Relationships between organisms and their environment

The word comes from the Greek oikos, meaning "home" or "place to live". The word ecology was coined by the German zoologist Ernst Haeckel, who applied the term ecology to "the relationship of an animal to both its organic and inorganic environment".

Thus, ecology deals with the organism and its environment, and the concept of ecology includes both other organisms and the physical environment, and includes the relationships between individuals within populations and between individuals of different populations, and these interactions between individuals, between populations, and between organisms and their environment form ecosystems or ecosystems.

Ecology has been variously defined as "the study of the interrelationships of organisms with their environment and with each other", "the economy of nature", and "the biology of ecosystems".

The later foundations of modern ecology were laid in the early work of plant and animal physiologists, in the early and mid-20th century, when two groups of botanists, one in Europe and the other in the United States, studied plant communities from different points of view.

European botanists were interested in studying the composition, structure, and distribution of plant communities, American botanists studied the development of plant communities, or succession (see Community ecology: Ecological succession), and both plant and animal ecology were developed.

There are many types of relationships between organisms and their environment. By organisms, one may mean individual individuals, groups of individuals, all members of a species, or the sum of many Of species, or the total mass of species (biomass) in an ecosystem. The term ecology includes not only the physical and chemical properties, but also the biological environment, which includes more living organisms. In practice, ecology consists of widely overlapping approaches and is divided into groups of species to be studied.

Scientists have wondered how some animals thrive in the driest deserts, where temperatures are often high and free-standing water is not available? How do bacteria survive in hot springs, which would cook most species? How do nematodes survive in the soil of the dry valleys of Antarctica?

Behavioral ecology studies the environmental factors that drive behavioral adaptations, the subject studies how individuals find food and avoid their enemies. For example, why do some birds migrate (see migration) while others remain? Why do some animals, such as lions, live in groups while others, such as tigers, live alone?

Controlled environmental chambers enable experimenters to maintain plants and animals under known conditions of light, temperature, humidity, and day length so that the effects of each variable (or combination of variables) on the organism can be studied. Bioassays and other electronic tracking equipment, which allow the movements and behavior of free-ranging organisms to be tracked remotely, can provide rapid sampling of populations. Radioisotopes are used to trace the paths of nutrients through ecosystems, to determine when and how much energy and nutrients are transferred through different components of an ecosystem, and to determine food chains.