The late summer crustacean zooplankton in western U.S.A reservoirs reflects ecoregion, temperature and latitude
The late summer crustacean zooplankton in western U.S.A reservoirs reflects ecoregion, temperature and latitude
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美国西部水库夏末甲壳类浮游动物反映了生态区、温度和纬度
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
R. M. Davidson
中科院分区：
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作者：
J. Beaver;Claudia E. Tausz;Thomas R. Renicker;G. Holdren;Denise M. Hosler;Erin E. Manis;Kyle C. Scotese;Catherine E. Teacher;Benjamin T Vitanye;R. M. Davidson
总结
我们测试了是否甲壳类浮游动物的物种组成和大小结构（这是重要的决定因素，在浮游生物食物网的能量流）在夏末在水库将涉及到生态区域名称，集水区土地利用，温度和纬度。我们还研究了是否减少枝藻体的大小随纬度降低（观察到的天然湖泊）的预测将是有效的水库。2010年夏末，从美国西部分布在北纬32.5 °至48.6°的三个主要生态区的102个水库中收集了浮游动物样品。
大型枝角类（蚤状水蚤复合体）和剑水蚤桡足类（Diacyclops thomasi）被发现在更深，更冷的水库与森林集水区（西北森林山脉）。小型枝角类（Daphnia retrocurva，Diaphanosoma spp.）和Chydorus sphaericus）和剑水蚤桡足类（Tropocyclops prasinus）在受农业影响的集水区（大平原）的生产性水库中更为常见。小型的枝角类（Bosmina longirostris）占主导地位，否则温和的甲壳类浮游动物位于集水区为主的万年青灌木植被有限的造林（西部干旱）水库。哲水蚤桡足类也表现出明显的生态区分布。
水温的升高和纬度的降低与水蚤和枝水蚤的平均体长和绝对生物量的降低有关。在温暖的沃茨（即北纬36 °以下和/或海拔低于500米的地点），水蚤类很少或不存在。
浮游动物的种类组成和平均体长与常见的肉食性鱼类鲑鱼（Oncorhynchus spp.）和湖鳟鱼（红点鲑属）在西北森林山脉，在大平原和threadfin鲱鱼（Dorosoma petenense）在西部干旱生态区的砂囊鲱鱼（Dorosoma cepedianum）。
我们的研究表明，水库中的枝藻浮游动物的分类组成和大小结构是高度连接到生态区域属性，如集水区土地利用，温度和纬度已观察到的天然湖泊。
Summary
We tested whether the crustacean zooplankton species composition and size structure (which are important determinants of energy flow in plankton food webs) during late summer in reservoirs would be related to ecoregional designations, catchment land use, temperature and latitude. We also examined whether the predictions of decreasing cladoceran body size with decreasing latitude (as observed for natural lakes) would be valid for reservoirs. Zooplankton samples were collected in late summer 2010 from 102 western U.S. reservoirs distributed over three major ecoregions from 32.5 to 48.6°N latitude.
Large-bodied cladocerans (Daphnia pulex complex) and cyclopoid copepods (Diacyclops thomasi) were found in deeper, cooler reservoirs with forested catchments (Northwestern Forested Mountains). Small-bodied cladocerans (Daphnia retrocurva, Diaphanosoma spp. and Chydorus sphaericus) and cyclopoid copepods (Tropocyclops prasinus) were more common in productive reservoirs in catchments influenced by agriculture (Great Plains). Small-bodied cladocerans (Bosmina longirostris) dominated the otherwise modest crustacean zooplankton in reservoirs located in catchments dominated by evergreen shrub vegetation with limited forestation (Western Xeric). Calanoid copepods also displayed clear distribution by ecoregion.
Increasing water temperature and decreasing latitude were associated with smaller mean Daphnia and cladoceran body lengths and lower absolute biomass of daphniids. Daphniids were rare or absent in warm waters (i.e. below 36o N latitude and/or from sites located <500 m altitude).
Species composition and mean body size of the cladoceran zooplankton were consistent with the feeding habits of the common planktivorous fish – salmon (Oncorhynchus spp.) and lake trout (Salvelinus spp.) in the Northwestern Forested Mountains, gizzard shad (Dorosoma cepedianum) in the Great Plains and threadfin shad (Dorosoma petenense) in the Western Xeric ecoregion.
Our study indicates that the taxonomic composition and size structure of the cladoceran zooplankton in reservoirs are highly connected to ecoregional attributes such as catchment land use, temperature and latitude as has been observed for natural lakes.