In situ short-term responses of Amazonian understory plants to elevated CO.

The response of plants to increasing atmospheric CO depends on the ecological context where the plants are found. Several experiments with elevated CO (eCO) have been done worldwide, but the Amazonian forest understory has been neglected. As the central Amazon is limited by light and phosphorus, understanding how understory responds to eCO is important for foreseeing how the forest will function in the future.