Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects
Abstract Background Many aquatic insects emerge as adults from water bodies to complete parts of their life cycle in terrestrial ecosystems and are potential prey for riparian predators. The benefits of riparian predators from aquatic insects include higher contents of long-chain polyunsaturated fat...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-01-01
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| Series: | Environmental Sciences Europe |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12302-023-00831-3 |
| _version_ | 1797355952901455872 |
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| author | Katharina Ohler Verena C. Schreiner Lukas Reinhard Moritz Link Matthias Liess Werner Brack Ralf B. Schäfer |
| author_facet | Katharina Ohler Verena C. Schreiner Lukas Reinhard Moritz Link Matthias Liess Werner Brack Ralf B. Schäfer |
| author_sort | Katharina Ohler |
| collection | DOAJ |
| description | Abstract Background Many aquatic insects emerge as adults from water bodies to complete parts of their life cycle in terrestrial ecosystems and are potential prey for riparian predators. The benefits of riparian predators from aquatic insects include higher contents of long-chain polyunsaturated fatty acids (PUFA) compared to terrestrial insects. Aquatic insects are therefore considered a high-quality food. Food containing high levels of PUFA can enhance growth and immune response of spiders. However, agricultural stressors like nutrient increase, pesticides and habitat degradation can affect the biomass of aquatic insects and in turn the diet of spiders. Studies quantifying the influence of land use on fatty acid (FA) profiles of emergent aquatic insects and riparian predators are lacking. We quantified differences in exports of FA, saturated FA, monounsaturated FA, and PUFA, FA profiles of aquatic insects and spiders between forested and agricultural sites over the primary emergence period within one year. The FA export to the riparian food web is crucial to understand energy fluxes between ecosystems. Furthermore, we monitored environmental variables to identify associations between agricultural stressors and FA profiles of aquatic insects and spiders. Results We found differences in FA export and profiles of aquatic insects between land-use types. The quantity of total FA export via aquatic insects was lower in agricultural sites (95% CI 1147–1313 µg m−2) in comparison to forested sites (95% CI 1555–1845 µg m−2), while the biomass export was higher in agricultural sites. Additionally, in spring the PUFA export was significantly lower (up to 0.06 µg d−1 m−2) in agricultural than forested sites. Agricultural stressors explained only little variation in the FA profiles of aquatic insects, e.g., 4% for caddisflies and 12% for non-biting midges. Percentage of shading and pool habitats were identified as most important variables explaining the variation in FA profiles. Conclusion The quality of aquatic insects as food source for riparian spiders was smaller in agricultural than forested sites, which can decrease the fitness of riparian predators. To improve our capacity to predict potential adverse effects in the riparian food web, future studies should identify the mechanisms underlying a lower PUFA content. |
| first_indexed | 2024-03-08T14:18:37Z |
| format | Article |
| id | doaj.art-e2820c842ebd4e768760a86f024997bf |
| institution | Directory Open Access Journal |
| issn | 2190-4715 |
| language | English |
| last_indexed | 2024-03-08T14:18:37Z |
| publishDate | 2024-01-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Environmental Sciences Europe |
| spelling | doaj.art-e2820c842ebd4e768760a86f024997bf2024-01-14T12:15:21ZengSpringerOpenEnvironmental Sciences Europe2190-47152024-01-0136111610.1186/s12302-023-00831-3Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insectsKatharina Ohler0Verena C. Schreiner1Lukas Reinhard2Moritz Link3Matthias Liess4Werner Brack5Ralf B. Schäfer6iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-LandauiES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-LandauiES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-LandauiES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-LandauDepartment System-Ecotoxicology, Helmholtz Centre for Environmental Research, UFZDepartment Effect-Directed Analysis, Helmholtz Centre for Environmental Research, UFZiES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-LandauAbstract Background Many aquatic insects emerge as adults from water bodies to complete parts of their life cycle in terrestrial ecosystems and are potential prey for riparian predators. The benefits of riparian predators from aquatic insects include higher contents of long-chain polyunsaturated fatty acids (PUFA) compared to terrestrial insects. Aquatic insects are therefore considered a high-quality food. Food containing high levels of PUFA can enhance growth and immune response of spiders. However, agricultural stressors like nutrient increase, pesticides and habitat degradation can affect the biomass of aquatic insects and in turn the diet of spiders. Studies quantifying the influence of land use on fatty acid (FA) profiles of emergent aquatic insects and riparian predators are lacking. We quantified differences in exports of FA, saturated FA, monounsaturated FA, and PUFA, FA profiles of aquatic insects and spiders between forested and agricultural sites over the primary emergence period within one year. The FA export to the riparian food web is crucial to understand energy fluxes between ecosystems. Furthermore, we monitored environmental variables to identify associations between agricultural stressors and FA profiles of aquatic insects and spiders. Results We found differences in FA export and profiles of aquatic insects between land-use types. The quantity of total FA export via aquatic insects was lower in agricultural sites (95% CI 1147–1313 µg m−2) in comparison to forested sites (95% CI 1555–1845 µg m−2), while the biomass export was higher in agricultural sites. Additionally, in spring the PUFA export was significantly lower (up to 0.06 µg d−1 m−2) in agricultural than forested sites. Agricultural stressors explained only little variation in the FA profiles of aquatic insects, e.g., 4% for caddisflies and 12% for non-biting midges. Percentage of shading and pool habitats were identified as most important variables explaining the variation in FA profiles. Conclusion The quality of aquatic insects as food source for riparian spiders was smaller in agricultural than forested sites, which can decrease the fitness of riparian predators. To improve our capacity to predict potential adverse effects in the riparian food web, future studies should identify the mechanisms underlying a lower PUFA content.https://doi.org/10.1186/s12302-023-00831-3AgricultureForestFatty acid profilesEmergent aquatic insectsSpiders |
| spellingShingle | Katharina Ohler Verena C. Schreiner Lukas Reinhard Moritz Link Matthias Liess Werner Brack Ralf B. Schäfer Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects Environmental Sciences Europe Agriculture Forest Fatty acid profiles Emergent aquatic insects Spiders |
| title | Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects |
| title_full | Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects |
| title_fullStr | Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects |
| title_full_unstemmed | Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects |
| title_short | Land use alters cross-ecosystem transfer of high value fatty acids by aquatic insects |
| title_sort | land use alters cross ecosystem transfer of high value fatty acids by aquatic insects |
| topic | Agriculture Forest Fatty acid profiles Emergent aquatic insects Spiders |
| url | https://doi.org/10.1186/s12302-023-00831-3 |
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