Collaborative Research: Impacts of in-stream restoration on hydrological, chemical, and biological heterogeneity in the hyporheic zone

每年在河流恢复上花费数十亿美元，但对恢复对河道内生态系统的影响的评估很少，而且几乎没有对潮汐影响的调查。大多数修复项目的目的是通过操纵河道形态来复制退化前的条件，以改善退化的河流结构和功能。与恢复结构有关的潜流带中地表和地下水流的复杂相互作用可能在这些项目的生态恢复中发挥重要作用，特别是在水质和水生生境方面。该项目的总体目标是评估1)河流修复项目通过诱导快速的水下相互作用模拟自然河床过程的程度，以及2)由此对河床中相关的物理、化学、热和生物模式的异质性产生的影响。将在实地对照尚未实施恢复项目的退化地点和代表理想状况并作为恢复设计依据的参考地点对恢复项目进行实地评估。计算建模将指导仪器，研究水通量的水力驱动因素，并将结果扩展到更大的范围长度。我们将解决的问题包括：1.设计的溪流恢复设计是否类似于自然溪流特征，以驱动水力并增强流过河床的水通量？河床流量的大小和空间异质性是否与作为工程设计基础的参考河段的流量相当？2.修复结构周围流过河床的水流是否产生了氧化还原条件和热模式的马赛克，这些条件和热模式在空间上更不均匀，跨越的范围比未恢复的地点更大？这些空间格局与参考地点的空间格局是否具有可比性？3.水文、氧化还原和热条件的镶嵌是否使浅生大型无脊椎动物的栖息地多样化，并导致与未恢复的地点相比，浅生无脊椎动物的分类丰富度和群落斑块程度更大？拟议的工作解决了我们目前对湿地修复项目如何影响浅海交换和改善浅海功能的认识空白，特别是在水质和栖息地恢复方面。我们的工作结果将为未来的修复设计提供参考，并证明修复设计考虑的应该是垂直部分，而不是简单的渠道形式和过程。通过对拟建修复结构周围潜水通量的探索性计算模拟，我们可以检验修复设计是否最大化了河流系统中的物理化学和生物多样性，恢复了生态功能。项目小组将通过参加每年在纽约州北部举办的关于溪流恢复的培训和讲习班，积极吸引从业者。我们的工作还将在州和联邦机构实施的项目中建立修复后监测。拟议的项目明确包括研究生和本科生积极参与研究。将积极招募妇女和传统上代表性不足的少数群体参加研究生课程。将招募三名本科生完成与该项目的建模和生物部分相关的独立研究项目。我们将通过将与积极研究直接相关的教育经验纳入锡拉丘兹大学和纽约州立大学ESF的四门课程的课程，积极吸引更多的研究生和本科生参与这一研究计划。

Billions of dollars are spent annually on stream restoration, but assessmentsof restoration impacts on in-channel ecosystems are rare, and investigations into hyporheic impacts are practically absent. Most restoration projects aim to improve degraded stream structure and function by manipulating channel morphology to replicate pre-degradation conditions. The complex interactions of surface and subsurface flow in the hyporheic zone associated with restoration structures may play an important role in the ecological recovery ofthese projects, particularly with respect to water quality and aquatic habitat. The overall objective of this project is to assess 1) the degree to which in-stream restoration projects mimicnatural bedform processes by inducing rapid hyporheic interaction, and 2) the resultant impacts on heterogeneity of associated physical, chemical, thermal and biological patterns in streambeds. Restoration projects will be assessed in the field relative to degraded sites, where restoration projects have not been implemented, and reference sites, which represent an ideal condition and on which the restoration design was based. Computational modeling will guidesite instrumentation, investigate hydraulic drivers of water flux, and scale the results to larger reach lengths. The questions we will address include:1. Does an engineered stream restoration design serve as an analog of natural stream features that drive hydraulics and enhance water flux through the streambed? Are streambed fluxes comparable in magnitude and spatial heterogeneity to those found at reference reaches thatserve as the basis for the engineering design?2. Does water flux through the streambed around restoration structures generate a mosaic of redox conditions and thermal patterns that are more spatially heterogeneous and span a greater range than those found at non-restored sites? Are these spatial patterns comparable to the spatial patterns found at reference sites?3. Does the mosaic of hydrologic, redox and thermal conditions diversify habitat for hyporheic macroinvertebrates and result in greater hyporheic invertebrate taxonomic richness and community patchiness, compared to non-restored sites?The proposed work addresses current gaps in our knowledge of how instreamrestoration projects impact hyporheic exchange and improve hyporheic function,particularly in terms of water quality and habitat restoration. The results of our work will inform future restoration design and demonstrate that restoration design considerations should include the vertical component, not simply channel form and process. Through exploratory computational modeling of hyporheic fluxes around proposed restoration structures, we can examine whether restoration designs maximize physicochemical and biological diversity in the stream system, restoring ecological function. The project team will actively engage practitioners through participation in training and workshops on stream restoration held annually throughout Upstate New York. Our work will also establish post-restoration monitoring at projects implemented by state and federal agencies. The proposed project explicitly incorporates the active participation of graduate and undergraduate students in research. Women and traditionally underrepresented minorities will be actively recruited for graduate student participation. Three undergraduate students will be recruited to complete independent research projects related to the modeling and biotic components of this project. We will activelyengage a broader audience of graduate and undergraduate students in this research program by incorporating educational experiences that are directly linked to active research into the curriculum of four courses at Syracuse University and SUNY ESF.