Introduction to ecology

Hey you! Yes you! Have you thought about your place in the world? Do you feel lonely, or wonder about the meaning of it all? What difference you make?

These are things everyone thinks about and wants answers to. But maybe there's comfort in knowing that everything on the planet is connected. Animals - such as humans - plants, bacteria, even the air we breathe, and the ground we walk on: everything affects everything else. We are going to look at some parts of a savannah ecosystem. An ecosystem is a community of living organisms, linked with the nonliving parts of their surroundings, for example temperature, bedrock, soil and the accessibility of water and nutrients.

Of course you're not a lion or an antelope, or absolutely not a tuft of grass. But stick around and you will hear how parts of life on the savannah are connected. The grass, herbivores, and predators are parts of the ecosystem here. The number of animals that can live in it partly depends on the amount of grass and other plants that can grow in the system. If, for a time, grass grows well on the savannah, there's more food for the herbivores, and they can multiply.

And when there's more herbivores, there's more prey for the predators, so they can multiply as well. As the number of predators increases, they kill and eat more of the herbivores. Meanwhile, a lot of the grass has been eaten. This means that there are fewer herbivores again. And then there will also be fewer predators.

In a bad year, when temperature, weather, or water accessibility limits grass growth, there will be fewer herbivores, and then the predators will again be reduced in number. However, if there's just the right amount of rainfall and sunshine, the grass growth will increase again! The effects of animals, plants, and other organisms on each other and their surroundings are called biotic factors. When things in the surroundings affect animals, plants, or other organisms - and they're non-biological - they are called abiotic factors. Among other things these include: temperature, bedrock, weather, and the amounts of accessible water or nutrients.

Everything is connected, and as all things are so closely interlinked, nothing is ever stable. Everything is in a constant state of change - for example when seasons progress. In nature there is ongoing, constant competition, both within species and between different species. It is the biotic and abiotic factors that provide the conditions for this competition. The herbivores compete for grass and the predators for herbivores.

Some individuals have traits that give them an edge in the competition. When new traits emerge - and are passed on - the species develop. This is called evolution. Evolution gives rise to new specializations, which leads to increased biodiversity. So you could say that ecology is evolution in operation, since ecology provides the limitations on who will be able to spread their genes.

And evolution, of course, applies to us humans as well. Everything on Earth is connected and affects everything else. Studying ecology is trying to understand how living things - biotic factors, and non-living things - abiotic factors, interact and impact each other. And in order to do so, it's not enough just to look at the biological pieces, we also have to include the sciences of geography and geoscience. When we put on our ecological glasses we view things from an holistic perspective, where the different parts, put together, form a more detailed picture.

A picture of life! Life on Earth!