Aerial maps created using LiDAR technology—light detection and ranging, which uses laser pulses to measure distances—have shown that Scotland's Cairngorms National Park has seen a significant expansion of woodland areas. A team from the University of Cambridge conducted surveys over 569 square kilometers of the park by scanning the land from a light aircraft flying at 600 meters above the ground. The data collected was analyzed with artificial intelligence, revealing over 6 million individual trees. Of these, 2.65 million were under 5 meters tall, indicating young, regenerating forests. These new trees were mostly found near the edges of existing forests, but some were even more than half a kilometer away from forested areas. The study also found that habitat type plays a role in tree growth, with fewer new trees in wet, boggy areas compared to drier heathlands. The research was carried out by Cairngorms Connect, a nature restoration partnership aiming to double the size of existing forests through natural regeneration. This partnership covers 60,000 hectares, and more than 5,235 hectares of land that was once open have now developed young woodland—defined as areas with more than 100 trees per hectare. Much of this growth has happened naturally, with only small areas requiring tree planting where natural seed sources are unavailable. This study highlights the potential of LiDAR technology to map regenerating trees at a large scale, which can help monitor ecological restoration efforts and track the effects of climate change, such as the increasing frequency of wildfires. The method used in the study could complement or even replace traditional ground-based surveys, offering a more efficient way to monitor forest expansion across the globe. Scotland's native coniferous forests have been declining for centuries due to deforestation for agriculture and hunting, with only about 4% of the original forest cover remaining. The Scottish government aims to create 3,000 to 5,000 hectares of native woodland each year. However, challenges such as deer browsing and the high cost of planting trees in fenced areas have historically hindered this goal. The formation of the Cairngorms Connect partnership a decade ago has helped overcome these obstacles, promoting natural forest regeneration. The study has been published in the Journal of Applied Ecology. Researchers involved, including Dr. Aland Chan from the University of Cambridge and Dr. Pip Gullett from Cairngorms Connect, emphasized the importance of tracking forest regrowth to guide future land management. The expansion of forested areas also benefits wildlife, such as the endangered capercaillie and red squirrels, which rely on these habitats for survival.