The term agroforestry covers practices that are promoted to maintain or even enhance biodiversity. However, the relationship between agroforestry and invasive species is rarely addressed, even though the spread of such species is an important issue, not only ecologically but also economically and socially. Over the past few decades, humans have greatly accelerated the process of biological invasions, to such an extent that they are now recognized as the second cause of rapid decline in biodiversity. In France (as in other parts in Europe), abandonment of agricultural land in remote areas is a major problem having socio-economic, landscape and environmental implications. The objective of the research presented here was to find a method for studying the relationship between traditional agroforestry systems and invasive species, despite a lack of available data. We investigated the evolution of a traditional agroforestry system in the Pyrenean foothills, where invasive species are abundant, by implementing two complementary methods: (1) interviews highlighting the local stakeholders’ perception of landscape evolution, invasive species and the challenges they represent for the local traditional agroforestry landscapes, and (2) detailed mapping of an area occupied by invasive plants, by means of very high-resolution spatial technologies using UAV’s and aerial photography. The results show that invasive species have spread in relation with the abandonment of agricultural land, which has also led to “landscape closure” by the encroachment of natural afforestation. They also underline the difficulty of assessing the spread of invasive species. This situation is of major importance in terms of land-use planning, as the various stakeholders have different perceptions of the problem, and it raises questions about the sustainability of practices and territories.

中文翻译：

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传统农林业景观的演变和入侵物种的发展：比利牛斯山脉的教训（法国）

农林业一词涵盖了为维持或什至增强生物多样性而促进的做法。但是，农林业与外来入侵物种之间的关系很少得到解决，尽管此类物种的传播不仅在生态上而且在经济和社会上都是一个重要问题。在过去的几十年中，人类极大地加速了生物入侵的进程，以至于人们现在已经认为它们是生物多样性迅速下降的第二个原因。在法国（与欧洲其他地区一样），偏远地区的农用土地被抛弃是一个具有社会经济，景观和环境影响的重大问题。这里提出的研究的目的是找到一种研究传统农林业系统与入侵物种之间关系的方法，尽管缺乏可用数据。我们通过实施两种补充方法，调查了入侵物种丰富的比利牛斯山麓地区传统农林业系统的演变：（1）采访突出了当地利益相关者对景观演变，入侵物种及其对当地的挑战的认识传统农林景观，以及（2）通过使用无人机和航空摄影的超高分辨率空间技术，详细绘制入侵植物所占的区域。结果表明，入侵物种随着农地的废弃而扩散，这也由于自然造林的入侵而导致了“景观封闭”。他们还强调了评估入侵物种扩散的难度。