La Taha, Spain by Lot Amoros - part of deadtrees.earth

This data paper consists of an orthophotograph taken on the perimeter of the Sierra Nevada Natural Park, Spain, located in the municipality of La Taha, at an altitude of approximately 1,500 metres above sea level.

The area has a diversity of tree species, such as chestnut trees (Castanea sativa), holm oaks (Quercus ilex), and Pyrenean oaks (Quercus pyrenaica), as well as shrub species, predominantly Adenocarpus decorticans.

The purpose of the orthophotography is to reveal the increase in chestnut tree mortality in Sierra Nevada, which are suffering from various conditions that may be due to: rising temperatures due to climate change, the abandonment of irrigation channels, or fungal diseases such as chestnut blight (Phytophthora cinnamomi) or chestnut canker (Cryphonectria parasitica), aggravated by the recent appearance of the chestnut gall wasp (Dryocosmus kuriphilus) pest.  

Several of the dead trees shown in the orthophotograph have died suddenly in the last year and are close to the irrigation ditch, so water stress can be ruled out. Others, however, have been dead for decades.

Technical production:
The photographs were taken at the end of May 2025, when all the trees had leafed out, especially the chestnut and oak trees, in order to distinguish the dead trees from the living ones.

The aerial photograph was obtained using the DJI Mavic 2 Pro unmanned aerial vehicle. The aerial route was planned using the Drone Deploy platform covering 5 hectares at a height of 35 metres. Although this height offers a resolution of 1 cm/pixel, this resolution is variable as the area has a very significant slope, resulting in a lower resolution in the lower areas of the orthophoto.

The process of integrating multiple images captured to generate the orthofoto was carried out using the open source software Open Drone Map.