| 文件类型： |
文章 |
| 所有的著者/提供者： |
Wendy J Palen; Craig E Williamson; Aaron A Clauser; Daniel E Schindler |
| ISSN: | 0962-8452 |
|---|
| OCLC号码： |
483039719 |
| 语言注释： |
English |
| 注意： |
Figure 1. Average proportion of embryos surviving to hatching when exposed to five experimental levels of UV-B ($kJ m^{-2}$) in the presence (filled circles) and absence (open circles) of photorepair radiation (PRR) for (a) R. cascadae (RACA), (b) P. regilla (PSRE), (c) A. macrodactylum (AMMA) and (d) A. gracile (AMGR). Solid line represents the best-fit nonlinear model for each series of experiments. Data are plotted as $means \pm 1 s.e.$Figure 2. Estimated dose of UV-B ($kJ m^{-2}$) corresponding to 50% embryonic survival ($LD_{50}$) for RACA, PSRE, AMMA and AMGR in the presence (filled diamonds) and absence (open diamonds) of PRR. $LD_{50}$ for each species is estimated from nonlinear model fits and plotted with 95% confidence intervals.
Figure 3. Relationship between two features of embryonic oviposition, (a-c) proportion of eggs shaded and (d-f) mean depth of eggs, at breeding sites of (a,d) AMMA, (b,e) AMGR and (c,f) RACA across a range of water transparency to UV-B (percentage surface UV-B at 10 cm water depth). A greater proportion of AMMA embryos are shaded from ambient light with increasing water transparency to UV-B ($a sin \sqrt{P_{shaded}} = 0.738a sin \sqrt{P_{UV-B}} + 0.173$, $r^{2} = 0.50$, p < 0.001), and the average depth (cm) of AMGR eggs in the water column increases with increasing water transparency to UV-B ($depth_{eggs} = 0.017a sin \sqrt{P_{UV-B}} - 0.024$, $r^{2} = 0.71$, p < 0.005). No other relationships were found to be statistically significant with $\alpha = 0.05$. Transmission of surface UV-B through the water column is determined by the diffuse attenuation coefficient ($K_{d}$) for UV-B wavelengths (290-320 nm), estimated by the absorption of 440 nm light in a spectrophotometer. |
| 奖励： |
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摘要：
Increasing ultraviolet-B radiation (UV-B) has recently captured the attention of ecologists as a key environmental stressor. Certain species may be particularly vulnerable as a result of either high natural exposure to UV-B or limited physiological capacity to withstand it. UV-B sensitivity has been examined at the cellular and individual level for a wide variety of taxa, but estimates of exposure to UV-B in natural systems are lacking and predictions of large-scale impacts are therefore limited. Here, we combine data on the physiological sensitivity to UV-B and patterns of field exposure across sites for embryos of several well-studied US Pacific Northwest amphibian species. We find substantial differences among species' physiological abilities to withstand UV-B and in the level of UV-B exposure of embryos in the field. More specifically, we find that species with the highest physiological sensitivity to UV-B are those with the lowest field exposures as a function of the location of embryos and the UV-B attenuation properties of water at each site. These results also suggest that conclusions made about species' vulnerability to UV-B in the absence of information on field exposures may often be misleading.
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文章 : 英语