A TAXONOMIC AND ECOLOGICAL STUDY OF DIATOMS FROM FRESHWATER HABITATS IN THE FALKLAND ISLANDS, SOUTH ATLANTIC
A TAXONOMIC AND ECOLOGICAL STUDY OF DIATOMS FROM FRESHWATER HABITATS IN THE FALKLAND ISLANDS, SOUTH ATLANTIC
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DOI：
10.1080/0269249x.2005.9705620
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发表时间：
2005-05
期刊：
影响因子：
1.8
通讯作者：
R. Flower
中科院分区：
文献类型：
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作者：
R. Flower
1.对福克兰群岛的硅藻植物群进行了调查，对28个有代表性的湖泊、池塘和溪流生境进行了取样。硅藻组合是中等多样性和贫营养的软沃茨的底栖生物类群的特点为主。2.特别是Fragilarioid和Achnanthoid类群具有异常小的阀，这种情况被认为是有利的普遍恶劣的环境条件。3. 11个新的硅藻分类群被描述，并提出了几个新的组合，但很可能进一步的研究将表明，至少有一些新的分类群将共同出现，在巴塔哥尼亚和其他地方，而不是在福克兰群岛特有的。4.分类群丰富度在不同地点之间变化很大，但分类群总数、区域特有分类群数量或稀有分类群与栖息地复杂性、栖息地大小或水pH值之间的趋势很弱（没有使用多样性模型，因为缺乏扩散和移民率数据）。5.世界性的类群是最常见的，但评估的植物群的一个重要部分（约三分之一）是由于与区域限制分布的类群。南美洲南部、亚热带和北美洲的成分都存在，但可能很少有分类群完全局限于福克兰群岛。6.宏观和微生态因素决定了硅藻样品中分类群的组成和数量。据认为，所记录的物种组合反映了福克兰群岛所有地点接近原始的水生条件（不过，还需要古湖泊学技术来检验关于本地和非本地分类群的假设）。7.尽管将硅藻数据与物种多样性模型拟合存在困难，但这些代表性样本中硅藻类群的出现和丰度提供了独特的特定地点生物特征，反映了水质和物理栖息地以及区域植物群属性。8.常规硅藻分析的生态目的需要准确的分类和一致性是至关重要的，但与地理和系统的研究相比，较低的精度水平可能是足够的。9.监测硅藻群落是感知环境变化的一种方式，全球变暖被认为是对福克兰群岛内陆沃茨生物完整性的最大威胁。
1. The diatom flora of the Falkland Islands was investigated by sampling twenty-eight representative lake, pond and stream habitats. Diatom assemblages were moderately diverse and dominated by benthic taxa characteristic of oligotrophic soft waters. 2. Particularly the Fragilarioid and Achnanthoid taxa possessed unusually small valves and this condition is thought to be favoured by the prevailing harsh environmental conditions. 3. Eleven new diatom taxa are described and several new combinations are proposed but it is likely that further research will show that at least some of the new taxa will co-occur, in Patagonia and elsewhere, rather than be endemic in the Falklands archipelago. 4. Taxon richness varied strongly between sites but only weak trends were indicated between total number of taxa, number of regional endemic taxa, or rare taxa and habitat complexity, habitat size or water pH (diversity models were not used because dispersal and immigration rate data are lacking). 5. Cosmopolitan taxa were most common but a significant portion (approximately one third) of the assessed flora was attributed to taxa with regionally restricted distributions. Southern South American, Subantarctic and North American elements were present but probably very few taxa are entirely restricted to the Falkland Islands. 6. Macro- and microecological factors determine both the composition and numbers of taxa in a diatom sample. The species assemblages recorded are thought to reflect near pristine aquatic conditions at all the Falkland sites (palaeolimnogical techniques are nevertheless required to test hypotheses about native and non-native taxa). 7. Irrespective of difficulties in fitting diatom data to species diversity models, the occurrence and abundance of diatom taxa in these representative samples provide a unique site-specific biological signature that reflects water quality and physical habitat as well as regional flora attributes. 8. Routine diatom analysis for ecological purposes requires accurate taxonomy and consistency is of paramount importance but, compared with biogeographic and systematic studies, a lower level of precision is probably adequate. 9. Monitoring diatom communities offers one way of perceiving environmental change and global warming is thought to pose the greatest threat to the biological integrity of the inland waters of the Falkland Islands.