Mass mortality of a dominant invasive species in response to an extreme climate event: Implications for ecosystem function
Mass mortality of a dominant invasive species in response to an extreme climate event: Implications for ecosystem function
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主要入侵物种因极端气候事件而大量死亡：对生态系统功能的影响
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
J. E. Byers
中科院分区：
文献类型：
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作者：
W. McDowell;W. McDowell;J. E. Byers
入侵物种对生态系统的影响往往取决于具体情况，因此，在气候基线发生变化和极端事件越来越普遍的情况下，很难进行经验性评估。我们记录了亚洲蛤的大规模死亡事件，河蚬，一种丰富的入侵蛤，它已取代本地贻贝成为美国东南部占主导地位的滤食性双壳类。在2012年夏天的一个极端炎热和干燥的时期，超过99%的Corbicula在我们格鲁吉亚布罗德河10公里的研究范围内死亡。由于蚬是生态系统中唯一具有大量生物量的滤食性生物，它们的死亡导致滤食性双壳类提供的生态系统服务几乎完全停止。我们估计，在大规模死亡事件发生后，采样范围内的周转时间（达到体积/总过滤量）从约5小时上升至1200小时以上。除了过滤能力的损失外，总溶解磷（TDP）和可溶性活性磷（SRP）的浓度在发生死亡的区域也高于没有死亡的上游区域。质量平衡计算和一个操作性的围隔实验预测TDP和SRP浓度远高于我们的观测值，这表明，快速生物或非生物吸收磷可能已经发生。我们的研究表明，气候变化可以增加提供关键生态系统功能的水生生物种群的时间变异性，并强调即使是脉冲式的短暂事件也会显着影响多样性减少的系统。
Impacts of invasive species on ecosystems are often context dependent, making empirical assessments difficult when climatic baselines are shifting and extreme events are becoming more common. We documented a mass mortality event of the Asian clam, Corbicula fluminea, an abundant invasive clam, which has replaced native mussels as the dominant filter‐feeding bivalve in the southeastern United States. During an extremely hot and dry period in the summer of 2012, over 99% of Corbicula died in our 10‐km study reach of the Broad River, Georgia. Because Corbicula were the only filter‐feeding organism in the ecosystem with substantial biomass, their death led to the nearly complete cessation of ecosystem services provided by filter‐feeding bivalves. We estimate that following the mass mortality event, turnover time within the sampling reach (reach volume/total filtration) rose from approximately 5 h to over 1200 h. In addition to the loss of filtering capacity, concentrations of total dissolved phosphorus (TDP) and soluble reactive phosphorus (SRP) were also higher in areas where die‐off was occurring than in an upstream area without mortality. Mass balance calculations and a manipulative mesocosm experiment predicted TDP and SRP concentrations much higher than our observed values, suggesting that rapid biotic or abiotic uptake of phosphorus may have occurred. Our study demonstrates that climate change can increase the temporal variability of populations of aquatic organisms that provide key ecosystem functions, and highlights that even pulsed, short‐lived events can markedly affect systems of reduced diversity.