The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists
There is a global concern over insect declines, including both species loss and population declines. In particular, declines of species, such as bees that anchor trophic interactions and shoulder many of the essential ecosystem services, have been the focus of broad public concern. However, our unde...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Insects |
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| Online Access: | https://www.mdpi.com/2075-4450/13/2/153 |
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| author | Claus Rasmussen Markus Arne Kjær Sydenham Hans Thomsen Schmidt Henning Bang Madsen |
| author_facet | Claus Rasmussen Markus Arne Kjær Sydenham Hans Thomsen Schmidt Henning Bang Madsen |
| author_sort | Claus Rasmussen |
| collection | DOAJ |
| description | There is a global concern over insect declines, including both species loss and population declines. In particular, declines of species, such as bees that anchor trophic interactions and shoulder many of the essential ecosystem services, have been the focus of broad public concern. However, our understanding of what characterizes those species that are lost because of declines over long periods is limited by a scarcity of comparative studies. We here compare the species composition from a collection of bees sampled over two decades (2000–2019) from the island of Lolland in Denmark, with a collection also sampled over two decades (1900–1919), but a century ago by Jørgensen and his contemporaries. We further test if (1) the probability that bee species that were sampled a century ago are also found today depends on their degree of floral specialization; (2) and use information from pollen samples from bees from the historical records to assess if certain floral resources have been lost. In total, 203 species were recorded in the two periods, but less than half, 92 species, occurred in both sampling periods. A total of 174 species of bees were recorded from 1900–1919, and 121 species were recorded from 2000–2019, including 29 species not reported in 1900–1919. Notably, we report a reduction in the species composition among forage specialist bees from 26.4% to 15.7% of the bee fauna, a consistent and highly significant decline both when correcting for parasitic and social species. Pollen swabs from bees collected in the first period, 1900–1919, did not identify any plants that are not available today but documented a series of plants that were important to bees back then. These plants are still common today, such as <i>Taraxacum</i> and <i>Salix</i>. Our findings highlight the importance of local and historical faunistic studies, such as that of Jørgensen, who was a resident schoolteacher on the island of Lolland in southern Denmark, for documenting how changes over time affect the species composition in bee communities. |
| first_indexed | 2024-03-09T21:42:34Z |
| format | Article |
| id | doaj.art-cd5ec211645f46eb88b932d23487830c |
| institution | Directory Open Access Journal |
| issn | 2075-4450 |
| language | English |
| last_indexed | 2024-03-09T21:42:34Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Insects |
| spelling | doaj.art-cd5ec211645f46eb88b932d23487830c2023-11-23T20:27:03ZengMDPI AGInsects2075-44502022-01-0113215310.3390/insects13020153The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the SpecialistsClaus Rasmussen0Markus Arne Kjær Sydenham1Hans Thomsen Schmidt2Henning Bang Madsen3Department of Agroecology, Aarhus University, 8830 Tjele, DenmarkNorwegian Institute for Nature Research (NINA), 0855 Oslo, NorwayIndependent Researcher, 7500 Holstebro, DenmarkDepartment of Biology, University of Copenhagen, 2100 Copenhagen Ø, DenmarkThere is a global concern over insect declines, including both species loss and population declines. In particular, declines of species, such as bees that anchor trophic interactions and shoulder many of the essential ecosystem services, have been the focus of broad public concern. However, our understanding of what characterizes those species that are lost because of declines over long periods is limited by a scarcity of comparative studies. We here compare the species composition from a collection of bees sampled over two decades (2000–2019) from the island of Lolland in Denmark, with a collection also sampled over two decades (1900–1919), but a century ago by Jørgensen and his contemporaries. We further test if (1) the probability that bee species that were sampled a century ago are also found today depends on their degree of floral specialization; (2) and use information from pollen samples from bees from the historical records to assess if certain floral resources have been lost. In total, 203 species were recorded in the two periods, but less than half, 92 species, occurred in both sampling periods. A total of 174 species of bees were recorded from 1900–1919, and 121 species were recorded from 2000–2019, including 29 species not reported in 1900–1919. Notably, we report a reduction in the species composition among forage specialist bees from 26.4% to 15.7% of the bee fauna, a consistent and highly significant decline both when correcting for parasitic and social species. Pollen swabs from bees collected in the first period, 1900–1919, did not identify any plants that are not available today but documented a series of plants that were important to bees back then. These plants are still common today, such as <i>Taraxacum</i> and <i>Salix</i>. Our findings highlight the importance of local and historical faunistic studies, such as that of Jørgensen, who was a resident schoolteacher on the island of Lolland in southern Denmark, for documenting how changes over time affect the species composition in bee communities.https://www.mdpi.com/2075-4450/13/2/153conservationfunctional traitsspecializationbee declinepollen preferencefloral resources |
| spellingShingle | Claus Rasmussen Markus Arne Kjær Sydenham Hans Thomsen Schmidt Henning Bang Madsen The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists Insects conservation functional traits specialization bee decline pollen preference floral resources |
| title | The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists |
| title_full | The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists |
| title_fullStr | The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists |
| title_full_unstemmed | The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists |
| title_short | The Native Bees of Lolland (Denmark) Revisited after 100 Years: The Demise of the Specialists |
| title_sort | native bees of lolland denmark revisited after 100 years the demise of the specialists |
| topic | conservation functional traits specialization bee decline pollen preference floral resources |
| url | https://www.mdpi.com/2075-4450/13/2/153 |
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