How wide is a stream? Spatial extent of the potential "stream signature" in terrestrial food webs using meta-analysis.
How wide is a stream? Spatial extent of the potential "stream signature" in terrestrial food webs using meta-analysis.
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DOI：
10.1890/12-1628.1
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发表时间：
2014
期刊：
影响因子：
4.8
通讯作者：
J. Muehlbauer;S. Collins;M. Doyle;K. Tockner
中科院分区：
文献类型：
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作者：
J. Muehlbauer;S. Collins;M. Doyle;K. Tockner
跨生态系统资源补贴的规模越来越得到人们的认可;然而，人们对这些补贴进入受援国景观的距离知之甚少。在溪流和河流中，这一距离可以界定“生物溪流宽度”，补充水文地貌措施（例如，河道河岸），其通常具有限定的河流生态系统边界。在这项研究中，我们使用荟萃分析来定义土地上的“溪流特征”，将溪流到土地的补贴与距离联系起来。例如，50%的流签名确定了补贴资源仍然处于其最大（流内或接近流）水平的一半的景观点。这些数据的衰减曲线最适合负幂函数，其中50%的水流特征集中在河岸附近（1.5米），但最大补贴水平的非平凡部分（10%）仍在距离水边> 0.5公里处。元分析还确定了影响流签名的解释变量。这提高了我们对生态系统条件的理解，允许空间上广泛的补贴传输，如在高生产力，中等秩序的溪流和河流。由此产生的多变量模型，从这个分析可能是有用的管理人员实施缓冲区规则和保护策略的流和河岸功能，因为它们有助于预测补贴的程度。我们的研究结果强调，大部分的补贴仍然在流附近，但也补贴（和水生生物）能够长距离扩散到邻近的环境中，有效的“生物流宽度”的流和河流生态系统往往是远远大于已定义的水文地貌指标。海洋和湖泊来源的有限数据与溪流特征数据重叠，表明“特征”方法也可适用于其他生态系统的补贴空间动态。
The magnitude of cross-ecosystem resource subsidies is increasingly well recognized; however, less is known about the distance these subsidies travel into the recipient landscape. In streams and rivers, this distance can delimit the "biological stream width," complementary to hydro-geomorphic measures (e.g., channel banks) that have typically defined stream ecosystem boundaries. In this study we used meta-analysis to define a "stream signature" on land that relates the stream-to-land subsidy to distance. The 50% stream signature, for example, identifies the point on the landscape where subsidy resources are still at half of their maximum (in- or near-stream) level. The decay curve for these data was best fit by a negative power function in which the 50% stream signature was concentrated near stream banks (1.5 m), but a non-trivial (10%) portion of the maximum subsidy level was still found > 0.5 km from the water's edge. The meta-analysis also identified explanatory variables that affect the stream signature. This improves our understanding of ecosystem conditions that permit spatially extensive subsidy transmission, such as in highly productive, middle-order streams and rivers. Resultant multivariate models from this analysis may be useful to managers implementing buffer rules and conservation strategies for stream and riparian function, as they facilitate prediction of the extent of subsidies. Our results stress that much of the subsidy remains near the stream, but also that subsidies (and aquatic organisms) are capable of long-distance dispersal into adjacent environments, and that the effective "biological stream width" of stream and river ecosystems is often much larger than has been defined by hydro-geomorphic metrics alone. Limited data available from marine and lake sources overlap well with the stream signature data, indicating that the "signature" approach may also be applicable to subsidy spatial dynamics across other ecosystems.