Free-living nematodes are key organisms that greatly enhance plant growth and nutrient uptake. In contrast, plant-parasitic nematodes are considered a major pest group in agriculture. The effect of nematodes, either positive or negative, on plant productivity depends on their ability to disperse in soils. Understanding the dispersal process of nematodes is therefore crucial but is still poorly documented. The aim of this study was to examine the effects of the endogeic tropical earthworm Pontoscolex corethrurus on the horizontal dispersal of nematodes in Ferralsols in Madagascar. A microcosm experiment was conducted under controlled laboratory conditions. Two factors modulating dispersion were studied: (i) the earthworm density with three modalities (without, five or ten individuals) and (ii) the duration of the experiment with two modalities (four and eight weeks). The results showed that P. corethrurus favored the horizontal dispersal of nematodes. This is mainly a dispersal mechanism through the earthworm casts that they deposit in the soil or on the soil surface during their movements. The total abundance of dispersed nematodes increased with the earthworm density and the duration of the experiment. Cephalobidae dominated the trophic structure of the dispersed nematodes, similar to the original populations. However, the original populations had a higher taxonomic diversity than the dispersed nematode communities. These results indicate that P. corethrurus, through dispersion, influences the spatial and temporal distribution, abundance and structure of nematode communities in the soil.

自由生活的线虫是极大促进植物生长和养分吸收的关键生物体。相比之下，植物寄生线虫被认为是农业中的主要害虫类群。线虫对植物生产力的影响，无论是积极还是消极，取决于它们在土壤中扩散的能力。因此，了解线虫的传播过程至关重要，但目前的记录仍然很少。本研究的目的是检查内生热带蚯蚓Pontoscolex corethrurus的影响马达加斯加费拉尔索尔斯线虫的水平扩散。在受控的实验室条件下进行了微观实验。研究了调节分散的两个因素：（i）三种模式下的蚯蚓密度（无、五或十个人）和（ii）两种模式下的实验持续时间（四周和八周）。结果表明，P. corethrurus有利于线虫的水平扩散。这主要是通过蚯蚓在运动过程中沉积在土壤中或土壤表面上的排泄物进行传播的机制。分散线虫的总丰度随着蚯蚓密度和实验时间的延长而增加。头虫科在分散的线虫的营养结构中占主导地位，与原始种群相似。然而，原始种群比分散的线虫群落具有更高的分类多样性。这些结果表明，P. corethrurus通过扩散影响土壤中线虫群落的时空分布、丰度和结构。