Within the field of ecology, functional ecology looks specifically at the functions fulfilled by various species in the natural world. A fair amount of interdisciplinary study is involved in functional ecology, with people coming to it from perspectives such as ecology, genetics, evolutionary biology, biology, meteorology, and even fields such as urban planning. Researchers in this field look at nature as an interconnected system, and examine the roles played by each of its parts.
It has long been known that ecosystems are complex systems which balance the activities of the weather and the organisms which inhabit them, and ecologists have long viewed the environment holistically. Functional ecologists get intimate with specific organisms to learn more about what they do, how they do it, why they might have evolved to exhibit that behavior, and how they are impacted by surrounding organisms. This can include work in the field, observing organisms in nature, as well as in the lab, studying things like behavior in controlled conditions and changes which occur on a genetic level.
In a simple example of functional ecology, researchers might study the role of trees in an environment like the rainforest. Trees play an active functional role in the forest, providing habitat, creating microclimates, enriching the soil, and sometimes even cultivating beneficial organisms. While people don't usually think of trees as farmers, trees can actually farm in a sense by influencing what grows, or does not grow, underneath their canopies, and they will actively promote plants and other organisms which are beneficial.
One important aspect of functional ecology is in sustainability studies. People cannot know whether a given activity is sustainable until they fully understand how that activity influences the natural environment. Thus, it's important to look at how human activities impact organisms in nature, and whether or not that creates a ripple effect. Removing a predator, for example, might create an imbalance which destabilizes an ecosystem, in which case removal of predators might be considered unsustainable. Conversely, adding something to the ecosystem could be equally damaging.
People who are interested in functional ecology can study at a number of colleges and universities around the world, with the flagship scientific journal in the field being published in Britain. There are numerous job opportunities for functional ecologists, including both lab and field work in the employ of educational institutions, government agencies, and private companies such as conservation organizations. People who work in this field usually have an interest in the environment and the complex interconnected systems which make up the world around us.