This text explores the significant concepts of modern ecology using a minimum of jargon and only basic/simple mathematics. Focuses on the development of four major concepts including their historical background: energy flow; nutrient cycles; population ecology; and community ecology. Contains coverage of abiotic factors & including air, insolation, precipitation, soils, nutrients, ionizing radiation, and fire; energy flow (with increased emphasis on decomposition); nutrient cycling; population ecology; and community ecology. Updates material on applied ecology/human ecology and ecological ethics.