Benthic-pelagic links: responses of benthos to water-column nutrient enrichment
Benthic-pelagic links: responses of benthos to water-column nutrient enrichment
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DOI：
10.2307/1468138
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发表时间：
1997-09-01
影响因子：
--
通讯作者：
Knight, SE
中科院分区：
文献类型：
--
作者：
Blumenshine, SC;Vadeboncoeur, Y;Knight, SE
虽然远洋藻类和无脊椎动物对营养丰富的梯度的反应是众所周知的，但关于底栖动物对这种梯度的反应或底栖和远洋反应如何相互作用，人们知之甚少。我们于2000年在野外进行了一个为期9周的实验--L中观系统，以测试水柱营养丰富对浮游植物、藻类在沉积物(表层)和坚硬表面(塑料条)以及浮游和底栖初级消费者的影响。试验设计包括4个养分富集量(0、0.5、1.0、2.0mgP L~(-1)d(-1)，配合N，N：P质量比为20：1)。营养物质的增加使浮游植物和附着的藻类中的叶绿素a显著增加，但对表层藻类的影响不明显。在最初的4wk的浓缩过程中，富营养化的中微体浮游动物生物量显著高于对照组，但这种影响在整个实验过程中并不持续。与对照相比，富营养化处理中栖息在沉积物中的无脊椎动物和与硬质底物相关的无脊椎动物的密度更高。底栖昆虫的出现也随着丰富而增加。底栖大型无脊椎动物的大小和种类组成在肥化处理和对照之间存在差异。我们的结果表明，添加到水柱中的营养物质迅速转化为海底生物量，可能会降低远洋对富集物的反应。
Although the responses of pelagic algae and invertebrates to gradients of nutrient enrichment are well known, less is known about the responses of benthos to such gradients or how benthic and pelagic responses may interact. We performed a 9-wk experiment in 2000-L mesocosms in the field to test for the effect of water-column nutrient enrichment on phytoplankton, algae on sediments (epipelon) and hard surfaces (plastic strips), as well as pelagic and benthic primary consumers. The experimental design consisted of 4 nutrient enrichment rates (0, 0.5, 1.0 and 2.0 mu g P L-1 d(-1), together with N to yield an N:P ratio of 20:1 by weight). Nutrient enrichment induced significant increases in chlorophyll a in phytoplankton and attached algae, but not epipelon. Zooplankton biomass was significantly higher in enriched mesocosms than in controls over the initial 4 wk of enrichment, but the effect was not sustained over the course of the experiment. Densities of sediment-dwelling, and hard-substrata-associated invertebrates were higher in enriched treatments relative to controls. Emergence of benthic insects also increased with enrichment. Size and species composition of benthic macroinvertebrates differed between enriched treatments and controls. Our results suggest that nutrients added to the water column were quickly converted into benthic biomass, likely reducing pelagic responses to enrichment.