Relics of past agricultural practices, former field systems have strongly imprinted many modern landscapes and have thus significantly disrupted forest ecosystems over the last centuries. Former field systems in the Hautes-Vosges mountain range (north-eastern France) date primarily to the medieval period (6–15th century C.E.) and consist of parcelled or linear structures on hillslopes and valley floors. These residual features fall into three categories: ridge and furrow, terraced slopes, and stone walls. LiDAR (light detection and ranging) can detect microrelief features, such as the topographical imprints of these field systems over extended areas, and thereby establish a new temporal baseline for reconstructing forest changes over relatively long timescales, i.e., before the first historical topographic maps. Here, we digitize former field systems in the south-eastern Vosges from a high-resolution LiDAR-derived DEM to assess their spatial distribution at the mountain-range scale (1185 km²) and in relation to topography. Former field systems cover approx. 6.6 % of the study area (78.5 km²), with terraced slopes (55.5 km²) and stone walls (20.6 km²) covering a greater extent than ridge and furrow (2.4 km²). Former field systems are preferentially located on south-facing slopes above an 800 m a.s.l. threshold; this pattern indicates systematic past agricultural practices across the entire region. We then compare the LiDAR-derived spatial features with a 19th-century map of France and a modern regional land-cover database to derive the spatio-temporal trajectories of landscapes. We observe that former field systems were progressively, but unevenly, abandoned and transformed into grasslands or forests. This mid-19th century abandonment of agricultural fields and their conversion to grassland and forest is highly dependent on slope and elevation (grassland and forest: 18–19° and 610–620 m). These values differ from those associated with agricultural sites that remain under cultivation today (approx. 16° and 550 m). Finally, we demonstrate the relevance of integrating former field systems for characterizing areas of ancient forest. Less than 2 % of the area mapped as forest in the 19th century was cultivated between the 6th and 15th century. Most importantly, our approach quantifies disturbed and undisturbed ancient forest areas at the mountain-range scale. While this study opens new perspectives for accurately assessing the age of forest ecosystems, it also reveals an evolutionary pattern of land-use change in the Hautes-Vosges that is similar to that observed in other European mountainous regions.

过去农业实践的遗迹，以前的田间系统在许多现代景观中留下了深刻的印记，因此在过去几个世纪中严重破坏了森林生态系统。Hautes-Vosges 山脉（法国东北部）的旧田野系统主要可追溯到中世纪时期（公元 6 至 15 世纪），由山坡和谷底上的分块或线性结构组成。这些残余特征分为三类：垄沟、梯田斜坡和石墙。LiDAR（光探测和测距）可以检测微地貌特征，例如这些野外系统在扩展区域上的地形印记，从而建立新的时间基线，用于重建相对较长时间尺度内的森林变化，即在第一张历史地形图之前。这里，我们通过高分辨率 LiDAR 衍生的 DEM 将 Vosges 东南部的前田野系统数字化，以评估它们在山脉尺度（1185 平方公里）和与地形相关的空间分布。以前的现场系统覆盖约。研究区域的 6.6%（78.5 平方公里² ), 梯田斜坡 (55.5 km ² ) 和石墙 (20.6 km ² ) 覆盖范围大于垄沟 (2.4 km ²). 以前的田间系统优先位于海拔 800 米以上的朝南斜坡上；这种模式表明整个地区过去有系统的农业做法。然后，我们将 LiDAR 衍生的空间特征与 19 世纪的法国地图和现代区域土地覆盖数据库进行比较，以得出景观的时空轨迹。我们观察到，以前的田间系统逐渐但不均衡地被遗弃并转变为草原或森林。这种 19 世纪中叶的农田废弃及其转变为草地和森林高度依赖于坡度和海拔（草地和森林：18–19° 和 610–620 米）。这些值不同于与今天仍在耕种的农业用地相关的值（约 16° 和 550 m）。最后，我们展示了整合以前的野外系统以表征古代森林区域的相关性。在 19 世纪绘制为森林的面积中，不到 2% 在 6 世纪和 15 世纪之间被开垦。最重要的是，我们的方法量化了山脉尺度上受干扰和未受干扰的古老森林区域。虽然这项研究为准确评估森林生态系统的年龄开辟了新的视角，但它也揭示了上孚日省土地利用变化的演变模式，这与在其他欧洲山区观察到的相似。我们的方法量化了山脉尺度上受干扰和未受干扰的古老森林区域。虽然这项研究为准确评估森林生态系统的年龄开辟了新的视角，但它也揭示了上孚日省土地利用变化的演变模式，这与在其他欧洲山区观察到的相似。我们的方法量化了山脉尺度上受干扰和未受干扰的古老森林区域。虽然这项研究为准确评估森林生态系统的年龄开辟了新的视角，但它也揭示了上孚日省土地利用变化的演变模式，这与在其他欧洲山区观察到的相似。