The Biosphere

The biosphere, which allows life to exist on earth, is the thin layer of air (the atmosphere), water (hydrosphere), and soil and rock (lithosphere) that surrounds the planet. The biosphere includes any place on, above, below, or within the earth's surface where life can be found. The living part of the biosphere is called the biotic component and includes everything from plants to insects. The nonliving, or abiotic component, includes the physical characteristics of the biosphere, like soil, air, and water. The biosphere is regulated by the cycling of minerals and water between the abiotic and biotic components. Humans have an impact on this regulation.

The study of the biosphere is divided into several scientific disciplines, or areas of study. For example, chemistry is the science that studies subatomic particles, atoms, and molecules. Biology is concerned with protoplasm, cells, tissues, and organ systems. Astronomy is the science that studies planets, stars, galaxies, and the universe.

These disciplines are all important for understanding the planet we live on; however, in this book we are concerned with the study of ecology. Ecology is the study of how all living things interact with one another and their nonliving environment. The study of ecology is concerned with five levels: organisms, populations, communities, ecosystems, and the biosphere. Organisms are individual living things that belong to the same species. Organisms of the same species that live in the same geographic area are called populations. A habitat is the place where the organism or population lives. A community includes all the populations of organisms that live and interact with one another in a given area at a given time. When scientists use the term ecosystem, they are referring to the interactions between a particular community and its physical environment.

We can no longer ignore the effect humans have on the planet. Even changes in places far away affect us and our environment. Our actions today may decide the future of the planet. The study of ecology increases our understanding of planet earth. You are now taking the first important step toward positive change for a healthier planet.

Дата добавления: 2014-11-20