Change search
Refine search result
1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Bodin, Örjan
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Crona, Beatrice
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Science, Sweden.
    Thyresson, Matilda
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Golz, Anna-lea
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Tengö, Maria
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Conservation Success as a Function of Good Alignment of Social and Ecological Structures and Processes2014In: Conservation Biology, ISSN 0888-8892, E-ISSN 1523-1739, Vol. 28, no 5, p. 1371-1379Article in journal (Refereed)
    Abstract [en]

    How to create and adjust governing institutions so that they align (fit) with complex ecosystem processes and structures across scales is an issue of increasing concern in conservation. It is argued that lack of such social-ecological fit makes governance and conservation difficult, yet progress in explicitly defining and rigorously testing what constitutes a good fit has been limited. We used a novel modeling approach and data from case studies of fishery and forest conservation to empirically test presumed relationships between conservation outcomes and certain patterns of alignment of social-ecological interdependences. Our approach made it possible to analyze conservation outcome on a systems level while also providing information on how individual actors are positioned in the complex web of social-ecological interdependencies. We found that when actors who shared resources were also socially linked, conservation at the level of the whole social-ecological system was positively affected. When the scales at which individual actors used resources and the scale at which ecological resources were interconnected to other ecological resources were aligned through tightened feedback loops, conservation outcome was better than when they were not aligned. The analysis of individual actors' positions in the web of social-ecological interdependencies was helpful in understanding why a system has a certain level of social-ecological fit. Results of analysis of positions showed that different actors contributed in very different ways to achieve a certain fit and revealed some underlying difference between the actors, for example in terms of actors' varying rights to access and use different ecological resources.

  • 2.
    Bradshaw, Clare
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Södertörn University, Sweden.
    Golz, Anna-Lea
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Gustafsson, Kerstin
    Coastal Ecosystem Effects of Increased Summer Temperature and Contamination by the Flame Retardant HBCDD2017In: Journal of Marine Science and Engineering, E-ISSN 2077-1312, Vol. 5, no 2, article id 18Article in journal (Refereed)
    Abstract [en]

    The combined effects of ocean warming and contaminants on marine ecosystems are poorly understood. In this study, we exposed model ecosystems comprising typical shallow coastal Baltic Sea communities to elevated temperature (+5 °C) and the flame retardant hexabromocyclododecane (HBCDD), both singly and in combination, for 13 days. Higher temperatures caused the release of PO4 from the sediment, which in turn stimulated the growth of the cyanobacteria Dolichospermum sp. This in turn led to an increase in the copepod Acartia bifilosa and other indirect effects in the plankton, interpreted as being caused by changes in predation, grazing, and competition. Elevated temperatures also stimulated benthic primary production and increased production of benthic mollusk larvae. Although increased temperature was the dominant driver of effects in these systems, HBCDD also appeared to have some effects, mainly in the zooplankton (both direct and indirect effects) and benthic meiofauna (an interactive effect with temperature). Although the study used model ecosystems, which are an approximation of field conditions, it highlights that interactive ecosystem effects between two stressors are possible and demonstrates the ecological and temporal complexity of such responses. Such unpredictable responses to warming and contaminants are a major challenge for ecosystem management to deal with multistressor situations in the Baltic Sea.

  • 3.
    Golz, Anna-Lea
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Role of ecological processes in determining effects of contaminants in aquatic ecosystems2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aquatic ecosystems cover approximately 70% of the Earth’s surface and support a wide range of ecosystem services. Despite their importance, aquatic ecosystems are increasingly exposed to anthropogenic stressors, such as contaminants and climate change impacts. Ecosystems comprise a complex web of interactions both between organisms and between organisms and the abiotic environment. While there is extensive evidence for the importance of ecological processes in determining net ecosystem effects of contaminants, most often their effects are studied in isolation and in a single species setting.

    The aim of this thesis is to investigate the ecological effects of contaminants in aquatic ecosystems, ranging from cellular to ecosystem endpoints, by using model ecosystems of increasing complexity. This thesis studies the effects of ionising radiation on the biochemical composition of microalgae and how these may affect consumers (Paper I), as well its effects on an artificial freshwater ecosystem (microcosms) in terms of ecological processes (Paper II) and carbon flows (Paper III). Finally, the thesis investigates the combined effects of a flame retardant and increased temperature on a model ecosystem comprised of a semi-natural Baltic Sea community (Paper IV).

    Ionising radiation caused biochemical changes in primary producers that affected the next trophic level, where the consumer responded with an increased feeding rate, suggesting a change in the food quality of the primary producer (Paper I). The microcosms exposed to ionising radiation showed significant dose related effects on photosynthetic parameters for all macrophyte species. Dose dependent trends were seen in snail grazing rates and reproduction indicating a potential for long-term effects (Paper II). Similarly, the carbon flow networks (Paper III) also indicated that the main effect of radiation was a decline in primary production of the macrophytes, while pelagic bacterial production increased. However, the relative distribution of flows from dissolved carbon changed only slightly with increasing dose rates, which mainly triggered an increase in the amount of carbon dissipated through respiration. Finally, in Paper IV, higher temperatures induced the release of PO4 from the sediment, which stimulated the growth of the cyanobacteria, in turn leading to an increase in copepod abundance.

    These results demonstrate that the effects of contaminants on ecosystems depend on ecological processes, which may influence species-specific responses and lead to indirect effects. This thesis builds on a body of literature calling for a more holistic approach of ecotoxicology and radioecology, where ecosystem level responses to contaminants are taken into consideration.

  • 4.
    Golz, Anna-Lea
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Bradshaw, Clare
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Gamma Radiation Induced Changes in the Biochemical Composition of Aquatic Primary Producers and Their Effect on Grazers2019In: Frontiers in environmental science, ISSN 2296-665X, Vol. 7, article id 100Article in journal (Refereed)
    Abstract [en]

    Changes in the biochemical composition of primary producers can after their food quality, influencing their consumers and further propagating through the food web. Gamma (gamma) radiation is an environmentally important type of ionizing radiation as it can damage macromolecules such as DNA, proteins, and lipids due to its high frequency, short wavelength, and high energy photons. Here, we investigate whether short-term gamma-radiation changes the biochemical composition of primary producers and if radiation-induced changes affect higher trophic levels. Two phytoplankton species were exposed to two doses of gamma-radiation and compared to a control. The metabolic profile and total protein content of the algae were measured at five time points within 24 h. Additionally, we measured carbon incorporation rates of Daphnia magna fed with the exposed algae. Gamma radiation had a significant effect on phytoplankton biochemical composition, although these effects were species-specific. The changes in phytoplankton biochemical composition indicate that gamma-radiation induced the production of reactive oxygen species (ROS). D. magna incorporated more carbon when fed with algae previously exposed to gamma-radiation; this could be due to radiation-induced changes in nutritional quality, algal anti-grazing defenses, or chemical feeding stimuli.

  • 5.
    Golz, Anna-Lea
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Bradshaw, Clare
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Gamma radiation induced changes in the biochemical composition of aquatic primary producers and their effect on grazersManuscript (preprint) (Other academic)
  • 6.
    Golz, Anna-Lea
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Burian, Alfred
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Winder, Monika
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Stoichiometric regulation in micro- and mesozooplankton2015In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 37, no 2, p. 293-305Article in journal (Refereed)
    Abstract [en]

    Aquatic ecosystems experience large natural variation in elemental composition of carbon (C), nitrogen (N) and phosphorus (P), which is further enhanced by human activities. Primary producers typically reflect the nutrient ratios of their resource, whose stoichiometric composition can vary widely in conformity to environmental conditions. In contrast, C to nutrient ratios in consumers are largely constrained within a narrow range, termed homeostasis. In comparison to crustacean zooplankton, less is known about the ability of protozoan grazers and rotifer species to maintain stoichiometric balance. In this study, we used laboratory experiments with a primary producer (Nannochloropsis sp.), three different species of protozoan grazers and one mesozooplankton species: two heterotrophic dinoflagellates (Gyrodinium dominans and Oxyrrhis marina), a ciliate (Euplotes sp.) and a rotifer (Brachionus plicatilis) to test the stoichiometric response to five nutrient treatments. We showed that the dependency of zooplankton C: N: P ratios on C: nutrient ratios of their food source varies among species. Similar to the photoautotroph, the two heterotrophic dinoflagellates weakly regulated their internal stoichiometry. In contrast, the strength of stoichiometric regulation increased to strict homeostasis in both the ciliate and the rotifer, similar to crustacean zooplankton. Our study further shows that ciliate and rotifer growth can be constrained by imbalanced resource supply. It also indicates that these key primary consumers have the potential to trophically upgrade poor stoichiometric autotrophic food quality for higher trophic levels.

  • 7.
    Golz, Anna-Lea
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Hevrøy, Tanya H.
    Scotti, Marco
    Bradshaw, Clare
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Carbon flow in a model ecosystem exposed to ionising radiationManuscript (preprint) (Other academic)
  • 8. Hevrøy, Tanya H.
    et al.
    Golz, Anna-Lea
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Xie, Li
    Hansen, Elisabeth L.
    Bradshaw, Clare
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Radiation effects and ecological processes in a freshwater microcosm2019In: Journal of Environmental Radioactivity, ISSN 0265-931X, E-ISSN 1879-1700, Vol. 203, p. 71-83Article in journal (Refereed)
    Abstract [en]

    Ecosystem response to gamma radiation exposure depends on the different species sensitivities and the multitude of direct and indirect pathways by which individual organisms can be affected, including the potential for complex interactions across multiple trophic levels. In this study, multi-species microcosms were used to in- vestigate effects of ionizing radiation in a model freshwater ecosystem, including endpoints at both structural and functional levels and ecological interactions. Microcosms were exposed for 22 days to a gradient of gamma radiation with four dose rates from 0.72 to 19mGyh−1, which are within the range of those seen at con- taminated sites. Results showed significant dose related effects on photosynthetic parameters for all macrophyte species. No significant effects of radiation were observed for the consumers in the microcosms, however trends indicate the potential for longer-term effects. We also witnessed a different response of Daphnia magna andLemna minor compared to previous single-species studies, illustrating the importance of multispecies studies, which aim to encompass systems more realistic to natural ecosystems. Microcosms allowed us to isolate specific relationships between interacting species in an ecosystem and test the effects, both direct and indirect, of ra- diation on them. In addition, the ecological pathways and processes, and the experimental design itself, was central to understanding the results we witnessed. This type of study is important for radioecology research that has been very much limited to high dose rates and single species studies. This approach to radioecology has been strongly promoted in recent decades and, to our knowledge, this is the first microcosm study performed at dose rates similar to those at contaminated field sites.

1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf