Norwegian Institute for Nature Research, FRAM - High North Research Centre on Climate and the Environment, NO-9296 Tromsø, Norway.
Sci Total Environ. 2013 Aug 1;458-460:101-6. doi: 10.1016/j.scitotenv.2013.04.027. Epub 2013 May 1.
In the recent decades, the atmospheric deposition of many metals has declined in northern Europe, mostly due to reductions of emissions in other parts of the Europe. However, less is known about the temporal trends at higher trophic levels in terrestrial food chains. In this study we measured 39 different essential and non-essential elements in tawny owl (Strix aluco) tail-feathers (n=633) collected annually between 1986 and 2005 in Central Norway. There was a strong decline in lead (Pb) concentrations (~94%) consistent with the termination of the use of Pb as a petrol additive. There were also significant declines in cadmium (Cd), cobalt (Co) and arsenic (As) concentrations. Zinc (Zn) may also have declined after 2000, but this is not yet clear due to possible analytical problems. More unexpected was a strong decline of boron (B) in the late 1980s and early 1990s with a subsequent leveling-off, but with high concentrations in 1999. The decline in B could be related to changes in the agricultural practices and use of fertilizers. Tin (Sn) showed an abrupt decline in the mid-1990s, after which the concentrations established at one fifth of the level before this time. Iron (Fe) was stable until the late 1990s, but showed an increase afterwards, whereas lanthanum (La) tended to increase up to the mid-1990s and then leveled-off. Aluminum (Al) showed decreasing levels until the mid-1990s, but a considerable increase afterwards. There was a small increase in praseodymium (Pr), but the only element showing a consistent strong increase over the study period (61%) was rubidium (Rb). The causes of the temporal trends in different elements may be changed input to the local ecosystem from local and trans-boundary sources, but possibly also variation in climate and feeding conditions for the owls.
在最近几十年，由于欧洲其他地区减少了排放，北欧的许多金属大气沉降量已经下降。然而，对于陆地食物链中更高营养级别的时间趋势知之甚少。在这项研究中，我们测量了 1986 年至 2005 年间在挪威中部每年收集的 633 只茶色猫头鹰（Strix aluco）尾羽中的 39 种不同的必需和非必需元素。由于终止了将铅作为汽油添加剂的使用，铅（Pb）浓度下降了约 94%（~）。镉（Cd）、钴（Co）和砷（As）浓度也显著下降。锌（Zn）浓度可能也在 2000 年后下降，但由于可能存在分析问题，目前还不清楚。更出人意料的是，硼（B）在 80 年代末和 90 年代初急剧下降，随后趋于平稳，但在 1999 年浓度较高。B 的下降可能与农业实践和肥料使用的变化有关。锡（Sn）在 90 年代中期突然下降，此后浓度稳定在该时期之前的五分之一。铁（Fe）在 90 年代末之前保持稳定，之后增加，而镧（La）则在 90 年代中期之前增加，然后趋于平稳。铝（Al）的水平一直下降到 90 年代中期，但此后有了相当大的增加。镨（Pr）略有增加，但唯一在研究期间持续呈强劲增长（61%）的元素是铷（Rb）。不同元素的时间趋势的原因可能是本地和跨境来源对当地生态系统的输入发生了变化，但也可能是气候和猫头鹰的摄食条件发生了变化。
