This document discusses different aspects of the environment and ecosystems. It defines environment and describes how human waste can pollute the air, water and soil. It explains the differences between biodegradable and non-biodegradable waste. It also defines ecosystems and their components, including biotic and abiotic factors. Food chains and food webs are described. The three R's of reduce, reuse and recycle are presented as ways to help the environment. Stakeholders in forests are identified. The uses of water and impacts of human activities on water availability are noted. Different methods of water harvesting are outlined.