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81.
It has been proposed that blue colouration in eggs has evolved as a signal of female quality that males can use to modulate
their parental investment. This hypothesis is based in the antioxidant properties of biliverdin whose costly deposition in
the eggshell is expected to signal female antioxidant capacity and egg quality. Since maternally derived androgens are costly
to produce and may adaptively affect offspring phenotype, high-quality females may benefit by signalling their androgen investment
through egg colouration. Our aim was to investigate whether egg colour variation in the spotless starling reflected the amount
of pigments on the eggshell and whether egg pigmentation was related to female and egg quality. Chromatography analyses revealed
that spotless starling eggshells contained two different pigments: biliverdin and protoporphyrin IX with no correlation between
them. Biliverdin contents correlated positively with egg colouration indicating that darker eggs with a higher peak in the
blue–green segment of the spectrum contained higher amounts of biliverdin. Eggs containing more biliverdin were laid by high-quality
females and contained higher yolk testosterone levels. However, despite the strong correlation between biliverdin and colorimetric
variables, egg colouration did not reflect accurately female and egg quality. Our results provide evidence that eggshell pigmentation
in the spotless starling is related to female and egg quality as shown by the yolk testosterone levels. However, the lack
of relation between egg colour and female condition and egg quality do not provide evidence to support the signalling function
of egg colouration. 相似文献
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Pablo Resco Ana Iglesias Isabel Bardají Vicente Sotés 《Regional Environmental Change》2016,16(4):979-993
Our aim was to explore the adaptation choices to climate change in the grapevine regions of Spain from two points of view. First, what are the main reasons for concern? Second, how large is the adaptation effort in each region? We address the first question by measuring sensitivity to climate change with Huglin, Cold Night and Dryness Indices over the entire territory, providing information on the adaptation type (e.g. varieties, zoning, water allocation). We then estimate probabilistic projections across scenario, zone and sensitivity indices in the 56 Protected Designation of Origin areas to inform on the magnitude of the adaptation effort. Second, we propose an adaptation effort measure that is framed according to the local environmental context. Results suggest that most areas urgently need an adaptation plan due to the deterioration of production and quality indices as a result of climate change. Potential opportunities in many climate regions might be limited by current policy. The production objectives of quality and quantity trade-offs will probably need to be revised by analysing the sustainability of grapevine production. 相似文献
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Irene Iniesta-Arandia Federica Ravera Stephanie Buechler Isabel Díaz-Reviriego María E. Fernández-Giménez Maureen G. Reed Mary Thompson-Hall Hailey Wilmer Lemlem Aregu Philippa Cohen Houria Djoudi Sarah Lawless Berta Martín-López Thomas Smucker Grace B. Villamor Elizabeth Edna Wangui 《Ambio》2016,45(3):383-393
This synthesis article joins the authors of the special issue “Gender perspectives in resilience, vulnerability and adaptation to global environmental change” in a common reflective dialogue about the main contributions of their papers. In sum, here we reflect on links between gender and feminist approaches to research in adaptation and resilience in global environmental change (GEC). The main theoretical contributions of this special issue are threefold: emphasizing the relevance of power relations in feminist political ecology, bringing the livelihood and intersectionality approaches into GEC, and linking resilience theories and critical feminist research. Empirical insights on key debates in GEC studies are also highlighted from the nine cases analysed, from Europe, the Americas, Asia, Africa and the Pacific. Further, the special issue also contributes to broaden the gender approach in adaptation to GEC by incorporating research sites in the Global North alongside sites from the Global South. This paper examines and compares the main approaches adopted (e.g. qualitative or mixed methods) and the methodological challenges that derive from intersectional perspectives. Finally, key messages for policy agendas and further research are drawn from the common reflection. 相似文献
86.
Simões Eliane de Sousa Junior Wilson C. de Freitas Débora M. Mills Morena Iwama Allan Y. Gonçalves Isabel Olivato Débora Fidelman Pedro 《Regional Environmental Change》2017,17(6):1739-1750
Regional Environmental Change - This paper examines barriers and opportunities for climate change adaptation in an urban coastal setting where adaptation is in its infancy. It draws on a diagnostic... 相似文献
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Angel Pérez-Ruzafa Concepción Marcos Isabel María Pérez-Ruzafa María Pérez-Marcos 《Journal of Coastal Conservation》2011,15(3):369-392
The European Water Framework Directive (WFD) establishes a well differentiated typology of water bodies on the basis of scientific
and biological criteria. For coastal waters, such criteria have long been established, while for transitional waters they
are still under discussion. One of the difficulties when applying the WFD to coastal lagoons is to include them in only one
of these categories, and while there is no doubt about the nature of estuaries as transitional waters, there is some controversy
concerning lagoons. To what extent, reference conditions may be similar for estuaries and lagoons, or whether features common
to all coastal lagoons are more important for differentiating them from other water bodies than the fact that there is (or
is not) any fresh water influence, is something that remains unclear and is discussed in this work. Coastal lagoons and estuaries
form part of a continuum between continental and marine aquatic ecosystems. Shelter, strong boundaries or gradients with adjacent
ecosystems, anomalies in salinity regarding freshwater or marine ecosystems, shallowness, etc. all contribute to the high
biological productivity of estuaries and lagoons and determine common ecological guilds in the species inhabiting them. On
the other hand, fresh water influence, the spatial organization of gradients and environmental variability (longitudinal one-dimensional
gradients in estuaries versus complex patterns and three-dimensional heterogeneity in lagoons) constitute the main differences,
since these factors affect both the species composition and the dominance of certain ecological guilds and, probably, the
system’s complexity and homeostatic capability. In the context of the WFD, coastal lagoons and estuaries are closer to each
other than they are to continental or marine waters, and, on the basis of the shared features, they could be intercalibrated
and managed together. However, coastal lagoons cannot be considered transitional waters according to the present definition.
To assume that fresh water influence is an inherent characteristic to these ecosystems could lead to important changes in
the ecological organization and functioning of coastal lagoons where natural fresh water input is low or null. In our opinion,
the present day definition of transitional waters should be changed substituting the criterion of fresh water influence by
another based on common features, such as relative isolation and anomalies in salinity in water bodies with marine influence.
Otherwise, coastal lagoons should be considered a particularly characteristic type of water mass for establishing reference
conditions of ecological status. 相似文献
89.
With the potential expansion of forest conservation programs spurred by climate-change agreements, there is a need to measure the extent to which such programs achieve their intended results. Conventional methods for evaluating conservation impact tend to be biased because they do not compare like areas or account for spatial relations. We assessed the effect of a conservation initiative that combined designation of protected areas with payments for environmental services to conserve over wintering habitat for the monarch butterfly (Danaus plexippus) in Mexico. To do so, we used a spatial-matching estimator that matches covariates among polygons and their neighbors. We measured avoided forest loss (avoided disturbance and deforestation) by comparing forest cover on protected and unprotected lands that were similar in terms of accessibility, governance, and forest type. Whereas conventional estimates of avoided forest loss suggest that conservation initiatives did not protect forest cover, we found evidence that the conservation measures are preserving forest cover. We found that the conservation measures protected between 200 ha and 710 ha (3-16%) of forest that is high-quality habitat for monarch butterflies, but had a smaller effect on total forest cover, preserving between 0 ha and 200 ha (0-2.5%) of forest with canopy cover >70%. We suggest that future estimates of avoided forest loss be analyzed spatially to account for how forest loss occurs across the landscape. Given the forthcoming demand from donors and carbon financiers for estimates of avoided forest loss, we anticipate our methods and results will contribute to future studies that estimate the outcome of conservation efforts. 相似文献
90.