Individual tree detection and crown segmentation based on metabolic theory from airborne laser scanning data

Laser scanning technology has enabled to study three-dimensional (3D) structures in forests. For example, airborne laser scanning (ALS) point cloud has been applied to detect individual trees and segment tree crowns. However, the accuracy of such approach remains a challenge because of the intersected crowns and complicated understories. We developed a metabolic theory-based algorithm for…

The impact of logging on vertical canopy structure across a gradient of tropical forest degradation intensity in Borneo

Forest degradation through logging is pervasive throughout the world’s tropical forests, leading to changes in the three-dimensional canopy structure that have profound consequences for wildlife, microclimate and ecosystem functioning. Quantifying these structural changes is fundamental to understanding the impact of degradation, but is challenging in dense, structurally complex forest canopies. We exploited discrete-return airborne LiDAR…

Monitoring ash dieback in British forests using hyperspectral remote sensing

Fungal ash dieback (Hymenoscyphus fraxineus) is posing an imminent threat to forest health in Europe. Using airborne hyperspectral imagery trained against 422 tree crowns of known species and ash dieback severity, we built PLS-DA and RF models that classified individual tree crowns (ITCs) into five species (>90% OA) and ash crowns into three disease severity…

Riparian buffers act as microclimatic refugia in oil palm landscapes

There is growing interest in the ecological value of set‐aside habitats around rivers in tropical agriculture. These riparian buffers typically comprise forest or other non‐production habitat, and are established to maintain water quality and hydrological processes, while also supporting biodiversity, ecosystem function and landscape connectivity. We investigated the capacity for riparian buffers to act as…

Do tall trees have a higher risk of wind damage?

When an intense tropical storm passes over a forest it leaves destruction in its wake. Post-damage surveys often show that the tall trees are disproportionately killed in these events. However, it is very difficult to attribute the cause of death of a large tree after the event. A tree may be snapped and lying on…

Resilience of Spanish forests to recent droughts and climate change

Time-series of canopy greenness derived from satellite imagery can beanalysed alongside environmental factors, species composition andmanagement regimes, to better understand forest resilience to drought.In Spain, forests are on average greening despite drying trends. Thisresilience manifests in the short-term with native species activatingdrought tolerance and avoidance mechanisms observable from space (i.e.losing and gaining little greenness like…