Economy THE DELICA BALANCE OF LIFE ON EART one or more elements that coexist in various habitats Every inhabitant must be accounted for because each has a role to play The sub title of this book is right on target Life on Earth is a balancing act one so delicate that any disruption to even the smallest living or nonliving element can have a ripple effect upsetting the balance in several areas As shown in these pages ecologists use applied methodology and experimentation to exam ine activity within the various types of life groups Doing so allows them to figure out if everything is running smoothly and identify where trouble spots might occur How ecologists study the environment also requires a multipronged approach For scientific purposes the Earth is divided into several life sustaining layers The largest is the biosphere which is the thin life supporting stratum of Earth's surface The biosphere can be broken down into major life ones called biomes But in order to fully understand how plants and creatures interact with one another ecologists break things down even further The majority of ecologists focus their studies on a smaller scale at the population community and ecosystem
INTRODUCTION At the population level ecologists study interactions within one particular species They can gauge the balance of various pop ulations by observing the size density and distribution of each Communities provide details of how two or more species interact and what effect this has on the community as a whole The examination of ecosystems shows how species of plants and animals interact with their physical surroundings The flow of energy and nutrient cycling are the two most important factors at this level A lot has changed since Haeckel first coined the term ecology As threats such as pollution species extinction and global warming have cast their long shadows over the planet the ecological sciences have grown in importance becoming a linchpin in international efforts to maintain and restore the environment to its natural state Most likely ecology will be providing clues to the stability of the natural world for some time to come After all the life of every organism on Earth may very well hang in the
THE NATURE OF ECOLOGY he study of the ways in which organ isms interact with their environment is called ecology The word ecology was coined in 1869 by the German zoologist Ernst Haeckel who derived it from the Greek oikos which means household Economics is derived from the same word However eco nomics deals with human housekeeping while ecology concerns the housekeeping of the natural world For many years most people did not con sider ecology to be an important or even a real science By the late 20th century how ever ecology had emerged as one of the most popular and important areas of biology The effect of the environment on the organisms that inhabit it and vice versa is now acknowl edged as a key element in a wide range of issues including population growth climate change environmental pollution species extinction and human health and medicine Many public health specialists are incorporating an ecological component in IO
THE NATURE OF ECOLOGY Ernest Haeckel Hulton Archive Getty Images II
