Using soundscapes to detect variable degrees of human influence on tropical forests in Papua New Guinea

There is global concern about tropical forest degradation, in part, because of the associated loss of biodiversity. Communities and indigenous people play a fundamental role in tropical forest management and are often efficient at preventing forest degradation. However, monitoring changes in biodiversity due to degradation, especially at a scale appropriate to local tropical forest management, is plagued by difficulties, including the need for expert training, inconsistencies across observers, and lack of baseline or reference data. We used a new biodiversity remote-sensing technology, the recording of soundscapes, to test whether the acoustic saturation of a tropical forest in Papua New Guinea decreases as land-use intensity by the communities that manage the forest increases. We sampled soundscapes continuously for 24 hours at 34 sites in different land-use zones of 3 communities. Land-use zones where forest cover was fully retained had significantly higher soundscape saturation during peak acoustic activity times (i.e., dawn and dusk chorus) compared with land-use types with fragmented forest cover. We conclude that, in Papua New Guinea, the relatively simple measure of soundscape saturation may provide a cheap, objective, reproducible, and effective tool for monitoring tropical forest deviation from an intact state, particularly if it is used to detect the presence of intact dawn and dusk choruses. Existe una preocupación global por la degradación del bosque tropical, en parte, por la pérdida asociada de la biodiversidad. Las comunidades y personas indígenas juegan un papel fundamental en el manejo del bosque tropical y son continuamente eficientes en la prevención de la degradación del bosque. Sin embargo, el monitoreo de cambios en la biodiversidad por causa de la degradación, especialmente a una escala apropiada para el manejo del bosque tropical local, está plagado de dificultades, incluyendo la necesidad de entrenamiento por expertos, inconsistencias entre los observadores, y la falta de una línea base de datos de referencia. Utilizamos una tecnología nueva de detección remota de la biodiversidad, la grabación del paisaje sonoro, para probar si la saturación acústica de un bosque tropical en Papua Nueva Guinea disminuye conforme incrementa la intensidad del uso de suelo por las comunidades que manejan el bosque. Muestreamos el paisaje sonoro continuamente durante 24 horas en 34 sitios en diferentes zonas de uso de suelo de tres comunidades. Las zo