Hectare for hectare, steep and mountainous areas in the tropics are arguably the most environmentally important real estate on the planet. Why?
For starters, it’s estimated that a third of the world’s biodiversity lives in mountainous areas, with much of that in the tropics. Mountains—especially tropical mountains—are notoriously rich in locally endemic species that occur nowhere else on Earth.
In addition, as our population skyrockets toward a projected 10 to 11 billion people this century, pressures on the planet are growing apace. Most population growth will occur in developing nations, often in the tropics. As demand for space and food increases, forests in flatter lowland areas—from the Amazon to the Congo to expanses of the Asia-Pacific—are being felled and razed for human uses. In many areas, forests in steeper areas are often all that survive—becoming critical refugia for ecosystems and biodiversity.
In addition to harboring huge concentrations of species, steepland forests also provide an array of environmental services of importance to humanity. Among these are their recognized roles in climate regulation—by storing billions of tons of carbon that would otherwise become heat-trapping greenhouse gases, and by transpiring great volumes of water vapor into the atmosphere, which produce life-giving clouds and rainfall.
Beyond this, steepland tropical areas serve as giant ‘biological sponges’, trapping and filtering rainfall. This limits destructive downstream flooding and landslides while helping to generate a steady flow of clean water for cities and local communities.
A recent report underscores the critical role of steepland tropics, especially in the New World. A joint publication of the Smithsonian Tropical Research Institute in Panama and the BIO Program of the Inter-American Development Bank, the report makes a compelling case for conserving and better managing steepland ecosystems.
The report, entitled “Managing Watersheds for Ecosystem Services in the Steepland Neotropics”, is a comprehensive treatise of the vital environmental services, threats from growing land-use pressures and climate change, and socio-economic and political drivers affecting steepland tropical ecosystems.
The editors of the report, led by the Smithsonian Institution’s Dr Jefferson Hall, are to be congratulated for their efforts to make the report highly readable and accessible. Attractively illustrated, it is available in English and Spanish versions, and in PDF and interactive formats.
A key element of the report is a set of guiding principles for sustaining tropical watersheds. Importantly, these principles are very practical in nature, framed to inform decision makers grappling with the pithy realities of balancing environmental sustainability with a range of competing pressures.
Beyond this, five case studies give the reader a clear sense of the challenges facing those attempting to manage and restore tropical watersheds—while illustrating the key importance of doing so. Notable among these are efforts by ELTI—the Environmental Leadership and Training Initiative—to promote reforestation and training for environmental leaders across the Neotropics.
Increasingly, steeper tropical areas are being recognized as a vital source of clean water supplies for cities and local people. Clean, reliable water supplies are almost impossible to overvalue, and yet again and again we see the forests that sustain those supplies being felled or degraded. From 2001 to 2014, for instance, every tropical nation in the New World has seen its forests shrink, sometimes dramatically.
The user-friendly report by the Smithsonian and Inter-American Development Bank could hardly be more timely or topical. I recommend it enthusiastically to anyone interested in the conservation, restoration and sustainable use of steeper tropical areas and the vital ecosystem services they provide for literally hundreds of millions of people.
On December the 8th the Smithsonian Tropical Research Institute and the Inter-American Development Bank will jointly launch “Managing Watersheds for Ecosystem Services in the Steepland Neotropics”.
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William Laurance is a Distinguished Research Professor and Australian Laureate at James Cook University in Cairns, Australia. He is director of the university’s Centre for Tropical Environmental and Sustainability Science, which has nearly 100 researchers working in more than 40 tropical countries around the world.