1.1 History of ecology

The term ecology was proposed by German Ernst Haeckel (1834—1919, Fig.1.1.1 and Table 1.1.1) in 1866. It came from two Greek words “oikos” meaning home and “logos” meaning understanding or study. Haeckel was a biologist, naturalist, philosopher, physician, professor and artist who discovered, described and named thousands of new species, mapped a genealogical tree relating all life forms, and coined many terms in biology. He described ecology as “the domestic side of organic life” and “the knowledge of the sum of the relations of organisms to the surrounding outer world, to organic and inorganic conditions of existence”.

Fig. 1.1.1　Ernst Haeckel

In fact, ancient Greek philosophers such as Hippocrates and Aristotle laid the foundations of ecology in their studies on natural history. Antonie van Leeuwenhoek (1632—1723) is best known for his work on the improvement of the microscope, but also first proposed the concept of food chains. Alexander von Humboldt (1769—1859, Fig.1.1.2) was the first to take on the study of the relationship between organisms and their environment. He is often considered a father of ecology. He exposed the existing relationships between observed plant species and climate, and described vegetation zones using latitude and altitude, a discipline now known as geobotany. The roots of scientific ecology may be traced back to Darwin (1809—1882). This contention may look convincing at first glance inasmuch as On the Origin of Species is full of observations and proposed mechanisms that clearly fit within the boundaries of modern ecology.

Fig. 1.1.2　Alexander Humboldt

Eugenius Warming (1841—1924) devised a new discipline that took biotic factors, such as drought, fire, salt, and cold, as seriously as biotic factors in the assembly of biotic communities. It explained why species occupying similar habitats, experiencing similar hazards, would solve problems in similar ways, despite often being of widely different phylogenetic descent. Warming gave the first university course in ecological plant geography.

Table 1.1.1 Key ecologist in the history of ecology

In the 19th century, ecology blossomed due to new discoveries in chemistry, notably the nitrogen cycle. After observing the fact that life developed only within strict limits of each compartment that makes up the atmosphere, hydrosphere, and lithosphere, the Austrian geologist Eduard Suess (1831—1914) proposed the term biosphere in 1875. The biosphere includes, for example, flora, fauna, minerals, matter cycles. In 1927 Charles Elton (1900—1991, Fig.1.1.3) defined ecology as scientific natural history in his book Animal Ecology.

Fig. 1.1.3　Charles Elton

It was in 1935 that Arthur Tansley (1871—1955), the British ecologist, coined the term ecosystem, the interactive system established between the biocoenosis (the group of living creatures), and their biotope, the environment in which they live. Ecology thus became the science of ecosystems. Tansley’s concept of the ecosystem was adopted by the energetic and influential biology educator Eugene Odum (1913—2002, Fig.1.1.4). Along with his brother, Howard T. Odum (1924—2002), Eugene wrote a textbook Fundamentals of Ecology, published in 1953, which educated more than one generation of biologists and ecologists. He defined ecology as the study of the structure and function of nature.

Fig.1.1.4　Eugene Odum

In 1972, Charles Krebs defined ecology as the scientific study of the interactions that determine the distribution and abundance of organisms in his book Ecology: The Experimental Analysis of Distribution and Abundance.

These and other notable figures and major contributions in the development of ecology are listed in Table.1.1.1.

In Oxford Dictionaries, ecology is the branch of biology that deals with the relations of organisms to one another and to their physical surroundings. In Wikipedia, ecology is the scientific study of the relationships that living organisms have with each other and with their natural environment. In Merriam-Webster the definition of ecology is the study of the relationships between organisms and their environment.

The subject matter of ecology is normally divided into four broad categories: physiological ecology, having to do with the response of single species to environmental conditions such as temperature or light; population ecology, usually focusing on the abundance and distribution of individual species and the factors that cause such distribution; community ecology, having to do with the number of species found at given location and their interactions; and ecosystems ecology, having to do with the structure and function of the entire suite of microbes, plants, and animals, and their abiotic environment, and how the parts interact to generate the whole.

Ecology is an interdisciplinary field that includes biology and earth science. It is not synonymous with environment, environmentalism, natural history, or environmental science. It is closely related to evolutionary biology, genetics, and ethology. Ecologists seek to explain: life processes and adaptations; distribution and abundance of organisms; the movement of materials and energy through living communities; the successional development of ecosystems, and the abundance and distribution of biodiversity in the context of the environment.

Ecology is a human science as well. There are many practical applications of ecology in conservation biology, wetland management, natural resource management (agroecology, agriculture, forestry, agroforestry, and fisheries), city planning (urban ecology), community health, economics, basic and applied science, and human social interaction (human ecology).