The document discusses human influence on ecosystems, including how the increasing human population over the past 300-1000 years has led to significant destruction of plants and animals. As population rose, consumption of resources also increased, depleting the Earth's natural resources. The document defines renewable resources as those that can replenish, such as through biological reproduction, compared to nonrenewable resources like fossil fuels. Pollution from human activity disrupts the environment. Conservation aims to balance human usage of the Earth's resources with maintaining ecological relationships.