dc.contributor.author | Lewington-Pearce, Leah | |
dc.date.accessioned | 2018-09-18T15:38:24Z | |
dc.date.available | 2018-09-18T15:38:24Z | |
dc.date.issued | 2018-08-30 | |
dc.date.submitted | 2018-09-18T15:10:24.123Z | |
dc.identifier.citation | Lewington-Pearce, L. 2018. Sustaining Ecosystem Functions Under Environmental Change: The Combined Impacts of Temperature, Species Diversity and Limiting Resources on Phytoplankton Communities. Sustaining Ecosystem Functions Under Environmental Change: The Combined Impacts of Temperature, Species Diversity and Limiting Resources on Phytoplankton Communities | en_US |
dc.identifier.uri | http://qmro.qmul.ac.uk/xmlui/handle/123456789/44691 | |
dc.description | PhD | en_US |
dc.description.abstract | Plankton play a key role in regulating nutrient and carbon cycles in freshwater
ecosystems. The uptake and processing of nutrients in planktonic biomass are highly
sensitive to changes in the environment, such as alterations in the availability of
limiting nutrients, increasing temperature due to climate change, and changes to the
composition of interacting species. The focus of this thesis is to use a variety of
experimental and theoretical methods to assess and predict the impact of multiple
perturbations on community structure, dynamics and ecosystem function, with a
particular focus on interactions between phytoplankton and their consumers
(zooplankton). Increases in both temperature and phytoplankton species diversity
independently decreased CO2 concentrations when the number of non-resource
species (those inedible to the zooplankton) were high. Using structural equation
modeling I show that the effect is indirect, resulting largely from the positive impacts
on total biomass of phytoplankton. Phytoplankton are limited by a range of
resources, and differences in the functional traits used to utilize light and nutrients
can explain the distributions of species under different temperature regimes. I found
that under light and nitrogen limitation, resource requirements are generally lowest at
intermediate temperatures, and that changes in temperature may therefore alter the
competitive hierarchy amongst species. Using the model freshwater phytoplankton
Chlamydomonas reinhardtii, I also find that previous selection environments govern
future competitive abilities in phytoplankton. Adaptation to a high salt and low
nutrient stress increases competitive ability under light limited conditions, indicating
a strong dependency of selection environment for overall competitiveness. This
thesis provides a mechanistic insight into the role of diverse plankton communities
for community dynamics and ecosystem functioning. | en_US |
dc.description.sponsorship | Queen Mary University of London. | en_US |
dc.language.iso | en | en_US |
dc.publisher | Queen Mary University of London | en_US |
dc.rights | The copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the author | |
dc.subject | Ecosystems | en_US |
dc.subject | Environmental Change | en_US |
dc.subject | Species Diversity | en_US |
dc.subject | Phytoplankton Communities | en_US |
dc.title | Sustaining Ecosystem Functions Under Environmental Change: The Combined Impacts of Temperature, Species Diversity and Limiting Resources on Phytoplankton Communities | en_US |
dc.type | Thesis | en_US |