Soils of southern South America, including Patagonia, have endured a high frequency of disturbances from volcanic eruptions, earthquakes, landslides, and erosion. In addition, massive fires in the mid-20th century were set to forests in the region in an effort to promote colonization. In 2010, another 17,000 acres of Patagonia burned, fueling an international reforestation effort. Although the young soils of southern South America may contain high phosphorus levels, the element is tightly bound to the soil, offering limited phosphorus available to plants.
So how can plants in this area take root and access that phosphorus?
According to a recent article published in the American Journal of Botany, scientists have identified a mechanism enabling a native tree species access to this limiting nutrient. As a result, the Chilean fire bush (Proteaceae, Embothrium coccineum), a tree endemic to Chile and Argentina, could have an important role in the reforestation of Patagonia. In the wild, E. coccineum colonizes highly disturbed land where other tree species rarely occur. Proteaceae species, common in the southern hemisphere, are known for a root structure adaptation that increases phosphorus acquisition from weathered, phosphorus-poor soils. The greater surface area of cluster roots increases root exudates of organic acids and phosphatases. These exudates enhance plant phosphorus acquisition from unavailable forms in the soil.
"I was particularly curious of the ecological role of this root adaptation," explained Frida Piper, a terrestrial ecosystem ecologist at the remote research center Centro de Investigacin en Ecosistemas de la Patagonia (CIEP) in Coyhaique, Chile. Piper designed a field study to better understand the role of cluster roots of E. coccineum across a natural precipitation and phosphorus gradient in it
|Contact: Richard Hund|
American Journal of Botany