Protected Area Zoning as a Strategy to Preserve Natural Soundscapes, Reduce Anthropogenic Noise Intrusion, and Conserve Biodiversity

Abstract

Protected area zoning is a management strategy used to define and delimit land units for specific purposes, such as critical areas for conservation and areas for recreation activities. Nevertheless, human activities in and around protected areas produce anthropogenic noise that is difficult to mitigate and control. To assess the efficacy of protected area zoning in preserving natural soundscapes, controlling anthropogenic noise intrusion, and conserving biodiversity in El Yunque National Forest, Puerto Rico, I simultaneously sampled three management zones (protected, recreational, and buffer) with passive acoustic monitoring and conducted a soundscape analysis. There was no difference in the overall acoustic space used among the three management areas, but compositional differences among the soundscapes were detected. Such variation was related to differences in species composition along the elevation gradient, habitat transformation, and anthropogenic noise. Anthropogenic noise was more conspicuous in the buffer and recreational areas, where many bird species are classified as highly vulnerable to noise. Although the management zones in El Yunque National Forest were not created for the purpose of noise control, management is shown to be useful for minimizing noise intrusion in the strictly protected zone. In recreational and buffer areas, complementary strategies such as traffic limitations, limiting access to specific areas, and noise reduction educational programs should be implemented to maintain the natural soundscape while conserving biodiversity. Finally, the noise vulnerability classification proposed in this study could be a useful tool for assisting managers and researchers in defining priority strategies for sensitive species that require special attention and protection.