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BACKGROUND AND AIMS: Tillering has a significant effect on canopy development and, hence, on resource capture, crop growth and grain yield in sorghum. However, the physiological basis of tillering and its regulation by environmental effects are not fully understood. The objective of this study was to understand and quantify the environmental effects on tillering in sorghum using a carbohydrate supply-demand framework. METHODS: A series of five experiments with a wide range of radiation and temperature conditions was conducted and details of the tillering responses of a single representative hybrid were monitored. The concept of internal plant competition for carbohydrate was developed for analysis of these responses. KEY RESULTS: Tiller appearance was highly synchronized with main shoot leaf appearance, with a consistent hierarchy for tillering across environments. The main environmental effect was on the frequency of tiller appearance, in particular of the lower-rank tillers. This explained some of the observed environmental differences in the onset of tillering. A generalized index of internal plant competition, which took account of plant assimilate supply and demand (S/Dindex) during the critical period for tillering, explained most of the variation in maximum tiller number observed across the five experiments. CONCLUSIONS: This result was consistent with the hypothesis that internal plant competition for assimilates regulates tillering in sorghum. Hence, the framework outlined has a predictive value that could provide the basis for dynamic simulation of tillering in crop growth models.

BACKGROUND AND AIMS: Genotypic variation in tillering can be caused by differences in the carbon supply-demand balance within a plant. The aim of this study was to understand and quantify the effects of genotype on tillering as a consequence of the underlying internal competition for carbohydrates. METHODS: Five sorghum hybrids, derived from inbred lines with a common genetic background and with similar phenology and plant height but contrasting tillering, were grown in five experiments. The experiments covered a wide range in radiation and temperature conditions, so that number of tillers produced varied significantly. Data on leaf area, tiller number, and biomass accumulation and partitioning were collected at regular intervals. To quantify internal plant competition for carbohydrates, a carbohydrate supply-demand index (S/Dindex) was developed and related to variation in tillering. KEY RESULTS: The appearance of main shoot leaves and tillers was highly co-ordinated across genotypes. High-tillering hybrids had a greater appearance frequency of early tiller ranks than low-tillering hybrids, and this was associated with narrower and hence smaller main shoot leaves. A generalized S/Dindex of internal plant competition accounted for most of the observed variation in maximum tiller number (Ntiller,max) across genotypes. However, genotypic differences in the relationship between the S/Dindex and Ntiller,max suggested that high-tillering hybrids also had a lower S/D threshold at which tillers appeared, possibly associated with hormonal effects. CONCLUSIONS: The results support the hypothesis that genotypic differences in tillering were associated with differences in plant carbon S/D balance, associated with differences in leaf size and in the threshold at which tillers grow out. The results provide avenues for phenotyping of mapping populations to identify genomic regions regulating tillering. Incorporating the results in crop growth simulation models could provide insight into the complex genotype-by-management-by-environment interactions associated with drought adaptation.

ContextEcological security pattern (ESP) can maintain regional ecological security and thus support sustainable development. ESP should not only protect regional ecological processes, but also meet human demand for ecosystem services.ObjectivesIt is aimed to propose a new method of identifying ecological sources in consideration of ecological background and demand, with a case study across the Guangdong-Hong Kong-Macao Greater Bay Area in view of interregional ecological conservation cooperation.MethodsEcological sources were identified with high supply and high comprehensively ecological supply–demand ratio (CESDR) of ecosystem services. Land use based resistance surface was modified using nighttime light intensity. Ecological corridors and potential ecological corridors were extracted using the Minimum Cumulative Resistance model.ResultsEcological sources were mainly distributed in the north, accounting for 13.46% of the total area. Macao and Dongguan had no ecological sources, due to the high level of land urbanization, and the mismatch between high supply and high CESDR patches, respectively. Ecological sources in Hong Kong were connected with that in Shenzhen, showing good background of natural ecosystem connectivity as the foundation for interregional ecological conservation cooperation. Ecological corridors were mainly distributed in the periphery of the study area, connecting most cities except for Macao. The overall ESP showed a spatially circular pattern around the Greater Bay Area.ConclusionsThe new method for ecological source identification could effectively enhance the sustainability of ecosystem conservation in view of integrating supply and demand of ecosystem services. It was necessary for all the three regions to strengthen ecological conservation cooperation.

Improving the supply-demand balance of ecosystem services (SDBES) from the perspective of land use is essential for managing regional ecosystem and realizing sustainable development. By combining land use with the supply and demand of ecosystem services (SDES), a technical framework for defining land use threshold and optimizing its structure to improve the SDBES state was constructed and applied to a practical case. The spatial pattern of supply and demand of each ES in Lancang county was distinctly heterogeneous, with significant differences in SDES across different land use types. Strong spatial heterogeneity existed in the ESDR of each ES at the grid scale, and the areas of deficit were ranked as carbon sequestration > water conservation > habitat quality > food production. The structure of dry land, paddy field, tea, evergreen broad-leaved forest, grassland, urban construction land, and industrial and mining construction land were the focus of land use optimization. Based on the land use area thresholds under the SDBES, the optimal land use structure for maximizing comprehensive benefits contributed to a balanced relationship between SDES and promoted sustainable regional development. The study provides a new perspective and method for improving the SDBES state, alleviating land conflicts, and managing ecological environment.

With the rapid development of economy and society, decision-makers need a deep understanding of the role of sustainable ecosystem management in practical application, which is crucial to the sustainable development of ecosystems. Understanding the relationship between ecosystem supply and social demand is key in overcoming the contradiction between humans and the ecosystem, as well as achieving successful ecological restoration and healthy regional development. However, there is still a lack of multi-scale and multi-method research on the supply–demand relationship of ecosystem services for key ecological-restoration zone. In this study, a typical ecological barrier (i.e., Ganzhou City of southern China) was selected as the research area, and five ecosystem services (ESs) including water yield (WY), carbon sequestration (CS), crop production (CP), soil retention ( SR ) and recreation service (RE) were investigated at the pixel, township and county scale in 2020. The balance and coordination analysis of ESs supply and the quantitative analysis of the supply–demand relationship (using the coupling coordination degree ( CD ), matching degree ( MD ), and supply–demand ratio ( SDR )) were executed under multiple scales. Finally, based on the MD at the township scale, Ganzhou City was divided into four areas: high-demand, low-demand, low-supply and high-supply areas. The results reveal a trade-off relationship between CP and CS at the pixel scale, with no trade-off relationships observed among the ESs at the other scales. The supply–demand relationships of different districts and counties in Ganzhou City are highly uncoordinated, with distinct spatial mismatching. Areas with high CD values are located in Chongyi County and Longnan County, while the low/value SDR area is located in Zhanggong District, with a relatively high population and GDP. The results of MD division based on township level in Ganzhou City show 17 townships are classified as high-demand areas (mainly in urban areas) and 23 townships are classified as low-demand areas (mainly in the suburbs); 77 townships are classified as low-supply areas and 167 townships are classified as high-supply areas, which are mainly distributed in forest areas. This study provides guide for regional ecological space planning, enhances the understanding of ESs management, and provides a more objective reference for decision makers to plan future ecological restoration.

Accurate supply and demand matching of ecosystem services (ESs) is important for managing regional ecosystems. On the basis of remote-sensing, meteorological, and socio-economic data, we mapped the supply, demand, and matching status of four ESs (i.e., water production, carbon sequestration, food supply, and soil conservation) using biophysical models and the ArcGIS spatial analysis module within the Zhengzhou–Kaifeng–Luoyang (ZKL) urban agglomeration in 2018. Four-quadrant analysis was employed to identify the spatial matching types of supply-demand relationships within the study region. The results are as follows. The supply-demand ratios of different ESs in the cell scale exhibit different spatial characteristics because of major influencing factors, including the natural environment (e.g., precipitation and temperature) and social development (e.g., urbanization level). Analysis of the supply-demand imbalances of the four ESs indicates that water production is deficient across the entire research area, whereas the whole research area’s carbon sequestration, food supply, and soil conversation are in the surplus state. Regarding the spatial matching types for supply and demand of the four ecosystem services, water production is dominated by the “low–low (low supply and low demand)” type. Carbon sequestration is dominated by the “low–low” and “high–low (high supply and low demand)” types. The “low–low” type dominates food supply and soil conservation. Due to the severity of the deficit in water production, all districts and counties in the ZKL urban agglomeration are identified as areas requiring ecological conservation, ecological restoration, or ecological improvement. Development guidance strategies and planning suggestions are proposed in different ecological areas. These policies could also be applied in other similar urban agglomerations.

This study presents the first application of the pressure-state-response (PSR) model in the comprehensive assessment of construction and demolition waste (CDW) recycling benefits. Unlike traditional methods, the PSR model provides a multi-dimensional analysis that integrates economic, environmental, and social factors, offering a more holistic approach to evaluating the impact of CDW recycling strategies. This model enables stakeholders to better understand the pressures, states, and responses involved in CDW management, providing actionable insights to optimize recycling efforts and support sustainable urban development. Using the pressure-state-response (PSR) logical framework of sustainable economics, this paper systematically analyzed the comprehensive benefit mechanism of the recycling of construction and demolition waste (CDW), and designed a comprehensive benefit evaluation model for CDW recycling. At the same time, taking Chongqing as an example, the management status of construction and demolition waste, the supply and demand matching of sustainable recycling products, and the impact of the input and output of CDW management were analyzed. The results were as follows: (1) The recovery rate of urban manure fluctuated between 0.13 and 0.17, mainly in temporary landfill. (2) Based on the latest market demand data of CDW recycled products, the supply–demand ratio of recycled products fluctuated between 0.11 and 0.21. This change in the supply–demand ratio reflects improvements in recycling technologies, such as the introduction of C2CA technology, which has greatly increased the supply of high-quality recycled materials. In addition, government policies encouraging the use of recycled products in public projects have contributed to this shift, further aligning supply with market demand. (3) The benefit–cost ratio of CDW management reflects new recycling technologies and the improved efficiency of CDW management. The benefit–cost ratio, which currently fluctuates between 0.32 and 0.39, more accurately reflects the current state of CDW management, which is increasingly adopting advanced technologies, resulting in increased efficiency and reduced costs. Based on this, this paper discusses the supply–demand relationship and benefit–cost ratio in CDW management from supply-side and demand-side perspectives, and puts forward corresponding countermeasures and suggestions. The research results provide a clear reference for improving the efficiency of building demolition waste resource utilization, especially in optimizing the balance of market supply and demand, and improving the economic benefits of recycled products. By analyzing the balance between the supply and demand ratio and the benefit–cost ratio, this study helps inform policy makers, businesses, and investors, to promote the sustainable development of CDW recycling projects to maximize resource efficiency, while reducing environmental pressures. These results not only provide practical guidelines for the implementation of CDW recycling projects, but also lay a foundation for future policy formulation and the setting of industry standards.

The intimidating surge in the procurement of Distributed Energy Resources (DER) has increased the number of prosumers, creating a new possibility of local energy trading across the community. This project aims to formulate the peer-to-peer energy (P2P) sharing model to encourage the DERs to share surplus energy among the consumers. An effective pricing method is developed based on the supply-demand ratio (SDR) with the importance of self-optimization, which allows the prosumers to maximize their energy sharing and profits. To implement this pricing method, a simplified dynamic matchmaking algorithm has been deployed to introduce the Outstanding Prosumer to interact with existing consumers to increase the efficiency and profitability of the trade network. Consumers also benefit from this model, as they can pick the most economical energy supplier instead of relying on the utility grid. The prosumer with high excess energy and the consumer with the highest energy demand will be prioritized to maintain the SDR ratio to one or greater than one. Here, all the above-stated features of the peer-to-peer energy trading have been demonstrated with some calculations to back up some tangible results. Finally, a case study is simulated among the residents of Dhaka, Bangladesh, to demonstrate how peers can profit from participating in trading at a given time. Comparing the results with and without P2P trading, there has been a 17.54% reduction in an electric bill on a typical day of July, and a 49.53% reduction in the interaction with the grid.

Global warming is caused by rising carbon dioxide concentrations, while ecological and environmental issues are becoming increasingly evident. Many governments’ main objective in addressing climate challenges is to achieve carbon balance. Exploring the distribution and changing trends of carbon balance can contribute to carbon balance strategies. This study takes the Yangtze River Economic Belt (YREB) as the study area, analyzing the spatial and temporal dynamic changes in carbon emissions and carbon sequestration in the YREB from 2000 to 2017. The county-level supply–demand ratios and accessibility are calculated based on the enhanced two-step floating catchment method according to the dynamic flow radius. According to our experimental results, carbon emissions can achieve different degrees of carbon balance according to the flow radius. After carbon emissions flow between counties within the province, some provinces can realize the transition from carbon surplus to carbon balance. With the expansion of the flow radius and the increase in internal mobility, more counties can participate in carbon sequestration, and some provinces can achieve carbon neutrality after carbon emissions transfer across provinces. Hubei, Chongqing, Zhejiang, Hunan and other provinces with special carbon sequestration capacity are very sensitive to changes in the radius of carbon emission flow. In 2017, when the carbon emission flow radius is 50 km, the net carbon emission of the flow can be reduced by 3%. If the radius is increased to 200 km, the YREB can achieve carbon balance. This study can provide decision-making information for carbon emission ecosystem management in the YREB.

As an essential platform for aggregating and coordinating distributed energy resources (DERs), the virtual power plant (VPP) has attracted widespread attention in recent years. With the increasing scale of VPPs, energy interaction and sharing among VPP clusters (VPPCs) have become key approaches to improving energy utilization efficiency and reducing operational costs. Therefore, studying the coordinated operation mechanism of VPPCs is of great significance. This paper proposes a two-stage coordinated operation model for VPPCs based on energy interaction to enhance the overall economic performance and coordination of the cluster. In the day-ahead stage, a cooperative operation model based on Nash bargaining theory is constructed. The inherently non-convex and nonlinear problem is decomposed into a cluster-level benefit maximization subproblem and a benefit allocation subproblem. The Alternating Direction Method of Multipliers (ADMM) is employed to achieve distributed optimization, ensuring both the efficiency of coordination and the privacy and decision independence of each VPP. In the intra-day stage, to address the uncertainty in renewable generation and load demand, a real-time pricing mechanism based on the supply–demand ratio is designed. Each VPP performs short-term energy forecasting and submits real-time supply–demand information to the coordination center, which dynamically determines the price for the next trading interval according to the reported imbalance. This pricing mechanism facilitates real-time electricity sharing among VPPs. Finally, numerical case studies validate the effectiveness and practical value of the proposed model in improving both operational efficiency and fairness.