Successful Ecological Restoration Research Articles

Co-Inoculation with Beneficial Soil Microorganisms Promoted Growth and Quality of Tabebuia rosea Seedlings

Abstract Poor seedling quality is a major limiting factor for the success of commercial afforestation and ecological restoration in the tropics. This is commonly due to poor nutrient availability of soil-based substrates used for seedling growth. Currently, the use of biofertilizers has gained attention as a biotechnological tool to overcome plant malnutrition and enhance seedling quality from the nursery. The aim of this study was to evaluate the effects of individual and combined inoculation with selected beneficial soil microorganisms on plant growth of Tabebuia rosea (Bertol.) Bertero ex A.DC. in the nursery stage. For this purpose, individual, dual, and triple inoculations were conducted with Rhizoglomus fasciculatum (arbuscular mycorrhizal fungus: AMF), Mortierella sp. (mineral-solubilizing fungus: MSF), and Azospirillum brasilense (plant growth-promoting bacteria: PGPB). After six months, the inoculation with PGPB significantly promoted plant growth over the uninoculated control. Dual inoculation with AMF+MSF and AMF+PGPB had lower but significant effects over the control. The results showed that biofertilization is an effective alternative to promote plant growth and quality of this species in the nursery and thus to produce better plants for forestry and ecological restoration in tropical areas.

The joint effect of host plant genetic diversity and arbuscular mycorrhizal fungal communities on restoration success

Abstract Drastic loss in the area and quality of natural and semi‐natural habitats over the last hundred years has placed biodiversity and related ecosystem functions under substantial threat. Restoration of degraded ecosystems is among the main solutions to counteract this trend. However, past restoration efforts have not always led to the anticipated halt of species loss, neither have they ensured sustainable provision of vital ecosystem services. It has been proposed that one of the reasons for the failure to stop biodiversity decline through ecological restoration lies in overlooking the importance of improving ecosystem complexity, including the recovery of interaction networks with co‐adapted species. In the current review, we show how simultaneously addressing these often unnoticed aspects has the potential to advance the success of ecological restoration. We focus on the relationship between the community composition of arbuscular mycorrhizal (AM) fungi and the genetic diversity of the host plant population as an example. Most terrestrial plant species associate with AM fungi, which have a fundamental role in ecosystem functioning through enhancing plant nutrition and tolerance to abiotic and biotic stress. Previous studies have highlighted the significance of these symbionts in increasing the restoration success of degraded habitats. In parallel, the role of gene‐level diversity within plant populations for creating sustainable ecosystems has increasingly been acknowledged over the last years. However, considering the possible interaction of these two aspects, that is taking AM fungal communities and genetic diversity of host plant populations into account to enhance restoration success, has received no attention. Evidence suggests that the genetic diversity within a host plant population can have a significant effect on the ability of the host plant to benefit from mycorrhizal associations. We suggest that novel genomic approaches, such as community genetics and landscape genomics, should be applied to shed light on this aspect of plant–fungal interactions and be incorporated in restoration planning. Fundamental understanding of the nature of such associations can benefit from using restoration frameworks as large‐scale experimental settings. A free Plain Language Summary can be found within the Supporting Information of this article.

Germination and seed traits in common alder (Alnus spp.): the potential contribution of rear‐edge populations to ecological restoration success

The degradation of riparian ecosystems occurring throughout the past decades has motivated efforts aimed at the restoration of these ecosystems. The success of active revegetation approaches to restoration requires appropriate selection of reproductive material, which in turn requires knowledge of seed traits and germination. Alnus glutinosa (L.) Gaertn. (common alder) is a key riparian tree widely used in restoration projects, and has recently been classified as comprising three species: A. glutinosa; A. lusitanica Vít, Douda, & Mandák; and A. rohlenae Vít, Douda, & Mandák. To help guide restoration species selection, we assessed differences among populations of these species by (1) investigating seed weight, morphology, and germination success from a large population set and (2) modeling germination success in each species in relation to morphological traits and environmental conditions. Seeds were collected from 12 populations encompassing the latitudinal extremes of the species complex, and were then characterized and germinated. Ploidy levels and species were distinguished using cytometric analysis. Site‐level climatic data and seed morphology data were used to model germination success for each species. All seed traits differed between populations and one morphological‐trait (seed weight‐to‐area ratio) differed significantly between the three species. Germination modeling showed that the southwestern species, A. lusitanica, responded positively to high temperature extremes, suggesting tolerance to the climate changes projected for southern Europe. Populations of A. lusitanica located at the latitudinal rear edge of common alder's distribution appear to show establishment‐facilitating adaptations, and therefore may contribute to ecological restoration efforts under a range of environmental conditions.

Australian native seed sector practice and behavior could limit ecological restoration success: further insights from the Australian Native Seed Report

The Australian native seed sector is critical for undertaking ecological restoration but faces serious challenges from interacting factors, including native vegetation loss and habitat fragmentation, low funding levels, and climate change impacts. The Australian Native Seed Survey was conducted in 2016–2017 to better understand sector structure, practitioner perceptions, and practice. It found that most native seed is collected from small and fragmented tenures and from geographic ranges that greatly exceed “local provenance”; that the diversity of species available for restoration is typically low; that native seed is seldom quality tested; and that most annual seed collections (wild or production) are small in volume suggesting overall seed yields are modest in quantity and not sufficient to support large‐scale restoration. Together, survey findings raise serious concerns about the ability of the sector, as currently constituted and resourced, to meet projected future increases in the demand for seed or for achieving the effectiveness and efficiency required to meet UN‐Decade type ecological restoration outcomes. Central to recommendations for sector improvement are the following focus areas: maturing the native seed sector; sustainability; seed production; licensing; seed testing and tracking; and research.

Microbial Ecology of Qatar, the Arabian Gulf: Possible Roles of Microorganisms

The Arabian Gulf ranks among the world’s most arid and warm regions; the land has high salinity levels with many Sabkhas and receives little precipitation. This region holds about one-third of the world’s oil supply. Qatar is the leading gas producer worldwide, which raises many concerns about the pollution of the sea, groundwater, and soil. Thus, the Arabian Gulf area has paid particular attention to environmental studies since the environmental status of this region imposed unique biological diversity, and microbial ecology has gained special importance following the identification of promising roles of microorganisms. This review article discusses the microbial ecology at the main habitats of the State of Qatar. We discuss important principles for successful ecological restoration and future perspectives of using biological approaches to solve many problems related to health, the economy, and agriculture. There are at least five microbial communities that have been recognized at the Qatari habitats: marine environment, salt marshes and mangrove forests, the arid lands (including dune communities), wetlands (including pond communities), and Rawdahs (including the Ghaf tree communities). Although, the environmental conditions of this region are almost the same, these habitats are compared with those at other countries of the Arabian Gulf whenever necessary, as each habitat has its own peculiar characteristics. Some case studies are presented to describe the biochemical characterizations of bacterial isolates from soils and leaf surface of native plants, including halophytes and xerophytes at these habitats. These studies rarely went beyond the general identification at species levels. There is a discussion about the possible roles of microorganisms at the rhizosphere, non-rhizosphere, and phyllosphere, and using plant exudates to control microbial activity. However, modern approach (culture-independent methods) addressing these topics has opened the door for deeper investigations, and to explore the roles played by microorganisms at these habitats. These methods have already begun during the last decade as serious step to solve many environmental issues. In the future, it is very likely that microorganisms will be used to tackle many pollution issues, as well as health, agricultural, and economic problems.

Ecological restoration success from community and agency perspectives: exploring the differences

Ecological restoration is an integral part of conservation efforts worldwide. Projects are actioned at all stakeholder levels, with many projects claiming success. However, debate over what constitutes “success” in the context of ecological restoration is long‐running. Local communities commonly collaborate with government agencies in restoration projects, with many taking on responsibilities for project management. This study surveyed restoration practitioners in New Zealand at both community and agency levels to explore perceptions of what constitutes restoration “success,” and how this is measured. We found all stakeholders perceived their projects to be successful, although different perceptions of determinants and measures of success were evident. Agencies with ecological management responsibilities claim to follow systems‐level attributes of success although monitoring is often limited to standards that are the easiest to measure. Community‐based practitioners identify with gains in ecosystem structure, but their measurements of success tend to be of species‐focused standards, possibly because of the ease by which such outcomes can be measured and, especially for New Zealand, focused by widespread publicity about threatened species and the impact of invasive species. Also, for long‐running projects, perceptions of success may shift as ecological milestones are achieved. Although all restoration stakeholders aspire to universal outcomes of improved ecological status, for many community‐based participants, social motivation, and rewards may be as important as their environmental stewardship intentions. We highlight the need to recognize the scientific and social duality of modern ecological restoration, particularly as community engagement is an explicit aspiration of the United Nations Decade on Ecosystem Restoration 2021–2030.

Assessing nature-based solutions for transformative change

Assessing nature-based solutions for transformative change

Evidences of homogenization in species assemblages of restored mixed Shorea robusta forest stands of Nepal

Recent forest assessment in Nepal has shown an increase in total forest area as a result of implementation of community-based forest management strategies and effective forest restoration interventions. However, success of ecological restoration in some forest stands are argued based on how restoration success is determined. Does increase in spatial coverage and stem densities of preferable plant species alone represent successful restoration or should benefits to alpha diversity of the assemblages also be required? Empirical studies comparing structural attributes of restored and reference forest stands are very limited in Nepal. In this context, species assemblages and structural metrics of woody plants in restored and natural stands of mixed Shorea robusta forests situated in the central lowland of Nepal were assessed and compared. Woody species were evaluated for 60 sub-plots, each of an area of 0.1 ha, established in two sets of stands of 3 Buffer Zone Community Forests. We observed significant difference (p = 0.002) in plant species composition between restored and natural forest stands. Species wise density showed S. robusta with significantly higher (p < 0.0001) density in restored stands compared to natural stands, but densities of other associated woody plants, such as Mallotus philippensis, Lagerstroemia parviflora, Casearia graveolens and Dillenia pentagyna were significantly higher (p < 0.0001) in natural stands. Restored and natural stands did not differ in means of overall basal area of woody plants, but when basal area of S. robusta was considered, it was greater in restored compared to natural stands. Alpha and beta diversity values for woody plant assemblages were significantly higher in natural compared to restored stands. Our study revealed emblematic density diversity deflections in restored forest stands. Indicator species analysis showed substantial fewer numbers of indicator species in restored compared to natural stands. We observed evidence of homogenization in species assemblages in all examined restored mixed S. robusta forest stands of Nepal, so future restoration interventions should focus on increasing species heterogeneity.

Morphoecological characteristics of grasses used to restore degraded semi‐arid African rangelands

AbstractProgressive loss of productivity and plant diversity is a concern in global rangelands. In African rangelands, this process is partly attributed to heavy and uncontrolled grazing by livestock and wildlife, leading to land degradation. Therefore, restoring such degraded rangelands is critical for enhancing ecosystem health and securing the livelihoods of millions of people.Active restoration strategies, for example, reseeding using indigenous perennial grasses, have been identified as a viable ecological solution for restoring degraded African rangelands. Grass species indigenous to African rangelandsCenchrus ciliarisL. (African foxtail grass),Eragrostis superbaPeyr. (Maasai love grass),Enteropogon macrostachyus(Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass),Chloris roxburghianaSchult. (Horsetail grass) andChloris gayanaKunth. cv Boma (Rhodes grass) were established in a semi‐arid rangeland in Africa under natural conditions to compare their morphoecological characteristics and suitability for use in ecological restoration. Biomass dry matter yields, plant densities, basal cover, seed production, tiller densities and plant height were measured.Chloris gayanacv Boma andE. superbaproduced significantly higher dry matter biomass yields and attained higher seed production than other species. High biomass and seed production indicate their suitability to support livestock production and replenish depleted soil seed banks, respectively.Enteropogon macrostachyusandC. ciliarisdisplayed significantly higher values for components of establishment and ecological restoration success, that is, plant densities, tiller densities and basal cover. Overall,C. roxburghianaranked lowest in the measured morphoecological characteristics.Successful restoration of degraded African semi‐arid rangelands using indigenous grass reseeding can best be achieved through careful selection of grasses to take advantage of their specific morphoecological characteristics. This selection should primarily be informed by the intended use of the rangeland and the specific challenges of restoring each site.

Effects of herbivory by the urchin Diadema antillarum on early restoration success of the coral Acropora cervicornis in the central Caribbean

In an era of coral reef decline, coral restoration is receiving increasing attention, with many recent developments in culture and transplant techniques. However, how the ecological processes operating on coral reefs influence the success of restoration efforts remains largely unexplored, particularly during the first months after outplanting which are considered crucial for colony survival. Herbivory is a key process well-known to maintain a coral-dominated state, and in the Caribbean Sea, the long-spine urchin Diadema antillarum is thought to aid coral success by removing algae from seafloor substrate that might otherwise outcompete coral outplants. In this study, we conducted a three-month manipulative experiment in southeastern Dominican Republic to test the effect of Diadema antillarum density on percent living tissue and growth rate of outplanted fragments of the critically endangered coral species Acropora cervicornis. Increasing herbivore density had no significant effect on coral survival or growth but did increase the percent of living tissue when urchin abundance was 3× ambient levels. The greatest growth and survival outcomes were instead related to the initial size of the outplanted coral and were reduced through predation by the fireworm Hermodice carunculata. Our results highlight the potential importance of considering ecological processes like herbivory and predation to maximize the success of ecological restoration.

Conceptual and methodological issues in estimating the success of ecological restoration

Ecological restoration (ER) of terrestrial ecosystems has become widespread in past decades. However, assessing its success is complex mainly due to the diversity of objectives pursued, actions undertaken but also statistical methods for treating data. We demonstrate here that, due to the heterogeneity of collected data, the success of restoration actions can be overestimated in meta-analyses. We advocate analyzing distinctly two types of actions in ER, those aiming at increasing an ecosystem attribute (e.g. species richness of a native plant species, ER+), and those aiming at decreasing it (e.g. invasive species cover, ER-). We also suggest that only one index for assessing the success of a restoration action is not enough. We propose here to complete RR (Remaining Recovery) by a novel index informing on ‘what has been restored by comparison to what should have been recovered’: the ‘Achieved Restoration’ index (AR).

Forest restoration by different nucleation techniques in Urochloa grassland

Abstract: The objective of this work was to evaluate the effect of brushwood, black plastic mulch, herbicide, and artificial perch on the natural regeneration of native species in Urochloa grassland. The experiment was conducted between February 2014 and February 2016 in the Dense Ombrophilous Forest, in the municipality of Morretes, in the state of Paraná, Brazil. The treatments were: herbicide, herbicide + perch, black plastic mulch, black plastic mulch + perch, brushwood + herbicide, brushwood + herbicide + perch, and a control treatment. The evaluations were carried out at 4, 8, 12, 18, and 24 months after the installation of the experiment, by counting and identifying regenerating woody species and estimating visually the percentage of herbaceous coverage. Initially, brushwood and black plastic mulch reduced the Urochloa grasses; however, this effect was lost over time due to the rapid growth of the grasses from the edges to the center of the plots. The use of perches in the treatments does not allow a significant increase of other species because of the continued inhibiting conditions for the establishment of seedlings. The herbicide is effective in removing the grasses; however, the recruitment of woody species is only satisfactory when perches are used to attract the dispersing fauna. For a successful ecological restoration of pastures, there is a need for the local elimination of Urochloa grasses.

Inland wetland time-series digital change detection based on SAVI and NDWI indecies: Wadi El-Rayan lakes, Egypt

Water resource scarcity and climate change impacts are putting pressure on Egyptian government to achieve the water, energy and food security nexus in order to find optimized choices compromising between environmental ecosystems and the society. Despite of being considered as an ecological restoration success, Wadi El-Rayan (WR) wetlands is becoming a depleted ecosystem due to water resources vulnerability. The primary objective of this study is to apply remote sensing (RS) data and GIS methods to the various components of the WR wetland ecosystem, including vegetation, water and soil, and to assess their recent status over the previous three decades. Four multi-temporal/multi-spectral Landsat were analyzed, including TM (1990, 1999 and 2010) and OLI-TIRS (2019). Vegetation and water indices were employed to extract the vegetation, water and soil features in order to assess the change scenarios. The results showed that open soil increased significantly during the study period, particularly during the past ten years, with a concomitant decrease in the vegetation and water body areas. The study therefore indicates that the protection of the existing wetland resources for sustainable use for the next generation must be urgently considered.

Using monitors to monitor ecological restoration: Presence may not indicate persistence

AbstractHabitat loss is a leading cause of biodiversity declines globally, and there has been increasing recognition in recent years of the importance of restoring degraded habitats to functional ecosystems to ameliorate this loss. Despite the critical roles animals play in ecosystems, animals are often overlooked in assessments of ecological restoration success, particularly beyond their presence or absence in these habitats. Apex predators are critical to ecosystems, regulating predator–prey dynamics, and in arid Australia, monitor lizards (Reptilia: Varanidae) often fill high‐order predatory roles. Varanids are highly diverse in size and occupy a variety of ecological niches, providing an ideal group for assessing habitat change over multiple spatial scales. Here, we assess the responses of varanids to early‐stage habitat restoration following the discontinuation of mining activities, by mapping behavioural signs of habitat usage including burrows, tracks and diggings. We recorded burrow size and track measurements to gauge the size of varanids utilising reference and restored habitats, and mapped tortuosity of tracks to assess their movement through habitats. Restored areas had significantly fewer signs of varanid presence than the reference bushland and largely appeared to be just traversed or used only by larger individuals. Restored landscapes, particularly those in early successional stages, often lack established vegetation cover and present increased metabolic costs and predation risks. Providing fauna refuges (e.g. hollow logs) to mitigate the metabolic costs and predation risks in areas undergoing restoration may aid in facilitating the return of varanids and of other animal populations, particularly during the early stages of vegetation establishment. Understanding the behavioural responses and movement ecology of animals within landscapes undergoing restoration is key to facilitating the conservation of self‐sustaining and functional ecosystems.

Identifying Mechanisms for Successful Ecological Restoration with Salvaged Topsoil in Coastal Sage Scrub Communities

Although aboveground metrics remain the standard, restoring functional ecosystems should promote both aboveground and belowground biotic communities. Restoration using salvaged soil—removal and translocation of topsoil from areas planned for development, with subsequent deposition at degraded sites—is an alternative to traditional methods. Salvaged soil contains both seed and spore banks, which may holistically augment restoration. Salvaged soil methods may reduce non-native germination by burying non-native seeds, increase native diversity by adding native seeds, or transfer soil microbiomes, including arbuscular mycorrhizal fungi (AMF), to recipient sites. We transferred soil to three degraded recipient sites and monitored soil microbes, using flow cytometry and molecular analyses, and characterized the plant community composition. Our findings suggest that salvaged soil at depths ≥5 cm reduced non-native grass cover and increased native plant density and species richness. Bacterial abundance at recipient sites were statistically equivalent to donor sites in abundance. Overall, topsoil additions affected AMF alpha diversity and community composition and increased rhizophilic AMF richness. Because salvaged soil restoration combines multiple soil components, including native plant and microbial propagules, it may promote both aboveground and belowground qualities of the donor site, when applying this method for restoring invaded and degraded ecosystems.

Development of a soil quality index for characterizing effects of land‐use changes on degradation and ecological restoration of rangeland soils in a semi‐arid ecosystem

AbstractThe aim of this research was to study the influence of land‐use changes on degradation and ecological restoration of rangeland soils by quantifying 15 soil attributes and the subsequent development of a soil quality index (SQI). Soil properties were determined to establish a minimum data set (MDS) for the development of an overall weighted additive SQI. The soil attributes were measured on samples (0 to 15 and 15 to 30‐cm depths) collected in undisturbed rangelands, cultivated rangelands, and restored rangelands following cultivation abandonment for 12 or 45 years in a semi‐arid ecosystem, Central Iran. The selected MDS indicators consisted of the mean weight diameter (MWD), total nitrogen (TN), microbial respiration (MR), and alkaline phosphomonoesterase activity (ALP). Overall, soil aggregation, N content, microbial activity, and ALP activity were found to be the key indicators contributing considerably to the SQI of rangeland ecosystems. Soil MWD had the highest contribution (31%) to the estimated SQI values, followed by TN (27%), MR (22%), and ALP (21%). Results indicated a clear difference in soil quality among the common land uses with a significant decline of SQI after conversion of native rangelands (0.80) to croplands (0.53). Restored rangeland soils were characterized by a higher value of SQI (0.63–0.73) as compared with cultivated rangelands (0.53). This suggests a good recovery of soil capacity and functions after the abandonment of cropping activity in previously cultivated rangelands. Vegetation restoration and plant productivity appeared to be the major driver of improved soil quality of the abandoned croplands in these rangelands. Our SQI tool could be useful to determine the success of agricultural abandonment and ecological restoration of rangeland soils in the studied semi‐arid environment.

Successional dynamics of soil fungal diversity along a restoration chronosequence post‐coal mining

Soil disruption from open‐cut mining practices can adversely impact microbial communities and the ecosystem services that they mediate. Despite this, assessment of impacts of soil disruption, and the subsequent recovery of microbial communities is rarely studied. Monitoring of ecological restoration success on mine sites has traditionally focused on vegetation; however, most plants rely, at least in part, on associations with soil fungi for enhanced nutrient and water acquisition. Here, we used high‐throughput phylogenetic marker gene sequencing to characterize the diversity of soil fungal communities along a restoration chronosequence ranging from 3 to 23 years at a rehabilitated mine site. We used nonmined analogue sites as a baseline for comparative purposes and examined the associations of soil fungal communities with soil physicochemical and aboveground vegetation variables. Fungal richness on rehabilitated sites was significantly larger than on nonmined sites, suggesting that mixing of topsoil during stockpiling resulted in a composite microbial community. Fungal community composition was significantly influenced by edaphic variables and the length of rehabilitation, with mined sites becoming more similar to nonmined sites over time. Fungal populations associated with ectomycorrhizae were relatively more abundant than those associated with arbuscular mycorrhizae and declined in response to disturbance, but recovered over time on the woody dominated sites indicating a strong coupling of these fungi with aboveground vegetation. Our data indicate that soil fungal diversity is a useful bioindicator of soil restoration in mined sites and may complement more traditional vegetation‐based surveys.

The utility of DNA barcoding as a tool to assess the success of ecological restoration using Hemiptera as a biological indicator

DNA barcoding uses a short, standardized DNA fragment to sort individuals into species. This molecular technique has applications in fields including ecology, evolution, conservation, and biogeography. In ecological applications such as species monitoring and habitat restoration, its potential has not been fully realized and implemented. Invertebrates are excellent biological indicators, as changes in species diversity or community assemblage provide important insights into the condition of, or changes in, the environment. This information is particularly useful within the context of restoration ecology. In this study, DNA barcoding is used to assess the potential of Hemiptera as a biological indicator of restoration success for the Buffelsdraai Landfill Site Community Reforestation Project (Durban, South Africa). A total of 393 Hemiptera specimens were collected from sites reforested at distinct phases (plots reforested in 2010, 2012, and 2015) and two reference sites (natural forest and grassland). The Hemiptera species composition and assemblage were assessed by analyzing diversity indices, ordination, unweighted pair‐group average cluster analysis, and phylogenetic analysis. Hemiptera species composition varied significantly across the chronologically different reforested sites, with a higher species richness observed in the older reforested plots. This suggests that Hemiptera diversity can be used to track restoration success, even over the small temporal scale used in this study. This study highlights the utility of DNA barcoding as a taxonomic sorting tool both to monitor ecological restoration and to discover specific taxa within Hemiptera that may be useful biological indicators.

Evaluation of ecological restoration success in mining‐degraded lands

AbstractThis review article analyzes the importance of assessing the success of ecological restoration by using four indicators: assemblage of the plant and animal communities; enzyme activity; litter accumulation and decomposition; and the improvement of soil quality. These indicators can be used alone or in combinations. Even though the Society for Ecological Restoration International provided a primer containing nine attributes to use as standards for measuring ecological restoration, only three of these attributes could be easily applied due to their low costs and low time requirements. These three attributes include: diversity, vegetation structure, and ecological processes. This review article emphasizes that the criteria for the selection of the indicator species should be based upon: habitat types, abundance of species, ease of measuring, quantifying and interpreting the results, gradual enhancement with time and cost‐effectiveness, sensitivity, variability of response, size, residential status, and requirements of the area. Principal component analysis was applied to calculate the reclaimed mine soil quality index (RMSQI) and the forest soil quality index (FSQI) and the RMSQI value was compared with FSQI (optimum index value of reference ecosystem) to evaluate the restoration success. Available phosphorus, exchangeable magnesium, organic carbon, clay content, field moisture, available nitrogen, electrical conductivity, and pH are identified as the most influential parameters that regulate the health of reclaimed mine soil. Exchangeable calcium, magnesium, cation exchange capacity, sand, silt, clay content, field moisture, available phosphorus, and pH are the controlling properties for forest soil. The observed values of the above‐stated soil indicator properties were converted into a unitless score (0–1.00) and integrated into index calculations (RMSQI and FSQI). The contribution of each soil indicator properties on the calculated index was analyzed, which provides insight into the reason for the measured index. A higher RMSQI indicates better ecological restoration success. The calculated RMSQI was found to be 0.473 in the reclaimed dump, which is 6% lower than the reference ecosystem.

A primer on choosing goals and indicators to evaluate ecological restoration success

We discuss aspects of one of the most important issues in ecological restoration: how to evaluate restoration success. This first requires clearly stated and justified restoration goals and targets; this may seem “obvious” but in our experience, this step is often elided. Indicators or proxy variables are the typical vehicle for monitoring; these must be justified in the context of goals and targets and ultimately compared against those to allow for an evaluation of outcome (e.g. success or failure). The monitoring phase is critical in that a project must consider how the monitoring frequency and overall design will allow the postrestoration trajectories of indicators to be analyzed. This allows for real‐time management adjustments—adaptive management (sensu lato)—to be implemented if the trajectories are diverging from the targets. However, as there may be large variation in early postrestoration stages or complicated (nonlinear) trajectory, caution is needed before committing to management adjustments. Ideally, there is not only a goal and target but also a model of the expected trajectory—that only can occur if there are sufficient data and enough knowledge about the ecosystem or site being restored. With so many possible decision points, we focus readers' attention on one critical step—how to choose indicators. We distinguish generalizable and specific indicators which can be qualitative, semiquantitative, or quantitative. The generalizable indicators can be used for meta‐analyses. There are many options of indicators but making them more uniform would help mutual comparisons among restoration projects.