Pollen Record of the Last 500 Years from the Doninos Coastal Lagoon (NW Iberian Peninsula): Changes in the Pollinic Catchment Size Versus Paleoecological Interpretation
Pollen Record of the Last 500 Years from the Doninos Coastal Lagoon (NW Iberian Peninsula): Changes in the Pollinic Catchment Size Versus Paleoecological Interpretation
复制标题
多尼诺斯沿海泻湖（伊比利亚半岛西北部）过去 500 年的花粉记录：花粉流域大小的变化与古生态学解释
DOI：
--
复制
发表时间：
2001
影响因子：
--
通讯作者：
M. S. Goñi
中科院分区：
文献类型：
--
作者：
Luisa Santos;R. Bao;M. S. Goñi
对在伊比利亚半岛西北部多尼诺斯沿海泻湖边缘采集的4.20米长的岩芯进行了花粉、硅藻、木炭和沉积学分析，提供了该泻湖在过去530年BP期间的环境演变信息。在此期间，当地环境变化，如沙障渗透性、冲积沉积和/或人类活动的变化，在这一海岸体系的演变中发挥了主要作用。这一情景使我们能够测试记录在沿海泻湖沉积物中的授粉信号在多大程度上受到当地过程的影响。硅藻和沉积学数据以及历史档案表明，层序底部发育了湖泊体系。因此，取心地点可能包括在泻湖本身。花粉数据似乎反映了作为大的授粉集水区的结果的区域植被。当地的栗树种植和人为砍伐森林也有记录。在层序的顶部，硅藻相表明，由于更常见的逆行屏障被打破的事件，此时海洋影响增加。这一点，加上冲积沉积造成的自然淤积和人为造成的泻湖边缘干涸，导致水体延伸逐渐减少。取心点现在在泻湖之外，这意味着授粉集水区的面积减少，导致当地周生植被的授粉降雨量逐渐增加。从这一海岸沉积物的花粉图来看，区域植被的特征被当地的花粉输入所淹没。不同花粉类群百分比的波动与盆地大小、人类活动和屏障突破之间的复杂相互作用有关。因此，必须谨慎对待来自沿海泻湖授粉研究的直接古气候推断，作为缺乏其他大陆矿床的替代方案。
Pollen, diatom, charcoal and sedimentological analyses of a 4.20-m long core collected in the margin of the Doninos coastal lagoon, northwest Iberian Peninsula, provide information about the environmental evolution of this lagoon during the last 530 yr BP. During this time period, local environmental changes, such as changes in the sand-barrier permeability, alluvial sedimentation and/or anthropogenic activity, played a major role in the evolution of this coastal system. This scenario allows us to test the degree the pollinic signal recorded in the sediments of coastal lagoons is reshaped by the influence of local processes. Diatom and sedimentological data as well as historical archives indicate the development of a lacustrine system at the bottom of the sequence. Therefore, the coring site might be included in the lagoon itself. Pollen data seems to reflect the regional vegetation as a consequence of the large pollinic catchment area. Local Castanea cultivation and anthropogenic deforestation are also recorded. At the top of the sequence, diatom facies suggest increased marine influence at this time as a consequence of the more common events of breaching of a retrograding barrier. This, plus natural silting up by alluvial sedimentation and man-induced drying up of the lagoonal margins, lead to a progressive decrease in the water body extension. The coring point is now outside of the lagoon, implying a reduction in the pollinic catchment area that gave rise to a gradual increase in the local pollinic rainfall of periphytic vegetation. From the pollen diagram of this coastal deposit signatures of regional vegetation are swamped by local pollen input. The fluctuations in the percentages of the different pollen taxa are related to the complex interaction between basin size, human activities and breaching of the barrier. Caution must therefore be taken with direct paleoclimatic inferences from pollinic studies in coastal lagoons as an alternative where other continental deposits are lacking.