We lose a lot more than carbon storage when we clearcut forests. Huge amounts of soil are lost when forests are cleared and erosion escalates. In Nepal, where trees are needed to stabilize steep slopes, between 30 to 75 tons of soil wash from each hectare of cleared land each year. Nepal may contribute as much as 240 million cubic meters of soil each year to neighboring India's lowlands and waterways. In Africa, the deforestation of Ethiopia's forests from about 10 percent of land cover to only 3 percent has resulted in topsoil flowing from the country's high lands into the Blue Nile River. There, it silts up the Roseires Dam, hundreds of miles downriver in Sudan.
Forests also help regulate the water cycle when tree roots soak up rainfall; stems, trunks and roots slow runoff; and tree leaves release water back into the atmosphere. In addition, plant and animal biodiversity depends on intact, mature forests. In some cases, even human health may rely on that biodiversity. Many medicines have been isolated from plant compounds. Deforestation can contribute to a resurgence or redistribution of infectious disease, when the ecosystem processes that allow natural pest control is disturbed. In South America, insecticide-resistance, declining investments in public health programs, and forest clearing have contributed to a resurgence in malaria. Malaria-carrying mosquitoes are normally consumed by a wide variety of reptiles, birds, bats, and fish. Forest clearing removes habitat for these creatures, but clears the way for standing water where mosquitoes can breed freely.
Valuing Nature: What Would You Pay?
How much would you pay to save a local wetland or a tract of tropical rain forest? How much would your neighbor pay? You and your neighbor may not agree about what's important in that wetland or forest. It's not easy to put a price tag on a wetland and every wetland probably has a different value. It's important, however, to understand the value of a natural resource if it's to be preserved, continue functioning and effectively providing ecological services.