Human impacts in soft-sediment assemblages at Casey Station, East Antarctica: Spatial variation, taxonomic resolution and data transformation
Human impacts in soft-sediment assemblages at Casey Station, East Antarctica: Spatial variation, taxonomic resolution and data transformation
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DOI：
10.1046/j.1442-9993.2003.01289.x
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发表时间：
2003-06
期刊：
影响因子：
1.5
通讯作者：
J. Stark;M. Riddle;R. Simpson
中科院分区：
文献类型：
--
作者：
J. Stark;M. Riddle;R. Simpson
在南极洲凯西站，海洋软沉积物组合之间的差异被发现在干扰（两个垃圾场，污水排放口和码头）和控制位置。这些差异是显着的背景空间变异性。潜水员采用分层、空间嵌套抽样设计收集岩芯样本，该设计包括四个尺度：㈠地点（相隔数千米）; ㈡地点（相隔数百米）; ㈢地块（相隔数十米）; ㈣地块内重复样本（相隔约1米）。控制位置有更大的物种丰富度和多样性比干扰的位置，有许多类群在控制位置，没有记录在干扰的位置。在干扰位置的组合比那些在控制位置的变量。与此相反，一些优势种的种群在干扰的位置比在控制位置更易变。个体类群的种群在所有尺度上也存在显著变化，虽然在位置水平上最大，但在最小尺度上，重复核心之间的变化也很大，表明类群种群中存在显著的小规模斑块。组合结构的模式是相似的，在罚款（77分类群）和中等（聚合到33分类群）水平的分类分辨率，但改变了粗的分辨率水平（9门）。凯西站的软沉积物组合与南极其他地区报道的有明显不同。在凯西的组合几乎完全由甲壳类动物（高达99%的总丰度）和多毛类动物是罕见的或在该地区调查的大多数地区丰度很低。这也是第一次证明小型南极研究站（20-50人）可能对邻近海洋环境造成可检测到的影响。
Differences between marine soft-sediment assemblages at disturbed (two waste dumps, a sewage outfall and a wharf) and control locations were found at Casey Station, Antarctica. These differences were significant against considerable background spatial variability. Core samples were collected by divers using a hierarchical, spatially nested sampling design incorporating four scales: (i) locations (thousands of metres apart); (ii) sites (hundreds of metres apart); (iii) plots (tens of metres apart); and (iv) among replicates within plots (approximately 1 metre apart). Control locations had greater species richness and diversity than disturbed locations and there were many taxa found at control locations that were not recorded at disturbed locations. Assemblages at disturbed locations were less variable than those at control locations. In contrast, populations of some dominant species were more variable at disturbed locations than at control locations. Significant variation in populations of individual taxa was also found at all scales and although greatest at the level of location, variation was also large at the smallest scale, between replicate cores, indicating significant small-scale patchiness in populations of taxa. Patterns of assemblage structure were similar at fine (77 taxa) and medium (aggregated to 33 taxa) levels of taxonomic resolution, but changed at coarse levels of resolution (nine phyla). Soft-sediment assemblages at Casey Station are markedly different from those reported from other areas of Antarctica. Assemblages at Casey are almost completely dominated by crustaceans (up to 99% total abundance) and polychaetes are rare or in very low abundances in most areas investigated in the region. This is also the first demonstration that small Antarctic research stations (population 20-50 people) may cause impacts that are detectable in the adjacent marine environment.