ECOSYSTEMS OF THE BIOSPHERE

History of the science of Ecology Exploration and collections Succession Food webs, the Biosphere, and the Ecosystem concept Focus on aquatic systems as environments Abiotic and biotic aspects of streams & lakes

ECOSYSTEM

No true ecology prior to the Darwinian revolution; however, many strands of thought began to be formed before the science of ecology came into its own in the early 20th century. These were applied to the old discipline of Natural History, a major part of Aristotelian philosophy.

Carl von Linné (Carolus Linnaeus) Provided a means to order the array of living things, thus providing the basis by which the diversity of life could be catalogued Proposed that nature was in balance, an economy of nature 1707-1778; Sweden

Voyages of Exploration Friedrich Wilhelm Heinrich Alexander von Humboldt (1769-1859) explored the Americas and stated principle of diversity gradient from the equator to the poles Inspired explorations of Darwin, Wallace, Huxley, Haeckel and many others

Ernst Heinrich Philipp August Haeckel Prolific writer and naturalist Coined the term Ecology, which means the study of the house. Haeckel (1834-1919, Germany) in the Canary Islands with his collecting assistant

Johannes Eugenius Bülow Warming One of the founders of the science of ecology Studied the ecology of plants in Denmark Expeditions to Scandinavia, South America, and Western Europe Beyond description he related how plants, though from different parts of the world and unrelated, solve environmental problems in similar ways. 1841-1924; Denmark

Stephen Alfred Forbes Illinois Natural History Survey The Lake as a Microcosm (1887) One of the earliest ecosystem studies The first indispensable requisite is a thorough knowledge of the natural order—an intelligently conducted natural history survey. Without the general knowledge which such a survey would give us, all our measures must be empirical, temporary, uncertain, and often dangerous (Forbes 1880). 1844-1930, USA

Types of Succession Primary Secondary Seasonal

Primary and Secondary Succession

Cowles, Clements, and Gleason Henry Chandler Cowles (1869-1939, USA) built on Warming’s work and studied succession of vegetation on dunes of Lake Michigan Frederic Edward Clements (1874-1945, USA) worked on prairie grasslands and thought of communities as living entities that return in a predictable, deterministic way through succession (theory held sway until 1960’s) Henry Allan Gleason (1882-1975, USA) challenged deterministic approach and suggested that succession was the collective change by all individual species and, therefore, not predictable

Charles Sutherland Elton Founded areas of Population and Community ecology Modern concept of the food web 1900-1991; Britain

FOOD WEBS

Law of Tolerance Justus von Leibig (1803-1873, Germany) and Law of the Minimum Victor Ernest Shelford (1877-1968, USA) and Law of Tolerance Worked with Cowles and became president of Illinois Natural History Survey, the first president of the Ecological Society of America, and a founder of the Nature Conservancy (because the ESA refused to take a political stance regarding conservation)

Vladimir Ivanovich Vernadsky Founder of biogeochemistry Began to look at the world as a living system in which elements were cycled Ecology is the science of the biosphere Though term had been coined by Eduard Suess (1831-1914, Austria) in 1875 (the place where life dwells), Vernadsky gave it the modern meaning in 1926 1869-1939, Ukraine and USSR

George Evelyn Hutchinson Zoologist who became interested in biogeochemistry of lakes Discovered Vernadsky and extended work of Forbes Place of each living thing in its ecological setting Taught at Yale for 43 years without Ph.D. Provided theoretical foundation for aquatic ecology Defined niche concept 1903-1991; Britain and USA

Raymond Laurel Lindeman Post doctoral student of Hutchinson Defined 10% Law for food pyramid in Cedar Creek Ecosystem in Minnesota 1915-1942, USA

The Brothers Odum Howard Thomas Odum (1924-2002; known as H.T.) was a student of G.E. Hutchinson One of the founders of systems ecology Together with his older brother, Eugene Pleasants Odum (1913-2002), who was a student of V. E. Shelford, modeled an ecosystem as energy flow through a system.

ENERGY FLOW IN THE ECOSYSTEM Ecosystem, a term coined by Arthur George Tansley (1871-1955, Britain) in 1935. Though the organisms may claim our prime interest, when we are trying to think fundamentally, we cannot separate them from their special environments, with which they form one physical system.

Biomes Concept pioneered by Shelford and Clements and modified by ecosystem paradigm

Streams and Lakes

John Wesley Powell Fought in the Civil War and lost his right arm Professor of Geology at Illinois Wesleyan University Explored the western US Two explorations of the Colorado River 2nd director of USGS The importance of considerations of water in the development of the west (not heeded) 1834-1902, USA

Luna Bergere Leopold Son of Aldo Leopold (1887-1948, USA) Preeminent geomorphologist and hydrologist in USA Management of aquatic systems can only be successful if based on geology, hydrology, and biology 1915-2006, USA

Parts of a Stream & River Continuum Concept

Life in a Stream

Life in a Lake

Lago di Monterosi Susquehanna River