What is the Biosphere?
The biosphere is defined either as “the place on earth’s surface where life dwells” (Edward Suess’ original 1875 definition) or in a more narrow sense as just the organisms themselves. The total global biomass is at least 3 trillion tonnes, probably more. The global total of above-ground woody biomass is approximately 422 billion tonnes. Human biomass is about 500 million tonnes, somewhat less than that of Antarctic krill. Biomass produced for human use exceeds three trillion tonnes. The bacterial biomass is estimated to be similar to that of plants. Complicating biomass measurements is that different researchers may publish figures of “dried biomass,” leaving out the weight of water, without explicit mention. In general, biomass is greater near the Equator and less near the Poles. Since at least 2.7 billion years ago, during the so-called the Oxygen Catastrophe, the biosphere has been intimately linked with the hydrosphere (oceans), lithosphere (crust), and atmosphere (air) of the pla
The biosphere is made up of all that is living on earth, from the smallest bacterium to the largest whale. It includes between 3 and 30 million species of plants, animals, and fungi, and also two kinds of single-celled living things: those without nuclei (“prokaryotes”) such as bacteria, and those with nuclei (“eukaryotes”) such as protozoans. The biosphere extends over the Earth’s surface in a thin layer from a few kilometers into the atmosphere, in very cold environments, to the deep-sea vents of the ocean depths, in very hot environments. (U.S. Fish & Wildlife Service/J & K Hollingsworth) The biosphere is a life-supporting global ecosystem, where each living things depends on each other and the environment. The ecosystem includes all living organisms and the abiotic or nonliving environment on which they depend for their energy and the nutrients they need to live. (U.S. Fish and Wildlife Service/Bruce Batten) (U.S. Fish and Wildlife Service/J.D.
The biosphere is the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform. From the broadest biophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere, and atmosphere. This biosphere is postulated to have evolved, beginning through a process of biogenesis or biopoesis, at least some 3.5 billion years ago.
Let us begin with clarifying what is meant by the term biosphere before we get into the questions posed above. The biosphere is the totality of all regions of the earth that support ecological systems, or more simply put: all those regions on the planet that support and are affected by life. The biosphere is made up of parts of the atmosphere (air), the hydrosphere (the realm of water), and the lithosphere (the solid portions of the earth, rocks). So, “Why are geographers interested in the processes occurring in the biosphere?” First of all, not all geographers are. There are really two kinds of geographers that are interested in the biosphere, one more directly than the other. The members of the first group would call themselves “biogeographers” because they look at the biosphere through geographical “glasses.” We’ll come back to that below. The other group, which is more broadly and more loosely defined, is made up of those geographers whose work falls into the nature-society traditi
