Ecological Restoration Efforts Research Articles

Assessment of the Divergent Influence of Natural and Non-Seasonal Hydrological Fluctuations on Functional Traits and Niche Characteristics of Plant Guilds along the Xiangxi River, China

The reservoir water level fluctuation zones (RWLFZs) and the natural riparian zones (NRZs) are two riparian ecosystems with dramatically opposite hydrological rhythms that notably influence the plant guilds. However, little is known about the discrepancies of the functional traits and niche characteristics of plant guilds in the RWLFZs and NRZs under different flooding rhythms. The aims of this study were to assess the divergent influence of natural and non-seasonal hydrological fluctuations on functional traits and niche characteristics of plant guilds. The results showed that 78 vascular plant species were identified in the riparian zones of the Xiangxi River basin. The dominant species were annuals in the two riparian ecosystems and their percentage increased temporally from 65.79% in the NRZs to 67.34% in the RWLFZs. Compared with the NRZs, the specific leaf area, vegetation coverage and the aboveground biomass in the RWLFZs significantly increased by 74%, 27% and 19.6%, respectively, while the water-use efficiency of the RWLFZ decreased by 59.6% and there was no significant difference in the net photosynthetic rate between them, which showed that annuals in the RWLFZs adopted the R adaptation strategy of being fast-growing with a short lifespan and quickly acquiring and investing resources by altering leaf morphology, including expanding the leaf area. The Simpson dominance index of RWLFZs was significantly higher than that of NRZ. Thus, counter-seasonally hydrological alterations had significant effects on functional traits of dominant species in the RWFLZs. Moreover, the highly adaptable and widely distributed species with larger niche breadths and high important values usually had a higher niche overlap value in the RWLFZs than in the NRZs, which showed that the competition in the plant communities after experiencing anti-seasonal flooding was much more intraspecific than interspecific and would facilitate the expansion of species niches. Our findings imply that the species with large niche breadths and high important values should be prioritized in ecological restoration efforts in the newly formed hydro-fluctuation zones of the TGR.

Precise mapping of coastal wetlands using time-series remote sensing images and deep learning model

Mapping coastal wetlands' spatial distribution and spatiotemporal dynamics is crucial for ecological conservation and restoration efforts. However, the high hydrological dynamics and steep environmental gradients pose challenges for precise mapping. This study developed a new method for mapping coastal wetlands using time-series remote sensing images and a deep learning model. Precise mapping and change analysis were conducted in the Liaohe Estuary Reserve in 2017 and 2022. The results demonstrated the superiority of Temporal Optimize Features (TOFs) in feature importance and classification accuracy. Incorporating TOFs into the ResNet model effectively combined temporal and spatial information, enhancing coastal wetland mapping accuracy. Comparative analysis revealed ecological restoration trends, emphasizing artificial restoration's predominant role in salt marsh vegetation rehabilitation. These findings provide essential technical support for coastal wetland ecosystem monitoring and contribute to the study of sustainability under global climate change.

No increase of soil wind erosion with the establishment of center pivot irrigation system in Mu-Us sandy land

Center Pivot Irrigation system (CPIs) is widely used in newly exploited arable land in sandy lands. These sandy lands are currently stable because of climate change and ecological restoration efforts since the beginning of the 21st century in northern China. The exploitation of these fixed sandy lands to arable land with CPIs may affect the soil wind erosion, yet it remains unknown. The temporal changes of CPIs and its effect on wind erosion module were analyzed and modeled from 2000 to 2020 in Mu-Us sandy land using satellite images and Revised Wind Erosion Equation (RWEQ). The establishment of CPIs started from 2010, boomed in 2015 and peaked in 2020. They were mainly transformed from woodland, grassland, and barren land near rivers in east and southeast, and from cropland in inter-dunes in west and southwest of Mu-Us sandy land. The temporal and spatial pattern of CPIs well aligns with the land consolidation and requisition-compensation balance policies. In most of the Mu-Us sandy land, the annual erosion module is <25 t ha−1 a−1. Despite great variation, the annual, Winter and Spring erosion module of the Mu-Us sandy land or in Otog Qian and Yuyang, the CPIs concentrated counties, all decreased during 2000–2019. Although, wind erosion module in CPIs was lower than the surrounding area, it increased in 2019 given the same climate conditions as in 2010. Our results suggest 1) the establishment of CPIs in Mu-Us sandy land greatly depends on the local policy and natural endowment, and 2) although the set-up of CPIs showed no impact on the wind erosion with CPIs accounting for <1 % of Mu-Us sandy land, post-harvest of CPIs should be carefully concerned to prevent soil wind erosion.

Drought in the middle growing season inhibited carbon uptake more critical in an anthropogenic shrub ecosystem of Northwest China

Large-scale ecological restoration efforts of the degraded desert steppe ecosystem in northwestern China have effectively combated desertification but have also resulted in the encroachment of shrubs. However, the function of the anthropogenic shrub ecosystem is still unknown under climate change, especially the response of carbon fluxes to drought, which hinders our further understanding of its sustainability in the future. Hence, based on the eddy covariance and environment sensors, continuous carbon and water fluxes and biophysical factors were monitored during 2019–2022 to investigate the characteristics of carbon fluxes and their response to seasonal drought in an anthropogenic shrub ecosystem dominated by Caragana liouana in the southern Mu Us sandy land, northwestern China. The results showed the shrub ecosystem was a stable carbon sink over the 4 years despite large interannual variability, with annual net ecosystem production (NEP) ranging from 54.37 to 150.35 g C·m−2·y−1. Interannual variability in NEP was mainly due to variation in gross primary productivity (GPP), which is driven by the fact that interannual variability in GPP was higher than interannual variability in ecosystem respiration (Reco). While drought inhibited GPP more than Reco, thus weakening the carbon sequestration ability of the ecosystem during the middle growing season, and thereby carbon fluxes in the shrub ecosystem were significantly suppressed by drought in the middle growing season but slightly in the early growing season. Furthermore, the magnitude and variation of carbon fluxes were determined by the maximum apparent photosynthetic capacity of the canopy (Pmax), leaf area index (LAI), and canopy conductance (gc), all of which are limited by water stress during drought. The work suggests that to keep the carbon sink of anthropogenic shrub ecosystems in arid and semi-arid areas, managers should focus on drought-relief measures in the middle growing season that are better adapted to future climate change.

Impact of Hill Fires on Dissolved Organic Matter in Watersheds of Karst Areas Based on Three-Dimensional Fluorescence-Parallel Factor Analysis

Hill fires have the potential to influence dissolved organic matter (DOM) in water bodies, yet fewer studies have investigated the effects of hill fires on DOM within watersheds in karst areas. In this study, we employed the three-dimensional fluorescence-parallel factor analysis (EEM-PARAFAC) method to analyze the DOM fluorescence peaks, component compositions, fluorescence indices, and sources within the water body of the Yuanteng River sub-basin, which was impacted by the hill fire, serving as our primary research focus. The results indicate the presence of three primary fluorescent fractions in the water body of the Yuanteng River: C1, resembling humic acid (fulvic acid); C2, consisting of biopolymers and microbial by-products; and C3, containing proteins such as tyrosine and tryptophan. The Yuanteng River exhibited elevated levels of humus-like substances, diminished concentrations of protein-like substances, and demonstrated higher biogenic, freshness, and humification indices compared to unaffected water samples, reflecting the impact of the hill fire. Elevated levels of exogenous humic acid-like inputs into the waters of the Yuanteng River, along with exogenous inputs of DOM, were primarily influenced by stable, high-molecular-weight organic matter. Additionally, agricultural effluent, domestic sewage, and anthropogenic activities contributed to these inputs to a lesser degree. The impacts of endogenous inputs are mainly related to the restoration of ecosystems. The occurrence of hill fires has significantly influenced the composition of dissolved organic matter in the waters of the Yuanteng River. A comprehensive analysis of the impacts of hill fires on dissolved organic matter in water bodies can serve as a valuable reference for characterizing DOM in the water bodies of the Yuanteng River. Furthermore, it can inform strategies for environmental protection, facilitate the traceability of pollutants in water bodies, and contribute to environmental and ecological restoration efforts following hill fires in the region.

Spatiotemporal variations in eco-environmental quality and responses to drought and human activities in the middle reaches of the Yellow River basin, China from 1990 to 2022

The middle reaches of the Yellow River basin (MYRB) are among the regions most severely affected by soil erosion globally. It has always held a pivotal role in soil and water conservation and ecological restoration efforts in China. Nonetheless, in the face of recurrent drought occurrences and growing human intervention, there have been notable alterations in the eco-environmental quality (EEQ) within the MYRB. However, the influences of drought and human intervention on the EEQ of MYRB remain unclear. In this study, the remote sensing ecological index (RSEI) was applied to quantify the spatiotemporal changes in EEQ and the contributions of drought and land use type transitions to EEQ in the MYRB from 1990 to 2022. The results showed that the EEQ in the MYRB fluctuated significantly and exhibited a weak overall improvement trend over the past 33 years. The proportion of good and excellent grades for EEQ significantly improved, while the proportion of poor and fair grades significantly decreased, especially in the northern regions. The trend of changes in EEQ follows a phased pattern. During the periods of 1990–2002 and 2011–2022, an improving trend is observed, while the period of 2003–2010 shows no significant change in EEQ. Drought had the strongest influence on the EEQ from 2003 to 2010, followed by that from 1990 to 2002, and had a lesser impact in the period from 2011 to 2022. The EEQ was primarily positively influenced by spring, autumn and winter droughts and negatively affected by summer droughts, especially in arid grassland and unused land areas. The EEQ in the MYRB improved primarily during the initial and final phases of the ecological projects, with a lesser impact from drought. The increase in EEQ during the initial phases of ecological project implementation was less noticeable, and drought significantly affected EEQ during this period.

Effect of topography and hydrological change on solute transport at the sediment-water interface in seasonal lakes

Study regionThe Poyang Lake is located in northern Jiangxi Province, which is the largest fresh water in China. The upstream connection with rivers and downstream access to the Yangtze River create seasonal hydrological regimes, resulting in over 100 seasonal lakes within the floodplain. These lakes provide important habitats for migratory birds to forage and nest during dry seasons, and contribute to floodwater regulation during wet seasons, maintaining lake ecosystem. Study focusThis study has combined laboratory experiments and numerical simulations to mechanically analyze the effect of the depth, width, slope of seasonal lakes, water level amplitude and dry season periods on water recharge patterns, exchange fluxes and solute transport characteristics at the sediment-water interface. New hydrological insights for the regionReducing the lake area by 33% through adjustments in depth or slope significantly reduces solute transport range (12.81% and 6.5% within 120 min) and high velocity area. The sensitivity of the solute amount in the lakebed to depth is the highest, followed by slope and width. Decreasing water level amplitude during dry seasons increases the flow velocity within the beach, facilitating short-term solute transport towards the lakebed. Extending the duration of dry periods increases cumulative flux of solutes entering the lakebed. These findings contribute to the ecological restoration efforts in floodplains and water pollution control measures.

Trophic facilitation in forest restoration: Can Nothofagus trees use ectomycorrhizal fungi of the pioneer shrub Leptospermum?

The benefits of plant-to-plant facilitation in ecological restoration are well recognized, yet the potential for indirect trophic facilitation remains understudied. Nothofagus (southern beech; Nothofagaceae) is an iconic southern hemisphere tree genus that is frequently the focus of ecological restoration efforts. One aspect of Nothofagus ecology that may limit restoration success is the availability of appropriate ectomycorrhizal fungi. It has been suggested that pioneer dual-mycorrhizal hosts such as Leptospermum species (Myrtaceae) could facilitate Nothofagus establishment by providing fungal inoculum, but the capacity for Nothofagus to use Leptospermum ectomycorrhizal fungi is unknown. To investigate potential indirect facilitation, we conducted a common garden pot trial to determine if Nothofagus cliffortioides (mountain beech) can use symbionts from Leptospermum scoparium (mānuka) ectomycorrhizal communities. Nothofagus and Leptospermum seedlings were grown in monoculture and mixed pairs with reciprocal "home" and "away" soil fungal inoculum. ITS2 metabarcoding of eDNA from hyphal ingrowth bags revealed that Nothofagus and Leptospermum inoculum contained different ectomycorrhizal fungal communities, but that half of the common ectomycorrhizal taxa identified were found in both soil types, suggesting generalist fungi exist. Nothofagus was able to form associations with some fungal species originating from Leptospermum inoculum, however, probable spore contamination meant that the proportion of root colonization associated with those species was ambiguous. Root ectomycorrhizal colonization rates were positively associated with seedling biomass, and there was some evidence of a home soil inoculum advantage in Nothofagus, but these effects were minor. Additionally, we found evidence that home inoculum provides a protective advantage against drought stress for Leptospermum seedlings. Our results indicate the potential for using Leptospermum to promote Nothofagus establishment in restoration plantings and highlight the possible benefits of considering fungal mutualists in ecological restoration projects.

Spatio-Temporal Evolution of Ecological Resilience in Ecologically Fragile Areas and Its Influencing Factors: A Case Study of the Wuling Mountains Area, China

The ecological environment of the Wuling Mountains region has been impacted by climate change and economic development, necessitating immediate reinforcement of ecological protection and restoration measures. The study utilized the normalized vegetation index (NDVI) as a proxy for ecological resilience. NDVI data from 2000 to 2020 were employed to compute the ecological resilience index of the Wuling Mountains area and to examine its spatial and temporal evolution as well as the factors influencing it. The findings indicate that: (1) The ecological resilience index increased in the Wuling Mountains area and Guizhou, Chongqing, and Hunan sub-areas but decreased in the Hubei sub-area. (2) The ecological resilience varies significantly in the Wuling Mountains area and the Guizhou, Hubei, and Hunan sub-regions, whereas it varies less in the Chongqing sub-region. (3) The primary elements influencing the ecological resilience capability of the Wuling Mountains area and its four sub-areas are climate conditions and socio-economic factors, respectively. The study can offer a scientific foundation for ecological conservation and restoration efforts in the Wuling Mountains area, as well as serve as a benchmark for measuring ecological resilience in other environmentally vulnerable regions.

Influence of mining on vegetation in semi-arid areas of western China based on the coupling of above ground and below ground – A case study of Daliuta coalfield

Underground mining operations are known to result in extensive surface subsidence, introducing a multitude of disturbances to surface vegetation, with particularly severe environmental impacts in the fragile ecosystems of arid and semi-arid regions. This study focuses on the Daliuta mining area located in semi-arid zones, selecting four distinct areas for data analysis. Areas A, B, and C fall within the mining perimeter and have all been affected by mining-related disturbances. Following coal extraction, Areas A and B underwent artificial rehabilitation measures, including fracture infilling and sea buckthorn plantation; Area C was left in its natural state without any artificial interference. Area D, unaffected by mining activities, was designated as the control group. The research utilized 60 Landsat satellite images spanning from 1988 to 2022. Employing the Normalized Difference Vegetation Index (NDVI) and the Fractional Vegetation Cover (FVC), the study classified the experimental zone’s vegetation cover and degradation into six levels, ranging from low to high. By comparing the average vegetation cover over an extended period, changes across different vegetation cover levels, and the degree of vegetation degradation before and after mining, the study assessed the impact of underground mining on surface vegetation. The conclusions drawn are as follows: Mining operations caused significant damage to the vegetation in Areas A and B, yet artificial restoration measures notably improved the vegetation quality, with an overcompensation effect observed in Area A, suggesting the potential for ecological restoration efforts to create a vegetative environment that exceeds its original condition in the long term. Mining activities also induced continuous ecological adverse effects in Area C, but the natural regeneration process progressively restored the vegetation to pre-mining levels over time. Based on these findings, the study reveals the spatiotemporal patterns of vegetation damage and recovery across different mining periods and land reclamation stages. It proposes a restoration strategy for mine areas in semi-arid regions that prioritizes natural regeneration supported by artificial guidance. This work provides valuable insights and guidance for assessing the impact of underground coal mining on surface vegetation in semi-arid areas, as well as for the rehabilitation and ecological reconstruction of mine areas, emphasizing the necessity and urgency of conducting environmental assessments and implementing restoration measures.

Ecological health assessment of Tibetan alpine grasslands in Gannan using remote sensed ecological indicators

ABSTRACT Ecosystem health assessments are crucial to protect the ecological environment and ensure the sustainable ecological functions of alpine ecoregions. At present, few studies evaluating the ecosystem health of the Gannan alpine grassland, China, an ecologically fragile area, based on a remote sensing theoretical framework exist. As such, this study assessed the ecosystem health of the Gannan alpine grassland based on the Remote Sensing-based Ecological Index (RSEI) and provided a comparative analysis of the RSEI and Gross Primary Productivity (GPP), extending the study of their spatiotemporal patterns and influencing factors. The results suggested that RSEI and GPP showed strong comparability in an ecological sense, with the RSEI better reflecting changes in ecosystem health of the Gannan alpine grassland than the GPP. Overall, the health of the Gannan alpine grassland ecosystem was good (RSEI of 0.61–0.76) and a slow, fluctuating upward trend was seen from 2000 (RSEI = 0.66) to 2020 (RSEI = 0.72). Notably, the RSEI was high in the south and low in the north of the region. Over the past 21 years, 43.92% of the ecologically healthy grassland in the southwest of Gannan has been degrading, while the poor ecological health of 39.04% of the grasslands in the southeast and northeast improved. The model test results show that RSEI could reasonably evaluate the ecosystem health of Gannan alpine grassland. Our assessment results provide important scientific data and information on health monitoring and targeted ecological restoration efforts in the Gannan region.

Renewable energy policies and wildlife conservation: A review of potential conflicts and coexistence strategies

The global push towards renewable energy sources as a response to climate change has led to an increasing overlap between renewable energy projects and critical wildlife habitats. This review explores the potential conflicts and synergies between renewable energy policies and wildlife conservation efforts. As nations strive to transition from fossil fuels to sustainable alternatives, the unintended consequences on biodiversity and ecosystems demand careful consideration. The analysis begins by examining the conflicts arising from the development of renewable energy infrastructure, such as wind and solar farms, in ecologically sensitive areas. These conflicts include habitat disruption, altered migration patterns, and the direct threat to endangered species. The paper also delves into the social implications of renewable energy projects, such as displacement of indigenous communities and the disruption of traditional land use. However, the review doesn't solely focus on conflicts but also explores coexistence strategies that can mitigate the adverse impacts of renewable energy development on wildlife. It highlights the importance of strategic project siting, wildlife-friendly design considerations, and effective mitigation measures. Additionally, the paper discusses the potential for incorporating ecological restoration efforts within renewable energy projects to enhance habitat quality and support biodiversity. Furthermore, the review addresses the role of policy frameworks in promoting sustainable coexistence between renewable energy development and wildlife conservation. It evaluates existing policies and proposes recommendations to strike a balance between the imperative of clean energy and the preservation of biodiversity. This review synthesizes current knowledge on the complex interplay between renewable energy policies and wildlife conservation, offering insights into potential conflicts and proposing coexistence strategies. Balancing the dual objectives of mitigating climate change and preserving biodiversity requires a nuanced understanding of the ecological, social, and policy dimensions involved. The findings presented contribute to a holistic approach that aims to harmonize renewable energy development and wildlife conservation for a sustainable future.

Patterns and Dominant Driving Factors of Carbon Storage Changes in the Qinghai–Tibet Plateau under Multiple Land Use Change Scenarios

Revealing the spatial–temporal evolution of carbon storage and its driving mechanisms in the Qinghai–Tibet Plateau could provide support for decision making in the protection of regional ecosystems and the achievement of regional dual-carbon goals. In this study, the spatial–temporal evolution of carbon storage in the Qinghai–Tibet Plateau was analyzed under various scenarios using PLUS-InVEST and a gravity center model, and the driving mechanisms of carbon storage were clarified with Geodetector. The results are as follows: (1) During 2000–2020, the areas of coniferous forest, evergreen broad-leaved forest, closed shrub, temperate shrub desert, multi-tree grassland, and grassland showed an increasing trend, while the areas of deciduous broad-leaved forest and mixed forest showed a decreasing trend. (2) During 2030–2060, there was a decreasing trend in the total carbon storage of the Qinghai–Tibet Plateau under three different scenarios. (3) During 2030–2060, the area of the Qinghai–Tibet Plateau was mostly represented by carbon balance (56%), while the areas of carbon sources and carbon sinks showed a scattered distribution. (4) The precipitation and topographic factors with a q value of 0.888 played a dominant role in affecting the spatio-temporal variations in carbon storage in the Qinghai–Tibet Plateau. (5) In future ecological protection and restoration efforts, more high-quality farmlands should be protected and constructed, which could contribute to the achievement of dual-carbon goals. In addition, the hydrothermal conditions should be improved to aid the carbon cycle process in the Qinghai–Tibet Plateau.

Priority effects of forbs arriving early: the role of root interaction and asymmetric competition

BackgroundThe priority effect of plant arrival is a key driver of community assembly and ecosystem succession during the restoration of degraded plant communities. However, the significance of the arrival order of different plant functional groups and their interactions with community assemblies remains unclear. Using a phytotron experiment with three fully crossed factors, we investigated the underlying mechanisms of priority effects and their relationships with the biomass and biodiversity effects in mixed plant communities by manipulating the order of arrival of species, isolation of roots, and removal of specific plants.ResultsThe results showed that the strength and direction of priority effects were influenced by arrival order, root interactions, asymmetric competition among species, and their interactions. The identities of early and late-sown species also determined the magnitude of priority effects. The priority effects were stronger in grass-first (24.76%) and legume-first communities (24.48%) than in forb-first communities. The pot biomass of the different priority treatments was highest in grass-first (5.85 g), followed by legume-first (3.94 g) and forb-first (2.48 g). The order of arrival in the mixture significantly affected the net biodiversity effects (P < 0.001), which were driven by dominance effects. The community had lower overall biomass when forbs were sown first, whereas the species grown later had fewer costs with an increased overall net benefit for the resulting community.ConclusionsOur results emphasize that root interactions and asymmetric competition are vital determinants of order-specific priority effects in community assemblies. In addition, the importance of the priority effect of forbs sown first is related to community assembly, which may be a key determinant in successfully establishing a highly diverse community in the early stages of restoration. Species with weak competition should be considered in the early stage of community assembly. The rational use of the priority effect is conducive to improving the quality and efficiency of ecological restoration efforts.

Plant life history strategies vary in subtropical forests with different disturbance histories: an assessment of biodiversity, biomass, and functional traits.

Disturbance alters environmental conditions in forests. Plants growing in forests with different disturbance histories in diverse environments may adopt varying life history strategies, but few studies focus on this effect. This study comprehensively investigated plant biodiversity, biomass, and functional traits in subtropical forests with two different disturbance histories in east China to explore differences in life history strategies. Biodiversity was slightly higher in disturbed compared to conserved forests. Significantly higher biomass was measured in conserved relative to disturbed evergreen broadleaved forests (P < 0.05). In conserved forests, leaf tissue density (LTD) was significantly higher and leaf thickness (LT), leaf dry matter content (LDMC), twig tissue density (TTD), twig dry matter content (TDMC), bark tissue density (BTD) and dry matter content (BDMC), and stem tissue density (STD) and dry matter content (SDMC) were significantly lower than in disturbed forests (P < 0.05). In terms of associated plant biodiversity, biomass, and functional traits, conserved forests adopted a resource acquisition strategy, reducing biodiversity and developing multiple functional traits such as high leaf area and specific leaf area and low LT, LDMC, TTD, TDMC, BTD, BDMC, STD, and SDMC to support a high biomass accumulation rate. Disturbed forests adopted a resource conservation strategy, enhancing biodiversity and developing converse trait combinations to lower the rate of biomass accumulation. A comprehensive investigation of plant biodiversity, biomass, and functional traits and subsequent assessment of plant life history strategies in conserved and disturbed forests will aid investigations of regional biodiversity and carbon reserves, contribute data to the TRY and Chinese plant trait databases, and improve ecological management and restoration efforts in east China.

Identification of ecological restoration priority areas integrating ecological security and feasibility of restoration

Ecological restoration is the guarantee of regional ecological security. Accurate identification of restoration areas is crucial for planning ecological programs. However, the question of how to recognize the range of restoration areas at the pixel scale in order to improve restoration efficiency still requires further discussion. In this study, a framework that integrates ecological security and feasibility of restoration through multi-criteria decision analysis was developed to identify the ecological restoration priority areas (ERPAs) in the Qinghai-Tibet Plateau (QTP). The results showed that areas with low ecological security accounted for 58.33 % of the QTP, primarily concentrated in the northwest. Areas that were feasible to be restored, represented 26.11 % of the QTP. The relatively high feasibility areas (F > 0.6) were mainly located in the northern and southwestern of the QTP, covering 23.88 % of the total feasible areas. This study ultimately identified 6.69 × 105 km2 of ERPAs, encompassing 26.05 % of the QTP. The high-priority areas were concentrated in the southwest and scattered in the northern part of the study area, accounting for 21.47 % of the ERPAs. The low-priority areas with the largest proportion (57.77 % of ERPAs) were widely distributed in the eastern part of the study area. Therefore, more attention should be paid to the southwestern region of the QTP in the subsequent ecological restoration efforts. The framework, which takes into consideration ecological security and restoration feasibility, can significantly enhance the spatial accuracy of ecological restoration area identification, providing a practical reference for further environmental optimization.

Investigating the spatio-temporal pattern evolution characteristics of vegetation change in Shendong coal mining area based on kNDVI and intensity analysis

Alterations in vegetation cover serve as a significant indicator of land ecology. The Shendong Coal Mining Area, being the largest coal base globally, holds significant importance for national energy security. Moreover, it has gained recognition for its environmentally conscious approach to coal mining, characterized by the simultaneous implementation of mining activities and effective governance measures. In order to assess the ongoing vegetation recovery and the temporal changes in vegetation within the Shendong Coal Mining Area, we initially utilized Landsat TM/ETM+/OLI remote sensing data. Using the Google Earth Engine (GEE), we developed a novel kernel-normalized vegetation index (kNDVI) and subsequently generated a comprehensive kNDVI dataset spanning the years 2000 to 2020. In addition, the Sen (Theil-Sen median) trend analysis method and MK (Mann-Kendall) test were utilized to examine the temporal trends over a span of 21 years. Furthermore, the Hurst exponent model was employed to forecast the persistent changing patterns of kNDVI. The utilization of the intensity analysis model was ultimately employed to unveil the magnitude of vegetation dynamics. The findings indicated a notable positive trend in the overall kNDVI of vegetation within the study area. In relation to the analysis of changing trends, the vegetation in the region underwent a slight improvement from 2000 to 2010, followed by a significant improvement from 2010 to 2020. During this transition period, a total of 289.07 km2, which represents 32.36% of the overall transition area, experienced a shift in vegetation. The predictive findings from the Hurst model indicate that while the majority of areas within the mining region will exhibit an upward trend in vegetation growth, there will be certain areas that will demonstrate a decline. These declining areas account for 39.08% of the total transition area. Furthermore, the intensity analysis results reveal notable disparities in the characteristics of vegetation growth and evolution between the periods of 2000-2010 and 2010-2020. Throughout the entirety of the transformation process, the transition from slight improvement to significant improvement prevails in terms of both relative intensity and absolute intensity, surpassing alternative transformation processes. Various trend transitions display diverse intensity characteristics that adhere to the overarching principles governing shifts in vegetation growth. Furthermore, the utilization of the intensity analysis framework and intensity spectrum employed in this study demonstrates their efficacy in elucidating the temporal dynamics of vegetation changes. Furthermore, this study plays a pivotal role in the surveillance and assessment of the efficacy of ecological restoration in mining regions. It carries substantial implications for comparable land ecological restoration efforts in mining and reclamation, thereby furnishing a theoretical foundation.

Temporal and spatial variations of carbon storage and carbon sink improvement strategy at the district and county level based on PLUS-InVEST model: Taking Yanqing District as an example

Under the background of the carbon peaking and carbon neutrality goals, the evolution of the spatiotemporal pattern of carbon storage has recently emerged as a research hotspot. The change in land use and land cover (LULC) is the primary driver of carbon storage changes. Understanding the spatiotemporal variations of LULC and carbon storage at the small scale of district and county level and proposing strategies to improve carbon sink, will contribute to the ecological conservation, restoration and sustainable development of districts or counties. With Yanqing District in Beijing as an example, we calculated carbon storage from 1990 to 2020 based on the InVEST model and used the PLUS model to predict LULC type changes under three scenarios (natural growth, ecological conservation and economic development) from 2020 to 2050. We further predicted the carbon storage and proposed mea-sures to improve carbon sink. The results showed that the key LULC change in Yanqing between 1990 and 2020 were the conversion of 88.9% of grassland to forest, 50.1% of farmland to forest, and 39.5% of cropland to impervious surface. The total carbon storage showed an upward trend, with an increase of 3.34×106 Mg. The spatial distribution of carbon storage presented "high in the northeast, low in the southwest, and high in the mountainous areas, low in the riverine areas." The increase in forest and the decrease in grassland were the main reasons for the increase and decrease in carbon storage, respectively. Between 2020 and 2050, the ecological restoration efforts under the ecological protection scenario increased, and the probability of other LULCs transforming into forest increased, resulting in a 5.8% increase in carbon storage, which had the highest increase and carbon storage under the three scenarios. High-value carbon storage areas were concentrated in the northeast, northwest, and south of Yanqing District, basically corresponding to the mountainous regions of Yanqing with high forest coverage, and the low-value areas generally corresponded to the plains with high development intensity and low forest coverage. We could implement comprehensive ecological protection and restoration measures, including forest and grassland ecosystem protection, water environment ecological restoration, farmland ecological restoration, to promote sustainable development in Yanqing District and to achieve the "dual carbon" goal.

Exploring the nexus between land cover change dynamics and spatial heterogeneity of demographic trajectories in rapidly growing ecosystems of south Asian cities

Rapid urbanization is a global trend that significantly alters Land Use and Land Cover Change (LULCC) patterns. Dhaka, a megacity, and Chittagong, the country’s second-largest city, have experienced substantial shifts in LULCC patterns over the past three decades. This study aims to examine the LULCC in Dhaka and Chittagong districts of Bangladesh from 1991 to 2021, focusing on identifying patterns and quantifying the effects of population growth and urbanization. Changes in LULCC patterns were identified by analyzing Landsat satellite imagery using remote sensing and geospatial techniques. The LULCC classes were classified using the Random Forest model and an inconsistency diagram, demonstrating high precision with an overall accuracy rate exceeding 85 %. The study’s findings reveal significant transformations in LULCC patterns across Dhaka and Chittagong districts from 1991 to 2021. A notable increase in built-up areas was observed in both districts, with Dhaka division witnessing a 129 % increase in built-up areas while Chittagong district saw a 515 % increase. This was due to transforming water bodies and barren land into built-up areas. However, the study also highlighted a promising increase in vegetation cover in both districts, indicating successful ecological restoration efforts. Chittagong and Dhaka saw increments of 597.95 km2 and 252.15 km2 in vegetation cover, respectively. Despite these positive changes, the study identified decreased surface water bodies in both regions. The results show a significant positive correlation between population growth/density and the built-up class, while a significant negative correlation with the barren land was observed in both districts. The findings could potentially guide policymakers in making informed decisions regarding land use, land cover, and urban sprawl management from an ecological restoration perspective. This could contribute to achieving sustainable development goals by promoting resilience ecological restoration practices.

Divergence of Seed Mass in Riparian Plant Communities Dominated by Filtering and Random Processes

Restoration of degraded riparian zones is the primary challenge for ensuring the sustainability of watershed ecosystems. An essential aspect of this endeavor is gaining a deep understanding of how riparian plant communities are assembled. The main focus of this study was to investigate how riparian plant communities respond to varying levels of flooding stress along the Three Gorges Reservoir (TGR) in China’s Yangtze River. To accomplish this, we calculated the diversity of plant taxonomy, traits and phylogeny, and used a null model to reflect the plant community assembly rules within the riparian zones along the TGR. The riparian zones were divided into four regions based on water regime: the fluctuating backwater area, the permanent backwater area, mainstream and tributaries of the TGR, covering the reservoir area of 1084 km2 with 180 sampling sites surveyed. Our results showed that within the permanent backwater area of the tributaries, the gradient variation in taxonomic and trait diversity of the riparian community was strongly aligned with the varying levels of flooding stress, which suggests that strong environmental selection plays a significant role in this section. Furthermore, through analysis of phylogenetic and trait structures based on the null model, we found that environmental filtering and random processes were the primary mechanisms shaping plant communities in the riparian zones across the entire study area. However, by further examining single traits, we found that seed mass was the sole trait displaying noteworthy divergence in the riparian communities throughout the study area. This finding highlights that seed mass appears as a pivotal divergent trait in the herb succession stage of the riparian communities that is strongly governed by filtering and random processes. In conclusion, we recommend prioritizing seed mass differences in ecological restoration efforts for herb succession in flooding-stressed riparian communities. This approach is crucial for enhancing source utilization, facilitating community assembly, and improving overall recovery outcomes.