氯酸钾对龙眼果园土壤动物群落多样性的影响

对土壤施用氯酸钾进行产期调控的反季节龙眼果园的土壤动物群落多样性与空间分布进行了初步调查。结果表明,共捕获的6182只土壤动物,分别隶属于4门8纲25目,优势种群为蚯蚓类和半翅类;在反季节龙眼果园内的土壤动物主要分布在0～10cm的深度范围内,而且随深度增加,数量和种类均呈下降趋势;对捕获的土壤动物进行群落多样性分析发现,施加各浓度氯酸钾的处理除Pielou均匀性指数外,数量、种类、Shannon-Wiener多样性指数、Simpson优势度指数和密度类群指数均无显著差异,表明在高温多雨的华南地区,龙眼施用氯酸钾催花剂量少于1000g·株~(-1)的条件下,对果园土壤动物的影响不大。

Effects of Potassium Chlorate on Soil Animal Communities in an off-Season Longan Orchard

Historically, chlorates once were used as non-selective contact herbicide, defoliant and desiccant in agriculture. Chlorine dioxide was used for disinfection of drinking water, and bleaching in pulp/paper/textile industries. Chlorate (ClO-3) is produced when chlorine dioxide is incompletely reduced to chloride during the industrial process. Recently potassium chlorate has been applied to stimulate the reproduction of longan trees for out-of-season fruit in longan orchard. But chlorates are a group of highly oxidizing substances with toxic effects. It can bring about significant ecological risk. There are very few reports available on the toxicity of potassium chlorate to soil animals, especially in out-of-season longan orchard at present. By using standardized researching methods, soil animal community structure and diversity were investigated in an off-season longan orchard used potassium chlorate. Total 6 182 soil animals were captured and identified, they belonged to 4 phyla, 8 classes and 25 orders, and among these animals, Oligchaeta and Hemiptera were the dominant communities. Soil animals mainly appeared in 0~10 cm soil layer and decreased with the increase of soil depth. All indexes except Pielou evenness index, including total number of individuals, number of taxonomy groups, Shannon-Wiener diversity index, Simpson dominance index and group density index, had no significant difference among different treatments. This result suggested that applying potassium chlorate at less than 1 000 g per longan tree had little impacts on soil animals in off-season longan orchards in South China.