Ecological Restoration Projects Research Articles

Rare microbial taxa as the major drivers of nutrient acquisition under moss biocrusts in karst area

Karst rocky desertification refers to the process of land degradation caused by various factors such as climate change and human activities including deforestation and agriculture on a fragile karst substrate. Nutrient limitation is common in karst areas. Moss crust grows widely in karst areas. The microorganisms associated with bryophytes are vital to maintaining ecological functions, including climate regulation and nutrient circulation. The synergistic effect of moss crusts and microorganisms may hold great potential for restoring degraded karst ecosystems. However, our understanding of the responses of microbial communities, especially abundant and rare taxa, to nutrient limitations and acquisition in the presence of moss crusts is limited. Different moss habitats exhibit varying patterns of nutrient availability, which also affect microbial diversity and composition. Therefore, in this study, we investigated three habitats of mosses: autochthonal bryophytes under forest, lithophytic bryophytes under forest and on cliff rock. We measured soil physicochemical properties and enzymatic activities. We conducted high-throughput sequencing and analysis of soil microorganisms. Our finding revealed that autochthonal moss crusts under forest had higher nutrient availability and a higher proportion of copiotrophic microbial communities compared to lithophytic moss crusts under forest or on cliff rock. However, enzyme activities were lower in autochthonal moss crusts under forest. Additionally, rare taxa exhibited distinct structures in all three habitats. Analysis of co-occurrence network showed that rare taxa had a relatively high proportion in the main modules. Furthermore, we found that both abundant and rare taxa were primarily assembled by stochastic processes. Soil properties significantly affected the community assembly of the rare taxa, indirectly affecting microbial diversity and complexity and finally nutrient acquisition. These findings highlight the importance of rare taxa under moss crusts for nutrient acquisition. Addressing this knowledge gap is essential for guiding ongoing ecological restoration projects in karst rocky desertification regions.

Dynamic Change and Attribution Regarding Fractional Vegetation Coverage in Mengdong River Basin

The situation of rocky desertification in the southwestern part of China is very serious and has been included as one of three major ecological problems. In this study, using Landsat images as the data sources, we estimated the fractional vegetation coverage (FVC) in the Mengdong River Basin in the Hunan Province over the past 40 years, analyzed its spatio-temporal variation characteristics, and explored the driving mechanism (climate and anthropogenic) using the Mann–Kendall, Hurst index, and partial correlation methods. Specifically, the impact of ecological engineering on the recovery of vegetation cover in rocky desertification areas was analyzed and discussed in this study. The results demonstrate the following: (1) The changes in FVC in the study area before and after the rocky desertification management ecological project differed significantly, with a very small change in the rate of change in the mean value of FVC between 1987 and 1999 (<0.1%), while the FVC had a significant linear growth trend between 2000 and 2022 (>0.9%). (2) The Hurst index of FVC ranged from −0.233 to 2.476, with an average value of 0.864. The area with an H value greater than 0.75 accounted for 80.12%, indicating that the future trend in the vast majority of regions will develop in accordance with the current change trend. (3) The average partial correlation coefficients between FVC and precipitation and between FVC and temperature were −0.02 and 0.27, respectively, showing that FVC is more sensitive to temperature than precipitation. The combination of climate change and human activities is the main cause of FVC change. The contributions of climate change (precipitation and temperature) and human activities to FVC variation are about 30% and 70%, respectively. Ecological restoration projects have a significant positive effect on the recovery of vegetation in rocky desertification areas. The results of this study are intended to provide a scientific basis for analyzing the characteristics of vegetation restoration in existing rocky desertification areas and ecological management in future rocky desertification areas.

Effects of different reclamation measures on soil quality restoration in open-pit mines: A meta-analysis based on the Chinese Loess Plateau

In the Loess Plateau region, ecological restoration projects have been implemented to restore the ecological environment of open-pit mines. However, no consistent conclusion has been reached regarding the response of soil remediation efforts to different ecological measures and restoration years. A meta-analysis was performed on the results of studies published over the past 30 years for open-pit mining areas on the Loess Plateau in China. The findings reveal that land rehabilitation considerably improved soil quality in open-pit mining areas on the Loess Plateau. Different ecological measures revealed a significant variability in soil quality restoration. Specifically, forestland reclamation affected soil organic matter and microbial carbon the most. Grassland reclamation substantially influenced soil total potassium, organic carbon, enzyme activity, and microbial abundance. Plowland caused the most effective improvement in soil total nitrogen and physical properties. However, total phosphorus and pH were unaffected by restoration measures. In addition, the period of land reclamation and soil nutrients showed a high correlation in the early stage of reclamation. After long-term reclamation, a decreased rate of soil quality improvement by remediation measures occurred after the soil quality returned to its premining level. A relatively lag was observed in the response of soil microbial indicators to environmental changes, and the premining level was reached after longer-term reclamation.

Assessing the impact of agriculture, coal mining, and ecological restoration on water sustainability in the Mu Us Sandyland

Balancing water demand for socio–economic development and ecosystem stability presents a challenge for regional sustainable management, especially in drylands. Previous studies have indicated that large–scale ecological restoration projects (ERPs) lead to a decline in terrestrial water storage (TWS) in the Mu Us Sandyland (MUS). However, the effects of other human activities (e.g., cropland reclamation, coal mining) on water resources remain unclear, raising concerns regarding water crisis and human–natural system sustainability. Through the utilization of coal mine location data, we found that the impact of coal mass loss on the Gravity Recovery and Climate Experiment (GRACE) products cannot be ignored in MUS, especially in the coal–rich northeastern part. Combining these data with auxiliary datasets, we observed a significant (p < 0.05) decrease in TWS (−0.85 cm yr−1) and groundwater storage (GWS, −0.95 cm yr−1) in the MUS, with human activities accounting for 79.23 % of TWS and 90.45 % of GWS reductions, primarily due to increased agricultural and industrial water consumption. Agricultural water consumption increased 2.23 times from 2001 to 2020, attributed to enhanced water use intensity (62.6 %) and cropland expansion (37.4 %). Industrial water consumption in Shenmu, a representative coal county, experienced a 4.16–fold rise between 2001 and 2020. Despite these challenges, local governments have alleviated water stress, ensured food security, and increased household income by comprehensive management strategies, such as enhancing water–saving technology and enforcing stringent policies. Previous studies have overestimated the amount of water resources consumed by ERPs. However, ERPs has played a critical role in stabilizing the regional ecological environment and ensuring the region as a vital food and energy supplier. Our findings can guide for socio-economic development and water management policies in similar regions.

Breaking the poverty trap in an ecologically fragile region through ecological engineering: A close-up look at long-term changes in ecosystem services

Ecological vulnerability and poverty are interrelated and must be addressed together. The resolution of this issue will help us to meet the challenges during the process of implementing concrete actions for realizing the 2030 UN sustainable development goals (SDGs). Ecological restoration projects (ERPs) can enhance ecosystem services (ESs) while providing policy support for improving people's livelihoods. However, processes and mechanisms of ERPs on the ecological environment and socioeconomic development in poverty-stricken and ecologically fragile areas have rarely been studied. To address these issues, we conducted a comparative analysis on the changes of land use and land cover (LULC), ecosystem services (ESs), and socioeconomic development in Bijie City, a karst rocky desertification area in southwest China, before and after the implementation of ERPs in 2000, as well as the complex relationship between these factors. ERPs have affected LULCs, ESs, socioeconomics, and poverty reduction significantly since 2000. Specifically, the total ecosystem service value (ESV) in the study area has increased by more than 3 times in the past 30 years, with the ESV of tourism services and carbon storage increasing the most, from CNY 0.001 and 337.07 billion in 1990 to CNY 11.07 and 108.97 billion in 2019, respectively. The correlation between ESs is mainly synergistic, while the tradeoff between carbon storage and water yield is in a fluctuating upward trend. LULC conversion of cropland to green, and cropland to water, wetland and shrubs has positive effects on carbon storage and water yield, respectively. During study period, GDP, urbanization increased by over 70 times, 5 times, respectively, whereas poverty population, poverty incidence, and employment rate of various sectors (i.e., agriculture, forest, animal, and fishery, or AFAF) decreased by 96.4%, 97.7%, and 18.24%, respectively. Our findings emphasized that ERPs can effectively help poor and ecologically fragile areas to get out of the poverty trap and achieve the “win-win” goals of ecological and socio-economic sustainable development. These results have profound environmental management references to China and other developing countries around the world in realizing ecological restoration, poverty reduction, and the SDGs.

Changes in floristic and vegetation structure in a chronosequence of abandoned gold-mining lands in a tropical Amazon forest

This study analyzes floristic and vegetation structure changes during forest succession after disturbances caused by small-scale gold mining in Madre de Dios (Peru). We compared the floristic and vegetation structure of a reference forest against three sites with different periods of abandonment after mining (5, 11 and 23-years). Three 20 × 60 m plots were defined on each site, and all tree species with a DBH >1 cm within the plots were inventoried. To evaluate species diversity and similarity, the Importance Value, effective numbers of species (0D, 1D, and 2D), and Chao-Jaccard similarity index were calculated. We used the Nonmetric multidimensional scaling for similarity ordination and the PERMANOVA test to evaluate differences in floristic composition. We recorded 129 tree species in the study areas and statistically significant differences between initial and intermediate stages were observed regarding floristic composition, basal area, height, and DBH. The transition from the initial successional stage to the reference forest produces an increase in basal area, species diversity, and floristic similarity. The 23-year-old stand had more species in common with the 11-year-old stand than the reference forest. Our results showed a high proportion of pioneer species and anemochory dispersal syndrome in the initial successional stages, but they decreased in later stages of the chronosequence. The floristic and structural attributes of forests throughout the chronosequence showed a fast recovery during secondary succession. After 23 years, the recovery of tree species density was 77 % of reference forest, while the relative recovery of species composition was much slower, on average 23 %. These results provide essential information to guide the selection of suitable species in ecological restoration projects after abandonment. Implementing forest restoration strategies based on reliable information to accelerate the process of vegetation succession is critical for recuperating areas degraded by gold mining at the Peruvian Amazon.

Coupled hydraulics and carbon economy underlie age-related growth decline and revitalisation of sand-fixing shrubs after crown removal.

Crown removal revitalises sand-fixing shrubs that show declining vigour with age in drought-prone environments; however, the underlying mechanisms are poorly understood. Here, we addressed this knowledge gap by comparing the growth performance, xylem hydraulics and plant carbon economy across different plant ages (10, 21 and 33 years) and treatments (control and crown removal) using a representative sand-fixing shrub (Caragana microphylla Lam.) in northern China. We found that growth decline with plant age was accompanied by simultaneous decreases in soil moisture, plant hydraulic efficiency and photosynthetic capacity, suggesting that these interconnected changes in plant water relations and carbon economy were responsible for this decline. Following crown removal, quick resprouting, involving remobilisation of root nonstructural carbohydrate reserves, contributed to the reconstruction of an efficient hydraulic system and improved plant carbon status, but this became less effective in older shrubs. These age-dependent effects of carbon economy and hydraulics on plant growth vigour provide a mechanistic explanation for the age-related decline and revitalisation of sand-fixing shrubs. This understanding is crucial for the development of suitable management strategies for shrub plantations constructed with species having the resprouting ability and contributes to the sustainability of ecological restoration projects in water-limited sandy lands.

Exploring the Spatiotemporal Alterations in China’s GPP Based on the DTEC Model

Gross primary productivity (GPP) is a reliable measure of the carbon sink potential of terrestrial ecosystems and is an essential element of terrestrial carbon cycle research. This study employs the diffuse fraction-based two-leaf light-use efficiency (DTEC) model to imitate China’s monthly GPP from 2001 to 2020. We studied the trend of GPP, investigated its relationship with climatic factors, and separated the contributions of climate change and human activities. The findings showed that the DTEC model was widely applicable in China. During the study period, China’s average GPP increased significantly, by 9.77 g C m−2 yr−1 (p &lt; 0.001). The detrimental effect of aerosol optical depth (AOD) on GPP was more widespread than that of total precipitation, temperature, and solar radiation. Areas that benefited from AOD, such as Northwest China, experienced significant increases in GPP. Climate change and human activities had a primary and positive influence on GPP during the study period, accounting for 28% and 72% of the increase, respectively. Human activities, particularly ecological restoration projects and the adoption of advanced agricultural technologies, played a significant role in China’s GPP growth. China’s afforestation plan was particularly notable, with the GPP increasing in afforestation areas at a rate greater than 10 g C m−2 yr−1. This research provides a theoretical foundation for the long-term management of China’s terrestrial ecosystems and helps develop adaptive ecological restoration tactics.

Interplay of soil characteristics and arbuscular mycorrhizal fungi diversity in alpine wetland restoration and carbon stabilization.

Alpine wetlands are critical ecosystems for global carbon (C) cycling and climate change mitigation. Ecological restoration projects for alpine grazing wetlands are urgently needed, especially due to their critical role as carbon (C) sinks. However, the fate of the C pool in alpine wetlands after restoration from grazing remains unclear. In this study, soil samples from both grazed and restored wetlands in Zoige (near Hongyuan County, Sichuan Province, China) were collected to analyze soil organic carbon (SOC) fractions, arbuscular mycorrhizal fungi (AMF), soil properties, and plant biomass. Moreover, the Tea Bag Index (TBI) was applied to assess the initial decomposition rate (k) and stabilization factor (S), providing a novel perspective on SOC dynamics. The results of this research revealed that the mineral-associated organic carbon (MAOC) was 1.40 times higher in restored sites compared to grazed sites, although no significant difference in particulate organic carbon (POC) was detected between the two site types. Furthermore, the increased MAOC after restoration exhibited a significant positive correlation with various parameters including S, C and N content, aboveground biomass, WSOC, AMF diversity, and NH4+. This indicates that restoration significantly increases plant primary production, litter turnover, soil characteristics, and AMF diversity, thereby enhancing the C stabilization capacity of alpine wetland soils.

Comparison of nonlinear trends and influencing factors of carbon sinks in four ecological restoration projects in China

AbstractChina's ecological restoration projects aim to safeguard natural forests, improve the ecological environment, and achieve carbon neutrality. Previous studies at multiple scales have reported that the ecological projects contributed to enhancing carbon sinks. However, the effect of these projects on the carbon sinks has remained uncertain. Thus, we conducted a comparative analysis of nonlinear trends and influencing factors of carbon sink trends in the four ecological restoration project areas. Our findings suggested that the Pearl River shelterbelt program and middle reaches of the Yellow River shelterbelt program areas have experienced significant enhancements in ecosystem carbon sinks. The carbon sink exhibiting monotonically increasing trends and decreasing to increasing trends (positive shifts) accounted for 74.48% and 71.76% in these two shelterbelt program areas, respectively. However, less than half of the carbon sinks (41.38% and 31.80%, respectively) demonstrated monotonically increasing trends or positive shifts in the Yangtze River and Three North Shelterbelt program areas. The high background value of carbon sinks played a crucial role in the monotonically increasing trends of carbon sinks in the four ecological restoration projects. Additionally, in the Pearl River program areas, economic development and urban greening promoted the monotonically increasing trends of carbon sink. In the Yellow River program areas, CO2 fertilization, appropriate warming, and increased precipitation were helpful to promote the carbon sink with monotonically increasing trends. Moreover, the positive shifts of the carbon sinks were attributed to the implementation of these two ecological restoration projects. However, the low temperature and drought hindered the enhancement of carbon sinks in the Three North program areas, and extreme climate (flood and drought) hindered it in the Yangtze River program areas. These findings can provide a comprehensive evaluation of the effectiveness of ecological restoration projects on terrestrial ecosystems and offer practical guidelines to achieve carbon neutrality.

A Multi-Scenario Simulation and Dynamic Assessment of the Ecosystem Service Values in Key Ecological Functional Areas: A Case Study of the Sichuan Province, China

The ecosystem service value (ESV) is an important basis for measuring an ecological environment’s quality and the efficient management of ecosystems. It is particularly necessary to explore a proven methodology for assessing and predicting ESV dynamics coupled with policy-oriented scenarios that can provide a theoretical groundwork for macro decision, particularly in the context of implementing ecological protection and restoration projects. This study selected the land cover (LC) of Sichuan Province at five periods and the spatiotemporal dynamic equivalent factor method to assess the ESVs from 2000 to 2020. Additionally, the study coupled the Markov chain and GeoSOS-FLUS model, and predicted the future pattern of ESVs under four future development scenarios. The results show that (a) the areas of forests, shrubs, waters, wastelands, wetlands, and impervious areas showed a continuous increase from 2000 to 2020, with the most frequent interchanges occurring among croplands, forests, and grasslands. (b) The implementation of ecological protection and restoration projects led to a 13,083.32 × 108 yuan increase in ESV, and barycenter of the ESVs is located in the northeastern part of Ya’an and exhibits a tendency to move towards the northeast. (c) The ESV aggregation pattern of each city has remained unchanged, with Ganzi being the only city with a high aggregation. Overall, there are more conflict cities than coordination cities between economic development and the ecological environment. (d) The total ESV in 2025 will continue to increase under all development scenarios, reaching a maximum of 50,903.37 × 108 yuan under the EP scenario. This study can provide insights for ecological planning decisions and sustainable regional socio-economic development.

Potencial Simbiótico de Microrganismos do Solo na Promoção do Crescimento de Espécies Arbóreas da Mata Atlântica

The objective of this study was to evaluate the potential of topsoil obtained from a natural forest fragment in the Brazilian Atlantic Forest to serve as a source of symbiotic microorganisms capable of promoting the growth of native tree species in ecological restoration projects. In greenhouse conditions, 14 experiments in a completely randomized design were conducted in 1,700 cm³ pots filled with sterilized substrate. The effect of adding 80 g of topsoil, either in natura or sterilized, to the substrate was tested on the growth of 14 tree species. Plant height, stem diameter, mycorrhizal colonization and dry masses of shoot, roots, and nodules of tree species were measured. Applying the topsoil to the pots generally resulted in significant increases in height and stem diameter of seedlings compared to the control group during the four to six-month evaluation period. This effect was particularly greater in the nodulating species Plathymenia reticulata, Dalbergia nigra and Mimosa bimucronata, with increases in height and stem diameter of up to 328% and 484%, respectively. Forest topsoil also had a positive impact on the growth of shoot, roots, and nodules of the plants, significantly differing from the control groups. Only the plants that received the topsoil in natura exhibited mycorrhizal colonization and the formation of nodules in nitrogen-fixing species. These plants that established mycorrhizas and nodules presented higher concentrations of phosphorous and nitrogen in their biomass, respectively. Under controlled conditions, the use of forest topsoil proved to be a promising strategy for the introduction of microorganisms that can enhance the growth of tree species, thereby holding potential for implementation in nurseries and field settings.&#x0D;  &#x0D;  

Research on the Ecological Restoration Effects of a Vallisneria natans (Lour.) Hara-Dominated Multitrophic Level Ecosystem

This study aims to assess the ecological restoration effects of Vallisneria natans in a multitrophic level ecosystem. The water-purification effects of two hierarchical configuration modes of V. natans-Bellamya aeruginosa and V. natans-B. aeruginosa-Hyriopsis cumingii were studied. Results show that a V. natans and B. aeruginosa configuration ratio of 15:2 stabilizes water quality at Grade IV (TN ≤ 1.5 mg/L, TP ≤ 0.3 mg/L), and increasing B. aeruginosa density significantly reduces total phosphorus. The V. natans, B. aeruginosa, and H. cumingii configuration at 15:2:10 stabilizes water at Grade III (TN ≤ 1.0 mg/L, TP ≤ 0.2 mg/L), with a positive correlation between H. cumingii density and chlorophyll-a removal. Furthermore, the filtration and biocycling actions of B. aeruginosa (snails) and H. cumingii (mussels) significantly reduce levels of Total Nitrogen (TN), Total Phosphorus (TP), and Ammonium (NH4+-N) in water, thus enhancing the self-purification capacity of the water bodies. However, the bioturbation effect of H. cumingii can temporarily increase phosphorus release from sediments, leading to a short-term rise in TP concentration in the water. Overall, the study concludes that multitrophic level ecosystems are effective in purifying water quality and offer significant ecological restoration benefits. This research provides crucial data support for future construction and ecological restoration projects involving multitrophic level approaches in China’s rivers and lakes.

Pathways to enhance the efficiency of forestry ecological conservation and restoration: empirical evidence from Heilongjiang Province, China

This paper proposes a theoretical framework for assessing ecological protection and restoration from the perspective of ecological efficiency. We applied the super-efficiency Slack-based measure model to examine the social and economic impacts of ecological resource consumption transformation in Heilongjiang Province, China. Additionally, a convergence analysis was used to evaluate and test the impact of the standard deviation ellipse method on regional sustainability. The results indicated that the land use structure was unstable; the conversion rate of resource consumption was low; and the average Ecological efficiency was only 0.343 in terms of the land use structure. Funds for forest ecological restoration have a significant impact on the effectiveness of ecological resource transformation. Implementing the Chinese ecological restoration project improves the ecological efficiency level of the communities. The center of gravity of ecological efficiency moved greatly in the years when forestry investment increased. Technological transfer and diffusion, experience imitation in environmental regulation, and eventually convergent steady-state levels of the ecological efficiency of different regions are necessary to improve the economic and social development level of regions with low environmental quality efforts should be made to reduce resource consumption intensity, increase fund utilization efficiency, and form a comprehensive and systematic system of ecological environment governance through reasonable enhancement of regional environmental regulations, increased investment in technological advancement, and funds for ecological protection and restoration.

Influence of the in-stream structures and parameters variation on transient storage

In-stream structures are designed to mimic natural topographic features in rivers and have emerged as an effective method for ecological restoration in recent years. However, there is a lack of studies exploring the impact of these structural designs on transient storage characteristics. We implemented a series of weirs and groynes in a stream and conducted conservative tracer experiments to quantify the influence of these structures on solute transport within the stream. Additionally, we utilized the one-dimensional transport with inflow and storage (OTIS) solute diffusive transport model to assess variations in solute transport parameters and characterize transient storage. Our analysis of the OTIS parameters and transient storage index revealed that in-stream structures can enhance the interaction between flowing water in the mainstem area and the transient storage area, consequently improve the stream's transient storage capacity. Notably, weirs had a greater effect on the transient storage characteristics of streams parameters than groynes. Furthermore, the effect of this impact intensified with an increase in the number, spacing, and height of the in-stream structures. However, it was observed that the coupling between the structures decreased simultaneously, resulting in a gradual weakening of the enhancement in transient storage capacity. This study deepens our understanding of how the design factors of in-stream structures influence transient storage characteristics, and provides a theoretical basis for optimizing in-stream structures in ecological restoration projects.

Enhancing water quality and ecosystems of reclaimed water-replenished river: A case study of Dongsha River, Beijing, China

The use of reclaimed water for urban river replenishment has raised concerns regarding its impact on water quality and aquatic ecosystems. This study aims to reveal the improvements seen in an urban river undergoing a practical water eco-remediation after being replenished with reclaimed water. A one-year monitoring of water quality, phytoplankton, and zooplankton was carried out in Dongsha River undergoing eco-remediation in Beijing, China. The results showed that compared to the unrestored river, the concentrations of COD, NH4+-N, TP, and TN decreased by 28.22 ± 7.88 %, 40.24 ± 11.77 %, 44.17 ± 17.29 %, and 28.66 ± 10.39 % in the restoration project area, respectively. The concentration of Chlorophyll-a in the restoration area was maintained below 40 μg/L. During summer, when algal growth is vigorous, the density of Cyanophyta in the unrestored river decreased from 46.84 × 104cells/L to 16.32 × 104cells/L in the restored area, while that of Chlorophyta decreased from 41.61 × 104cells/L to 11.87 × 104cells/L, a reduction of 65.16 % and 71.47 %, respectively. The dominant phytoplankton species were replaced with Bacillariophyta, such as Synedra sp. and Nitzschia sp., indicating that the restoration of aquatic plants reduces the risk of Cyanophyta blooms. Zooplankton species also changed in the restoration area, especially during summer. The density of pollution-tolerant Rotifer and Protozoa decreased by 31.06 % and 27.22 %, while the density of clean water indicating Cladocera increased by 101.19 %. We further calculated the diversity and evenness index of phytoplankton and zooplankton within and outside the restoration area. The results showed that the Shannon-Weaver index for phytoplankton and zooplankton in the restoration area was 2.1 and 1.91, which was higher than those in the river (1.84 and 1.82). This further confirmed that aquatic plant restoration has positive effects. This study can provide a practical reference and theoretical basis for the implementation of water ecological restoration projects in other reclaimed water rivers in China.

Can the impacts of invasive African Olive on native Cumberland Plain Woodland plants be mitigated through bioinoculation?

SummaryInvasive plants often impact the abiotic and biotic conditions of the ecosystems they invade. These impacts can persist after the removal of the invader as legacy effects that may hamper restoration. We assessed whether the invasion of Cumberland Plain Woodland in Australia by African Olive impacts the performance of native species through legacy effects. We also tested whether the addition of soil inocula from uninvaded Cumberland Plain Woodland and rhizosphere soils can mitigate the effects of invaded soils on native plant performance. To do this, we grew four native Cumberland Plain Woodland species (Australian Indigo, Climbing Saltbush, Hickory Wattle, Wedge‐leaf Hop‐bush) in mesocosms containing either uninvaded Cumberland Plain Woodland soil, African Olive‐invaded Cumberland Plain Woodland soil or invaded Cumberland Plain Woodland soil inoculated with uninvaded or native rhizosphere soil. We found invaded soils to not consistently impact the growth of the Cumberland Plain Woodland species studied. In invaded soil, Hickory Wattle produced lower above and belowground biomass, Climbing Saltbush produced lower belowground biomass and Australian Indigo had a lower root to shoot ratio compared to plants grown in Cumberland Plain Woodland soil. The nodulation of Australian Indigo did not differ between soil treatments, while that of Hickory Wattle responded positively to inoculation. Our results suggest that the addition of native soil biota may improve the outcomes of ecological restoration projects on a species‐specific basis.

Multi-objective ecological restoration priority in China: Cost-benefit optimization in different ecological performance regimes based on planetary boundaries

In the context of the “United Nations Decade on Ecosystem Restoration”, optimizing spatiotemporal arrangements for ecological restoration is an important approach to enhancing overall socioecological benefits for sustainable development. However, against the background of ecological degradation caused by the human use of most natural resources at levels that have approached or exceeded the safe and sustainable boundaries of ecosystems, it is key to explain how to optimize ecological restoration by classified management and optimal total benefits. In response to these issues, we combined spatial heterogeneity and temporal dynamics at the national scale in China to construct five ecological performance regimes defined by indicators that use planetary boundaries and ecological pressures which served as the basis for prioritizing ecological restoration areas and implementing zoning control. By integrating habitat conservation, biodiversity, water supply, and restoration cost constraints, seven ecological restoration scenarios were simulated to optimize the spatial layout of ecological restoration projects (ERPs). The results indicated that the provinces with unsustainable freshwater use, climate change, and land use accounted for more than 25%, 66.7%, and 25%, respectively, of the total area. Only 30% of the provinces experienced a decrease in environmental pressure. Based on the ecological performance regimes, ERP sites spanning the past 20 years were identified, and more than 50% of the priority areas were clustered in regime areas with increased ecological stress. As the restoration area targets doubled (40%) from the baseline (20%), a multi-objective scenario presents a trade-off between expanded ERPs in areas with highly beneficial effects and minimal restoration costs. In conclusion, a reasonable classification and management regime is the basis for targeted restoration. Coordinating multiple objectives and costs in ecological restoration is the key to maximizing socio-ecological benefits. Our study offered new perspectives on systematic and sustainable planning for ecological restoration.

Nature-Based Solutions vs. Human-Induced Approaches for Alpine Grassland Ecosystem: “Climate-Help” Overwhelms “Human Act” to Promote Ecological Restoration in the Three-River-Source Region of Qinghai–Tibet Plateau

How climate change and human activities drive the evolution of the regional environment and where the quality of ecosystems improve or decline over time have become widespread concerns. In this study, we took the Three-River-Source (TRS) region of the Qinghai–Tibet Plateau as a case, aiming to identify and quantify the contribution of the natural and anthropogenic factors to the ecosystem changes over the past years from 1980 to 2018 using the methods of remote sensing and spatial statistical analysis. Based on the land cover map interpreted by reference to satellite remote sensing imagery data, we defined the Ecological Restoration Area Proportion (ERAP) as the bare land patch decrement to indicate the ecologically restored quantity in space. Assembling the restoration project information, we digitalized and vectorized the ecological Restoration Intensity (RI) including the spatial range and temporal duration. Combining the ERAP and the net primary productivity (NPP), which indicates the quantity and quality of ecosystems, respectively, the ecological asset Index (EAI) was developed and calculated. Having integrated the datasets of the vegetation monitoring, climatic factors, geographical factors, and human activities, we performed multi-variable analysis of the attribution of how the change in the EAI, the NPP, and the EAI have been affected by these factors together. The NPP of the middle and eastern parts of the TRS region has improved the most, as the average growth rate of NPP reached approximately 2.5 kg C/m2/10a. Due to such dynamic pattern, we found that human-induced re-vegetation has made limited contributions in our multi-regression model as the variance explained by the RI merely amounts to 4.4% to 8.8%, while the changes were mostly dependent on the regional temperature and the precipitation which contributed over 45% to the ecological restoration on average. It was summarized that “climate-help” overwhelms “human act” in such alpine grassland ecosystem. The regression results for the different aspects of the ERAP and NPP demonstrated that the ecological restoration project helped most in regard to ecosystem quality improvement rather than the restored ecosystem quantity. Our study has developed a comprehensive assessment methodology that can be reused to account for more ecological asset. The case is an example of an alpine ecosystem in which the success of ecological restoration needs favorable climatic conditions as supporting evidence for the nature-based solution.

Nature-based Solutions can help restore degraded grasslands and increase carbon sequestration in the Tibetan Plateau

The Tibetan grassland ecosystems possess significant carbon sink potential and have room for improved carbon sequestration processes. There is a need to uncover more ambitious and coherent solutions (e.g., Nature-based Solutions) to increase carbon sequestration. Here, we investigated the rationale and urgency behind the implementation of Nature-based Solutions on sequestering carbon using literature review and meta-analysis. We also project the changes in terrestrial carbon sink of Tibetan Plateau grassland ecosystems using model simulations with different future emissions scenario. The results show that the Nature-based Solution projects are expected to increase the carbon sink of Tibetan Plateau grassland ecosystems by 15 to 21 tetragrams of carbon by 2060. We defined a conceptual framework of Nature-based Solutions that integrates initiatives for the restoration of degraded grasslands and carbon sequestration. Our framework consists of four stages: theory, identification, practice, and goal. Traditional Tibetan knowledge plays an important role in reframing the proposed Nature-based Solutions framework. We also apply this framework to optimize ecological restoration techniques and projects and to evaluate the annual changes in the carbon sink under different socioeconomic pathway scenarios.