Seaweed Invasions and Novel Chemical Defences
Biological invasions pose a risk to the biodiversity and the functioning of ecosystems in invaded areas. The reasons why some introduced species become dominant and widespread in their new environments is still largely an unsettled question. It has commonly been predicted that introduced plants will...
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ftunivgoeteborg:oai:gupea.ub.gu.se:2077/30534 2023-10-29T02:38:38+01:00 Seaweed Invasions and Novel Chemical Defences Enge, Swantje 2012-11-08 application/pdf http://hdl.handle.net/2077/30534 eng eng Enge, S., Nylund, G.M., Harder, T., and H. Pavia. 2012. An exotic chemical weapon explains low herbivore damage in an invasive alga. Ecology, ::doi::10.1890/12-0143.1 Sagerman, J., Enge, S., Pavia, H., and S.A. Wikström. Divergent ecological strategies determine different impacts on community production by two introduced seaweeds. Unpublished manuscript. Enge, S., Nylund, G.M., and H. Pavia. Native generalist herbivores promote invasion of a chemically-defended seaweed via refuge-mediated apparent competition. Unpublished manuscript. Nylund, G.M., Enge, S., and H. Pavia. Costs and benefits of chemical defence in the red alga Bonnemaisonia hamifera. Unpublished manuscript. Enge, S., Pereyra, R., and H. Pavia. Preliminary insights into the diversity and population structure of the red alga Bonnemaisonia hamifera in its introduced and native ranges. Unpublished manuscript. 978-91-628-8587-8 http://hdl.handle.net/2077/30534 biological invasions enemy release increased competitive ability novel weapon chemical defence plant-herbivore interactions competition seaweeds Bonnemaisonia hamifera Text Doctoral thesis Doctor of Philosophy 2012 ftunivgoeteborg 2023-10-04T21:07:06Z Biological invasions pose a risk to the biodiversity and the functioning of ecosystems in invaded areas. The reasons why some introduced species become dominant and widespread in their new environments is still largely an unsettled question. It has commonly been predicted that introduced plants will invade when they are less affected by herbivores, since this will provide the introduced species with a competitive advantage over native plants. Furthermore, it has been suggested that introduced species with chemical defences that are novel to native herbivores in the new range are most likely to become successful invaders. The scope of this thesis was to investigate ecological processes that underlie the successful invasion of plant/seaweed species and how chemical compounds mediate these processes, using the filamentous red alga Bonnemaisonia hamifera as a model organism. Having its origin in the Northwest Pacific, this alga has invaded large parts of the North Atlantic rocky shores and became dominant in many seaweed communities. Feeding preference experiments showed that native generalist herbivores explicitly preferred native seaweeds to the invader (paper I). Using a bioassay-guided fractionation, B. hamifera was found to be chemically defended against native herbivores by producing 1,1,3,3-tetrabromo-2-heptanone as the main feeding deterrent compound (paper I). The production of this compound was demonstrated to be costly, but also to increase the fitness of the invader by reducing the impact of pathogenic bacteria (paper IV) in addition to the shown reduced herbivory. Resource allocation to a chemical defence may also explain the relatively poor performance (in terms of growth) of B. hamifera in direct interactions with native seaweeds when herbivores were absent in experimental algal communities (paper II, III). In the presence of herbivores, however, the abundance of B. hamifera increased in the community as a result of both consumption of neighbouring algal competitors and an enhanced performance of the ... Doctoral or Postdoctoral Thesis North Atlantic University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive) |
institution |
Open Polar |
collection |
University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive) |
op_collection_id |
ftunivgoeteborg |
language |
English |
topic |
biological invasions enemy release increased competitive ability novel weapon chemical defence plant-herbivore interactions competition seaweeds Bonnemaisonia hamifera |
spellingShingle |
biological invasions enemy release increased competitive ability novel weapon chemical defence plant-herbivore interactions competition seaweeds Bonnemaisonia hamifera Enge, Swantje Seaweed Invasions and Novel Chemical Defences |
topic_facet |
biological invasions enemy release increased competitive ability novel weapon chemical defence plant-herbivore interactions competition seaweeds Bonnemaisonia hamifera |
description |
Biological invasions pose a risk to the biodiversity and the functioning of ecosystems in invaded areas. The reasons why some introduced species become dominant and widespread in their new environments is still largely an unsettled question. It has commonly been predicted that introduced plants will invade when they are less affected by herbivores, since this will provide the introduced species with a competitive advantage over native plants. Furthermore, it has been suggested that introduced species with chemical defences that are novel to native herbivores in the new range are most likely to become successful invaders. The scope of this thesis was to investigate ecological processes that underlie the successful invasion of plant/seaweed species and how chemical compounds mediate these processes, using the filamentous red alga Bonnemaisonia hamifera as a model organism. Having its origin in the Northwest Pacific, this alga has invaded large parts of the North Atlantic rocky shores and became dominant in many seaweed communities. Feeding preference experiments showed that native generalist herbivores explicitly preferred native seaweeds to the invader (paper I). Using a bioassay-guided fractionation, B. hamifera was found to be chemically defended against native herbivores by producing 1,1,3,3-tetrabromo-2-heptanone as the main feeding deterrent compound (paper I). The production of this compound was demonstrated to be costly, but also to increase the fitness of the invader by reducing the impact of pathogenic bacteria (paper IV) in addition to the shown reduced herbivory. Resource allocation to a chemical defence may also explain the relatively poor performance (in terms of growth) of B. hamifera in direct interactions with native seaweeds when herbivores were absent in experimental algal communities (paper II, III). In the presence of herbivores, however, the abundance of B. hamifera increased in the community as a result of both consumption of neighbouring algal competitors and an enhanced performance of the ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Enge, Swantje |
author_facet |
Enge, Swantje |
author_sort |
Enge, Swantje |
title |
Seaweed Invasions and Novel Chemical Defences |
title_short |
Seaweed Invasions and Novel Chemical Defences |
title_full |
Seaweed Invasions and Novel Chemical Defences |
title_fullStr |
Seaweed Invasions and Novel Chemical Defences |
title_full_unstemmed |
Seaweed Invasions and Novel Chemical Defences |
title_sort |
seaweed invasions and novel chemical defences |
publishDate |
2012 |
url |
http://hdl.handle.net/2077/30534 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Enge, S., Nylund, G.M., Harder, T., and H. Pavia. 2012. An exotic chemical weapon explains low herbivore damage in an invasive alga. Ecology, ::doi::10.1890/12-0143.1 Sagerman, J., Enge, S., Pavia, H., and S.A. Wikström. Divergent ecological strategies determine different impacts on community production by two introduced seaweeds. Unpublished manuscript. Enge, S., Nylund, G.M., and H. Pavia. Native generalist herbivores promote invasion of a chemically-defended seaweed via refuge-mediated apparent competition. Unpublished manuscript. Nylund, G.M., Enge, S., and H. Pavia. Costs and benefits of chemical defence in the red alga Bonnemaisonia hamifera. Unpublished manuscript. Enge, S., Pereyra, R., and H. Pavia. Preliminary insights into the diversity and population structure of the red alga Bonnemaisonia hamifera in its introduced and native ranges. Unpublished manuscript. 978-91-628-8587-8 http://hdl.handle.net/2077/30534 |
_version_ |
1781064857189089280 |