Biology

Insect and spider biodiversity increases organic nutrient availability across ecosystems, large-scale study shows

Sampling locations for aquatic and terrestrial arthropods throughout Switzerland. Credit: Science (2024). DOI: 10.1126/science.adp6198

Insects and spiders are important components of food webs in aquatic and terrestrial ecosystems. As an international research team led by Ehwag and WSL scientists recently demonstrated, as biodiversity declines, food supplies for birds, fish, reptiles, amphibians, and small mammals are not only in short supply, but also important. It has also been found that there is a deficiency in fatty acids.

Not only do animals need sufficient calories to function, they also need essential nutrients such as omega-3 and omega-6 polyunsaturated fatty acids (PUFAs). Insects and arachnids are important sources of these essential fatty acids for birds, hedgehogs, lizards, and more. However, its content varies depending on the specific type of insect or spider being consumed.

Aquatic insects such as caddisflies and dragonflies have far more omega-3 long-chain (LC) long-chain (LC) PUFA-rich algae than terrestrial insects, as PUFA-rich algae form the basis of the food chain in aquatic ecosystems. (LC) Contains PUFA. Fatty acid content can also accumulate throughout the food chain. Mayflies contain more fatty acids than the algae they feed on, but often less than the fish that prey on them.

There is existing research on this, and a lot of research has also been done on how plant and algal biodiversity affects the availability of biomass in ecosystems. “However, little is known about the influence of insect and arachnid biodiversity on the availability of fatty acids in the ecosystem’s food web,” said Ewag, head of the Food Web Ecophysiology Group at the Aquatic Research Institute in Zurich. says Cornelia Twining, a professor at the College of Engineering.

She and her colleagues aimed to fill this knowledge gap with a new study published in the journal Science.

Explore over 700 land and water ecosystems

The researchers used a dataset containing more than 500,000 observations of around 7,600 insect and spider species in Switzerland. The approximately 400 aquatic and 300 terrestrial ecosystems studied were located in natural habitats such as vast pastures and forests, while others were located in agricultural areas or in the middle of cities. Land use is different.

For each of these ecosystems, the researchers calculated the biomass and biodiversity of insects and arachnids, as well as the total amount of various key PUFAs they provided.

“We were interested in how land use shapes energy and nutrient availability and whether there are important differences between aquatic and terrestrial ecosystems,” says WSL Snow. said Ryan Shipley, a researcher at the Snow and Avalanche Research Institute SLF and lead author of the study.

“Land use change ranks among the most pressing global challenges, making it essential to understand how human activities impact fundamental ecosystem functions.” explains Shipley.

As biodiversity decreases, fatty acid content in food webs decreases

Data analysis revealed that biomass and content of major fatty acids decreased in all communities studied, along with a decrease in insect and spider biodiversity. “Even in terrestrial communities, we see big differences based on land use,” Twining says.

Even with the same biodiversity, insect and spider communities in urban parks typically have lower amounts of omega-3 LC-PUFA than in forested areas. “This is partly because the species composition of these populations is different, and partly because there is less biomass in urban areas. “They have fewer predators,” Twining said.

“What surprised us was that the effects of land use were less pronounced in aquatic communities. For a given number of species, urban streams have similar fatty acid content as forest streams. Masu.”

Researchers explain this by noting that aquatic insects generally contain higher amounts of omega-3 LC-PUFAs compared to terrestrial taxa. On land, the difference is more pronounced. When predators such as spiders that accumulate large amounts of essential fatty acids disappear from an ecosystem, the impact is substantial.

“But this doesn’t mean that aquatic insect biodiversity is any less important,” Twining says. On the contrary, aquatic ecosystems can be an important source of fatty acids for terrestrial food webs. Aquatic insects have become an even more important source of essential fatty acids for birds, bats, or lizards in urban areas where increasing human land-use pressures have particularly high losses of insects and spiders.

Unfortunately, this “superfood” is increasingly found in pollutants in streams, rivers, and lakes. “Our research shows how important it is to improve water quality to protect biodiversity and maintain food webs for ecosystem function, especially in agricultural and urban areas.” emphasizes Mr. Twining.

Further information: J. Ryan Shipley et al., Consumer biodiversity increases organic nutrient availability across aquatic and terrestrial ecosystems, Science (2024). DOI: 10.1126/science.adp6198

Provided by EAWAG: Swiss Federal Institute of Fisheries Science and Technology

Citation: Insect and spider biodiversity increases organic nutrient availability across ecosystems, large-scale study shows (October 23, 2024) https://phys.org/news/ Retrieved October 23, 2024 from 2024-10-insect-spider-biodiversity-nutrient-availability.html

This document is subject to copyright. No part may be reproduced without written permission, except in fair dealing for personal study or research purposes. Content is provided for informational purposes only.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button