Model parameters for representative wetland plant functional groups

Authors: Williams, Amber; Kiniry, James; MUSHET, D - Us Geological Survey (USGS); SMITH, L - Oklahoma State University; MCMURRY, S - Oklahoma State University; ATTEBURY, K - Natural Resources Conservation Service (NRCS, USDA); LANG, M - Us Fish And Wildlife Service; McCarty, Gregory; SHAFFER, J - Us Geological Survey (USGS); EFFLAND, W - Natural Resources Conservation Service (NRCS, USDA); JOHNSON, M-V - Natural Resources Conservation Service (NRCS, USDA)

Submitted to: Ecosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2017
Publication Date: 10/1/2017
Publication URL: https://handle.nal.usda.gov/10113/5832879
Citation: Williams, A.S., Kiniry, J.R., Mushet, D., Smith, L., McMurry, S., Attebury, K., Lang, M., McCarty, G.W., Shaffer, J.A., Effland, W.R., Johnson, M.V. 2017. Model parameters for representative wetland plant functional groups. Ecosphere. 8(10) article e01958:1-14. https://doi.org/10.1002/ecs2.1958.
DOI: https://doi.org/10.1002/ecs2.1958

Interpretive Summary: Wetlands provide a wide variety of ecosystem service benefits to water quality, biodiversity, groundwater recharge, and floodwater storage. To estimate the benefits of these ecosystem services requires reasonable computer simulation of the water cycle of each site and realistic simulation of upland and wetland plant growth. Objectives of this study were to quantify leaf area, interception of light by the leaves, and plant nutrient concentrations in natural stands of representative plant species for some major plant groups in the U.S. The plant groupings in this study were based on plant growth types to enable use of computer simulation models for wetlands. We collected data at four locations representing some of the main wetland regions of the U.S. At each site we collected on-the-ground measurements of fraction of light intercepted, leaf area, and dry matter within the 2013 to 2015 growing seasons. Leaf area and light interception variables showed noticeable variations among sites and years, while overall averages and functional group averages give useful estimates for multisite simulation modeling. Variation within each species gives an indication of what can be expected in such natural ecosystems. For phosphorus and potassium, the concentrations from highest to lowest were spikerush, reed canary grass, smartweed, cattail, and hardstem bulrush. Spikerush had the highest nitrogen concentration, followed by smartweed, bulrush, reed canary grass, and then cattail. These values will be useful for the actual wetland species measured and for the wetland plant groups they represent. These plant variables and their associated computer simulation models offer promise as valuable tools for evaluating environmental benefits of wetlands and for evaluating impacts of various agronomic practices in adjacent areas as they affect the wetlands.

Technical Abstract: Wetlands provide a wide variety of ecosystem services including water quality remediation, biodiversity refugia, groundwater recharge, and floodwater storage. Realistic estimation of ecosystem service benefits associated with wetlands requires reasonable simulation of the hydrology of each site and realistic simulation of the upland and wetland plant growth cycles. Objectives of this study were to quantify leaf area index (LAI), light extinction coefficient (k), and plant nitrogen (N), phosphorus (P), and potassium (K) concentrations in natural stands of representative plant species for some major plant functional groups in the U.S. Functional groups in this study were based on these parameters and plant growth types to enable process-based modeling. We collected data at four locations representing some of the main wetland regions of the U.S. At each site we collected on-the-ground measurements of fraction of light intercepted, LAI, and dry matter within the 2013 to 2015 growing seasons. Maximum LAI and k variables showed noticeable variations among sites and years, while overall averages and functional group averages give useful estimates for multisite simulation modeling. Variation within each species gives an indication of what can be expected in such natural ecosystems. For P and K, the concentrations from highest to lowest were spikerush (Eleocharis macrostachya), reed canary grass (Phalaris arundinacea), smartweed (Polygonum spp.), cattail (Typha spp.), and hardstem bulrush (Schoenoplectus acutus). Spikerush had the highest N concentration, followed by smartweed, bulrush, reed canary grass, and then cattail. These parameters will be useful for the actual wetland species measured and for the wetland plant functional groups they represent. These parameters and the associated process-based models offer promise as valuable tools for evaluating environmental benefits of wetlands and for evaluating impacts of various agronomic practices in adjacent areas as they affect wetlands.