Raw taxonomic and abundances data

BIOGEOGRAPHY OF THE SOUTHERN OCEAN: ENVIRONMENTAL FACTORS DRIVING MESOPLANKTON DISTRIBUTION SOUTH OF AFRICA

Spatial distribution of zooplankton communities depends on numerous factors, especially temperature and salinity conditions (hydrological factor), sampled depth, trophic factor, and dial cycle. We analyzed and compared the impact of these factors on abundance, biodiversity, quantitative (QNT-structure based on proportion of taxa) and qualitative (QUAL-structure based on presence/absence of taxa) structure of mesoplankton in the Southern Ocean. Samples (43 stations, three vertical strata sampled at each station, 163 taxa identified) were collected with a Juday net along the SR02 transect in December 2009. Mesoplankton abundance in discrete vertical layers ranged from 0.2 to 13743.6 ind. m-3 (five orders of magnitude), maximal and minimal values were recorded in the upper mixed and in the deepest layer, respectively. Within the combined 300-m layer, abundances ranged from 16.0 to 1455.0 ind. m-3(five orders of magnitude) suggesting that integral samples provide little information about actual variations of mesoplankton abundances. A set of analyses (CCAs, ANOSIM, clustering) showed that depth was the major driver of mesoplankton distribution (abundance, biodiversity, QNT-structure), hydrological factors influenced two of them (QNT-structure and QUAL-structure), trophic factor (surface chlorophyll as a proxy) strongly affected one parameter (QNT-structure), and dial cycle had an insignificant effect on mesoplankton distribution. Using our current knowledge of the fine structure of the Antarctic Circumpolar Current, we compared effects of four hydrological fronts (boundaries between different water-masses with distinct environmental characteristics) and eight dynamic jets (narrow yet very intense currents) on mesoplankton distribution. Three hydrological fronts (Subtropical, Polar, Subantarctic) drove QNT-structure and QUAL-structure of mesoplankton assemblages (decreasing in order of influence), while the fourth front (Southern Boundary) affected only QUAL-structure. Effects of dynamic jets were insignificant. We suggest that mesoplankton composition is driven by hydrological parameters and further maintained through compartmentalization by fronts. Impact of local eddies and meanders on biodiversity, abundance, QUAL and QNT-structure of mesoplankton is comparable to that of hydrological fronts. QUAL-structure of mesoplankton assemblages mirrors hydrological structure of the Southern Ocean better than QNT-structure and is therefore greatly worth for solution of biogeographic tasks. We compared results of our survey and a survey conducted along the same transect within the same 0-300 m layer in 1992/1993 (17 years before). No significant changes in mesoplankton distribution were found. In spite of different sampling methods, spatial variations in abundance, distribution, and taxa richness were similar in both surveys.

《南大洋生物地理学：非洲南部以南海域中层浮游动物分布的驱动环境因子》

浮游动物群落的空间分布受诸多环境因子调控，其中尤以温盐条件（水文因子）、采样深度、营养因子以及昼夜周期最为关键。本研究针对南大洋中层浮游动物，分析并对比了上述因子对其丰度、生物多样性、定量结构（QNT-structure，基于类群占比构建）以及定性结构（QUAL-structure，基于类群有无构建）的影响。

研究样本于2009年12月沿SR02断面使用Juday网采集完成，共设置43个采样站位，每个站位采集三层垂直分层样品，最终鉴定出163个浮游动物类群。各独立垂直分层的中层浮游动物丰度介于0.2至13743.6 个·立方米⁻¹之间，跨度达五个数量级；丰度最大值与最小值分别出现在上层混合层与最深采样层。而整合后的300米层段内，丰度范围为16.0至1455.0 个·立方米⁻¹，同样跨越五个数量级，这表明整合采样样本难以反映中层浮游动物丰度的真实变化情况。

通过一系列分析（CCAs、ANOSIM、聚类分析）结果显示：深度是调控中层浮游动物分布（包括丰度、生物多样性与QNT-structure）的首要驱动因子；水文因子对其中两项指标（QNT-structure与QUAL-structure）存在显著影响；营养因子（以表层叶绿素为替代指标）对QNT-structure具有极强的调控作用；而昼夜周期对中层浮游动物分布的影响并不显著。

结合当前对南极绕极流（Antarctic Circumpolar Current）精细结构的认知，本研究对比了四类水文锋面（具有独特环境特征的不同水团间边界）与八处动力射流（狭窄但强度极高的海流）对中层浮游动物分布的影响。其中三类水文锋面——亚热带锋、极地锋、亚南极锋——对中层浮游动物群落的QNT-structure与QUAL-structure均存在调控作用（影响强度依次递减），而第四类锋面（南界锋）仅对QUAL-structure产生影响。动力射流的影响则不显著。

本研究认为，中层浮游动物的群落组成主要受水文参数调控，并通过锋面的分隔效应得以维持。局地涡旋与流弯对中层浮游动物生物多样性、丰度、QUAL-structure与QNT-structure的影响强度，与水文锋面相当。相较于QNT-structure，中层浮游动物群落的QUAL-structure更能反映南大洋的水文结构，因此在解决生物地理学相关研究问题中具有更高的应用价值。

本研究还将本次调查结果，与1992/1993年（即本次调查前17年）沿同一断面、同一0-300米层段开展的另一项调查结果进行了对比。结果未发现中层浮游动物分布存在显著变化。尽管两项调查采用了不同的采样方法，但二者在浮游动物丰度、分布以及类群丰富度的空间变异特征上表现一致。