How Do African Forest Elephants Influence Canopy Structure? An Analysis of a Critically Endangered Species' Ecological Role Using Lidar.

Recently classified as a unique species by the IUCN, African forest elephants (Loxodonta africana cyclotis) are critically endangered due to severe poaching. With limited knowledge about their ecological role due to the dense tropical forests they inhabit in Central Africa, it is unclear how the Afrotropics would change if forest elephants were to go extinct. Although their role as seed dispersers is well known, they may also drive large-scale changes in forest structure through the creation of elephant trails and browsing of the understory which allows larger, more carbon-dense trees to succeed. Lope National Park, Gabon is one of the last strongholds of forest elephants and happens to have overlapping lidar (light detection and ranging) datasets from NASA's LVIS, GEDI, and airborne discrete return lidar from 2015-2022. These data provide detailed canopy structural information which can be used in conjunction with elephant trail geolocation data collected in Lope NP in January, 2022. Using multiple lidar sensors and machine learning techniques, research questions regarding understory openness, canopy height, vertical distribution ratios of leaf area, and basal area in proximity to trails can be addressed. This study addresses multiple unanswered questions about the role forest elephants play as ecosystem engineers and helps determine their impact on habitat heterogeneity.