Clarification as I totally misunderstood your comment (possibly due to not knowing the relevance of the term basin here): The BBC article covering this article

Clarification as I totally misunderstood your comment (possibly due to not knowing the relevance of the term basin here): The BBC article covering this article describes this as being caused by deforrestation / dying trees. Part of the Anazon rainforrest is still a carbon sink and as a whole it is as well. But for how long? Note that the scientific paper (at least at the time of the BBC article) is yet to be published.