Chevalier R, Webster J M
Former Graduate Student and Professor, Simon Fraser University, Department of Biological Sciences, Burnaby, BC, Canada V5A 1S6.
J Nematol. 2006 Dec;38(4):466-73.
To assess the effect of an inundative release of entomopathogenic nematodes on soil organisms, population densities of soil-dwelling organisms were monitored before and after an application of an aqueous suspension of Heterorhabditis megidis to field plots in mown grassland (Exp. I) at a level of 0.38 million/m(2) and to plots (Exp. II) situated in a forested area, a grass sports field and an orchard at a level of 1.5 million/m(2). At the forested site, heat-killed H. megidis (1.5 million/m(2)) also were applied to two plots to compare the impact on soil organisms of a large introduction of living and dead nematodes. Post-treatment, temporary changes in natural population densities of several nematode genera and other organisms were detected in H. megidis-treated plots in both experiments. Temporary changes in the nematode trophic structure occurred in the percentages of nematode omnivores, herbivores and predators in both experiments. Evidence from all sites suggests that the changes were temporary and that the presence of decaying H. megidis following treatment contributed to nutrient enrichment of the soil and to direct and indirect effects on the nematode community.
为评估大量释放昆虫病原线虫对土壤生物的影响，在割草地的田间地块（实验I）以每平方米38万条的剂量施用大异小杆线虫水悬浮液之前和之后，监测了土壤栖息生物的种群密度；在森林地区、草地运动场和果园的地块（实验II）以每平方米150万条的剂量施用。在森林地区，还对两个地块施用了热灭活的大异小杆线虫（每平方米150万条），以比较大量引入活线虫和死线虫对土壤生物的影响。在两个实验中，处理后，在大异小杆线虫处理的地块中均检测到几个线虫属和其他生物的自然种群密度出现暂时变化。在两个实验中，线虫杂食性、草食性和捕食性线虫的百分比发生了线虫营养结构的暂时变化。所有地点的证据表明，这些变化是暂时的，处理后大异小杆线虫的腐烂有助于土壤养分富集以及对线虫群落的直接和间接影响。
