Science Inventory

Non-floodplain Wetlands Affect Watershed Nutrient Dynamics: A Critical Review

Citation:

Golden, H., A. Rajib, C. Lane, J. Christensen, Q. Wu, AND S. Mengistu. Non-floodplain Wetlands Affect Watershed Nutrient Dynamics: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 53(13):7203-7214, (2019). https://doi.org/10.1021/acs.est.8b07270

Impact/Purpose:

Maintaining, restoring, and constructing wetlands has gained popularity in recent decades, in part because of their capacity to remove nitrogen and phosphorus from surface waters. As a result, wetlands are often considered a viable option for improving water quality at local scales, such as their implementation for mitigating point and non-point source pollution of a small land parcel. However, little is known about the cumulative influence of wetlands outside of floodplains on surface water quality at watershed scales. Such evidence is important to efficiently and effectively meet global, national, regional, and local water quality goals. In this critical review, we synthesize the state of the science about the watershed-scale effects of non-floodplain wetlands (NFWs) on nutrient-based (nitrogen, phosphorus) water quality. We further highlight how watershed-scale measurements and models commonly disregard these surface water storage systems when estimating management impacts on downstream water quality. We then demonstrate, via example model simulations, how explicitly considering NFWs changes predicted nutrient fluxes to receiving waters - and how this may potentially affect water quality management decisions. Finally, we briefly outline future research recommendations to improve our scientific understanding of how NFWs affect downstream water quality.

Description:

Wetlands have the capacity to retain nitrogen and phosphorus and are thereby often considered a viable option for improving water quality at local scales. However, little is known about the cumulative influence of wetlands outside of floodplains, i.e., non-floodplain wetlands (NFWs), on surface water quality at watershed scales. Such evidence is important to meet global, national, regional, and local water quality goals effectively and comprehensively. In this critical review, we synthesize the state of the science about the watershed-scale effects of NFWs on nutrient-based (nitrogen, phosphorus) water quality. We further highlight where knowledge is limited in this research area and the challenges of garnering this information. On the basis of previous wetland literature, we develop emerging concepts that assist in advancing the science linking NFWs to watershed-scale nutrient conditions. Finally, we ask, “Where do we go from here?” We address this question using a 2-fold approach. First, we demonstrate, via example model simulations, how explicitly considering NFWs in watershed nutrient modeling changes predicted nutrient yields to receiving waters–and how this may potentially affect future water quality management decisions. Second, we outline research recommendations that will improve our scientific understanding of how NFWs affect downstream water quality.