The macroinvertebrate seedbank promotes community persistence in temporary rivers across climate zones
The macroinvertebrate seedbank promotes community persistence in temporary rivers across climate zones
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大型无脊椎动物种子库促进跨气候区临时河流中群落的持久存在
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
T. Datry
中科院分区：
文献类型：
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作者：
R. Stubbington;T. Datry
1.栖息在临时河流中的水生大型无脊椎动物通常被描述为对河床干燥具有低抵抗力。然而，很少有研究已经检查了干河床沉积物，其中包括水生生物阶段，在脱水沉积物中生存，并从活跃的生物可能只发展后，地表水返回的“种子库”。
2.我们综合了已发表和未发表的数据，从实验上再水化沉积物从干河床收集的研究，建立种子库的重要性，促进大型无脊椎动物群落的阻力。包括来自不同气候区的研究，以审查种子库与环境严酷性，特别是沉积物水分的关系。我们还评估了种子库的重要性，相对于替代栖息地促进持久性的流动河流（FR）组合。我们预测，FR组合存在于再水化沉积物（RS）的比例将减少与环境的严酷性，由于沉积物内的条件变得不利于生物群的生存。
3. FR类群的比例存在于RS和苛刻之间的负相关关系进行了观察，这有助于减少FR和RS组合的组成相似性，苛刻增加。在一些系统中，沉积物含水量和大型底栖动物群落指标（密度和类群丰富度）之间存在显着的正相关关系。
4.外部的干旱区，这有助于社区的恢复力，总是居住着更多的FR类群比再水化沉积物。然而，再水化沉积物包括几个FR类群，没有发现在任何其他栖息地在干燥阶段，包括鞘翅目和双翅目的家庭。
5.我们的研究结果表明，种子库的重要性，作为一个临时的河流大型无脊椎动物的阻力机制。随着气候变化情景预测河床干涸的增加，在干旱阶段保持有利于昆虫群落持续存在的生境越来越成为一个优先事项。我们确定了沉积物水分和类群丰富度之间的密切关系，因此，河流管理和恢复活动的目的是保持水分干燥沉积物，通过操纵参数，如河岸阴影。
1. Aquatic macroinvertebrates inhabiting temporary rivers are typically described as having low resistance to riverbed drying. However, little research has examined the ‘seedbank’ within dry riverbed sediments, which comprises aquatic life stages that survive in dewatered sediments and from which active organisms may develop only after surface water returns.
2. We synthesised published and unpublished data from studies that had experimentally rehydrated sediments collected from dry riverbeds, to establish the importance of the seedbank in promoting macroinvertebrate community resistance. Studies from across climate zones were included, to examine seedbank importance in relation to environmental harshness and, in particular, sediment moisture. We also assessed the importance of the seedbank relative to alternative habitats promoting persistence of the flowing river (FR) assemblage. We predicted that the proportion of the FR assemblage present in rehydrated sediments (RS) would decrease with environmental harshness, due to conditions within the sediments becoming less conducive to the survival of biota.
3. A negative relationship between the proportion of FR taxa present in RS and harshness was observed, and this contributed to a reduction in the compositional similarity of FR and RS assemblages as harshness increased. Significant positive correlations were identified between sediment moisture content and macroinvertebrate community metrics (density and taxon richness) in some systems.
4. Habitats external to the dry reach, which contribute to community resilience, were invariably inhabited by a greater number of FR taxa than rehydrated sediments. However, rehydrated sediments included several FR taxa that were not found in any other habitats during the dry phase, including families of Coleoptera and Diptera.
5. Our results indicate the importance of the seedbank as a resistance mechanism for temporary river macroinvertebrates. With climate change scenarios predicting an increase in riverbed drying, maintaining habitats that facilitate the persistence of instream communities during dry phases is an increasing priority. We identified strong relationships between sediment moisture and taxon richness, and river management and rehabilitation activities should therefore aim to retain moisture in drying sediments, by manipulating parameters such as riparian shading.