Outbreak of an undetected invasive species triggered by a climate anomaly
Outbreak of an undetected invasive species triggered by a climate anomaly
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气候异常引发未被发现的入侵物种爆发
DOI：
10.1002/ecs2.1628
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发表时间：
2016
期刊：
影响因子：
2.7
通讯作者：
M. J. Zanden
中科院分区：
文献类型：
--
作者：
J. Walsh;S. Muñoz;M. J. Zanden
当一个入侵物种出现在一个新的地点时，我们通常不知道导致这一时刻的种群动态。入侵繁殖体的建立是否紧随着种群的出现？或者，是否有一个既定的低密度人口，从限制中释放出来，越过了检测阈值？入侵过程的早期阶段是我们知识中的一个关键空白，但对于入侵的检测和管理至关重要。在这里，我们提出了多条证据支持入侵物种爆发的滞后情景。2009年夏季，在美国威斯康星州的门多塔湖发现了一种入侵捕食性浮游动物--长刺水蚤（Bythotrephes longimanus），并迅速达到并维持了极高的密度。为了评估Bythotrephes是在引入后立即爆发还是从已建立的低密度种群中爆发，我们构建了门多塔湖Bythotrephes的种群模型。在该模型中，Bythotrephes在低水平上无限期地持续存在，直到2009年有利的热条件，自1895年以来最冷的7月，使其能够以高密度喷发并在湖泊沉积物中建立一个大型卵库。尽管回到不利的热条件，这是进一步支持的人口统计数据表明，在一年中不断的贡献，从鸡蛋银行的人口稳定在高密度状态。在2009年之前的存档样本中检测到两个单独的Bythotrephes，以及在可追溯到1994年（±5年）的湖泊沉积物芯层中检测到Bythotrephes刺，证实了长期滞后情景。总之，我们的研究结果表明，Bythotrephes持续至少十年低于检测限，直到最佳的热条件引发人口爆发。这项工作强调了环境条件引发低密度种群入侵物种爆发的可能性。
When an invasive species appears at a new location, we typically have no knowledge of the population dynamics leading up to that moment. Is the establishment of invasive propagules closely followed by the appearance of the population? Or alternatively, was there an established low-density population that was released from a constraint and crossed the detection threshold? The early stages of the invasion process are a critical gap in our knowledge, yet vitally important for the detection and management of invasions. Here, we present multiple lines of evidence supporting the lag scenario for an invasive species outbreak. The invasive predatory zooplankton, spiny water flea (Bythotrephes longimanus), was detected in Lake Mendota, Wisconsin (USA), in summer of 2009 and rapidly reached and sustained exceptionally high densities. To evaluate whether Bythotrephes' outbreak immediately followed introduction or erupted from an established low-density population, we constructed a population model of Bythotrephes in Lake Mendota. In the model, Bythotrephes persisted indefinitely at low levels until favorable thermal conditions in 2009, the coolest July since at least 1895, allowed it to erupt to high densities and establish a large egg bank in the lake sediments. The egg bank stabilized the population in the high-density state despite a return to nonfavorable thermal conditions, which is further supported by demographic data suggesting a constant contribution from the egg bank during the year. The prolonged lag scenario is corroborated by the detection of two individual Bythotrephes in pre-2009 archived samples, and the detection of Bythotrephes spines in lake sediment core layers dating back to 1994 (±5 yr). Together, our results suggest that Bythotrephes persisted for at least a decade below the detection limit, until optimal thermal conditions triggered a population outbreak. This work highlights the potential for environmental conditions to trigger invasive species outbreaks from low-density populations.