Innovative study in Bosque Pehuén analyzes habitat use in three-dimensional environments of the vertical profile of temperate rainforests in Chile

The purpose of the research was to understand how wildlife uses the whole vertical profile of the forest and to analyze possible interactions between different species and vertical forest strata, using camera traps and species occupancy models.

The study, entitled “Habitat use in three-dimensional environments: A camera-trap assessment of vertical profile use by wildlife in the temperate forests of Chile“, was carried out in the area under private protection (APP) managed by Fundación Mar Adentro, Bosque Pehuén, in the Andean Araucanía, and was prepared by Dr. Iván Díaz, together with Javier Godoy-Güinao, Eduardo A. Silva-Rodríguez and Brayan Zambrano, from the Laboratory of Biodiversity and Canopy Ecology of the Universidad Austral de Chile, the Austral Patagonia Program, the Research Center for Sustainability, and the Doctoral Program in Conservation Medicine of the Universidad Andrés Bello.

 It should be noted that this study is one of the first of its kind in Chile, and complements a little explored area of research on wildlife in the forest, which is usually monitored from the ground and does not consider the vertical structure of the forest as a habitat of various species. This may be due to the technical implications and difficulties involved in studies of fauna in the canopy (for example, installation of camera traps at high altitudes, specialized technical equipment, among others). This lack of attention to the upper layer of the forest could lead to biases in estimates of abundance, occupancy, size of the species’ distribution area and activity patterns of the species that use the vertical profile of the forests. For the team of researchers, understanding how wildlife use the vertical structure in temperate rainforests is highly relevant to “provide important information for forest wildlife conservation, monitoring and management” (Walther, 2003 cited by Godoy et al.2023)

 For this research, four vertical strata were defined (forest floor, understory, lower
canopy, and upper canopy)that range from 0 to 32 m from the ground, and 16 camera traps were installed for each of these. The cameras were active 24 hours a day between January and April 2019. The use of each stratum by seven different taxa or species was analyzed using species occupancy models. Twenty-four vertebrate taxa were detected, including 17 birds, six mammals, and one reptile.

 The occupancy models showed that rodents and two species of birds were associated with the forest floor or lower strata (floor and understory), while a furnarid bird (a family of birds to which the “rayadito” and other species belong) and a marsupial (monito del monte) used the vertical profile more frequently than the forest floor. Finally, the lizard and a furnarid bird preferentially used the upper and lower canopy. And for all but one of the species, the activity patterns were similar between the upper and lower strata of the forest.

 The results suggest that vertical heterogeneity and forest stratification, expressed as the presence and connectivity of different vegetation strata (trees, lianas and climbing plants, shrubs, sub shrubs and herbs) play an important role in how fauna is distributed in forest ecosystems, and this should be considered in forest biodiversity assessments.