Data from: Wetland restoration: Predicting vegetation trajectories over 25 years

Worldwide wetland loss has made the conservation of these ecosystems a
policy priority and led to the multiplication of restoration programs.
However, the lack of long-term monitoring limits our understanding of the
processes influencing the vegetation composition of restored wetlands and
our ability to predict outcomes over multiple decades. Here, we assessed
the extent to which hydrological regime and planting density of target
species, two critical factors driving wetland vegetation and restoration
success, can predict restoration outcomes. Using correlation analyses and
generalized models, we assessed the role of target species planting
density and analogous hydrological conditions (e.g. level, variation,
seasonality) to reference wetlands for achieving and predicting restored
vegetation similarity to reference plant communities in 12 sedge and/or
willow dominated wetlands in Mountain Village, Colorado over 25 years
post-restoration. We found a significant positive correlation between
hydrological similarity and vegetation similarity, peaking at 15 years
post-restoration (rho = 0.61). Similarly, planting density was positively
correlated with vegetation similarity, peaking 5 years after restoration
(rho = 0.75). For both variables, communities with the shallowest water
table exhibited the strongest correlations. The similarity of restored
vegetation to the reference community can be predicted using hydrological
similarity and planting density. The models that combined these two
variables outperformed single-variable models. However, the model accuracy
decreased 25 years after restoration, making predictions over two decades
inaccurate for most communities. Synthesis and applications: Hydrological
similarity to a reference, combined with appropriate planting densities,
reliably predicts restored wetland vegetation convergence towards
reference communities over two-decades. Such models could provide managers
with tools to assess failure risks across potential restoration sites,
allowing them to select the most suitable locations and tailor planting
efforts to maximize wetland restoration success.