A framework for interdisciplinary understanding of rivers as ecosystems (original) (raw)

Eco-geomorphology: an interdisciplinary approach to river science

2002

Eco-geomorphology is an interdisciplinary approach to the study of river systems that integrates hydrology, fluvial geomorphology and ecology. This approach facilitates a new understanding of river systems by bridging dominant paradigms from individual disciplines. Each discipline views river systems from a spatial and temporal perspective, but we suggest that one of the main impediments to further expansion of interdisciplinary study is the mismatch of scales between disciplines. A hierarchical and integrative framework for interdisciplinary study is required and would overcomes scale issues by matching a problem with a river system process to identify causal explanations at the correct spatial and temporal scales. We use the example of environmental flows to demonstrate the utility of an eco-geomorphological approach for identification of characteristic scales of hydrological, geomorphological and ecological influence in the Condamine-Balonne River.

The riverine ecosystem synthesis: toward conceptual cohesiveness in river science

2008

A model for the integrated management of river ecosystems

Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 2006

Rivers and fluvial corridors consist in high complexity systems in regard to: (l) the environment, where ecological nets are featured by high biodiversity and complex self-purif)ring processes (CUMMI'iS 2002, FISRWG 1998, MALMQVIST 2002, P!NAY et al. 2002); and (2) the landscape as synthesis ofnatural (geological!hydrological!morphological and vegetational; TocKNER et al. 2002) and human (historical/social/ economical) evolution. These systems represent the most problematic areas in the definition ofthe River Basin Management Plan. The use of water, river and soi l resources often conflict and are not compatible with protection of vulnerable areas (annex !V of the WFD 60/2000; E.C. 2000) or with flood risk. The effects ofthe drivers (pressures) e an impact several components o f the river, including the fluvial corridor system and the environmental landscape. They can also modify the ecological status o f water bodies, the physical-chemical quality of groundwaters and the surfac...

Integrating ecology with hydromorphology: a priority for river science and management

Aquatic Conservation: Marine and Freshwater Ecosystems, 2009

1. The assessment of links between ecology and physical habitat has become a major issue in river research and management. Key drivers include concerns about the conservation implications of human modifications (e.g. abstraction, climate change) and the explicit need to understand the ecological importance of hydromorphology as prescribed by the EU's Water Framework Directive. Efforts are focusing on the need to develop 'ecohydromorphology' at the interface between ecology, hydrology and fluvial geomorphology. Here, the scope of this emerging field is defined, some research and development issues are suggested, and a path for development is sketched out. 2. In the short term, major research priorities are to use existing literature or data better to identify patterns among organisms, ecological functions and river hydromorphological character. Another early priority is to identify model systems or organisms to act as research foci. In the medium term, the investigation of patternprocesses linkages, spatial structuring, scaling relationships and system dynamics will advance mechanistic understanding. The effects of climate change, abstraction and river regulation, eco-hydromorphic resistance/ resilience, and responses to environmental disturbances are likely to be management priorities. Large-scale catchment projects, in both rural and urban locations, should be promoted to concentrate collaborative efforts, to attract financial support and to raise the profile of eco-hydromorphology. 3. Eco-hydromorphological expertise is currently fragmented across the main contributory disciplines (ecology, hydrology, geomorphology, flood risk management, civil engineering), potentially restricting research and development. This is paradoxical given the shared vision across these fields for effective river management based on good science with social impact. A range of approaches is advocated to build sufficient, integrated capacity that will deliver science of real management value over the coming decades.

Linking the physical form and processes of rivers with ecological response

IAHS-AISH publication, 2002

Fluvial eco-geomorphology seeks to link the physical form and processes of rivers with ecological responses by adopting an ecosystem perspective in research and management. It is recognized that the physical habitat is not static, and there are numerous and complex interconnections at various scales that determine fluvial form and processes. In turn, the physical environment exerts a strong control on river biota, but the effects can be indirect and mediated through complex interactions. As a consequence, there are considerable uncertainties in manipulating fluvial systems; hence an adaptive approach to management is required. Contributions from papers presented from the session on eco-geomorphology in the IAHS-ICCE-UNESCO International Symposium on the Structure, Function and Management Implications of Fluvial Sedimentary Systems are discussed in the context of two major themes of ecosystem management: physical habitat improvement and restoration of flow regimes. Challenges and opp...

Hierarchical patterns of physical–biological associations in river ecosystems

Geomorphology, 2007

The interplay of biological and physical patterns and processes within river ecosystems generates a complex matrix of interactions. A challenge in interdisciplinary river science is to dissect patterns and processes in multi-causal river ecosystems into hierarchical levels of organization. Hierarchy theory, and the associated concept of scale, provides a sound framework for achieving this. We present two interdisciplinary case studies that demonstrate how a multi-scale approach can dissect hierarchies of organization in river ecosystems. The first case study examined patterns of large wood character and distribution at three scales of a hierarchy of morphological river system organization in the large, lowland River Murray. The character and distribution of large wood was uniform at the largest reach scale (95 km length of river) because stream energy conditions are relatively uniform within the reach. However, there was an association between lower-level functional sets (straight or bend sections of river) and functional units (12 quadrats within each functional set) and the character and distribution of large wood, because stream energy differs between straight and bend morphologies, and the inner- and outer-channel functional units. Thus, functional sets and functional units are important levels of organization for large wood in the River Murray. The second case study examined the associations between macroinvertebrate assemblage distribution and environmental influences across a hierarchy of river system organization in the upland Murrumbidgee River catchment. We previously demonstrated that macroinvertebrate assemblages were arranged hierarchically at the region, cluster within region, reach within cluster and riffle within reach scales, with region and reach being the strongest signatures. In this study we related different scaled environmental factors, collected across a hierarchy of catchment, zone (valley confinement), reach (similar stream orders) and riffle scales to the region and cluster levels of macroinvertebrate distribution. The hierarchical pattern of large, region-level and local, reach-level macroinvertebrate distribution was matched by a large catchment-scale and local reach-scale of environmental influence. Intermediate zone-scale environmental factors and smaller riffle-scale factors were not important influences. Thus, large regions and catchments and local reaches are important levels of organization for macroinvertebrate-environment associations in rivers of the upper Murrumbidgee catchment. Both case studies support the applicability of hierarchy theory to describe the organization of physical–biological associations in river ecosystems. The multi-scaled approach allowed the detection of levels of hierarchical organization, and showed other hierarchical characteristics such as emergent properties and top–down constraint/bottom–up influence. Hierarchical understanding of river ecosystem organization will enhance river conservation and management because it facilitates a holistic, ecosystem perspective rather than a partial, single-scale, single-component or single-discipline perspective.

A Model of Biocomplexity in River Networks-Part II: Tenets and Predictions

A Model of Biocomplexity in River Networks-Part I: General Theory

The riverine ecosystem synthesis: biocomplexity in river networks across space and time

River Research and Applications, 2006

We propose an integrated, heuristic model of lotic biocomplexity across spatiotemporal scales from headwaters to large rivers. This riverine ecosystem synthesis (RES) provides a framework for understanding both broad, often discontinuous patterns along longitudinal and lateral dimensions of river networks and local ecological patterns across various temporal and smaller spatial scales. Rather than posing a completely new model, we arrange a conceptual marriage of eco-geomorphology (ecological aspects of fluvial geomorphology) with a terrestrial landscape model describing hierarchical patch dynamics. We modify five components of this terrestrial model for lotic ecosystems: (1) nested, discontinuous hierarchies of patch mosaics; (2) ecosystem dynamics as a composite of intra- and inter-patch dynamics; (3) linked patterns and processes; (4) dominance of non-equilibrial and stochastic processes; and (5) formation of a quasi-equilibrial, metastable state. Our conceptual model blends our perspectives on biocomplexity with aspects of aquatic models proposed from 1980–2004.Contrasting with a common view of rivers as continuous, longitudinal gradients in physical conditions, the RES portrays rivers as downstream arrays of large hydrogeomorphic patches (e.g. constricted, braided and floodplain channel areas) formed by catchment geomorphology and climate. The longitudinal distribution of these patches, which are identifiable using standard geomorphic techniques, varies amongst rivers and is difficult to forecast above ecoregional scales. Some types of hydrogeomorphic patches may reoccur along this downstream passage. Unique ecological ‘functional process zones’ are formed by individual types of hydrogeomorphic patches because of physiochemical habitat differences which affect ecosystem structure and function.The RES currently includes 14 tenets predicting how patterns of individual species distributions, community regulation, lotic ecosystem processes, and floodplain interactions will vary over spatiotemporal scales, especially as they relate to the functional process zones formed by hydrogeomorphic differences in the river network. Copyright © 2006 John Wiley & Sons, Ltd.

A framework for interdisciplinary understanding of rivers as ecosystems (original) (raw)

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