Ancient ecological legacies and past land use changes may inform on the present structure of biological communities. However, regions providing such successive ecosystems are scarce. In France, the ‘Landes de Gascogne’ area provides such ecological shifts since a few ancient moorland, peatland and oak areas prior the afforestation with maritime pine (Pinus pinaster) 160 years ago still remain. Focusing on soil-borne parasites such as plant-parasitic nematodes (PPN), because forests were recently increasingly impacted by the introduction of intensive agriculture, this study is therefore aimed at comparing the diversity and the community patterns of these organisms at different scales (intra- and intersites) and between different successive ecosystems. The understory vegetation as well as the pedo-climatic characterization of the sampled sites were also considered. Common diversity indices were not impacted by this transition from ancient to past ecosystems. Although the most colonizer nematodes prevailed in all the ecosystems, PPN community structures significantly diverged between both ecosystems. In the logged pine forests, the sediment legacy could have primarily impacted the diversity. Moreover, the PPN diversity would mainly respond to the soil hydromorphicity that determined the associated understory vegetation. Consequently, a significant shift in community structure from moorlands to logged pine to logged pine forests was observed, regarding especially high pathogenic species such as Pratylenchus spp. Thus, analyzing PPN community structure highlights the PPN potential risk to consider during the introduction of intensive cropping systems.

古代的生态遗产和过去的土地利用变化可能会影响目前的生物群落结构。但是，提供这种连续生态系统的区域很稀少。在法国，“加德涅山脉”地区提供了这样的生态转变，因为在海上松林造林之前，一些古老的荒地，泥炭地和橡树地区（松树松树）160年前仍然存在。由于森林最近受到集约化农业的影响越来越大，因此关注森林等植物传播的线虫（PPN）等土壤传播的寄生虫，因此，本研究旨在比较这些生物在不同规模上的多样性和群落模式（内部-和站点间）以及不同的连续生态系统之间。还考虑了下层植被以及采样点的古气候特征。从古代生态系统过渡到过去的生态系统不会影响共同的多样性指数。尽管大多数生态系统中都存在着大多数殖民地线虫，但PPN群落结构在两个生态系统之间都存在很大差异。在砍伐的松树林中，沉积物遗留物可能主要影响了多样性。此外，PPN的多样性将主要取决于确定相关林下植被的土壤亲水性。因此，对于特别是高致病性物种（例如：Pratylenchus spp。因此，对PPN群落结构的分析突出显示了在集约化耕种系统引入期间要考虑的PPN潜在风险。