Abstract Chile’s temperate forest is a global biodiversity hotspot. An upsurge in alien forest plantations has disturbed and fragmented the landscape, promoting biological invasions. The invasion process is not fully understood since monitoring large and inaccessible areas can be prohibitively expensive and logistically challenging using field-based methods alone. Here, a remote sensing approach using Sentinel-2 satellite imagery, fragmentation analysis, and random forest modelling is applied to detect alien tree stands and describe their extent in relation to fragmentation and landscape structure in study areas around Malalcahuello National Reserve and Villarrica National Park. Detailed vegetation maps are produced, with classification accuracies >81% and including four forest classes, two native and two alien. An altitudinal pattern was observed in both sites. At lower altitudes, there was greater total area covered by alien trees and more fragmented native forests than at higher altitudes. However, Villarrica had less alien tree cover than Malalcahuello, but was a more fragmented landscape. Random forest modelling identified that alien pine tree mean patch area was positively correlated with both land cover diversity and Araucaria araucana forest mean patch area in both sites. Given their conservation and cultural relevance, the locations of protected areas need reconsidering to strengthen the protection of A. araucana, which could be outcompeted by alien trees in a context of increasing productive forestry. This is especially urgent in Villarrica, where protected areas already have a substantial presence of alien trees, with most A. araucana found outside protected areas.

中文翻译：

---

在智利温带森林中使用 Sentinel-2 卫星图像检测和建模外星树木的存在

摘要 智利的温带森林是全球生物多样性热点。外来森林种植的激增扰乱了景观并使其支离破碎，促进了生物入侵。入侵过程尚不完全清楚，因为仅使用基于现场的方法监测大面积且无法进入的区域可能会非常昂贵且在后勤方面具有挑战性。在这里，使用 Sentinel-2 卫星图像、碎片分析和随机森林建模的遥感方法被应用于检测外星林分，并描述它们与 Malalcahuello 国家保护区和比亚里卡国家公园周围研究区域中的碎片和景观结构的关系。生成详细的植被图，分类精度>81%，包括四个森林类别，两个本地和两个外来森林。在两个地点都观察到了海拔模式。在低海拔地区，与高海拔地区相比，外来树木覆盖的总面积更大，原生森林也更支离破碎。然而，比利亚里卡的外星树木覆盖率比马拉卡韦洛少，而是一个更加零散的景观。随机森林模型确定外来松树平均斑块面积与两个地点的土地覆盖多样性和南洋杉森林平均斑块面积呈正相关。鉴于其保护和文化相关性，需要重新考虑保护区的位置，以加强对 A. araucana 的保护，在增加生产性林业的背景下，外来树木可能会胜过。这在比亚里卡尤为紧迫，那里的保护区已经有大量外来树木，大多数 A.