Temporal variability of phytoplankton community structure based on pigment analysis
Temporal variability of phytoplankton community structure based on pigment analysis
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DOI：
10.4319/lo.1993.38.7.1420
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发表时间：
1993-11
影响因子：
4.5
通讯作者：
Ricardo M Letelier;R. Bidigare;Dale V. Hebel;M. Ondrusek;C. D. Winn;D. Karl
中科院分区：
文献类型：
--
作者：
Ricardo M Letelier;R. Bidigare;Dale V. Hebel;M. Ondrusek;C. D. Winn;D. Karl
定期测定了藻类叶绿素和类胡萝卜素的分布。ALOHA（22“45”N，158“OO 'W），以记录浮游植物丰度和组成的变化。年平均深度积分（O-200分贝）浓度的叶绿素a显示显着的年际变化。叶绿素a浓度的季节性模式被认为是深度依赖性的。冬季混合层叶绿素a浓度升高是混合层加深后光适应的结果。叶绿素a的增加，在春季的深层叶绿素最大层（DCML）被解释为增加养分供应所造成的加深的DCML相对于bg = 24.25密度表面。一个算法的基础上的比值Chl a的诊断色素存在于特定的藻类类群被用来估计的贡献，总Chl a的主要藻类集团内DCML。结果表明，在DCML浮游植物群落的存在下，以下平均组成：原绿球藻属。(39%）、蓝细菌（24%）、报春植物（22%）和金藻（13%）。没有一个单一的类群是负责春季增加叶绿素a观察到在这个栖息地。大小分级和正相高效液相色谱法的结果证实，原球菌属。是Chl a对DCML的主要贡献者。浮游植物生产和生物量的季节性周期幅度被认为是纬度相关的，低纬度地区的变化最小（库欣1959;海因里希1962; Sournia 1969）。因此，中低纬度海洋区域需要健全的采样计划和精确的分析，以区分浮游植物生物量和产量的季节性波动与随机事件产生的变异。
Algal chlorophyll and carotenoid distributions were measured periodically in the euphotic zone of Sta. ALOHA (22”45’N, 158”OO’W) between February 1989 and October 1991 to document the variability in phytoplankton abundance and composition. The annual mean depth-integrated (O-200 db) concentration of Chl a displayed significant interannual variability. Seasonal patterns in Chl a concentration were found to be depth-dependent. Elevated Chl a in the mixed layer is the result of photoadaptation as the mixed layer deepens in winter. Increases in Chl a at the deep chlorophyll maximum layer (DCML) in spring are explained by increased nutrient availability caused by a deepening of the DCML relative to the bg = 24.25 density surface. An algorithm based on the ratios of Chl a to diagnostic pigments present in specific algal taxa was used to estimate the contribution to total Chl a by the major algal groups represented within the DCML. Results indicate the presence of a phytoplankton community at the DCML with the following mean composition: Prochlorococcus spp. (39%), cyanobacteria (24%), prymnesiophytes (22%),and chrysophytes (13%). No single taxon is responsible for the springtime increase in Chl a observed in this habitat. Results from size fractionation and normal-phase high performance liquid chromatography confirm that Prochforococcus spp. are the principal contributors of Chl a to the DCML. The amplitude of the seasonal cycle in phytoplankton production and biomass is thought to be latitude-dependent with the smallest variations at low latitudes (Cushing 1959; Heinrich 1962; Sournia 1969). Consequently, mid- and low-latitude oceanic regions require robust sampling schedules and precise analyses to discern seasonal fluctuations in phytoplankton biomass and production from variability produced by stochastic events.