Assessing, with limited resources, the ecological outcomes of wetland restoration: a South African case

Abstract

Resources for evaluating the ecological outcomes of ecosystem restoration projects are often limited, especially within government-funded programs. In order to rapidly assess the ecological outcomes of wetland restoration, an improved approach has been developed, which was applied in the assessment of the ecological outcomes at nine restoration sites of South Africa's Working for Wetlands program. The sites encompass a diversity of restoration problems and land use contexts. The approach begins by distinguishing hydrogeomorphic (HGM) units, for which ecological condition is assessed and reported for hydrology, geomorphology, and vegetation pre-and post-restoration. These three components are closely linked but, as demonstrated at some of the sites, may respond differentially to restoration interventions. For most HGM units, overall ecological condition was improved by between 10 and 30%, with the greatest contribution of restoration generally being to the hydrology component. Having determined the integrity and costs of the interventions, cost-effectiveness is then reported in South African Rands per hectare equivalent restored, which was found to vary by more than an order of magnitude across the HGM units assessed. Cost-effectiveness must be interpreted in the light of the long-term integrity of the interventions, the site's landscape context, and the contribution of restoration to ecosystem services provision. Some sites may be considerably less cost-effective than others, but the cost may nonetheless be justified if the sites make key contributions to ecosystem services provision. The study was conducted in the context of a formative evaluation and the findings are envisaged to improve wetland restoration practice. Implications for Practice• Even when faced with very limited resources for assessment, the contribution of wetland restoration to ecological condition can be tracked using an approach for scoring the hydrology, geomorphology, and vegetation components of ecological condition, which is scientifically defensible but not onerous in terms of data and expertise. • Expressed as costs per hectare equivalent of ecological condition restored, useful comparisons can be made across different restoration sites. • However, results must be interpreted in the light of the site's landscape context, type of restoration problems, and the long-term integrity of the restoration interventions. • The approach has potential to improve future wetland restoration practice, including planning, as well as monitoring and evaluation in relation to specific restoration objectives and ecological condition targets.

Need to Seed? Ecological, Genetic, and Evolutionary Keys to Seed-Based Wetland Restoration

“…With increased urgency for, but limited successful examples of, seed-based wetland restoration around the globe, intensive monitoring of seed and seedling outcomes is imperative. For example, if monitoring can identify the limiting seed or seedling life stage for restoration, as has been done effectively in dryland restorations (James et al, 2011), additional restoration interventions can be implemented and sites can be chosen more strategically to ensure seed and seedling success (Kotze et al, 2019). The details of developing a monitoring plan are beyond the scope of this review but see these excellent resources as examples (Elzinga et al, 1998;Neckles et al, 2002;Perillo, 2009;Apfelbaum and Haney, 2012;Rieger et al, 2014).…”

Wetland Health in Two Agro-Ecological Zones of Lesotho: Soil Physico-Chemical Properties, Nutrient Dynamics and Vegetation Isotopic N15

“…Ewing et al, [41] reported that wetlands in Juniper Bay were crop production had occurred had in their surface horizons significantly greater amounts of extractable P, Ca, Mg, Mn, Zn, and Cu, along with higher base saturation and pH than soils in the reference bays. Similarly, Zedler and Kercher [16] and Kotze et al [11] reported that the nutrient-rich soils resulting from agricultural production make wetland restoration more difficult. Thus, the reasons for the slow rate of restoration of the KHL wetlands may be attributed to higher contents of base cations in the surface and subsoils compared to the HM wetlands where no restoration efforts are yet to be embarked upon.…”

“…Land use is often used as a surrogate for disturbance and has been correlated with biological attributes in wetlands [11,29]. In Lesotho, agricultural activity (i.e.…”

WET-EcoServices Version 2: A revised ecosystem services assessment technique, and its application to selected wetland and riparian areas

“…Many of the techniques were geared primarily for the developed world and mainly for wetlands in northern temperate regions, and thus a locally relevant technique was developed. The first version has since been applied fairly widely within South Africa as well as further afield, mainly in other African countries (Namaalwa et al, 2013;Rebelo et al, 2013;Sullivan et al, 2008;Cowden et al, 2014;Kotze et al, 2018). Nevertheless, since the technique was first developed, the understanding of how wetlands and riparian areas function and supply services to society has advanced (e.g.…”