Ecological balance
The physical and biological set-up in which the interactions needed for the life of living things take place can be called the environment.
The physical part
Soil, water and air
Temperature, pressure, humidity and sunlight are counted as environmental conditions.
The biological part
Animals, including humans
Plants and micro-organisms
Ecological balance
A balanced relationship works between living things and the physical environment they live in. This healthy relationship is called ecological balance.
Even a small change in the environment affects its survival, and the environment has the ability to restore such changes to their original state. But today, fast-moving human activity has created a situation in which ecological balance can no longer be kept.
Why the balance can mend itself — up to a point
Think of a paddy field after a dry spell. Fewer insects hatch, so fewer frogs are fed and their numbers fall; when rain returns, insects recover, and so do the frogs. Each part pushes the others back towards where they were. Nature's corrections are slow, though, working over seasons. Clearing a forest for a road, draining a marsh or pouring waste into a river happens in weeks, far faster than the environment can repair. This chapter looks first at how the living world is organised and how energy and materials move through it, and then at what human activity is doing to that balance and how it can be protected.
Balance is not stillness
A balanced environment is always changing — numbers rise and fall, seasons come and go. What stays steady is the overall pattern, because the changes keep correcting each other.
Living and non-living in balance
Ecological balance is the healthy relationship between living things and their physical environment. Rapid human activity is now upsetting it.