The practices of Yanesha, left, and Tibetan farmers offer new insights into climate change and agricultural diversity.
Humans have always been subject to changes in their environment. They’ve struggled to adapt to a variety of extremes. The “Little Ice Age” in the 16th and 17th centuries killed livestock and crops, particularly in Europe. Prolonged droughts in what is now the Southwestern United States, beginning in the 11th century A.D., forced many of the region’s inhabitants to abandon their city-states. Only in recent years, however, have scientists begun to realize that humans also can have a negative impact on their environment. Unsanitary living conditions in medieval Europe allowed the spread of the bubonic plague in the 14th century. Overpopulation on tiny Easter Island led to almost complete deforestation.
Yet, there are examples of people whose cultural beliefs imbue them with a sense of personal responsibility towards their surroundings. The Yanesha of the upper Peruvian Amazon and the Tibetans of the Himalayas are among them. Over the last 40 years, Dr. Jan Salick, senior curator and ethnobotanist with the William L. Brown Center of the Missouri Botanical Garden has worked with both cultures. She explains how their traditional knowledge and practices hold the key to conserving and managing biodiversity in a paper entitled, “Biodiversity in Agriculture: Domestication, Evolution, and Sustainability,” published by Cambridge University Press.
The Yanesha and Tibetans are two different groups living in radically dissimilar environments, but both cultures utilize and value plant biodiversity for their food, shelters, clothing and medicines.
“Both cultures use traditional knowledge to create, manage and conserve this biodiversity, and both are learning to adapt to and mitigate the effects of climate change,” said Salick. “They have much to teach and to offer the world if we can successfully learn to integrate science and traditional knowledge.”
The Yanesha live a few hundred meters above sea level at the headwaters of the Amazon basin in central Peru. They possess traditional knowledge about one of the most diverse tropical rainforests in the world. Salick studied the cocona, a nutritionally important fruit native to the upper Amazon. She found the Yanesha have increased the genetic diversity of the species over time through preferential selection of oddly sized and shaped fruits.
The Yanesha also rely on species richness and diversity in indigenous agriculture and forestry management. They plant more than 75 species of crops in home gardens and more than 125 species in swidden fields (an ecological and sustainable system of traditional agriculture) to protect against potential crop destruction from pests, disease or weather. This biodiversity includes species rarely grown outside of indigenous agriculture. Studies have concluded that the species diversity in indigenous agriculture is unparalleled in modern agriculture and forestry, which often reduces natural diversity rather than enhancing it.
In contrast, the Tibetans dwell on the slopes of sacred Mt. Khawa Karpo and the upper Mekong River. Tibetan traditional knowledge, like that of the Yanesha of the Amazon, has long emphasized adaptation and biodiversity, and is now challenged by climate change.
Tibetans depend on biodiversity and entire landscapes for their livelihoods. Salick’s team measured the biodiversity on Mt. Khawa Karpo by sampling vegetation along vertical transects up the mountain. They found tremendously high variation of plant species at different elevations. These diverse alpine mountain ranges are also among those most likely to suffer critical species losses as the result of global climate change. Contemporary photos of the Himalayas show exceptional glacial retreat and tree line and shrub advance, more so than other alpine areas around the globe. Some of the most threatened, slow-growing plants such as the endemic snow lotus, used to treat blood pressure and hemorrhaging, could become extinct while more common “weedy” species take over and lessen the region’s biodiversity. But, Tibetans are adapting. They now grow grapes, which previously could never survive the severity of Himalayan winters, to make wine – ice wine is their specialty. They are mitigating climate change by incorporating large quantities of organic matter into soil, conserving forests that are expanding (afforestation) and preserving sacred areas with high biodiversity and old-growth forests.
As the U.S. and other developed nations debate the merits of climate change and other controversial subjects, I feel it’s important we pay attention to so-called primitive culture like the Yanesha and the Tibetans. They’ve apparently been doing something right. Otherwise, they wouldn’t have been able to survive all these centuries.