Yasuni is often called the 'jewel of the Amazon'--arguably one of the most important national parks in the world, and quite possibly the most biologically diverse.
The park also overlays sizable petroleum deposits, estimated at 840 million barrels. To agree not to construct roads and drilling facilities in the park, Ecuador's president Rafael Correa wanted donors to pony up $3.6 billion.
Not surprisingly, that figure was ultimately too much for the international community to raise, although over $300 million was committed by various donors. So, in August 2013, Correa unilaterally canceled the no-drill-for-cash offer.
Many were upset by the outcome, including actor Leonardo DiCaprio. But it turns out it was probably just a faux deal anyway--a way for Correa to provide himself with political cover for his decision to drill away at Yasuni.
As badly as this reflects on Correa, China doesn't come out looking good either--although experienced observers won't be surprised. As we've seen again and again, China can be highly predatory in pursuing the natural resources it wants.
Sadly, one of the world's most important parks will suffer for it.