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  • 1
    Publication Date: 2019-02-27
    Description: Predictive species distribution models are mostly based on statistical dependence between environmental and distributional data and therefore may fail to account for physiological limits and biological interactions that are fundamental when modelling species distributions under future climate conditions. Here, we developed a state-of-the-art method integrating biological theory with survey and experimental data in a way that allows us to explicitly model both physical tolerance limits of species and inherent natural variability in regional conditions and thereby improve the reliability of species distribution predictions under future climate conditions. By using a macroalga-herbivore association (Fucus vesiculosus - Idotea balthica) as a case study, we illustrated how salinity reduction and temperature increase under future climate conditions may significantly reduce the occurrence and biomass of these important coastal species. Moreover, we showed that the reduction of herbivore occurrence is linked to reduction of their host macroalgae. Spatial predictive modelling and experimental biology have been traditionally seen as separate fields but stronger interlinkages between these disciplines can improve species distribution projections under climate change. Experiments enable qualitative prior knowledge to be defined and identify cause-effect relationships, and thereby better foresee alterations in ecosystem structure and functioning under future climate conditions that are not necessarily seen in projections based on non-causal statistical relationships alone.
    Type: Article , PeerReviewed
    Format: text
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  • 2
    ISSN: 1573-8477
    Keywords: pre-copulatory mate guarding ; intersexual conflict ; sex ratio ; mating cycle synchronicity ; compromised solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An evolutionarily stable strategy (ESS) on pre-copulatory mate-guarding duration is separately obtained for males and females, by assuming that either the male or female can control perfectly the timing of guarding. A difference between sexes in an ESS brings on an intersexual conflict, in particular when the ESS of the actively searching sex (usually male) is longer than that of the other. We analyse two extreme situations, in which the female mating stages are either perfectly synchronized or uniformly distributed. The analysis reveals that (1) the male ESS for guarding duration is longer than the female ESS in the synchronized case if the sex ratio is male-biased, (2) the difference in ESSs is higher for a more male-biased sex ratio, less guarding costs or a higher encounter rate, and (3) an asynchronous female mating cycle extends the conflict region towards female-biased sex ratios. We show by including conflict costs in fitnesses of both sexes that intersexual conflict may be resolved by a compromised solution, where the starting time of mate guarding is an intermediate value between the ESSs of the two sexes. This compromised strategy depends on both fitness increments of winning the conflict and physical power in controlling the opponent and tends to approach the ESS of the commoner sex in highly biased sex ratios. If both actors engaged in a conflict have enough information on each other, a compromise without an overt struggle may be reached.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1939
    Keywords: Key words Habitat choice ; Cannibalism ; Intraspecific predation ; Habitat heterogeneity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Intraspecific microhabitat segregation is expected to arise when there are age- or sex-specific differences in predation risk. The degree to which conspecific predation (cannibalism) can generate this risk, however, is poorly understood. In this paper, we examine microhabitat use, cannibalism, and individual responses to the presence of conspecifics in Thermosphaeroma thermophilum, an endangered isopod crustacean species that is endemic to a single, thermal spring in Socorro, N.M. USA. In samples from the natural habitat, juveniles (mancas) were found mainly on vegetation, whereas adults were found predominantly on bottom sediments. Females were found on vegetation more often than males. In laboratory containers without refuges, males cannibalized females, males and females cannibalized mancas, and mancas cannibalized each other, even in the presence of alternative food. When placed in containers provided with refuges, mancas actively avoided adults. We suggest, therefore, that cannibalism in T. thermophilum generates age-, size-, and sex-specific predation risks which are responsible for microhabitat segregation between mancas and adults, and between males and females. Since interspecific predation in the spring is negligible, cannibalism appears to play a significant role in population regulation and behavioral evolution in this species. We recommend, given the current “endangered” status of this species, that microhabitat heterogeneity be maintained in its native spring because it provides refuges from cannibalism and may support a larger and more viable natural population.
    Type of Medium: Electronic Resource
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  • 4
    Publication Date: 2016-03-01
    Description: Separating individual compounds by HPLC represents an effective method for the detection and quantification of phenolic compounds and has been widely utilised. However, phlorotannins are commonly quantified using colorimetric methods, as the total amount of the whole compound group. In the present paper the separation of a set of individual soluble phlorotannins from the phenolic crude extract of Fucus vesiculosus was achieved by HPLC with UV photodiode array detection. Different gradient programs for reversed- and normal-phase HPLC methods were developed and tested. Normal-phase (NP) conditions with a silica stationary phase and a mobile phase with a linear gradient of increasing polarity were found to separate 16 individual components of the phenolic extract. The suitability of the NP-HPLC method for mass spectrometric application was preliminarily tested. Sample preparation was found to be a critical step in the analysis owing to the rapid oxidation of phlorotannins; ascorbic acid was used as an antioxidant.
    Type: Article , PeerReviewed
    Format: text
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  • 5
    Publication Date: 2019-05-16
    Description: We investigated the effects of local nutrient enrichment, among-population variation in quality, and within-plant variation in quality on growth, development, and food consumption (total amount of food ingested) of the marine isopod Idotea baltica when fed Fucus vesiculosus. We found that the proximity of fish farms increased carbon/nitrogen ratio, but did not change the concentration of phlorotannins in the F. vesiculosus thallus. Algal diets taken from sites close to or far from fish farms did not affect the growth, development, or total amount of food ingested of I. baltica. Therefore, eutrophication may not necessarily decrease the level of plant resistance. We found that different F. vesiculosus beds vary in quality and led to differences in total amount of food ingested and production efficiency of I. baltica. The variation in quality of F. vesiculosus in different locations may generate variance in grazing pressure between the belts. Idotea baltica was most sensitive to within-plant variation, as the isopods grew more and had higher production efficiency on apical than basal parts of F. vesiculosus. Idotea baltica did not compensate for the lower quality of basal parts by increasing consumption. This may indicate that the low quality of the basal thallus is related to higher levels of secondary metabolites and not to lower levels of soluble sugars or nitrogen that might have encouraged compensatory consumption. Our results suggest that within-plant variation in the quality of the F. vesiculosus is more important for herbivores than possible environmental variation caused by eutrophication.
    Type: Article , PeerReviewed
    Format: text
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  • 6
    Publication Date: 2019-09-24
    Description: Stress regimes defined as the synchronous or sequential action of abiotic and biotic stresses determine the performance and distribution of species. The natural patterns of stress to which species are more or less well adapted have recently started to shift and alter under the influence of global change. This was the motivation to review our knowledge on the stress ecology of a benthic key player, the macroalgal genus Fucus. We first provide a comprehensive review of the genus as an ecological model including what is currently known about the major lineages of Fucus species with respect to hybridization, ecotypic differentiation and speciation; as well as life history, population structure and geographic distribution. We then review our current understanding of both extrinsic (abiotic/biotic) and intrinsic (genetic) stress(es) on Fucus species and how they interact with each other. It is concluded that (i) interactive stress effects appear to be equally distributed over additive, antagonistic and synergistic categories at the level of single experiments, but are predominantly additive when averaged over all studies in a meta-analysis of 41 experiments; (ii) juvenile and adult responses to stress frequently differ and (iii) several species or particular populations of Fucus may be relatively unaffected by climate change as a consequence of pre-adapted ecotypes that collectively express wide physiological tolerences. Future research on Fucus should (i) include additional species, (ii) include marginal populations as models for responses to environmental stress; (iii) assess a wider range of stress combinations, including their temporal fluctuations; (iv) better differentiate between stress sensitivity of juvenile versus adult stages; (v) include a functional genomic component in order to better integrate Fucus’ ecological and evolutionary responses to stress regimes and (vi) utilize a multivariate modelling approach in order to develop and understand interaction networks.
    Type: Article , PeerReviewed
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  • 7
    Publication Date: 2019-09-23
    Description: Coastal global oceans are expected to undergo drastic changes driven by climate change and increasing anthropogenic pressures in coming decades. Predicting specific future conditions and assessing the best management strategies to maintain ecosystem integrity and sustainable resource use are difficult, because of multiple interacting pressures, uncertain projections, and a lack of test cases for management. We argue that the Baltic Sea can serve as a time machine to study consequences and mitigation of future coastal perturbations, due to its unique combination of an early history of multistressor disturbance and ecosystem deterioration and early implementation of cross-border environmental management to address these problems. The Baltic Sea also stands out in providing a strong scientific foundation and accessibility to long-term data series that provide a unique opportunity to assess the efficacy of management actions to address the breakdown of ecosystem functions. Trend reversals such as the return of top predators, recovering fish stocks, and reduced input of nutrient and harmful substances could be achieved only by implementing an international, cooperative governance structure transcending its complex multistate policy setting, with integrated management of watershed and sea. The Baltic Sea also demonstrates how rapidly progressing global pressures, particularly warming of Baltic waters and the surrounding catchment area, can offset the efficacy of current management approaches. This situation calls for management that is (i) conservative to provide a buffer against regionally unmanageable global perturbations, (ii) adaptive to react to new management challenges, and, ultimately, (iii) multisectorial and integrative to address conflicts associated with economic trade-offs.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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  • 8
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    PANGAEA
    In:  Supplement to: Barboza, Francisco R; Kotta, Jonne; Weinberger, Florian; Jormalainen, Veijo; Kraufvelin, Patrik; Molis, Markus; Schubert, Hendrik; Pavia, Henrik; Nylund, Göran M; Kautsky, Lena; Schagerström, Ellen; Rickert, Esther; Saha, Mahasweta; Fredriksen, Stein; Martin, Georg; Torn, Kaire; Ruuskanen, Ari T; Wahl, Martin (2019): Geographic variation in fitness‐related traits of the bladderwrack Fucus vesiculosus along the Baltic Sea‐North Sea salinity gradient. Ecology and Evolution, 9(16), 9225-9238, https://doi.org/10.1002/ece3.5470
    Publication Date: 2019-11-02
    Description: Data on morphological and biochemical traits of the bladderwrack Fucus vesiculosus were obtained from individuals simultaneously collected in September 2011 in 20 stations along the Baltic Sea and 4 stations in the North Sea. The individuals included in the analysis were collected at 0.5-1.0 m depth. Frond length, frond width, stipe width and number of fronds were directly determined in the field. All collected individuals were transported to the laboratory in cooler boxes at temperatures below 5 °C, then frozen at -20 °C within 12 h, and shipped to the GEOMAR-Helmholtz Centre for Ocean Research Kiel (Germany) on dry ice. Measurements of chlorophyll a and fucoxanthin in surface and tissue extracts, mannitol, phlorotannins and carbon:nitrogen ratio were performed in the laboratory (see further methodological details in the related article). The relative palatability of the algal material collected in all 24 stations was determined in palatability assays, using reconstituted algal pellets and the pan-Baltic grazer Idotea balthica. In addition to the trait information, environmental data on sea surface salinity, sea surface summer temperature, photosynthetically active radiation (PAR), wave exposure and total nitrogen have been obtained from the Swedish Meteorological and Hydrological Institute (SMHI) or local monitoring services.
    Type: Dataset
    Format: application/zip, 3 datasets
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  • 9
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