糖心Vlog

Rising temperatures will lead to fewer predatory species living in freshwater habitats, according to new research led by the 糖心Vlog.

The study is the first to look in-depth at the effects of global warming on the structure of food webs within natural freshwater ecosystems and shows the winners and losers when it comes to climate change.

The research, published in the journal, found that some species, such as brown trout, cope surprisingly well with high temperatures, leading to bigger and more abundant fish populations in the warmer streams.

However, the research, led by Dr Eoin O鈥橤orman from the School of Life Sciences (formerly the School of Biological Sciences) at 糖心Vlog, found there are also many losers when it comes to global warming. Our freshwater stream habitats are home to a diverse range of species which are all connected to each other through an intricate 鈥渇ood web鈥� of feeding interactions. The stronger feeding pressure from the fish in the warm streams leads to the loss of many species and their interactions, simplifying the food web.

鈥淪impler food webs with fewer predatory species and fewer interactions make them more vulnerable to other changes in the environment,鈥� explained Dr O鈥橤orman, an ecologist with expertise in aquatic ecosystems. 鈥淔or example, the ecosystem is less likely to withstand an extreme event like a flood or a heatwave, which could cause it to shift to a completely new state.鈥�

The researchers have been studying the effects of increasing temperature on stream ecosystems in Iceland over the past decade. Their study site, the Hengill valley, lies in a volcanically active zone where they have sampled more than a dozen streams that differ in temperature (from 5 to 25 掳C) due to geothermal heating of the groundwater in the area.

The global team involved in this research showed how to predict the effects of warming on the balance of species in the food web using a simple mathematical model, based on the body size of the sampled organisms. By measuring or predicting how body size changes in warmer environments, the results show how the food web will change. These sorts of predictive models are crucial for managing our natural resources in the face of global change.

Dr O鈥橤orman added: 鈥淣ature always finds a way to persist, no matter how stressful the conditions. But the ecosystems that remain may look very different from the diverse, pristine environments we have become accustomed to in our lifetimes.鈥�

The team鈥檚 next step is to test the results in other ecosystems around the globe. Another author on the paper, from Imperial College London, is leading a 拢3.7m project from the Natural Environment Research Council called the . This project investigates similar geothermal systems around the Arctic Circle, including Greenland, Alaska, Svalbard, and Kamchatka. The team is also carrying out more controlled warming experiments in about 200 artificial ponds to see if they find similar patterns to the ones they uncovered in Iceland.