Effects of repeated salt pulses on ecosystem structure and functions in a stream mesocosm
Effects of repeated salt pulses on ecosystem structure and functions in a stream mesocosm
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DOI：
10.1016/j.scitotenv.2013.12.067
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发表时间：
2014-04-01
影响因子：
9.8
通讯作者：
Schaefer, Ralf B.
中科院分区：
文献类型：
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作者：
Canedo-Argueelles, Miguel;Bundschuh, Mirco;Schaefer, Ralf B.
受采矿活动影响的河流和溪流，由于水溶性储存物质被冲进接收水体，往往会在短期内急剧增加含盐量。我们进行了一项中尺度研究，以探索结构（硅藻和溪流无脊椎动物群落）和功能描述子（叶绿素a浓度、真菌生物量和叶片分解）对重复的短盐度脉冲（持续3小时，标称电导率为5、10和15 mS cm(-1)）的响应，模拟受盐矿影响的河流的暴露模式。该实验在12个人工通流系统中进行，历时16天。盐脉冲对生态系统结构和功能的影响并不完全符合我们的大多数初始假设，群落的响应比预测的要弱。然而，在整个实验过程中，硅藻群落以耐盐物种为主，对处理没有一致的反应。无脊椎动物的响应与群落结构（即不同分类群的丰度）的变化有统计学意义，但与分类群丰富度的变化无统计学意义。盐脉冲影响了生态系统的一些功能描述：真菌生物量对处理强度表现出单峰响应，藻类生长（即chl a生物量）随着电导率的增加而受到阻碍，高处理显著降低了叶片分解。(C) 2013 Elsevier B.V.版权所有
Rivers and streams affected by mining activities often receive short-term sharp salinity increases due to watersoluble stockpiled materials being washed into receiving water bodies. We conducted a mesocosm study to explore the response of structural (diatom and stream invertebrate communities) and functional descriptors (chlorophyll a concentration, fungal biomass and leaf decomposition) to repeated short salinity pulses (3 h of duration, with nominal electrical conductivities of 5, 10 and 15 mS cm(-1)), mimicking the exposure pattern occurring at salt-mine affected rivers. The experiment was conducted in 12 artificial flow-through stream systems over 16 days. The effect of the salt pulses on the ecosystem structure and functioning did not fully match most of our initial hypotheses, with the community response being weaker than predicted. The diatom community was, however, dominated by salt-tolerant species throughout the experiment, showing no consistent response to the treatment. The invertebrate response was associated with statistically significant changes in community structure (i.e. abundance of the different taxa) but no statistically significant changes in taxa richness. The salt pulses affected some functional descriptors of the ecosystem: fungal biomass exhibited a unimodal response to treatment magnitude, algal growth (i.e. chl a biomass) was hampered with increasing conductivity and leaf decomposition was significantly reduced in the high treatment. (C) 2013 Elsevier B.V. All rights reserved.