Complex sentence: Forests provide ecosystem services to humankind; however, human dependence upon these services has economic, environmental, health, and aesthetic consequences, as human interactions with the forest, including harvesting forest resources, affect the forest ecosystem.
Split into simpler sentences: Forests provide ecosystem services to humankind, but human dependence upon these services also imposes economic, environmental, health, and aesthetic costs. Human interactions with the forest, including harvesting forest resources, affect the forest ecosystem.