Ecological resistance in urban streams: the role of natural and legacy attributes
Ecological resistance in urban streams: the role of natural and legacy attributes
复制标题
城市河流中的生态阻力：自然和遗产属性的作用
DOI：
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发表时间：
2016
影响因子：
1.8
通讯作者：
Krista L. Jones
中科院分区：
文献类型：
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作者：
R. Utz;K. Hopkins;L. Beesley;D. Booth;R. Hawley;M. Baker;M. Freeman;Krista L. Jones
城市化大大改变了河流的物理化学和生物学特性。负面影响的轨迹在世界各地大致相似，但对城市增长的生态反应的性质和程度因地点而异。城市发展水平和城市水资源管理属性的差异导致了响应的一些异质性。然而，异质性也可能出现在水文，生物和物理化学的模板，城市发展之前的形状流生态系统的变化。我们提出了一个框架来发展假设，预测自然流域和通道属性在城市发展前的状态可能会赋予生态阻力的城市化。我们提出了6个可检验的假设，在我们的框架下探索这些属性的表达：1）更大的蓄水能力减轻了水文状况的变化，2）粗糙的基质和侵蚀力与沉积物供应缓冲区形态变化之间的平衡，3）天然高离子浓度和pH值使生物群预先适应水质压力，4）集合种群的连通性导致物种丰富度的保持，5）高功能冗余缓冲了物种损失对营养功能的影响; 6）土地利用历史掩盖或逆转了富营养化的预期轨迹。过去的比较分析数据支持这些假设，但严格的测试将需要有针对性的调查，解释混杂或相互作用的因素，如城市基础设施属性的多样性。更好地了解河流生态系统的易感性或抵抗力可以大大加强城市河流的保护、管理和监测工作。我们希望这些初步的概念性假设将鼓励其他人进一步探索这些想法，并为在城市河流中观察到的异质性提供更多的解释。
Urbanization substantially changes the physicochemical and biological characteristics of streams. The trajectory of negative effect is broadly similar around the world, but the nature and magnitude of ecological responses to urban growth differ among locations. Some heterogeneity in response arises from differences in the level of urban development and attributes of urban water management. However, the heterogeneity also may arise from variation in hydrologic, biological, and physicochemical templates that shaped stream ecosystems before urban development. We present a framework to develop hypotheses that predict how natural watershed and channel attributes in the pre-urban-development state may confer ecological resistance to urbanization. We present 6 testable hypotheses that explore the expression of such attributes under our framework: 1) greater water storage capacity mitigates hydrologic regime shifts, 2) coarse substrates and a balance between erosive forces and sediment supply buffer morphological changes, 3) naturally high ionic concentrations and pH pre-adapt biota to water-quality stress, 4) metapopulation connectivity results in retention of species richness, 5) high functional redundancy buffers trophic function from species loss, and 6) landuse history mutes or reverses the expected trajectory of eutrophication. Data from past comparative analyses support these hypotheses, but rigorous testing will require targeted investigations that account for confounding or interacting factors, such as diversity in urban infrastructure attributes. Improved understanding of the susceptibility or resistance of stream ecosystems could substantially strengthen conservation, management, and monitoring efforts in urban streams. We hope that these preliminary, conceptual hypotheses will encourage others to explore these ideas further and generate additional explanations for the heterogeneity observed in urban streams.