Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics
Parasitic plants are found in nearly every major terrestrial ecosystem and can be divided into two groups, holoparasites (lacking chlorophyll) and hemiparasites (chlorophyllous). The host-parasite connection is either situated above (stem parasites) or below ground (root parasites). In this thesis I...
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Ekologihuset, SE-223 62 Lund, Sweden
2000
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ftulundlup:oai:lup.lub.lu.se:00060cfa-4b0d-42d3-9b31-c5d78a7b0fcd 2023-05-15T16:08:29+02:00 Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics Nilsson, Carin H 2000 https://lup.lub.lu.se/record/40578 eng eng Ekologihuset, SE-223 62 Lund, Sweden https://lup.lub.lu.se/record/40578 urn:isbn:91-7105-139-2 other:ISRN: SE-LUNBDS/NMME-00/1059 Ecology population dynamics selectivity Phenotypic plasticity fitness Plant ecology Växtekologi thesis/doccomp info:eu-repo/semantics/doctoralThesis text 2000 ftulundlup 2023-02-01T23:30:40Z Parasitic plants are found in nearly every major terrestrial ecosystem and can be divided into two groups, holoparasites (lacking chlorophyll) and hemiparasites (chlorophyllous). The host-parasite connection is either situated above (stem parasites) or below ground (root parasites). In this thesis I examine the host-parasite interactions, host range and selection, and population dynamics of four root hemiparasitic species in a subarctic habitat in northernmost Sweden. Two species were annuals (Euphrasia frigida and Rhinanthus minor) and two were clonal perennials (Bartsia alpina and Pedicularis lapponica). Resources (e.g., nitrogen and carbon) are usually thought to be transported only from the host plant to the hemiparasite, thus promoting the growth of the parasite. Interestingly, however, in a study on B. alpina I found that there is probably transport in the opposite direction as well. Furthermore, nitrogen-rich hosts have often been shown to result in stronger parasite growth, but in the study on B. alpina I found that a species with a lower content of nitrogen might effect the higher growth stimulation, perhaps due to its mycorrhizal connections. A surprisingly high number of species was found to be hosts for B. alpina and P. lapponica using two methods: visually examining haustoria and monitoring carbon flow from potential hosts. As potential hosts differ in suitability, I experimentally tried to find out whether E. frigida and R. minor could selectively choose their hosts. No clear answer emerged; the results differed depending on whether the actual number of haustorial connections or the number of haustoria per g host root was analysed. The positive effect of a suitable host, however, seems to last only one generation in the annual E. frigida since I found no carry-over effects from the maternal host. All four species fluctuated in both density and flowering frequency during a five-year study period, particularly the two annual species. Both weather variables, coexisting species, and the presence of ... Doctoral or Postdoctoral Thesis Euphrasia frigida Subarctic Lund University Publications (LUP) |
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Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Ecology population dynamics selectivity Phenotypic plasticity fitness Plant ecology Växtekologi |
spellingShingle |
Ecology population dynamics selectivity Phenotypic plasticity fitness Plant ecology Växtekologi Nilsson, Carin H Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics |
topic_facet |
Ecology population dynamics selectivity Phenotypic plasticity fitness Plant ecology Växtekologi |
description |
Parasitic plants are found in nearly every major terrestrial ecosystem and can be divided into two groups, holoparasites (lacking chlorophyll) and hemiparasites (chlorophyllous). The host-parasite connection is either situated above (stem parasites) or below ground (root parasites). In this thesis I examine the host-parasite interactions, host range and selection, and population dynamics of four root hemiparasitic species in a subarctic habitat in northernmost Sweden. Two species were annuals (Euphrasia frigida and Rhinanthus minor) and two were clonal perennials (Bartsia alpina and Pedicularis lapponica). Resources (e.g., nitrogen and carbon) are usually thought to be transported only from the host plant to the hemiparasite, thus promoting the growth of the parasite. Interestingly, however, in a study on B. alpina I found that there is probably transport in the opposite direction as well. Furthermore, nitrogen-rich hosts have often been shown to result in stronger parasite growth, but in the study on B. alpina I found that a species with a lower content of nitrogen might effect the higher growth stimulation, perhaps due to its mycorrhizal connections. A surprisingly high number of species was found to be hosts for B. alpina and P. lapponica using two methods: visually examining haustoria and monitoring carbon flow from potential hosts. As potential hosts differ in suitability, I experimentally tried to find out whether E. frigida and R. minor could selectively choose their hosts. No clear answer emerged; the results differed depending on whether the actual number of haustorial connections or the number of haustoria per g host root was analysed. The positive effect of a suitable host, however, seems to last only one generation in the annual E. frigida since I found no carry-over effects from the maternal host. All four species fluctuated in both density and flowering frequency during a five-year study period, particularly the two annual species. Both weather variables, coexisting species, and the presence of ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Nilsson, Carin H |
author_facet |
Nilsson, Carin H |
author_sort |
Nilsson, Carin H |
title |
Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics |
title_short |
Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics |
title_full |
Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics |
title_fullStr |
Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics |
title_full_unstemmed |
Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics |
title_sort |
hemiparasites in the subarctic: resource acquisition, growth and population dynamics |
publisher |
Ekologihuset, SE-223 62 Lund, Sweden |
publishDate |
2000 |
url |
https://lup.lub.lu.se/record/40578 |
genre |
Euphrasia frigida Subarctic |
genre_facet |
Euphrasia frigida Subarctic |
op_relation |
https://lup.lub.lu.se/record/40578 urn:isbn:91-7105-139-2 other:ISRN: SE-LUNBDS/NMME-00/1059 |
_version_ |
1766404535744462848 |