Hydroecological model predictions indicate wetter and more diverse soil water regimes and vegetation types following floodplain restoration

Abstract

[1] Transitions between aquatic and terrestrial ecosystems represent zones where soil moisture is a dominant factor influencing vegetation composition. Niche models based on hydrological and vegetation observations can be powerful tools for guiding management of these zones, especially when they are linked with physically based hydrological models. Floodplain restoration represents a unique opportunity to utilize such a predictive vegetation tool when a site's hydrology is altered to create a wetter environment. A variably saturated groundwater flow model was developed and used to simulate the soil moisture regime across a floodplain in Wisconsin where post-settlement alluvium was removed with the intent of increasing regionally threatened wetland plant species. Hydrological niche models based on simultaneous observations of vegetation composition and surface effective saturation were used to predict probability of presence for two plant species (Carex vulpinoidea (fox sedge) and Elymus canadensis (Canada wildrye)) and wetland indicator score (a composite indicator of relative frequency of species in five habitat categories) based on simulated surface effective saturation. The vegetation predictions following restoration are more wetland-species dominant overall. However, zones of the study site where a confining layer is present that decouples groundwater from the near-surface soil zone tend to be drier following restoration due to restricted upward groundwater flow and less soil water storage above the confining layer. As reflected by an increase in the interquartile range in the predicted wetland indicator score, this restoration technique may increase the site-scale spatial diversity of plant community types while simultaneously accomplishing the goal of increasing wetland plant species occurrence.Citation: Booth, E. G., and S. P. Loheide II (2012), Hydroecological model predictions indicate wetter and more diverse soil water regimes and vegetation types following floodplain restoration,

Hydrological‐niche models predict water plant functional group distributions in diverse wetland types

“…, Merritt et al. , Booth and Loheide , b). Such data could potentially reveal clearer niche differentiation among the groups, but would be difficult to obtain over large spatial scales.…”

“…Hydrological‐niche models quantify these differences, typically describing the probability that a species will be present for a given value of these hydrological variables (Henszey et al. , Booth and Loheide , b, Funk et al. ).…”

“…). However, local‐scale validation of hydrological niche model predictions (Booth and Loheide ) suggest it could be possible to build probabilistic models based on functional groups that could make more generally applicable predictions of response under change scenarios (Auble et al. , Merritt et al.…”

“…[Colour figure can be viewed at wileyonlinelibrary.com] deductive, where the presence of functional groups with a generally understood depth-duration preference has been used to identify the water regime needed to maintain a specific community (e.g., Casanova 2011, Johns et al 2015. However, local-scale validation of hydrological niche model predictions (Booth and Loheide 2012b) suggest it could be possible to build probabilistic models based on functional groups that could make more generally applicable predictions of response under change scenarios (Auble et al 2005, Merritt et al 2010.…”

Behavior of water balance components at sites with shallow groundwater tables: Possibilities and limitations of their simulation using different ways to control weighable groundwater lysimeters

“…Along with that, it determines the amount of water that is available for plants and, in the long term, the composition of the site's plant community (Booth and Loheide, 2012;Lowry et al, 2011;Muneepeerakul et al, 2008;Orellana et al, 2012;Tamea et al, 2009). Hence, the processes involved are not purely hydrological but also include biological and ecological ones, even though the temporal scales on which they operate may differ.…”