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Live fast, die small: how global heating is simplifying the world’s ecosystems

Source: theconversation.com

Global warming is one of the biggest threats to biodiversity worldwide. As temperatures increase, many species are forced to move to new habitats, like fish fleeing warming waters. While the fish have to adapt to new conditions elsewhere, it’s the effect that their departure has on other species that unpicks the delicate relationships that comprise ecosystems. Seabird colonies which were accustomed to finding fish in a particular place may soon find their food source has moved on to cooler waters further north.

But increasing temperatures have direct effects on individual organisms, too. Metabolism, respiration and reproduction all happen at a faster rate under warmer conditions. This means that animals reach their reproductive age faster and attain a smaller size. The average body size within populations shrinks over time as a result.

These individual changes have ecosystem-wide consequences. Experiments have shown that species don’t tend to get smaller in synchrony across the food web. Instead, prey species shrink faster relative to their predators as habitats warm, and these larger predators need to eat more of a given prey population to maintain their numbers. MORE

Header image: As their prey get smaller, predators will have to eat more to sate their appetite. Credit: FiledIMAGE/Shutterstock.