Generalizing Riparian Zone Function at the Landscape Scale: New Tools, New Approaches, Gaps in Knowledge and Future Research Directions; Bloomington, Indiana; November 2007

Indiana University, Bloomington IN

Investigators

Abstract

Because of their critical position between terrestrial upland and freshwater systems, riparian zones are critical elements of the hydrological landscape. In addition, because of their potential role as nutrient/contaminant sink in the landscape, they are widely recommended best management practices worldwide. Nevertheless, the cumulative effect of riparian zones on water quality at the watershed scale remains poorly understood. It is crucial to develop strategies to estimate the spatial and temporal variability in contaminant removal in riparian zones and the cumulative effect of individual riparian zones on water quality at the watershed scale. There is also a need to synthesize current knowledge on nutrient fluxes through riparian systems during episodic precipitation events/snowmelt in order to be able to understand the role of riparian zones in annual nutrient fluxes. Finally, efforts need to be made to determine major gaps in knowledge impeding our ability to quantify the impact of human modifications to the environment (e.g. stream incision, artificial drainage) on riparian zone functioning, i.e. hydrological functioning (water table fluctuation/depth, subsurface flow path, groundwater fluxes, seasonality) and biogeochemical functioning (P-adsorption, redox conditions, vegetation uptake, denitrification...). The main objectives of this workshop are therefore 1) to synthesize current knowledge on approaches/techniques that could be used to determine riparian zone hydrological and biogeochemical functionning and the role of riparian zones as nutrient/contaminant sinks at the watershed scale, and 2) to identify gaps in knowledge and major research challenges that will need to be overcome to achieve this goal. We propose to bring together 30 scientists/students working on various aspects of riparian zone hydrology and biogeochemistry and/or on the linkages between the terrestrial and aquatic boundary to address these objectives. The workshop will specifically focus around three integrative themes: 1) Can we develop a decision matrix taking into account landscape hydrogeomorphic, vegetation, climatic and land use characteristics to generalize riparian zone function at the watershed scale? 2) Can a decision tree using landscape hydrogeomorphic characteristics, vegetation, climatic and land use data be developed to classify riparian zone function during dynamic hydrologic conditions? 3) How do human induced changes in riparian zone form impact riparian zone function, and how can we integrate these changes at the watershed scale? The workshop will be open to all individuals that are involved in riparian zone research and interested in developing tools/strategies to identify the role of riparian zones as nutrient/contaminant sinks at the landscape scale. This will include students and scientists from academic institutions, government agencies and private partners involved in riparian zone management. The intellectual merit of this workshop proposal includes bringing together riparian scientists to identify future research needs in riparian zone research and especially strategies to better understand the role of riparian zones at the watershed scale, write review papers and host special sessions at conferences. The broader impacts of our proposed activity include developing interactions between promising graduate students, post-doctoral fellows and university, government and private sector scientists, and contribute to the development of better strategies to manage riparian zones at the watershed scale in order to mitigate the impact of non-point source pollution on water quality. We expect that the findings from this workshop will have far reaching implications for society by contributing knowledge to riparian zone management to meet our society's objectives in term of environmental quality in the 21st century.