Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies
Body mass shapes processes from cell metabolism to community dynamics. Little is known, however, about how the average body mass of individuals varies among ecological communities. Ants alter colony mass by independently changing worker mass and/or worker number. In a survey of 49 ecosystems from tu...
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ftpubmed:oai:pubmedcentral.nih.gov:555972 2023-05-15T18:40:32+02:00 Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies Kaspari, Michael 2005-04-05 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555972 http://www.ncbi.nlm.nih.gov/pubmed/15788538 https://doi.org/10.1073/pnas.0407827102 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555972 http://www.ncbi.nlm.nih.gov/pubmed/15788538 http://dx.doi.org/10.1073/pnas.0407827102 Copyright © 2005, The National Academy of Sciences Biological Sciences Text 2005 ftpubmed https://doi.org/10.1073/pnas.0407827102 2013-08-30T04:36:28Z Body mass shapes processes from cell metabolism to community dynamics. Little is known, however, about how the average body mass of individuals varies among ecological communities. Ants alter colony mass by independently changing worker mass and/or worker number. In a survey of 49 ecosystems from tundra to tropical rainforest, average worker mass and worker number were uncorrelated (rs = 0.2, P > 0.14) and varied 100-fold. Data supported the hypothesis that higher mean monthly temperatures, T, reduce worker mass by increasing metabolic costs during worker development. In contrast, worker number was unimodal over a 1,000-fold gradient of net primary productivity (NPP, g of carbon per m2 per yr), a measure of organic carbon available to consumers. At the lowest levels of NPP colonies appeared to be carbon-limited; above 60 g of carbon per m2 per yr average worker number decreased to a global low. This decline in worker number with increasing NPP supports the hypothesis that abundant carbon ameliorates the Achilles heel of small taxa in competition with large taxa: their relatively high metabolic demands. Higher predation rates in resource-rich environments may also play a role in limiting worker number. In all, about half the global variation in worker mass and number was accounted for by gradients of NPP and T. Changes in global temperature and rainfall may thus mold gradients of ectotherm size, with consequences for the structure and function of the ecosystems. Text Tundra PubMed Central (PMC) Achilles Heel ENVELOPE(-63.596,-63.596,-64.500,-64.500) Proceedings of the National Academy of Sciences 102 14 5079 5083 |
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Biological Sciences |
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Biological Sciences Kaspari, Michael Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies |
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Biological Sciences |
description |
Body mass shapes processes from cell metabolism to community dynamics. Little is known, however, about how the average body mass of individuals varies among ecological communities. Ants alter colony mass by independently changing worker mass and/or worker number. In a survey of 49 ecosystems from tundra to tropical rainforest, average worker mass and worker number were uncorrelated (rs = 0.2, P > 0.14) and varied 100-fold. Data supported the hypothesis that higher mean monthly temperatures, T, reduce worker mass by increasing metabolic costs during worker development. In contrast, worker number was unimodal over a 1,000-fold gradient of net primary productivity (NPP, g of carbon per m2 per yr), a measure of organic carbon available to consumers. At the lowest levels of NPP colonies appeared to be carbon-limited; above 60 g of carbon per m2 per yr average worker number decreased to a global low. This decline in worker number with increasing NPP supports the hypothesis that abundant carbon ameliorates the Achilles heel of small taxa in competition with large taxa: their relatively high metabolic demands. Higher predation rates in resource-rich environments may also play a role in limiting worker number. In all, about half the global variation in worker mass and number was accounted for by gradients of NPP and T. Changes in global temperature and rainfall may thus mold gradients of ectotherm size, with consequences for the structure and function of the ecosystems. |
format |
Text |
author |
Kaspari, Michael |
author_facet |
Kaspari, Michael |
author_sort |
Kaspari, Michael |
title |
Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies |
title_short |
Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies |
title_full |
Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies |
title_fullStr |
Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies |
title_full_unstemmed |
Global energy gradients and size in colonial organisms: Worker mass and worker number in ant colonies |
title_sort |
global energy gradients and size in colonial organisms: worker mass and worker number in ant colonies |
publisher |
National Academy of Sciences |
publishDate |
2005 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555972 http://www.ncbi.nlm.nih.gov/pubmed/15788538 https://doi.org/10.1073/pnas.0407827102 |
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ENVELOPE(-63.596,-63.596,-64.500,-64.500) |
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Achilles Heel |
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Achilles Heel |
genre |
Tundra |
genre_facet |
Tundra |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555972 http://www.ncbi.nlm.nih.gov/pubmed/15788538 http://dx.doi.org/10.1073/pnas.0407827102 |
op_rights |
Copyright © 2005, The National Academy of Sciences |
op_doi |
https://doi.org/10.1073/pnas.0407827102 |
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Proceedings of the National Academy of Sciences |
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102 |
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14 |
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5079 |
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5083 |
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1766229915636596736 |