微生物生物量氮,但对土壤动物个体密度和类群数量以及可溶性碳含量影响不显著.总体上,萘作为抑制剂,在川西亚高山森林土壤能够有效地抑制土壤动物节肢动物,且并未显著影响土壤呼吸,但对土壤碳氮组分造成了不同程度的影响.

Effects of naphthalene on soil respiration,dissolved organic matter and microbial biomass in the subalpine forest of western Sichuan,China.

The effects of naphthalene on soil respiration, dissolved organic matter and microbial biomass, and its inhibition efficiency for soil fauna of subalpine forest in western Sichuan were studied by in situ control experiment. The results showed that naphthalene application significantly inhibited the individual density and group number of soil macro- and meso-/micro- arthropods, with the individual density being decreased by 76.3%-78.5% and 83.3%-84.8% respectively, and the number of groups being decreased by 48.3%-56.1% and 45.8%-58.3%, respectively. The seasonal dynamics of soil respiration rate showed single peak curves in both naphthalene treatment and control. The lowest and the highest soil respiration rates were observed in February and August, respectively. The naphthalene treatment had little effect on soil respiration. Compared with the control, naphthalene treatment significantly reduced the contents of soil dissolved carbon and dissolved nitrogen in August and October as well as microbial biomass carbon (MBC) in April and August, but increased MBC/MBN in April. The naphthalene treatment and sampling time significantly interacted to affect the MBC and MBN, but had no significant effect on individual density, the number of groups of soil fauna and DC content. In all, naphthalene as biocide could effectively inhibit the soil arthropods and had no significant effect on soil respiration, but it had varying degrees of effects on soil carbon and nitrogen components in subalpine forest of western Sichuan.