Carbon Sequestration Services Research Articles

Carbon stock assessment of mangrove forests along Macajalar Bay, Misamis Oriental, Philippines

Mangrove ecosystems are widely recognized for their crucial role in mitigating climate change through carbon storage and sequestration services. These ecosystems possess significant carbon reservoirs, particularly in their soils. Nevertheless, the unremitting development of coastal areas and alterations in land use constitute impending threats to these ecosystems, endangering the continuity of their invaluable services. Recognizing the crucial role of mangrove ecosystems in mitigating climate change, this study meticulously evaluates the cumulative carbon stocks encompassing the aboveground and soil components within three mangrove-protected areas in the Macajalar Bay region of Misamis Oriental. The study adheres to a logical structure with causal connections between statements, presents information in clear and concise sentences, and follows conventional academic writing formatting. Vocabulary is precise and avoids biased or emotional language. The text adheres to grammatical correctness, consistently uses technical terms, and employs a formal register. The study is free from filler words and employs a passive tone and impersonal construction. Additionally, the text features a consistent footnote style and accurately cites sources. The research findings show that soil carbon makes up a significant portion, ranging from 40% to 90%, of the total carbon stocks in the three study areas. This emphasizes the crucial function of mangrove soils as carbon repositories. Furthermore, the study establishes a direct connection between the age of mangrove stands and the occurrence of large-girth trees, both of which add to the rise in carbon stocks. Despite their substantial carbon storage capacity, mangrove forests in the Macajalar Bay region are still facing encroachments due to urbanization pressures. This assessment of carbon stocks in these coastal ecosystems plays a critical role in developing localized strategies that align with the United Nations Framework Convention on Climate Change's (UNFCCC) REDD+ initiatives, thus preventing further degradation of these vital carbon sinks.

Assessing the Impact of Climate and Human Activities on Ecosystem Services in the Loess Plateau Ecological Screen, China

The ecosystem services (ES) can be influenced by various environmental factors. In order to efficiently allocate resources and manage ecosystems, it is important to understand the mechanisms by which these environmental effects impact the interactions and trade-offs among different ES. While previous studies have primarily examined the impact of individual environmental factors on ES, the intricate mechanisms underlying the effects of multiple environmental factors have been largely overlooked. In this study, we adopted a path analysis approach that considered interactions among explanatory variables. We analyzed multiple geospatial datasets from various sources, including remote sensing and climate data, to examine the main drivers—precipitation, temperature, FVC (fractional vegetation cover), NPP (net primary productivity), human activities, and altitude—affecting five ecosystem services: carbon sequestration service (C), habitat provision service (HP), soil conservation service (SCS), sand-stabilization service (SSS), and water conservation service (WCS) in arid and semi-arid mountainous regions. Our investigation found that all five ES have shown an upward trajectory over the past two decades. The most significant growth was observed in C, which increased by 39.4%. Among the environmental factors examined, precipitation has been identified as the predominant factor influencing the ES and the synergies and trade-offs among ES. The influence of precipitation on SCS reached a coefficient of 0.726. Human activity factors had the greatest influence on HP of the five ES with a path coefficient of 0.262. Conversely, temperature exhibited a suppressive influence on ES. The impact of factors such as NPP and altitude on ES was comparatively modest. Notably, human activities assumed a substantial contributory role in shaping the relationship encompassing WCS. It is worth noting that individual factors exerted differential effects on ES along distinct environmental gradients, including anthropogenic gradients. In this context, the combination of high altitude and substantial FVC demonstrated a notable contribution to WCS. Our study can provide valuable insights for the management of ES which can be utilized to optimize the regulation of the Loess Plateau Ecological Screen (LPES) ecological construction and promote regional sustainable development.

Dry forests conservation: A comprehensive approach linking ecosystem services to ecological drivers and sustainable management

Assessing ecosystem services supply is an efficient way to facilitate ecosystem management, but there is no clear way to link ecosystem services to sustainable management decision-making. This study links sustainable supply of ecosystem services to sustainable management goals to evaluate the conservation value of dry forests. Hence, 11 ecosystem services (water yield, timber production, fruit production, carbon sequestration, soil retention, pollination, aesthetic, tourism, heritage, soil organic matter and habitat provision) were quantified in three dry forest communities. Evergreen forest communities were more successful in supplying ecosystem services than other ones. Pearson correlation analysis showed that water yield and carbon sequestration had a trade-off relationship with pollination (P < 0.001). Total ecosystem services of plant communities were estimated by considering both trade-off and synergy relationships between ecosystem services. Precipitation (R2 = 0.465) and leaf lifespan (R2 = 0.422) were the main ecological drivers of ecosystem services based on Nonmetric multidimensional scaling (NMDS). Criteria importance through intercriteria correlation (CRITIC) showed that water yield and carbon sequestration services had the highest weights for sustainable management. Maximizing economic and social benefits was also the most important sustainable management criterion. The importance of plant communities for conservation was determined by integrating the relative importance of ecosystems for sustainable supply of services and the importance of services for sustainable management. The comprehensive approach presented in this study not only ecologically contributes to the ecosystem health and supports the sustainable supply of ESs, but also meets other goals of sustainable management and supports management decision-making towards optimization of sustainable supply of ESs.

Plant functional traits explain long-term differences in ecosystem services between artificial forests and natural grasslands

Declining ecosystem services have prompted numerous studies aiming at developing more sustainable management practices for vegetation restoration. Advances in functional ecology indicate that the sustainable management of afforestation ecosystems should be performed based on plant functional traits, which provides pivotal knowledge for long-term sustainable vegetation restoration. Currently, the mechanism of how plant functional traits affect long term ecosystem services in restored areas is still unclear. This study investigates plant functional traits and the associated ecosystem services from artificial forestlands (Robinia pseudoacacia, Caragana korshinskii) and natural grasslands following different durations of vegetation restoration (10, 20, 30 and 40 years) in the Danangou watershed, a loess hilly-gully region in the Loess Plateau, China. The results showed that 1) the water conservation services of artificial forestlands first decreased and then increased over time, whereas the soil conservation service had an opposite trend; in turn, natural grassland led to a consistent increase in soil conservation and carbon sequestration services over time. 2) Artificial forestlands had greater soil conservation and carbon sequestration services than natural grassland but had lower water conservation services. 3) Leaves had a greater impact on carbon sequestration and water conservation services than did root length and root biomass density. 4) Root biomass density had a greater effect on soil conservation services than did leaf carbon content and soil organic matter. 5) Leaf carbon content, specific root length, and root biomass density had significant effects on the trade-off value between any two ecosystem services with increasing time after restoration of artificial forestland. 6) Specific leaf area had a greater effect on the trade-off values among the three services than did the other functional traits in the natural grassland. In arid ecosystems, natural grasslands are the best restoration strategy given their higher water conservation services. However, in soil erosion-affected areas, restoration through artificial forestlands is more appropriate. To mitigate the trade-offs between ecosystem services, it is recommended that artificial forestlands be thinned before the leaf carbon content, specific root length, and root biomass density reach a maximum (i.e., mature forestland).

Research on ecological compensation based on the supply and demand of ecosystem services in the Qinling-Daba Mountains

Quantifying the spatial displacement process of ecosystem service flow (ESF) between supply, connection and demand is the key to deeper understanding of the spatial mechanism of ecosystem service (ES) action, and is an important basis for accurate identification of ecological compensation (EC) areas and accounting of compensation standards. At present, there are few studies on the spatial flow process of ecosystem service flows between supply and demand areas, which are at the stage of conceptual analysis and lack of quantitative simulation studies. In view of this, the supply and demand matching of Qinling-Daba Mountains carbon sequestration and water yield services were quantitatively assessed by model simulation methods, and the supply and benefit areas of ecosystem services were identified. Based on the gravity model and breakpoint formula, a comparative ecological radiation force (CERF) model is proposed to simulate the flow path and ecosystem service flow of regional ecosystems, and quantitatively evaluate the total amount of ecological compensation. The results are as follows: (1) there is a mismatch between supply and demand of the two ecosystem services, urban areas are more mismatched than rural areas. (2) The two ecosystem services have surpluses in most areas (such as Diebu County, Lushi County, Xiahe County, Badong County, etc.), which made the ecosystem service flow mainly occur in areas with more ecosystem service surpluses. (3) The total amount of ecological compensation is about 1.5 billion RMB, including 0.12 billion RMB for carbon sequestration services and 1.38 billion RMB for water yield services. This study not only provided theoretical support for sustainable ecological-economic development in mountainous areas, but also laid the foundation for the government to formulate ecological compensation policies.

Quantifying synergistic effects of multi-temporal ecosystem service bundles for degraded ecosystem restoration: a case study in Hubei Province, China

Ecological restoration is vital for combating ecosystem degradation and enhancing ecosystem services. However, conventional approaches typically tend to focus on a single ecosystem service at a particular time, resulting in a limited understanding of the interactions and trade-offs among various services. This study proposes a novel method that utilizes ecosystem service bundles (ESBs) over time to identify degraded areas of prioritize restoration efforts. By employing ESBs, double-counting is avoided, and accuracy is improved. In this study, the area of degraded ecosystems identified based on ESBs accounted for approximately 40.27% of the total area of individual ecosystem service degradation. Restoration measures are shown to vary in effectiveness for different ESBs across different scenarios, with land-to-lake restoration improving ESB II (flood regulation services), while other measures significantly enhance ESB I (pollination services, habitat provision services, and carbon sequestration services). Strengthening shelterbelts on both sides of rivers, lakes and wetlands, as well as expanding habitat restoration scope, can effectively improve both ESB I and ESB II. Artificial afforestation can boost all three ESBs simultaneously, but its impact is limited due to land availability. Restoration efforts may also result in trade-offs, with ESB III (water production services and soil conservation services) declining. The findings provide decision-makers with a useful tool for prioritizing ecological restoration areas and selecting appropriate restoration measures to enhance multiple ecosystem services synergistically.

A wavelet coherence approach to zoning supply-demand matching of carbon sequestration service

Carbon sequestration (CS) is an important regulating service provided by natural ecosystem which plays an important role in mitigating global climate change. However, there is often spatial mismatch between the carbon sequestration supply and demand (CSSD), which makes it difficult to reduce carbon emissions and increase carbon sinks to achieve local carbon balance. Therefore, it is important to clarify the optimal scale to explore spatial matches and mismatches between CSSD and delimit spatial units for implementing effective carbon-focused management policies. Taking Hunan Province, China as an example, we evaluated CSSD in 2001 and 2017, and identified the optimal scale of spatial matching based on wavelet coherence analysis. The results showed that from 2001 to 2017, CS supply in Hunan Province increased by 6.45 %, while CS demand increased by 261.11 %. 8.40 km was identified as the optimal scale of CSSD spatial matches and mismatches, and Hunan Province could be divided into 3231 spatial units including four types according to the combination of CSSD, i.e. High supply-High demand, Low supply-Low demand, High supply-Low demand and Low supply-High demand. Based on the type changes of spatial units from 2001 to 2017, it was found that the key areas in need of ecological restoration were located in the east side of Xuefeng Mountains and the west side of Luoxiao Mountains, which could support accurate ecosystem monitoring and management under the background of improving the ‘one map’ of territorial space in Hunan Province. Based on wavelet coherence analysis, this study provided a spatial zoning approach for sustainable land use management, with a special focus on carbon sequestration supply and demand.

Ecosystem Service Optimisation in the Central Plains Urban Agglomeration Based on Land Use Structure Adjustment

By using the methods of scenario analysis, model simulation, and the multi-objective spatial optimisation algorithm Non-dominated Sorting Genetic Algorithm-II (NSGA-II), the Pareto optimal solutions for water supply, water purification (N retention), as well as carbon storage and sequestration service (carbon service) of the Central Plains Urban Agglomeration (CPUA) were sought by adjusting the land use structure. It showed that, to reach the Pareto optimal solution goal, (1) in Scenario 1 (S1), the water supply service needs to increase by 10.682 billion cubic metres, the water purification (N retention) service needs to decrease by 11,400 tons, and the carbon service need to decrease by 2.487 billion tons. In Scenario 2 (S2), the water supply service needs to increase by 8.243 billion cubic metres, the water purification (N retention) service needs to decrease by 11,000 tons, and the carbon service needs to decrease by 2.466 billion tons. In Scenario 3 (S3), the water supply service needs to increase by 4.089 billion cubic metres, the water purification (N retention) service needs to decrease by 10,800 tons, and the carbon service needs to decrease by 2.380 billion tons. (2) After land use optimisation and adjustment, the S3 ecological land structure is complete and consistent with the vision of ecological protection and urban development in the study area, which is the optimal scenario. (3) Optimising the ecosystem service supply pattern through land use structure adjustment could balance the overall ecosystem service supply pattern of the study area In regions wherein ecosystem supply is insufficient and there is a spatial mismatch between supply and demand for ecosystem services, this study can guide regional land planning and assist in the formulation of ecosystem service management policies.

Comparative Valuation of Three Ecosystem Services in a Canadian Watershed Using Global, Regional, and Local Unit Values

Economic valuations of ecosystem services often transfer previously estimated global unit values to the geographical setting of interest. While this approach produces quick results, its reliability depends on how representative the large-scale average unit values are for the given local context. Here, we estimate the values of three ecosystem services (ES)—water filtration, nutrient cycling, and carbon sequestration—in the Grand River watershed (GRW) of southern Ontario, Canada. The watershed covers nearly 7000 km2, has a humid continental climate and a population of close to one million people. Land cover is dominated by agriculture. We compare ES valuations using locally derived (i.e., GRW-specific) unit values to valuations based on unit values from a regional database and those compiled in the global Ecosystem Services Valuation Database (ESVD). The regional database includes mean unit values from three case studies within southern Ontario and one boreal watershed in British Columbia. As expected, the regional database yields average monetary values for the three ES that are close to those obtained using the local unit values but with larger associated uncertainties. Using the ESVD, however, results in significantly higher monetary values for the ES. For water filtration, the ESVD value is more than five times higher than the regional and local estimates. We further illustrate the effect of the extent of aggregation of forested and agricultural land categories on the ES values. For example, by subdividing the forest category into three subcategories (deciduous, coniferous, and mixed forest), the estimated value of the carbon sequestration service from forested areas within the GRW decreases by 7%. Overall, our results emphasize the importance of critically assessing the origin of unit values and the land cover resolution in ES valuation, especially when ES valuation is used as a policy-guiding tool.

Spatial-Temporal Evolution, Trade-Offs and Synergies of Ecosystem Services in the Qinba Mountains

A scientific understanding of the trade-offs and synergies of ecosystem services is the prerequisite for maintaining the structure, function and health of forest ecosystems, which is conducive to promoting the “win-win” goal of economic development and ecological protection. As an important ecological function area in China, the Qinba Mountain region is responsible for important ecological services such as biodiversity conservation and water conservation, and exploring the trade-offs and synergistic relationships of ecosystem services is important for ecological conservation and high-quality development in this region. This paper analyzes the spatial and temporal characteristics of water conservation, soil conservation, carbon sequestration, and habitat quality services and their synergistic/balancing relationships in the Qinba Mountain region from 1990 to 2020 using tools such as the InVEST model, ArcGIS, and Matlab. The results showed that (1) the overall trend of water connotation, soil conservation and carbon sequestration in the Qinba Mountains is increasing, while the trend of habitat quality is fluctuating and decreasing. The spatial distribution pattern of water conservation and soil conservation services was “high in the southwest and low in the northeast”, while the spatial pattern of habitat quality services was the opposite; the spatial distribution pattern of carbon sequestration services was “low in the middle and high around”. (2) Habitat quality in the Qinba Mountains has a trade-off relationship with water connotation and soil conservation, as water connotation–soil conservation is a synergistic relationship, while carbon sequestration is unrelated to water connotation–soil conservation and habitat quality. (3) The area of habitat quality–water conservation showed a decreasing trend; the area of habitat quality–soil conservation showed an increasing trend; the area of habitat quality-water conservation showed a decreasing trend; the area of habitat quality-soil conservation showed an increasing trend; the area of water conservation-soil conservation service synergistic relationship showed a decreasing and then increasing trend; while the area of carbon sequestration service and In most of the regions, carbon sequestration, soil conservation and habitat quality services are not related to each other.

Assessment of ecosystem service flow and optimization of spatial pattern of supply and demand matching in Pearl River Delta, China

Exploring the spatial flow pattern of ecosystem services and clarifying the transmission path between the supply area and the demand area will help to formulate more scientific and reasonable ecological protection policies. This paper takes the rapid urbanization area representing the Pearl River Delta urban agglomeration as an example. Using Invest model to quantitative the assessment of the supply and demand of carbon sequestration services and water ecosystem services from 2000 to 2020, a spatial flow model of ecosystem services is constructed to clarify the spatial flow of regional ecosystem services pattern. In addition, the Geo-detector model is used to explore the driving factors of the supply and demand relationship of ecosystem services, and the spatiotemporal geographic weighted regression model is further used to analyze the temporal and spatial differentiation of the impact degree. Finally, based on the Bayesian belief network, the optimal state factor configuration is selected to optimize the spatial pattern, and the corresponding optimization strategy is given. The main conclusions are as follows: (1) The supply of carbon sequestration services in the Pearl River Delta decreased gradually during 2000–2020, while the demand increased gradually. The supply of water ecosystem services increased first and then decreased, while the demand showed a downward trend. (2) In terms of spatial heterogeneity of supply and demand matching, the main driving factors of carbon sequestration services included night light brightness value, temperature and vegetation index; The main driving factors of water ecosystem services include night light brightness value, land use type and vegetation index. (3) In terms of optimal areas for supply and demand matching, carbon sequestration services were mainly distributed in Zhaoqing, Huizhou and Jiangmen; The optimal matching areas of water ecosystem service supply and demand were mainly distributed in Zhaoqing, Guangzhou, Huizhou and other cities.

Impacts and prediction of land use change on ecosystem carbon sequestration in Zhejiang Province, China.

It is crucial to clarify the impact of land use change on ecosystem carbon sequestration service for exploring natural-based carbon neutral solutions. We used InVEST and FLUS models to analyze land use change and its impacts on ecosystem carbon sequestration service in Zhejiang Province from 2000 to 2021, and predict ecosystem carbon sequestration service potential and its economic value of land use pattern in 2035 and 2050 under three scenarios of natural development, ecological protection, and cultivated land protection. The results showed that the area of cultivated land, forest, grassland, and water was continuously reducing and the area of construction land was continuously increasing from 2000 to 2021 in Zhejiang Province. The total amount of ecosystem carbon sequestration service decreased by 29.9658 million t, and the net income of carbon sequestrqtion service was -170.7184 million dollars. The distribution of ecosystem carbon sequestration services showed a spatial pattern of high in the southwest and low in the northeast. In the future, the total amount of ecosystem carbon sequestration services in Zhejiang Province would be the highest under the ecological protection scenario, followed by the cultivated land protection scenario, and the lowest under the natural development scenario. From 2021 to 2035 and 2050, ecosystem carbon sequestration services in Zhejiang Province would increase by 3.2326 million and 4.73 million t respectively under the ecological protection scenario, generating carbon sequestration service benefits of 77.0786 million and 111.8391 million dollars, respectively. Under the cultivated land protection scenario, it would be reduced by 10.1318 million and 16.1611 million t, and the net loss of carbon sequestration service value would be 241.3849 million and 381.9109 million dollars, respectively. Under the natural development scenario, it would be reduced by 11.6490 million and 16.1651 million t, resulting in a net loss of carbon sequestration service value of 277.5393 million and 382.0063 million dollars, respectively. In the context of actively addressing climate change and striving to achieve the goal of carbon neutrality, Zhejiang Province should focus on protecting ecological land such as woodlands, grasslands, and water, expand the scale of ecological land, optimize the spatial structure of ecological land, and continuously enhance carbon sequestration and sink enhancement functions of ecological land.

Carbon storage and sequestration in Southeast Asian urban clusters under future land cover change scenarios (2015–2050)

Land-use land-cover (LULC) changes are occurring rapidly in Southeast Asia (SEA), generally associated with population growth, economic development and competing demands for land. Land cover change is one of the vital factors affecting carbon dynamics and emissions. SEA is an important region to study urban-caused LULC emissions and the potential for nature-based solutions (NBS) and nature climate solutions (NCS), as it is home to nearly 15% of the world’s tropical forests and has some of the world’s fastest rates of urban growth. We present a fine-scale urban cluster level assessment for SEA of current (2015) and future (2050) scenarios for carbon sequestration service and climate mitigation potential. We identified 956 urban clusters distributed across 11 countries of SEA. Considering the urban expansion projected and decline in forests, this region could see a carbon loss of up to 0.11 Gigatonnes (Scenario SSP4 RCP 3.4). Comparing carbon change values to urban emissions, we found that the average offset value ranging from −2% (Scenario SSP1 RCP 2.6) to −21%. We also found that a few medium and large urban clusters could add to more than double the existing carbon emissions in 2050 in the SSP3 and SSP4 RCP 3.4 scenarios, while a minority of clusters could offset their emissions under SSP1. Our study confirms that NCS, and particularly reforestation, are in many cases able to offset the direct emissions from land cover conversion from SEA urban clusters. Hence, documenting the plausible LULC transitions and the associated impacts gains significance in the SEA region as the results can be useful for informing policy and sustainable land management.

Increase in precipitation and fractional vegetation cover promote synergy of ecosystem services in China’s arid regions—Northern sand-stabilization belt

Research on synergies and trade-offs between ecosystem services (ES) contributes to a better understanding of the linkages between ecosystem functions. Relevant research mainly focuses on mountain areas, while research in arid areas is obviously insufficient. In this research, we use the northern sand-stabilization belt (NSB) as an example to explore how the synergies and trade-offs between different ES vary with the gradient of precipitation and fractional vegetation cover (FVC) over the period 2000-2020. Based on five simulated ecosystem services (habitat provision, sand-stabilization service, water conservation service, soil conservation service and carbon sequestration service), the Pearson correlation coefficient method was used to analyze the various characteristics of the trade-offs and synergies among the different ES pairs along the FVC and precipitation gradients. Results showed that: Synergies between most paired ES increased significantly with increasing precipitation and FVC. However, ES have different sensitivities to environmental change, FVC promotes bit more synergy of ES pairs than precipitation. The study also found that land use/land cover may be an important driving factor for trade-offs and synergies between paired ES. The findings demonstrate that increased precipitation and FVC promote synergy of ecosystem services in arid regions of China. In the future, it can be investigated whether anthropogenic increase in FVC in arid regions can significantly contribute to the synergy of ES. In the meantime, this study could improve our understanding of arid and semi-arid (or macro-regional) ecosystems and contribute to the development of ecosystem management and conservation measures in NSB.

Identification of priority areas for UGI optimisation under carbon neutrality targets: Perspectives from China

Carbon neutrality targets are a common objective for cities and regions worldwide, the achievement of which relies on the transformation of urban infrastructure. Urban green infrastructure (UGI) is the only resilient carbon sequestration subsystem within cities in the carbon cycle process; however, a straightforward and feasible evaluation system for guiding the regulation and planning decisions regarding UGI as a carbon sink has yet to emerge. Here, we simulated the net primary productivity (NPP) of vegetation in Wuhan in 2020 based on the Sentinel-2 improved CASA model and assessed the efficiency of UGI carbon sequestration by combining the biomass-carbon conversion coefficient and zonal statistical tool. Potential influencing variables were explored based on the P-S-R model. Then, the optimal parameter-based geodetector revealed the driving mechanism of spatial heterogeneity in the efficiency of the UGI carbon sequestration service supply in highly urbanized regions, based on which we developed the ‘Carbon Sequestration Enhancement Priority Index’ (CSEPI), a strategic planning tool for identifying priority areas in which to implement carbon sink-enhanced field intervention measures. For these ‘high-priority’ areas, further UGI partition management tools and partition optimisation strategies are proposed. Our study contributes to the scientific planning and management of UGI in the context of combating climate change and with limited national public investment.

Spatial effects of nitrogen deposition on soil organic carbon stocks in patchy degraded saline-alkaline grassland

Soil organic carbon (SOC) represents the largest carbon sink and plays a critical role in mitigating global warming. Elevated nitrogen (N) deposition has substantial effects on soil carbon sequestration in grassland ecosystems. However, almost no study has examined the effects of N deposition in widely degraded saline-alkaline grasslands. This is a critical knowledge gap because saline-alkaline degradation is one of the key global threats to carbon sequestration services provided by grasslands. Here, we conducted a 3-year N addition experiment in a patchy degraded saline-alkaline grassland to examine the effects of simulated N deposition on SOC stocks, along with spatial effects for five types of saline-alkaline degraded patches (multi-species-mixture patches; Leymus chinensis patches; Puccinellia tenuiflora patches; Chloris virgata patches and Artemisia anethifolia patches). N addition had no overall effect on SOC stocks in the degraded saline-alkaline grassland, but showed pronounced spatial effects depending on the saline-alkaline characteristics of degraded patches. Specifically, SOC decreased in multi-species-mixture patches with low saline-alkaline stress (soil 7 < pH < 8), but no change was observed in other types of degraded patches with high saline-alkaline stress (soil pH > 9). Although N addition promoted plant growth and increased aboveground biomass in all degraded patches, the resulting aboveground carbon input did not further contribute to soil carbon sequestration. Rather than aboveground biomass, soil pH was the critical controlling factor for soil carbon in the saline-alkaline grassland. However, N addition did not alter soil pH in all degraded patches. In multi-species-mixture patches with lightly saline-alkaline soils, N addition reduced species richness and increased microbial C:N ratio, which could accelerate soil carbon decomposition, thereby decreasing SOC stocks. Our findings suggest that increased global N deposition would not restore natural soil carbon in degraded saline-alkaline grassland, and instead, may further deteriorate soil carbon sequestration in lightly degraded patches with high plant diversity and low saline-alkaline stress.

Mediating Effect of Heat Waves between Ecosystem Services and Heat-Related Mortality of Characteristic Populations: Evidence from Jiangsu Province, China.

In the context of climate change, heat waves are a serious hazard having significant impacts on human health, especially vulnerable populations. Many studies have researched the association between extreme heat and mortality. In the context of urban planning, many studies have explored the cooling effect of green roofs, parks, urban forests and urban gardens. Nevertheless, few studies have analyzed the effect mechanism of specific ecosystem services (Ess) as mitigation measures to heat waves. This study aimed to determine the relationship among Ess, heat waves and the heat-related mortality risk of different groups by diseases, age and sex. The research was conducted in three cities in Jiangsu Province, including Nanjing, Suzhou and Yancheng. We quantified five ecosystem services, i.e., water supply service, carbon sequestration service, cooling service, biodiversity and cultural service. Based on the previous studies, we took the frequency of heat waves into account, extending the concept of the Heat Wave Magnitude Index (HWMI). A distributed lag nonlinear model (DLNM) was applied to estimate the effect of extreme heat on mortality. Then, the study used the process analysis method to explore the relationship among Ess, heat waves and heat-related mortality risks. The results indicated that (i) water supply service, carbon sequestration service, cooling service and biodiversity can reduce heat-related mortality while cultural service increases; (ii) the effects of carbon sequestration service and cultural service are stronger than other Ess; (iii) the effects of Ess on cardiorespiratory disease, stroke and chronic obstructive pulmonary disease (COPD) mortality risks are higher than others; and (iv) women and elderly heat-related mortality risks are more affected by the Ess. This study can provide a theoretical support for policy makers to mitigate heatwave events, thus limiting heat-related mortality.

Spatiotemporal Changes in Supply–Demand Patterns of Carbon Sequestration Services in an Urban Agglomeration under China’s Rapid Urbanization

Quantifying the urban supply and demand of carbon sequestration services is an important prerequisite for achieving global carbon neutrality goals. However, the spatiotemporal patterns for balancing the supply and demand of carbon sequestration services in urban agglomerations remain unclear. In this study, NPP/VIIRS nighttime light data were used to identify the carbon sequestration service demand and were then combined with the carbon sequestration service supply to analyze the spatiotemporal patterns of supply and demand for carbon sequestration services in the Harbin-Changchun urban agglomeration (HCUA) in Northeast China. Our results indicate that both the supply and demand of carbon sequestration services showed increasing trends from 2012 to 2020 in the HCUA. The regions with increasing supply and demand trends were mainly located in the eastern mountainous and western urban areas, respectively. The total supply and demand of carbon sequestration services in the HCUA were 2080.3 Mt·C yr−1 and 433.6 Mt·C yr−1, respectively. Carbon surpluses (supply &gt; demand) were found in most areas (98%), although particularly in the southeastern mountainous region. However, with rapid urbanization, in most cities, the supply–demand ratio decreased from 2012 to 2020, and the proportion of carbon deficit regions showed a continuous increase, which was mainly distributed in newly developed urban areas. The low supply–high demand (L-H) pattern showed significant spatial mismatching for supply and demand in the HCUA. The proportion of regions with the L-H pattern also showed a rapidly increasing trend from 2012 to 2020, indicating a more obvious carbon deficit trend in the future. This study provides important guidelines for formulating effective policies for energy consumption and carbon sequestration to combat global warming under China’s rapid urbanization.

Contribution of different types of terrestrial protected areas to carbon sequestration services in China: 1980–2020

Exploring the contribution of protected areas to carbon sequestration services is meaningful to enhance the role of protected areas in climate change mitigation globally. However, less attention has been paid to the contribution of different types of protected areas to carbon sequestration services as well as their changes, which is not conducive to provide more effective solutions in the context of future climate change. Here, we identified the status and changes of carbon sequestration in different types of terrestrial protected areas in China and calculated the amount of carbon sequestration in different ecosystems in terrestrial protected areas and in different climatic zones. Our results indicated that carbon sequestration of China’s terrestrial protected areas had shown a significant increasing trend over the past 40 years (1980–2020) (R2 = 0.862, p &amp;lt; 0.05). Among the different types of terrestrial protected areas in China, nature reserves had the greatest carbon sequestration, accounting for 64–66% of the carbon sequestration in China’s terrestrial protected areas from 1980 to 2020. Although the carbon sequestration per unit area of forest parks was the highest among all types of protected areas, the proportion of carbon sequestration of forest parks tended to decrease significantly over the past 40 years. Carbon sequestration of protected areas in the humid zone had been mainly contributed by forest ecosystems, while grassland and desert ecosystems in terrestrial protected areas in regions with low rainfall (e.g., semi-arid and arid) had made more contribution to carbon sequestration services. Our study showed that China’s terrestrial protected areas had played an important role in carbon sequestration over the past 40 years, but there are still some gaps compared to the global level, and the planning and establishment of protected areas need to be further strengthened in the future.

Ecosystem carbon sequestration service supports the Sustainable Development Goals progress

Ecosystem carbon sequestration service (ECSS) is the benefits humans derive from the ecosystem carbon sequestration process, which is key to regulating climate, stabilising the natural foundation for development, and supporting the Sustainable Development Goals (SDGs) achievement. However, how ECSS contributes to the SDGs still needs to be discovered. Here, based on downscaling localisation SDG indicators, regression methods, and mechanism analysis, we identified the contribution of ECSS to the SDGs, taking China's Loess Plateau (LP) region as an example. The results showed that the LP made higher progress on resource and environmental SDGs, such as SDGs 13, 12, 6, and 7 (climate, consumption and production, water, and energy) in the last two decades. As for the relationships between ECSS and SDGs, the progress of SDGs 6, 7, 13 and 15 (water, energy, climate, and ecosystems) showed positive linear responses to ECSS. The response of SDGs 1, 4, 8, and 12 (poverty reduction, education, economic growth, and consumption and production) to ECSS showed a threshold when the standardised ECSS value was 0.11. To improve ECSS for a more sustainable ecological foundation underpinning the SDGs, ECSS management should be improved to protect the ecosystem carbon pool and improve carbon sequestration function, as well as to promote the social-ecological co-benefits. This work links carbon sequestration service to sustainable development and can help in leveraging nature's contributions towards carbon neutrality and the 2030 Agenda.