A lowland European bison grazes at a park on the outskirts of Europe's last ancient forest, the Bialowieza Primeval Forest July 23, 2009. The 150,000-hectare (380,000-acre) forest, home to Europe's largest herd of bison, faces an uncertain future because of climate change, but residents worry that tougher conservation efforts will damage the local economy. To match feature POLAND-FOREST/ REUTERS/Peter Andrews (POLAND ENVIRONMENT BUSINESS ANIMALS)