Landscape-level human disturbance results in loss and contraction of mammalian populations in tropical forests
by Ilaria Greco, Lydia Beaudrot, Chris Sutherland, Simone Tenan, Chia Hsieh, Daniel Gorczynski, Douglas Sheil, Jedediah Brodie, Mohammad Firoz Ahmed, Jorge Ahumada, Rajan Amin, Megan Baker-Watton, Ramie Husneara Begum, Francesco Bisi, Robert Bitariho, Ahimsa Campos-Arceiz, Elildo A. R. Carvalho Jr, Daniel Cornélis, Giacomo Cremonesi, Virgínia Londe de Camargos, Iariaella Elimanantsoa, Santiago Espinosa, Adeline Fayolle, Davy Fonteyn, Abishek Harihar, Harry Hilser, Alys Granados, Patrick A. Jansen, Jayasilan Mohd-Azlan, Caspian Johnson, Steig Johnson, Dipankar Lahkar, Marcela Guimarães Moreira Lima, Matthew Scott Luskin, Marcelo Magioli, Emanuel H. Martin, Adriano Martinoli, Ronaldo Gonçalves Morato, Badru Mugerwa, Lain E. Pardo, Julia Salvador, Fernanda Santos, Cédric Vermeulen, Patricia C. Wright, Francesco Rovero Tropical forests hold most of Earth’s biodiversity and a higher concentration of threatened mammals than other biomes. As a result, some mammal species persist almost exclusively in protected areas, often within extensively transformed and heavily populated landscapes. Other species depend on remaining remote forested areas with sparse human populations. However, it remains unclear how mammalian communities in tropical forests respond to anthropogenic pressures in the broader landscape in which they are embedded. As governments commit to increasing the extent of global protected areas to prevent further biodiversity loss, identifying the landscape-level conditions supporting wildlife has become essential. Here, we assessed the relationship between mammal communities and anthropogenic threats in the broader landscape. We simultaneously modeled species richness and community occupancy as complementary metrics of community structure, using a state-of-the-art community model parameterized with a standardized pan-tropical data set of 239 mammal species from 37 forests across 3 continents. Forest loss and fragmentation within a 50-km buffer were associated with reduced occupancy in monitored communities, while species richness was unaffected by them. In contrast, landscape-scale human density was associated with reduced mammal richness but not occupancy, suggesting that sensitive species have been extirpated, while remaining taxa are relatively unaffected. Taken together, these results provide evidence of extinction filtering within tropical forests triggered by anthropogenic pressure occurring in the broader landscape. Therefore, existing and new reserves may not achieve the desired biodiversity outcomes without concurrent investment in addressing landscape-scale threats.
by Ilaria Greco, Lydia Beaudrot, Chris Sutherland, Simone Tenan, Chia Hsieh, Daniel Gorczynski, Douglas Sheil, Jedediah Brodie, Mohammad Firoz Ahmed, Jorge Ahumada, Rajan Amin, Megan Baker-Watton, Ramie Husneara Begum, Francesco Bisi, Robert Bitariho, Ahimsa Campos-Arceiz, Elildo A. R. Carvalho Jr, Daniel Cornélis, Giacomo Cremonesi, Virgínia Londe de Camargos, Iariaella Elimanantsoa, Santiago Espinosa, Adeline Fayolle, Davy Fonteyn, Abishek Harihar, Harry Hilser, Alys Granados, Patrick A. Jansen, Jayasilan Mohd-Azlan, Caspian Johnson, Steig Johnson, Dipankar Lahkar, Marcela Guimarães Moreira Lima, Matthew Scott Luskin, Marcelo Magioli, Emanuel H. Martin, Adriano Martinoli, Ronaldo Gonçalves Morato, Badru Mugerwa, Lain E. Pardo, Julia Salvador, Fernanda Santos, Cédric Vermeulen, Patricia C. Wright, Francesco Rovero Tropical forests hold most of Earth’s biodiversity and a higher concentration of threatened mammals than other biomes. As a result, some mammal species persist almost exclusively in protected areas, often within extensively transformed and heavily populated landscapes. Other species depend on remaining remote forested areas with sparse human populations. However, it remains unclear how mammalian communities in tropical forests respond to anthropogenic pressures in the broader landscape in which they are embedded. As governments commit to increasing the extent of global protected areas to prevent further biodiversity loss, identifying the landscape-level conditions supporting wildlife has become essential. Here, we assessed the relationship between mammal communities and anthropogenic threats in the broader landscape. We simultaneously modeled species richness and community occupancy as complementary metrics of community structure, using a state-of-the-art community model parameterized with a standardized pan-tropical data set of 239 mammal species from 37 forests across 3 continents. Forest loss and fragmentation within a 50-km buffer were associated with reduced occupancy in monitored communities, while species richness was unaffected by them. In contrast, landscape-scale human density was associated with reduced mammal richness but not occupancy, suggesting that sensitive species have been extirpated, while remaining taxa are relatively unaffected. Taken together, these results provide evidence of extinction filtering within tropical forests triggered by anthropogenic pressure occurring in the broader landscape. Therefore, existing and new reserves may not achieve the desired biodiversity outcomes without concurrent investment in addressing landscape-scale threats.
