Restoration Trajectories Research Articles

Passive revegetation limited by seed availability in a salt marsh sediment addition site

Many approaches to restoring salt marsh habitats assume flora will naturally colonize the restoration site following the reinstatement of tidal hydrology that is appropriate for halophytes. However, this passive strategy can fail to meet restoration targets because of unfavorable site conditions and/or limited propagule dispersal. This study analyzes propagule availability in a restored southern California salt marsh that experienced slow passive revegetation following sediment addition to combat subsidence‐driven habitat loss. We performed a seedling emergence experiment to assess the quantity and species composition of viable halophyte seeds in the restoration site compared to nearby established salt marsh habitat. Additionally, we irrigated seed bank samples with freshwater or saltwater to test the effects of restoration site salinity conditions on seedling emergence and survival. Due to the proximity of the restoration site to seed sources, we expected to find ample seeds within its seed bank. However, only two seedlings emerged from restoration site seed bank samples (collected over 1.18 m2 of soil surface area), compared to an average of 44.33 seedlings from control site samples. Control site samples receiving saltwater irrigation had similar quantities of seedlings emerge, but seedlings in salt water had a reduced survival rate compared to seedlings in the freshwater treatment. Overall, these results suggest that passive restoration should be paired with techniques that retain seeds, such as increasing the topographic complexity of the restoration site. However, in scenarios where salinity or elevation may limit seedling recruitment, active planting should be considered to speed restoration trajectories.

The assembly and dynamics of ecological communities in an ever‐changing world

AbstractAlternative perspectives on the maintenance of biodiversity and the assembly of ecological communities suggest that both processes cannot be investigated simultaneously. In this concept and synthesis, we challenge this view by presenting major theoretical advances in structural stability and permanence theory. These advances, which provide complementary views, allow studying the short‐ and long‐term dynamics of ecological communities as changes in species richness, composition, and abundance. Here, the global attractor, technically named informational structure (IS), is the central element to construct from information of species' intrinsic growth rates and their strength and sign of interactions. The global attractor has four main properties: (1) It contains all the limits of what is feasible and unfeasible of the dynamical behavior of an ecological system, therefore, (2) it provides a thorough characterization of all combinations of species' richness and composition in which species can coexist (i.e., feasible and stable equilibrium), (3) as well as all connections (paths) of assembly between coexisting communities. Importantly, (4) such topology of coexisting communities and their connections changes when environmental (abiotic and biotic) variation affects the ability of species to grow and interact with others. Overall, these four properties allow switching from a traditional evaluation of species coexistence at equilibrium to a much more realistic nonequilibrium perspective where changes in the structure of the global attractor underlie the transient ecological dynamics. Several fields in ecology can benefit from the study of an IS. For instance, it can serve to evaluate community responses after the end of a perturbation, to design restoration trajectories, to study the consequences of biological invasions on the persistence of native species within communities, or to assess ecosystem health status. We illustrate this latter possibility with empirical observations of 7 years in Mediterranean annual grasslands. We document that extremely wet or dry years generate ISs supporting few coexisting communities and few assembly paths. The remaining communities distinguish winners from losers of ongoing climate change and indicate the limits to future community assembly opportunities. A fully tractable operational framework is readily available to understand and predict the assembly and dynamics of ecological communities in an ever‐changing world.

Standards‐based evaluation inform ecological restoration outcomes for a major mining activity in a global biodiversity hotspot

The International Principles and Standars for the Ecological Restoration and Recovery of Mine Sites were used to assess the restoration quality of one of the world's largest mines, located in the world's most biodiverse temperate forest. Quantitative analysis of longitudinal data spanning 35 years scored restoration quality at 2‐stars against a 5‐star forest ecosystem restoration target, with little indication of improvements from adaptive management. Two‐thirds of indicator plants were significantly under‐represented in early‐stage restoration and declined with age. Most plant species were effectively absent, including key structural species. Invasive plants and native legumes were persistently overabundant. Time required for the maturation of tree species will prevent the production of fundamental ecosystem features for well over a century (e.g. hollows and fallen logs), inhibiting functional fauna return (reptiles, bats, and conservation priority cockatoos in particular). The significantly different outcome compared with previous assessments is due to the age of restoration assessed and previous assumptions that early‐stage success indicate that restoration is on the correct, prolonged trajectory toward full ecological restoration. However, previous assessment methods did not consider many key metrics of the standards, nor accurately predict future restoration trajectory. In particluar, initial plant species richness (the only measure of biodiversity in the company's restoration completion criteria) did not reflect future restoration quality. These substandard restoration outcomes may result from removing the deep, multi‐layered bauxitic substrate on which the ecosystem evolved and establishing restoration on shallow topsoil over a more homogenized, impervious substrate. This study demonstrates the value of a robust, adaptable multi‐factor framework and methodology to evaluate restoration outcomes.

Practical applications of soil microbiota to improve ecosystem restoration: current knowledge and future directions.

Soil microbiota are important components of healthy ecosystems. Greater consideration of soil microbiota in the restoration of biodiverse, functional, and resilient ecosystems is required to address the twin global crises of biodiversity decline and climate change. In this review, we discuss available and emerging practical applications of soil microbiota into (i) restoration planning, (ii) direct interventions for shaping soil biodiversity, and (iii) strategies for monitoring and predicting restoration trajectories. We show how better planning of restoration activities to account for soil microbiota can help improve progress towards restoration targets. We show how planning to embed soil microbiota experiments into restoration projects will permit a more rigorous assessment of the effectiveness of different restoration methods, especially when complemented by statistical modelling approaches that capitalise on existing data sets to improve causal understandings and prioritise research strategies where appropriate. In addition to recovering belowground microbiota, restoration strategies that include soil microbiota can improve the resilience of whole ecosystems. Fundamentally, restoration planning should identify appropriate reference target ecosystem attributes and - from the perspective of soil microbiota - comprehensibly consider potential physical, chemical and biological influences on recovery. We identify that inoculating ecologically appropriate soil microbiota into degraded environments can support a range of restoration interventions (e.g. targeted, broad-spectrum and cultured inoculations) with promising results. Such inoculations however are currently underutilised and knowledge gaps persist surrounding successful establishment in light of community dynamics, including priority effects and community coalescence. We show how the ecological trajectories of restoration sites can be assessed by characterising microbial diversity, composition, and functions in the soil. Ultimately, we highlight practical ways to apply the soil microbiota toolbox across the planning, intervention, and monitoring stages of ecosystem restoration and address persistent open questions at each stage. With continued collaborations between researchers and practitioners to address knowledge gaps, these approaches can improve current restoration practices and ecological outcomes.

Ten years of directing seeding restoration in the Brazilian savanna: Lessons learned and the way forward

Savannas and grasslands have lost almost 50% of their original cover worldwide. Therefore, the development of methods and information on open-canopy ecosystem restoration is urgent for the inclusion of these ecosystems into global and regional priorities. In the Brazilian savanna, the most diverse savanna in the world, restoration efforts focused on open ecosystems have been virtually absent, but have increased in the last 10 years. Such efforts are frequently threatened by invasive exotic grasses (IEG) that invade and dominate areas excluding native species, oftentimes aided by altered soil conditions. Long-term studies of savanna restoration trajectories are rare. In this study, we surveyed 22 savanna restoration areas established two to ten years before the study with similar restoration methods to assess their current status. We show that the current restoration methods are successful in establishing native species and allowing species turnover but they are threatened by IEG. Restoration success varies and is affected by soil conditions, IEG landscape cover and post-sowing weeding. Despite that, the simultaneous introduction of different plant functional groups allows turnover from fast to slow-growing plants. Establishing savanna native species is possible at an operational scale with current knowledge and techniques. However, native species establishment fails to prevent IEG reinfestation, which needs to be managed in restoration efforts in the Brazilian savanna.

Ecological restoration trajectory of the Taitema Lake wetland in arid northwest China: A 36-year wetland health assessment using Landsat time series data

The Taitema Lake wetland in the lower reaches of the Tarim River (northwest China) is sensitive to hydrological changes and provides necessary ecosystem functions for biodiversity conservation. Monitoring and evaluating the long-term dynamics of the Taitema Lake wetland is essential for conserving and restoring regional wetland ecosystems. This paper used a dense time series of Landsat images from 1986 to 2021 to map the Taitema Lake wetlands. It analyzed the annual and seasonal variations of the wetlands by ten ecological indicators, which include area extent, vegetation, hydrology, and landscape features. A systematic assessment of the ecological quality of the wetlands over the past 36 years, along with their influencing factors, was conducted from the perspective of wetland health. The results showed that (1) the recovered water areas and the wetlands showed a clear trend of ecological restoration since 2000, accompanied by an increased fragmentation. The total wetland area increased from 69.95 km2 in 1986 to 1164.47 km2 in 2021, with a 15.6-fold increase, and the vegetation area increased twentyfold to 639.84 km2. (2) The wetness in the core zone increased consistently across seasons, coupled with a simultaneous vegetation expansion surrounding the core zone. The areas with increasing wetness levels account for 48 % during winter and spring, and the areas with vegetation expansion account for 81 % and 72 % in summer and autumn, respectively. (3) The wetland ecological health status recovered to a “Good” level in 2021 and has not reached the “Excellent” status. The expansion of the water body is the primary driver behind the promotion of wetland ecological recovery. Small water bodies within the area range of 0.05 to 0.1 km2 notably exhibited the most stimulating effects on the wetlands. Thus, increasing the count of smaller water bodies helps rehabilitate vegetation growth and mitigating the water supply’s stress to sustain large lacustrine bodies.

Comparing Pixel- and Object-Based Approaches for Classifying Multispectral Drone Imagery of a Salt Marsh Restoration and Reference Site

Monitoring salt marshes with remote sensing is necessary to evaluate their state and restoration. Determining appropriate techniques for this can be overwhelming. Our study provides insight into whether a pixel- or object-based Random Forest classification approach is best for mapping vegetation in north temperate salt marshes. We used input variables from drone images (raw reflectances, vegetation indices, and textural features) acquired in June, July, and August 2021 of a salt marsh restoration and reference site in Aulac, New Brunswick, Canada. We also investigated the importance of input variables and whether using landcover classes representing areas of change was a practical way to evaluate variation in the monthly images. Our results indicated that (1) the classifiers achieved overall validation accuracies of 91.1–95.2%; (2) pixel-based classifiers outperformed object-based classifiers by 1.3–2.0%; (3) input variables extracted from the August images were more important than those extracted from the June and July images; (4) certain raw reflectances, vegetation indices, and textural features were among the most important variables; and (5) classes that changed temporally were mapped with user’s and producer’s validation accuracies of 86.7–100.0%. Knowledge gained during this study will inform assessments of salt marsh restoration trajectories spanning multiple years.

Evaluation of mangrove restoration effectiveness using remote sensing indices - a case study in Guangxi Shankou Mangrove National Natural Reserve, China

As one of the most productive marine ecosystems in the coastal wetlands, mangrove forests have been severely threatened by intensive human activities. Many countries and regions have carried out mangrove restoration projects. The evaluation of mangrove restoration effectiveness is of great significance for scientific decision-making for restoration engineering and wetland management. In this study, we presented a remote-sensing-based Mangrove Restoration Effectiveness Index (MREI) to evaluate mangrove restoration effectiveness. We took the Guangxi Shankou Mangrove National Natural Reserve (GSMNNR) in China, a UNESCO Biosphere Reserve, as our study area, where four phases of afforestation were implemented during 1990-2022. The MREI was developed based on Landsat-series images by considering the change in mangrove area and the Normalized Difference Vegetation Index (NDVI) from the start year to the end year of each afforestation phase (evaluation period). We further evaluated the Persistence of Restoration Effectiveness (PRE) based on the MREI change trajectory during the whole evaluation period, and the Process-based Restoration Effectiveness Index (PREI) was developed to evaluate the restoration effectiveness at village scale. The results showed that MREI can effectively represent the trajectory of mangrove restoration and showed consistent pattern with high-spatial-resolution imagery. From 1990 to 2022, the mangrove forest area increased from 235.26 ha in 1990 to 873.27 ha in 2022, and 84.59% of the mangrove forest was converted from tidal flats in the reserve. The average value of MREI in the five evaluation phases were 0.48, 0.24, 0.29, 0.17, and 0.72, respectively. The dynamic change of MREI showed that 5.24% of the zones had poor PRE, 44.17% of the zones had excellent PRE. From the perspective of spatial distribution, the Zones with PREI values ranging from high to low were follows: Zone A, E, J, G, C, H, I (D), F, B. Overall, the high value zones of PREI were mainly distributed in the central of the Dandou Sea and the northern part of the Yingluo Bay. The low value zones were distributed in the northwest of the Dandou Sea. We expect the MREI and PREI have great potential to be applied to other regions to evaluate mangrove restoration effectiveness.

Characteristics and gaps in the assessment of progress in mine restoration: insights from five decades of published literature relating to native ecosystem restoration after mining

Desires that mine sites are restored to self‐sustaining native ecosystems providing benefits for people have been longstanding. However, achieving and demonstrating progress toward mine restoration goals is complex and requires sustained assessment of numerous disparate components. The recently released Society for Ecological Restoration Mine Site Restoration Standards (SER MSRS) recommend utilizing restoration science assessments to determine whether sites are developing toward similarity with targeted ecosystems and exhibiting self‐sustainability. We conducted a global review of publications that assessed restoration to native ecosystems after mining. Our objectives were to (1) document case studies of long‐term assessments of mine restoration and (2) evaluate the extent to which restoration assessment has reported the achievement of varied mine restoration goals on a global scale, including (3) whether any ecosystem components and restoration attributes are underrepresented in published assessments. Among the 712 publications we collated, we documented case studies with sustained reporting on similar restoration and significant increase over time in the quantity and breadth of attributes and ecosystems assessed. Nevertheless, notable gaps remain, or underreporting persists. For example, there have been relatively few assessments targeting understanding of key ecosystem processes, resilience, and threats to ecosystem persistence that are necessary for demonstrating “self‐sustainability.” Our review also revealed limited consideration of ecosystem services that rarely involved impacted communities. We recommend efforts to collate and expand assessments of similar restoration trajectories, placing more focus on indicators that enable the evaluation of characteristics and progress toward a self‐sustaining socioecological ecosystem, to help achieve the goals of mine site restoration.

The use and abuse of keystone plant species in restoration practices of terrestrial ecosystems

Keystone plant species are commonly used for restoring degraded terrestrial sites because, despite being encountered in low abundances in natural communities, they interact with multiple species across multiple niche dimensions. Nevertheless, the demographic characteristics of these “great interactors” are often disregarded in restoration planning, which may bring unintended consequences for restoration trajectories once the outcome of species relationships interplays between positive and negative effects depending on the density of interacting species. Therefore, while replanting keystone species at their characteristically low densities may re‐entangle food webs and allow novel plant and animal recruitment, restoring them at high densities can assemble asymmetrical relationships strong enough to affect sympatric plant species establishment, survival, and reproduction. Here, we explore the negative consequences of overusing keystone plant species in sites undergoing restoration and provide specific guidelines for practitioners to maximize the benefits of keystone plants in restoration initiatives.

The common predator, Sheepshead (Archosargus probatocephalus), enhances survival of the Eastern oyster (Crassostrea virginica) in an experimental setting

Oyster reefs are a vital but declining component of nearshore, estuarine ecosystems. Global efforts to restore this important habitat are ongoing but have had varied success. The potential for biotic factors such as predation to influence restoration trajectories is rarely considered; however, there is mounting evidence that a better understanding of trophic relationships could aid in the restoration of the ecologically critical Eastern oyster (Crassostrea virginica). A common predator-prey interaction within the oyster reef community was examined through manipulative experiments to determine what effect predator presence had on early survivorship of oyster spat – a factor known to influence the success of oyster reef restoration. The juvenile stone crab (Menippe spp.) is a known predator of spat (<30 mm) sized Eastern oysters but also serves as prey for mobile predatory fish. Sheepshead (Archosargus probatocephalus), a fish with a diet high in structure-associated invertebrates, are one of many predatory fishes that utilize oyster reefs. Adult Sheepshead presence was found to significantly increase oyster spat survival. Oyster spat survival can be attributed to both trait and density-mediated indirect interactions. These results suggest that changes in the presence of an exploited finfish species can influence oyster spat survivorship.

Success of passive and active restoration of lowland hay meadows with regard to current and historical references

The restoration of hay meadows is one of the major challenges in temperate Europe, to overcome the drastic loss and degradation of these semi-natural habitats. Evaluation of restoration success requires the definition of a relevant reference ecosystem. Historical phytosociological relevés dating from the 1960s–1970s, before large scale agriculture intensification, may be used as the reference framework for such purposes. However, this reference framework may no longer be pertinent in our present-day ecological and socio-economic context. In this study, we assessed the success of three restoration techniques for lowland hay meadows, based on plant species richness and composition and functional traits, by comparing the restoration trajectories to historical and current references. The three restoration techniques, passive restoration mowing, active fresh hay transfer and active sowing of threshing material, were implemented depending on the initial level of degradation and the proximity to well-preserved meadows. The species composition of restored meadows clearly differed from historical references but converged toward current references, for both passive and active restoration techniques. Historical references are characterized by short, stress-tolerant dicotyledonous plant species with small specific leaf area, indicators of nutrient-poor environments. The gap observed between plant communities of historical and current meadows suggests that the historical data are an over-ambitious target for restoration purposes and can hardly be considered relevant to our present-day context. Therefore, creation of a new reference framework of lowland hay meadows is needed for the adequate implementation of restoration projects. Successful outcomes of active and passive techniques must encourage practitioners to adapt the choice of the restoration method depending on the local ecological context, i.e., level of degradation and proximity to well-preserved habitats.

Changes in the spatial distribution of total phosphorus in sediment and water column of a shallow subtropical lake

Julian PJ II, Schafer T, Cohen MJ, Jones P, Osborne TZ. 2023. Changes in the spatial distribution of total phosphorus in sediment and water column of a shallow subtropical lake. Lake Reserv Manage. 39:213–230. In shallow lakes, interactions between bed sediment and the water column strongly influence the availability and transport of nutrients. Lake Okeechobee, in South Florida, is a eutrophic, shallow, polymictic lake that exhibits frequent mixing of the water column and resuspension of unconsolidated sediments. The objective of this study was to evaluate the temporal and spatial patterns of water and sediment characteristics and evaluate the linkage of sediment and water column total phosphorus (TP) concentrations. Spatiotemporal generalized additive models identified key periods during which both surface water total suspended solids (TSS) and TP increased, corresponding to hurricane and tropical storm activity. Our models identified regions with persistently greater water column concentrations than the lake average, indicating potential hot spots in resuspension processes and/or internal loading. Sediment bulk density (BD) and TP were inversely correlated, indicating that light, less dense sediments have greater TP concentrations, potentially contributing to the redistribution of sediments and P. An integrated evaluation of surface water and sediment characteristics using a generalized additive model revealed that sediment TP strongly influences water column TP concentrations, potentially explaining the spatial distribution of surface water TP concentrations. The area of the lake with sediment TP concentration ≤500 mg/kg is increasing while the low bulk density sediments area is decreasing, marking a potential improvement in sediment conditions. If this trend persists, it indicates that the lake is increasingly storing P in sediments that can resist entrainment, with significant implications for assessing the trajectory of lake restoration.

Restoration and replication: a case study on the value of computational reproducibility assessment

Open science is vital to the interdisciplinary field of ecology due to its integrative nature and use of longitudinal datasets that build upon earlier data collections. To highlight the importance of open science in the rapidly growing discipline of restoration ecology, we conducted a “computational reproducibility” assessment of a publication on a mining restoration program spanning several decades and over 250 km2 in a global biodiversity hotspot. Open data and code provided alongside the original publication were assessed for consistency with the results and conclusions of the original publication, as were potential limitations in findings due to the methodology. The impacts of inconsistencies and limitations were qualitatively assessed against the key findings from the publication and data were reanalyzed where impacts were potentially significant. Of the six inconsistencies and limitations identified, two had a significant impact on 5 of the 11 key findings of the original publication and one new key finding was made. The impact of this is of high ecological significance as the findings related to key restoration parameters: species richness (similarity of species richness between forest and 25‐year‐old restoration), functional diversity (correlation of species richness and functional diversity), and the restoration trajectory (long‐term trends and restored areas' resilience to disturbance). These outcomes highlight the importance of open data and the value of detailed third‐party data reviews, particularly in restoration ecology which relies on research findings to inform decision‐making and policy and drive adaptive management.

Ecological indicators of forest regeneration in areas of Araucaria Forest in South Brazil

Assessing and monitoring are essential steps for the restoration process. These processes require ecological indicators to evaluate the re-establishment of the ecological processes that maintain the forest dynamics. However, the majority of studies involving ecological indicators developed in Brazil are aimed at monitoring active restorations, with specific indicators. In this context, the current study aimed to characterize the seed rain and litterfall, and verify their applicability as relevant ecological indicators in the evaluation of the passive forest restoration process in riparian forest. These areas are of different ages, post-harvest of Pinus taeda L. stands, within the Araucaria Forest, which is part of an important global hotspot for biodiversity conservation. We evaluated the floristic composition of the seed rain and the measurement of the litter supply at five different ages of the restoration process, for one year. The efficiency of these indicators was defined by means of a classification based on aspects and descriptors. We hypothesized that these two indicators are suitable for assessing and monitoring the restoration trajectory and can describe the reestablishment of ecological processes in anthropized areas. These indicators are important because they determine the restoration of the functionality of altered ecosystems. The results showed that both are good indicators, mainly due to the sensitivity and scale criteria, since the indicators showed seasonal differences in the evaluated period. They can be used as scientific indicators for monitoring forest restoration in altered ecosystems.

Linking below‐ and aboveground indicators under different forest restoration interventions in a mosaic landscape with different land‐use legacies

Deforestation and forest degradation continue at alarming rates. Landowners often clear forest patches for alternative use, creating landscape mosaics of different land‐use legacies. Ecological restoration is usually monitored by aboveground processes, while belowground processes are far less studied. We addressed how the abundance and activity of nutrient improvement bacteria contribute to restoration success, considering different restoration interventions and land‐use legacies. We assessed the abundance and potential activity of N‐fixing and P‐mineralizing bacteria in the rhizosphere of 279 two‐year‐old Quercus mexicana plantlets in a disturbed oak forest in central Mexico. We analyzed the differences across landscape patches (eroded landslide, pastureland, and forest) of four common restoration interventions: passive restoration, artificial shading, topsoil translocation, and combining both treatments. Restoration interventions modified soil functioning differently across landscape patches with a significant increase of P‐mineralizing bacteria abundance and potential activity in the landslide and pastureland. In contrast, N‐fixing bacteria increased only in the landslide site where we registered the lowest organic matter content. Surprisingly, interventions that enhance bacterial activity and abundance do not necessarily improve short‐term seedling performance. We recommend considering the landscape heterogeneity to better match the restoration interventions with the prevailing degradation factor in each landscape patch. Also, combining restoration strategies does not necessarily result in synergy and may imply a useless expense of resources. Finally, monitoring soil health provides novel insights to understand restoration trajectories that remain undetected when focusing only on seedling performance.

Restoration of riparian ecosystems posterior to tin mining in the Central Amazon: Restoration indicators and selection of suitable species for planting

Riparian forests are fundamental for water and soil protection and favor the creation of gene flow corridors between forest remnants. The restoration of riparian forests by seedling planting can usually accelerate the succession process, but these ecosystems are seldom evaluated in post-mined areas in the Amazon. In this context, the objective of this study was to evaluate the restoration trajectory of riparian forests after tin mining, using composition and structure indicators along with the selectin of the most suitable species for planting according to height and DBH increments. A total of eight riparian forests of different planting ages (2014, 2015, 2016, 2017, and 2021/2022) were evaluated, being currently 8.5 (RF_8.5), 7.5 (RF_7.5), 6.5 (RF_6.5), 5.5 (RF_5.5) and ≤ 1.5 (RF_1.5) years old. Permanent plots of 30 m × 30 m were allocated in each forest, with the number of units varying according to the total area size, with a minimum of 3 plots allocated. Our results show a gradual increase in the density of individuals and species over the three evaluations performed, emphasizing RF_6.5 and RF_1.5 areas. Using the NMDS analysis, the RF_8.5 and RF_1.5 did not present any floristic-structural similarities. The 10 species with the highest IVI represented more than 60% of the total in all the restored ecosystems. V. guianenses presented the highest relative density for all ecosystems under restoration, except for RF_1.5, which S. alata was highlighted. P. pendula was the most suitable for planting in all assessed riparian forests when mortality and height and diameter increments were taken into consideration. Species with bioeconomic potential, such as C. guianensis, H. courbaril, E. precatoria and M. flexuosa, were also classified as efficient and considered structuring species.

Fall fertilization during nursery production increases nitrogen status of Purshia tridentata seedlings: implications for outplanting

During container nursery production of Purshia tridentata (antelope bitterbrush), we found that three fall fertilization applications successfully loaded plants with nitrogen (N) with little effect on plant biomass. Using 15N‐labeled fertilizer to track N movements, we observed that N‐loaded seedlings attained luxury consumption and ultimately translocated more N toward roots. In trees, such N‐loading efforts have been reported to increase seedling survival and growth after outplanting by improving initial root growth. This leads to enhanced access to water and nutrients that increases overall plant competitiveness and performance. Our results add, in general, to the paucity of information concerning fall fertilization of shrubs, and specifically that this technique offers promise to enhance the quality of antelope bitterbrush seedlings. This could improve overall planting success of this important shrub native to western United States rangelands. Increasing the effectiveness of planting antelope bitterbrush, which can often improve restoration trajectories more than direct seeding or reliance on natural regeneration of this species, could accelerate the pace and scope of critical habitat restoration. Restoration is needed as antelope bitterbrush abundance has been reduced across the landscape because of conversion to agriculture, invasion by nonnative annual grasses, and an increase in fire frequency and intensity, among other reasons. In addition, this species provides browse for ungulates and critical habitat for at‐risk species, such as Centrocercus urophasianus (greater sage‐grouse). Although N loading antelope bitterbrush has potential to improve outplanting performance, the resulting higher nutrient status of this preferred browse species may lead to elevated browsing during seedling establishment.

Spatiotemporal Relationship between Ecological Restoration Space and Ecosystem Services in the Yellow River Basin, China

Ecological restoration is an important implement to avoid land degradation and improve the sustainability of ecosystems. As a spatial definition of ecological restoration, ecological restoration space (ERS) is recognized to have a positive impact on the environment. However, its spatiotemporal pattern and magnitude of contribution to ecosystem services (ESs) remain uncertain. In this study, an ecological restoration trajectories model was developed to investigate the spatiotemporal pattern and evolution of ERS. The InVEST model and geographically weighted regression were used to evaluate the dynamic relationship between ERS and crucial ESs. Results demonstrated that from 1990 to 2015, the cumulative area of ERS in the Yellow River Basin (YRB) was 184,197.05 km2, with Inner Mongolia, Qinghai, and Shaanxi having the largest distribution. The change in geographical center of three subcategories, forest restoration space (FRS), grassland restoration space (GRS), and shrub restoration space (SRS), showed a pronounced geographical migration. Meanwhile, the distribution of ERS significantly improved the conditions of habitat quality (HQ), carbon storage (CS), and soil conservation (SC) on 75.48%, 71.86%, and 56.75% of the grids, respectively. This study provides a scientific foundation for the ecosystem conservation and land management of the YRB.

Adapting ecosystem restoration for sustainable development in a changing world

Adapting ecosystem restoration for sustainable development in a changing world