Founder’s Briefs: An occasional series where Mongabay founder Rhett Ayers Butler shares analysis, perspectives and story summaries.
Researchers have been using sound to study ecosystems for years. A study from ETH Zürich uses it to examine Costa Rica’s payment for ecosystem services program, reports Mongabay’s Abhishyant Kidangoor.
Giacomo Delgado, a doctoral researcher, compares the method to a physician using a stethoscope. With enough experience, a doctor can distinguish a healthy heartbeat from an irregular one. Forests, he suggests, also produce patterns that can be compared across sites.
To test this, Delgado and colleagues deployed recorders across 119 sites on the Nicoya Peninsula in northwestern Costa Rica. They gathered more than 16,000 hours of audio from various types of landscapes: protected forests, areas regenerating under the country’s payment for ecosystem services (PES) scheme, monoculture plantations, and active pastures. Costa Rica’s PES program, launched in 1997, compensates landowners for maintaining forest cover and is frequently used as a reference point in conservation policy.
Satellite data show that forest cover has recovered after steep declines in the late 20th century. They don’t show whether those forests function as habitats. Counting trees is simpler than assessing species diversity or ecological interactions.
Sound offers a different way to assess this. Insects, birds and amphibians produce layered soundscapes that change over the course of a day. Forests with more activity tend to show pronounced peaks at dawn and dusk. Pastures do not.
The recordings that Delgado and his team collected suggest that naturally regenerated forests under PES resemble protected forests more closely than degraded land. Plantations show signs of recovery, though less consistently.
The method doesn’t resolve all uncertainties. It can’t establish what would have happened without financial incentives. Even so, it provides a more direct measure of ecological condition than canopy cover alone. Delgado’s team is now expanding the analysis across the country.
Read the full story Abhishyant Kidangoor here.
Banner image of a forest in Costa Rica. Image by Rhett A. Butler/Mongabay.
Source:
news.mongabay.com