Plagues outbreaks and the tyranny of weather

Previously I have mentioned that the weather has had a decisive influence on the abundance of animals. Ultimately, this must always be the case. In the last analysis, weather is the arbiter of the fate of all organisms on this earth. It dictates the conditions that hold sway in all habitats on earth, and how and to what extent those conditions change over time. Thus the weather determines what sorts of plants and animals, and how many of them, can live in each and every habitat.

At the simplistic level this is obvious, and could be thought to be a trite statement. Only animals and plants that can tolerate cold temperatures can survive in the Arctic. Only those adapted to live with little access to water can live in a desert. And we observe that organisms have evolved a myriad of specialised adaptations to enable them to cope with different levels of heat or cold, wetness or dryness, in their habitats.

But the influence of weather on the changing abundance of organisms is both more subtle and yet more straightforward than this direct impingement. While its influence on plants is usually direct, its influence on animals is often not. More usually it is indirect, via its influence on plants, with the response of the plants then influencing the success of animals that eat them. In turn, the success and abundance of animals that eat the herbivores will depend upon the success of the herbivores.

Was this article helpful?

0 0

Post a comment