To watch people trying to get to the nuts was incredibly amusing. First, generally a man would take the machete and try to lodge the blade into the nut. It would take numerous tries before the blade would actually stick. Next, they would bring the nut stuck in the blade to a hard surface, like a tree stump and continue to pound away at it. Almost always the nut would come unlodged from the blade, roll away and the nut cracker would start again. Finally, after repeated attempts, the nut would burst open like a piñata and the nuts inside would scatter across the ground.
For squirrels that lacked machetes and opposable thumbs, there is a small opening in the capsule where the squirrels can gnaw open the casing and get the nuts inside. After eating a nut or two, the squirrel needs to save the rest for another meal and buries the nuts but it forgets where he buried it and it grows into a tree.
The trees are gigantic and grow to be 160 ft tall. We climbed stairs 100 feet up to a canopy stand and gazed out across all the tree tops and the brazilian tree stood tall and much higher than the tops of all the trees below it.
So while it's great that the trees aren't logged and the South America countries can produce income from just the nuts, major harvesting of the nuts is still a detriment to the environment and the continuation of the brazilan nut tree.