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411.
Liliana D’Alba Matthew D. Shawkey Peter Korsten Oscar Vedder Sjouke A. Kingma Jan Komdeur Steven R. Beissinger 《Behavioral ecology and sociobiology》2010,64(6):1037-1045
Female birds can influence offspring fitness by varying the relative quantities of egg components they deposit within and
between clutches. Antimicrobial proteins (lysozyme, ovotransferrin, and avidin) are significant components of the avian albumen
and likely aid in defense of embryos from microbial infection. Within clutches, females may enhance antimicrobial defense
of early-laid eggs to protect them from the high risk of infection incurred before the onset of incubation. Among entire clutches,
females may invest more resources in young sired by more attractive males because they have higher reproductive value. We
tested these hypotheses by quantifying antimicrobial protein distribution within and among clutches in blue tit eggs. Contrary
to our hypothesis, clutches showed no differential deposition of lysozyme or avidin within clutches, but eggs laid in the
middle of the sequence had higher concentrations of ovotransferrin than eggs in the beginning and end. Consistent with our
second hypothesis, we found that females produced eggs with higher concentrations of lysozyme (although not ovotransferrin
or avidin) when mated to more attractive (more UV-reflective) males. Furthermore, females mated to polygynous males deposited
less lysozyme than those mated to monogamous males. These data suggest that allocation of lysozyme at the clutch level may
be a maternal effect mediated by male qualities. 相似文献
412.
Sexual selection is often assumed to increase the viability of populations by increasing the quality of offspring produced.
Presently, human-induced environmental changes are altering the process of sexual selection by influencing male–male interactions
and female mate choice. Here, we show that increased density of filamentous algae due to eutrophication reverses parasite-mediated
selection during reproduction in threespine sticklebacks (Gasterosteus aculeatus). When we manipulated the density of artificial algae in a breeding area in the Baltic Sea, more males nested in dense than
in sparse vegetation, but the males in dense vegetation were more parasitized. Interestingly, heavily parasitized males acquired
more eggs than less parasitized males in dense vegetation but not in sparse vegetation. The higher probability of reproduction
for parasitized males in dense algae growth could be due to impaired visibility relaxing male–male competition or reducing
female choosiness. This could favour males in poor condition that often invest more in attracting females than males in good
condition. In sparse vegetation, parasitized males may have a lower reproductive success due to intense male–male competition,
careful female choice and high predation rate selecting against parasitized males. The results suggest that eutrophication
could alter the fraction of the population that reproduces, which could have long-term evolutionary consequences. 相似文献
413.
Martin Forsius Maximilian Posch Julian Aherne Gert Jan Reinds Jesper Christensen Lars Hole 《Ambio》2010,39(2):136-147
For more than a decade, anthropogenic sulfur (S) and nitrogen (N) deposition has been identified as a key pollutant in the
Arctic. In this study new critical loads of acidity (S and N) were estimated for terrestrial ecosystems north of 60° latitude
by applying the Simple Mass Balance (SMB) model using two critical chemical criteria (Al/Bc = 1 and ANCle = 0). Critical loads were exceeded in large areas of northern Europe and the Norilsk region in western Siberia during the
1990s, with the more stringent criterion (ANCle = 0) showing the larger area of exceedance. However, modeled deposition estimates indicate that mean concentrations of sulfur
oxides and total S deposition within the Arctic almost halved between 1990 and 2000. The modeled exceeded area is much reduced
when currently agreed emission reductions are applied, and almost disappears under the implementation of maximum technically
feasible reductions by 2020. In northern North America there was no exceedance under any of the deposition scenarios applied.
Modeled N deposition was less than 5 kg ha−1 y−1 almost across the entire study area for all scenarios; and therefore empirical critical loads for the eutrophying impact
of nitrogen are unlikely to be exceeded. The reduction in critical load exceedances is supported by observed improvements
in surface water quality, whereas the observed extensive damage of terrestrial vegetation around the mining and smelter complexes
in the area is mainly caused by direct impacts of air pollution and metals. 相似文献
414.
Heinz Rüdel Annette Fliedner Jan Kösters Christa Schröter-Kermani 《Environmental science and pollution research international》2010,17(5):1025-1034
Purpose
As one component of the German ecological environment observation, the Environmental Specimen Bank program was initiated in the mid-1980s. Under the program, representative specimens of marine, fresh water, and terrestrial ecosystems are sampled regularly and archived under chemically stable conditions. An initial characterization of the samples provides data regarding the status quo of the respective ecosystems. The aim of the present publication is to give insight into these real-time monitoring data, which have been generated for the last 10 to 20 years. This is done exemplarily for the heavy metals cadmium (Cd), mercury (Hg), and lead (Pb) in marine specimens of the Baltic and the North Sea. 相似文献415.
Josef Hrnčiřík Jiří Pšeja Jan Kupec Světlana Bernkopfová 《Journal of Polymers and the Environment》2010,18(2):98-103
This work focused on anaerobic biodegradation of blends composed of glycerol-plasticized polyvinyl alcohol (PVA) and biopolymer
(starch, gellan, xanthan) in an aqueous environment, after inoculation with digested activated sludge from a municipal wastewater
treatment plant. Glycerol degradability is comparable to degradability of used modifying agents. Modifying agents added in
the 20–40 wt% range proportionally increased biodegradation degree (Dt) calculated from balance of transformed carbon in the system. Biodegradation degree of polysaccharides and glycerol attained
95% and over. For PVA it was only 6.5% (in breakdown times up to 500 h). Content of polysaccharides favorably affects biodegradation
degree of polyvinyl alcohol blends, but at the expense of reduced mechanical properties of resultant products. 相似文献
416.
Klára Řehounková Lukáš Čížek Jiří Řehounek Lenka Šebelíková Robert Tropek Kamila Lencová Petr Bogusch Pavel Marhoul Jan Máca 《Environmental science and pollution research international》2016,23(14):13745-13753
Open interior sands represent a highly threatened habitat in Europe. In recent times, their associated organisms have often found secondary refuges outside their natural habitats, mainly in sand pits. We investigated the effects of different restoration approaches, i.e. spontaneous succession without additional disturbances, spontaneous succession with additional disturbances caused by recreational activities, and forestry reclamation, on the diversity and conservation values of spiders, beetles, flies, bees and wasps, orthopterans and vascular plants in a large sand pit in the Czech Republic, Central Europe. Out of 406 species recorded in total, 112 were classified as open sand specialists and 71 as threatened. The sites restored through spontaneous succession with additional disturbances hosted the largest proportion of open sand specialists and threatened species. The forestry reclamations, in contrast, hosted few such species. The sites with spontaneous succession without disturbances represent a transition between these two approaches. While restoration through spontaneous succession favours biodiversity in contrast to forestry reclamation, additional disturbances are necessary to maintain early successional habitats essential for threatened species and open sand specialists. Therefore, recreational activities seem to be an economically efficient restoration tool that will also benefit biodiversity in sand pits. 相似文献
417.
Disaggregated contributions of ecosystem services to human well-being: a case study from Eastern Europe 总被引:1,自引:0,他引:1
Andra-Ioana Horcea-Milcu Julia Leventon Jan Hanspach Joern Fischer 《Regional Environmental Change》2016,16(6):1779-1791
Aggregated analyses of the benefits from ecosystem services (ES) to well-being neglect important differences among beneficiaries and fail to capture the complexity of factors that mediate the ES–well-being relationship. Based on 25 group interviews, we disaggregated the ES–well-being relationships across six groups of potential beneficiaries in a farming landscape in central Romania, Eastern Europe. We explored what mediates distributional patterns of needs and benefits among beneficiaries and identified six contextual factors: (1) characteristics of the appropriated ES; (2) policies, formal institutions, and markets; (3) social and power relations, and informal institutions; (4) household decisions and individual contexts; (5) different perceptions and understandings of equity; and (6) individually held values. Based on these empirically derived factors, we developed a conceptual model of mediating factors that holistically takes into account the contextual space between ES and human beneficiaries. This model provides a framework for unpacking ES–well-being relationships that may guide ES research across varying socioeconomic cases. Notably, this model of mediating factors incorporates an equity perspective that is more refined than the dominant discourse on the relation between poverty and ES (which typically emphasizes that poor people are most dependent on ES, but neglects factors such as power relations and held values). Recognizing multiple contextual factors that shape the contribution of ES to well-being opens doors for harnessing new interdisciplinary collaborations and can help to inform more holistic policy interventions. 相似文献
418.
Controls on coarse wood decay in temperate tree species: birth of the LOGLIFE experiment 总被引:1,自引:0,他引:1
Cornelissen JH Sass-Klaassen U Poorter L van Geffen K van Logtestijn RS van Hal J Goudzwaard L Sterck FJ Klaassen RK Freschet GT van der Wal A Eshuis H Zuo J de Boer W Lamers T Weemstra M Cretin V Martin R Ouden Jd Berg MP Aerts R Mohren GM Hefting MM 《Ambio》2012,41(Z3):231-245
Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term 'common-garden' experiment to disentangle the effects of species' wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation. 相似文献
419.
Biomarkers and low-molecular weight polyaromatic compounds have been extensively studied for their fate in the environment. They are used for oil spill source identification and monitoring of weathering and degradation processes. However, in some cases, the absence or presence of very low concentration of such components restricts the access of information to spill source. Here we followed the resistance of high-molecular weight sulfur-containing aromatics to the simulated weathering condition of North Sea crude oil by ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry. The sulfur aromatics in North Sea crude having double bond equivalents (DBE) from 6 to 14 with a mass range 188-674 Da were less influenced even after 6 months artificial weathering. Moreover, the ratio of dibenzothiophenes (DBE 9)/naphthenodibenzothiophenes (DBE 10) was 1.30 and 1.36 in crude oil and 6 months weathered sample, respectively reflecting its weathering stability. It also showed some differences within other oils. Hence, this ratio can be used as a marker of the studied crude and accordingly may be applied for spilled oil source identification in such instances where the light components have already been lost due to environmental influences. 相似文献
420.
Impact changes of climatic extremes on arable farming in the north of the Netherlands 总被引:1,自引:1,他引:0
Schaap Ben F. Blom-Zandstra Margaretha Hermans Christiane M. L. Meerburg Bastiaan G. Verhagen Jan 《Regional Environmental Change》2011,11(3):731-741
Agriculture is vulnerable to climate change in multiple ways. Here, we use the northern region of the Netherlands as a case
study to explore how risk assessments for climate change impacts on crop production can address multiple vulnerabilities.
We present a methodology, which we call agro climate calendar (ACC) that (i) includes potential yield losses, as well as loss
of product quality, and (ii) assesses the risks of a variety of climate factors including weather extremes and the emergence
and abundance of pests and diseases. Climate factors are defined for two time slices: 1990 (1976–2005) and 2040 (2026–2055);
the frequency of occurrence of the factors is compared for the two periods, and the resulting frequency shifts are presented
in a crop calendar on a monthly basis. This yields an indication of the magnitude and direction of changes in climatic conditions
that can lead to damage by extreme events and pests and diseases. We present results for the two most important crops in the
region, seed potato, and winter wheat. The results provide a good overview of risks from climate factors, and the most important
threats and opportunities are identified. This semi-quantitative approach is firmly rooted in farm management, which is the
level where operational and strategic decisions are made. Thus, the approach is well suited to assist local stakeholders such
as farmers and policy makers to explore farm-level adaptation. This work is complementary to previous modeling work that focused
mainly on the relation between mean climate change factors (i.e., temperature) and crop yield. 相似文献