两种生态控草措施对丘陵茶园杂草群落及物种多样性的影响

实现丘陵茶园杂草生态控制, 可有效减少茶园土壤水分和养分的消耗, 减少或避免使用化学除草剂.本研究根据生态位先估和生态位竞争原理, 设计覆盖稻草和间种豆科绿肥白三叶草(Trifolium repens)两种杂草生态控制技术, 同时设置清耕对照(CK), 采用小样方多点取样连续两年调查茶园杂草种群数量、生物量、平均株高等指标, 发现茶园共有杂草16科31属31种; 3个处理春季(4月)发生的杂草特征表现为生长速度较慢、生物量小、株高在30 cm以下; 夏季(7月)和秋季(9月)对照的优势恶性杂草多度(Pi)高达0.788和0.759, 稻草覆盖处理分别为0.256和0.420, 间种白三叶草处理恶性杂草种类较少发生(Pi值均低于0.050); 稻草覆盖处理茶园春、夏和秋季杂草物种丰富度(S)、种群多样性(H)、均匀度(J)等指数均高于对照, 优势集中性指数(C)低于对照; 间种白三叶草处理春、夏和秋季杂草总数量和生物量均显著低于对照, 夏、秋季杂草平均株高显著低于对照.结果表明两种生态控草处理措施能改变茶园杂草群落结构, 有效控制杂草的生长.

Effect of ecologically-based weed management strategies on weed community and diversity in hilly tea plantations

Ecologically controlling weeds does not only reduce consumption of soil water and nutrient, but also avoid or reduce application of chemical herbicides. Two ecologically-based weed management strategies based on pre-evaluation and competition of niche, straw mulching and white clover intercropping, were conducted in hilly tea plantations in 2005 and 2006, with clean tillage as the CK. Characteristics of weed community, including weed abundance, dominance, evenness, biomass and mean height were investigated via multi-sampling in small plot and the effects of two ecologically-based weed management strategies were compared with the clean tillage. About 16 families and 31 species of weeds are identified in the study. In April, the dominant weed species are those growing slowing with low biomass and lower than 30 cm. In July and September, the abundance (Pi) of malignant weed in CK respectively reaches 0.788 and 0.759, while that in straw mulching treatment is respectively 0.256 and 0.420, and a lower malignant weed occurrence frequency is found in white clover intercropping treatment with Pi<0.050. Weed richness, species diversity and evenness under straw mulching treatment are all higher than those under CK, though the dominant concentration index is lower than that of CK in spring, summer and autumn. Total number, biomass in spring, summer and autumn, and mean weed height in summer and autumn under white clover intercropping treatment are lower than those under the control. The two ecologically-based treatments have a favorable effect on weed control than the clean tillage. It therefore implies that white clover intercropping and straw mulching are effective ecological weed control measures.