Sometime in the 19th century, Ernest Haeckel, a naturalist, came up with the word ‘ecology’ to draw attention to something that he thought was important: the ‘entire relations’ of an organism. By this, he meant that it was not enough to study one plant or animal species at a time. He believed it was important to study not only the organism but also its relationships with other living organisms and how it interacts with non-living things like climate, water, soil and light.
This came from the idea that an organism’s home (habitat or surroundings) has a great influence on its form (what a plant or animal looks like) and its behaviour (how it grows, moves, communicates and so on).
Ecology is derived from the Greek ‘oikos’ which means home or household. It is the study of the relationships that exist among living things and between living things and their environment. This includes both non-living things like water, soil, climate and minerals, and other organisms that are of the same or different species.
All plants, animals, fungi and microorganisms form a complex web of relationships—an ecosystem—that supports their survival. Interactions occur at many levels and there are different types of relationships.
A group of the same species living in an area make up a population. Think, for example, of the myna birds you see anywhere near your home: together they make up your neigbourhood’s myna population.
Ecologists can study populations of organisms, examining their behaviours, their adaptations to their habitats, and how their numbers change over time and geographic regions. Some ecologists will spend years studying individuals in a population. They will record their births and deaths, diets, movements, and the impact they have on their surroundings.
Plants or animals also interact with other species in their habitats. A community is a set of several, different species that occupy a given area.
Take a simple house garden. Its trees, flowering shrubs, grass, worms, birds, bees, butterflies, snails, moss and mushrooms form a small community. As a community, they interact with each directly (bees feeding on flower nectar) and indirectly (worms dig through soil and this makes it better for plants to grow later).
Communities can be as small as that of a thinly-populated backyard garden or be found within huge national forests.
Interactions within communities involve processes like pollination, decomposition, and feeding. These benefit the organisms and also provide many services for us. Ecosystem services include:
- food and fuel provision
- fresh water supply
- pest and pathogen control
- soil improvement
- climate regulation
Ecologists study such relationships and their outcomes, exploring how ecosystems are formed and how they are sustained. Thus, ecology studies contribute to a wide range of fields and practices including agriculture, conservation, natural resource management and sustainable development.
Here are some of the questions that ecologists try to answer:
- How do behaviour and physiology change in response to the physical environment?
- How do organisms use the resources in their habitats?
- How will ecosystems respond to human activities?
- How can we restore degraded ecosystems?
As the world deals with changing environmental conditions, pollution, food security and species loss, ecology helps us understand ecosystems and how to protect them—for our own well-being and that of the planet.
Egerton, F.N. (2013), History of Ecological Sciences, Part 47: Ernst Haeckel’s Ecology. The Bulletin of the Ecological Society of America, 94: 222-244. doi:10.1890/0012-9623-94.3.222
You can learn more about ecology and ecosystems closer to home here: