Global southern limit of flowering plants and moss peat accumulation
Global southern limit of flowering plants and moss peat accumulation
复制标题
DOI：
10.3402/polar.v30i0.8929
复制
发表时间：
2011-01-01
期刊：
影响因子：
1.9
通讯作者：
Tyler, Andrew N.
中科院分区：
文献类型：
--
作者：
Convey, Peter;Hopkins, David W.;Tyler, Andrew N.
南极半岛西部的生态系统是世界上区域气候变暖趋势最快的地区之一，它是重要的“早期预警”指标，可用来预测其他地区更复杂系统的应对措施。在这种区域变暖的反应中，被广泛报道的是南极本土的两种开花植物--南极洲德香花和木莲的种群和活动范围的扩大。然而，对范围扩大的预测的确认需要物种分布的基线知识。我们报道了这两种植物在该地区已知的自然分布向南和向西的显著扩展，以及在一个不寻常的苔藓群落中的几个范围的扩展，这是基于在南极半岛南部亚历山大岛西北部拉扎雷夫湾的一个以前没有被研究和命名的低海拔半岛上的一项新的调查工作。因此，这些植物物种在南极的自然活动范围比之前想象的要大得多。这一地点在该区域南部边界附近提供了一个潜在的重要监测地点，目前证明该区域受到迅速变化的气候趋势的影响。结合放射性碳和铅同位素的放射性测年表明，这一地区极有可能在19世纪末充分消融，使泥炭开始堆积，我们初步将其与1870年后的气候改善阶段联系起来。我们的结论是，该地区植被的建立不太可能与南极半岛自20世纪中叶以来记录的快速区域变暖趋势有关。
The ecosystems of the western Antarctic Peninsula, experiencing amongst the most rapid trends of regional climate warming worldwide, are important "early warning" indicators for responses expected in more complex systems elsewhere. Central among responses attributed to this regional warming are widely reported population and range expansions of the two native Antarctic flowering plants, Deschampsia antarctica and Colobanthus quitensis. However, confirmation of the predictions of range expansion requires baseline knowledge of species distributions. We report a significant southwards and westwards extension of the known natural distributions of both plant species in this region, along with several range extensions in an unusual moss community, based on a new survey work in a previously unexamined and un-named low altitude peninsula at 69 degrees 22.0'S 71 degrees 50.7'W in Lazarev Bay, north-west Alexander Island, southern Antarctic Peninsula. These plant species therefore have a significantly larger natural range in the Antarctic than previously thought. This site provides a potentially important monitoring location near the southern boundary of the region currently demonstrated to be under the influence of rapidly changing climate trends. Combined radiocarbon and lead isotope radiometric dating suggests that this location was most likely deglaciated sufficiently to allow peat to start accumulating towards the end of the 19th century, which we tentatively link to a phase of post-1870 climate amelioration. We conclude that the establishment of vegetation in this location is unlikely to be linked to the rapid regional warming trends recorded along the Antarctic Peninsula since the mid-20th century.