Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot
Global climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the r...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-02-01
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| Series: | Insects |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4450/12/2/135 |
| _version_ | 1797414571637473280 |
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| author | Keng-Lou James Hung Sara S. Sandoval John S. Ascher David A. Holway |
| author_facet | Keng-Lou James Hung Sara S. Sandoval John S. Ascher David A. Holway |
| author_sort | Keng-Lou James Hung |
| collection | DOAJ |
| description | Global climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the relative magnitude of impacts from drought in fragmented habitat patches versus unfragmented natural reserves. Bee richness and diversity were higher in assemblages surveyed before the drought compared to those surveyed after the drought. However, bees belonging to the <i>Lasioglossum</i> subgenus <i>Dialictus</i> increased in abundance after the drought, driving increased representation by small-bodied, primitively eusocial, and generalist bees in post-drought assemblages. Conversely, among non-<i>Dialictus</i> bees, post-drought years were associated with decreased abundance and reduced representation by eusocial species. Drought effects were consistently greater in reserves, which supported more bee species, than in fragments, suggesting that fragmentation either had redundant impacts with drought, or ameliorated effects of drought by enhancing bees’ access to floral resources in irrigated urban environments. Shifts in assemblage composition associated with drought were three times greater compared to those associated with habitat fragmentation, highlighting the importance of understanding the impacts of large-scale climatic events relative to those associated with land use change. |
| first_indexed | 2024-03-09T05:35:18Z |
| format | Article |
| id | doaj.art-27d001782d1e4e2eaaebcbf7c9e4ba67 |
| institution | Directory Open Access Journal |
| issn | 2075-4450 |
| language | English |
| last_indexed | 2024-03-09T05:35:18Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Insects |
| spelling | doaj.art-27d001782d1e4e2eaaebcbf7c9e4ba672023-12-03T12:28:52ZengMDPI AGInsects2075-44502021-02-0112213510.3390/insects12020135Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity HotspotKeng-Lou James Hung0Sara S. Sandoval1John S. Ascher2David A. Holway3Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California—San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USASection of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California—San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USADepartment of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, SingaporeSection of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California—San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USAGlobal climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the relative magnitude of impacts from drought in fragmented habitat patches versus unfragmented natural reserves. Bee richness and diversity were higher in assemblages surveyed before the drought compared to those surveyed after the drought. However, bees belonging to the <i>Lasioglossum</i> subgenus <i>Dialictus</i> increased in abundance after the drought, driving increased representation by small-bodied, primitively eusocial, and generalist bees in post-drought assemblages. Conversely, among non-<i>Dialictus</i> bees, post-drought years were associated with decreased abundance and reduced representation by eusocial species. Drought effects were consistently greater in reserves, which supported more bee species, than in fragments, suggesting that fragmentation either had redundant impacts with drought, or ameliorated effects of drought by enhancing bees’ access to floral resources in irrigated urban environments. Shifts in assemblage composition associated with drought were three times greater compared to those associated with habitat fragmentation, highlighting the importance of understanding the impacts of large-scale climatic events relative to those associated with land use change.https://www.mdpi.com/2075-4450/12/2/135coastal sage scrubglobal climate changehabitat loss and fragmentationpollinatorsCalifornia drought<i>Lasioglossum</i> <i>Dialictus</i> |
| spellingShingle | Keng-Lou James Hung Sara S. Sandoval John S. Ascher David A. Holway Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot Insects coastal sage scrub global climate change habitat loss and fragmentation pollinators California drought <i>Lasioglossum</i> <i>Dialictus</i> |
| title | Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot |
| title_full | Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot |
| title_fullStr | Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot |
| title_full_unstemmed | Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot |
| title_short | Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot |
| title_sort | joint impacts of drought and habitat fragmentation on native bee assemblages in a california biodiversity hotspot |
| topic | coastal sage scrub global climate change habitat loss and fragmentation pollinators California drought <i>Lasioglossum</i> <i>Dialictus</i> |
| url | https://www.mdpi.com/2075-4450/12/2/135 |
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