应用生态学报最新文献

Exploring the effects of nitrogen (N) addition on the stoichiometric characteristics of rhizosphere and bulk soil, microorganisms, and extracellular enzymes can provide theoretical insights into the impacts of N deposition on soil carbon dynamics and nutrient limitation status. We conducted a field experiment in a secondary Larix gmelinii forest in the Greater Khingan Mountains to examined the effects of N addition on the stoichiometric characteristics of soil, microorganisms and extracellular enzymes, as well as extracellular enzyme activities. There were four treatments: control (CK), low N (LN), medium N (MN), and high N (HN), with the rate of 0, 25, 50, and 75 kg N·hm^-2·a^-1, respectively. The results showed that N addition significantly increased total soil organic carbon (SOC), total nitrogen (TN), SOC∶TN and SOC∶TP in rhizosphere soil, as well as TN, SOC∶TP and TN∶TP in bulk soil, but significantly decreased total phosphorus (TP) in bulk soil. SOC and SOC∶TN in bulk soil were significantly increased under LN and MN treatments. Nitrogen addition significantly increased microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), MBC∶MBN, MBC∶MBP, and MBN∶MBP in rhizosphere soil. In addition, microbial biomass phosphorus (MBP) in rhizosphere soil, as well as MBC, MBN, MBC∶MBN, MBC∶MBP, and MBN∶MBP in bulk soil significantly increased under LN and MN treatments. Enzyme activities related to carbon, nitrogen, and phosphorus acquisition, and extracellular enzyme nitrogen-to-phosphorus ratio (E_N∶P) in both rhizosphere and bulk soils were enhanced by N addition. Nitrogen addition significantly decreased the extracellular enzyme carbon-to-nitrogen ratio (E_C∶N) and carbon-to-phosphorus ratio (E_C∶P) in rhizosphere soil by 10.9%-17.6% and 7.0%-9.0%, respectively. E_C∶P in bulk soil increased significantly by 7.2%-7.4% under LN and MN treatments. Results of enzyme vector analysis showed that N addition alleviated carbon limitation in rhizosphere microorganisms and phosphorus limitation in bulk soil microorganisms. In rhizosphere soil, E_C∶N showed a linear negative correlation with MBC∶MBN and SOC∶TN, while E_C∶P showed a linear negative correlation with MBC∶MBP and SOC∶TP. In bulk soil, E_C∶P was positively correlated with SOC∶TP and MBC∶MBP. In summary, the stoichiometric characteristics of soil, microorganisms, and extracellular enzymes in rhizosphere and bulk soils responded differently to N addition. Our results would provide a theoretical basis for understanding the rhizosphere effects on forest soil nutrient cycling under N deposition.

Saline-alkali soils pose severe challenges to agricultural production and the sustainable utilization of land resources. Efficient amelioration and utilization of saline-alkali land is of great significance for expanding agricultural production and safeguarding national food security. Rice cultivation is an important approach to ameliorate saline-alkali soils, offering dual benefits in ecological improvement and economic development. We reviewed research on improving saline-alkali land through rice cultivation over the past two decades. Long-term (≥5 years) rice cultivation exerts positive effects on saline-alkali soils. Specifically, soil pH and electrical conductivity decreased by 5.9%-23.0% and 22.1%-89.7%, respectively. Soil organic matter, alkali-hydrolyzable nitrogen, available phosphorus, and available potassium contents increased significantly by 60.0%-66.7%, 90.2%-131.0%, 68.9%-89.2%, and 6.7%-179.2%, respectively. In addition, the richness (Ace index) of soil bacterial and fungal communities increased by 10.5%-23.4% and 23.8%-52.8%, and the Shannon index increased by 60.9%-98.7% and 18.3%-107.0%, respectively. Improvements in the physicochemical and biological properties of saline-alkali soils enhanced rice yield and yield components, with thousand-grain weight, grains per panicle, and overall grain yield be increased by 10.1%-17.2%, 9.3%-46.6%, and 48.2%-91.1%, respectively. Future research should focus on innovations in salt-alkali tolerant rice germplasm resources and variety breeding, rhizosphere microbial remediation strategies for salt-alkali tolerant rice, carbon sequestration potential assessment systems for saline-alkali paddy fields, and diversified development approaches. These efforts would provide a reference for deeply exploring the comprehensive utilization potential of saline-alkali land and advancing the sustainable use and efficient remediation.

Understanding the trade-offs, synergies, and dynamics among ecosystem services (ESs) under both current and future conditions is crucial foundation for promoting holistic ecosystem conservation and scientific management of national park. Using the PLUS and InVEST models, we assessed land use and ES changes of Shennongjia National Park in 2030 and 2050 under three scenarios: Natural development, ecological conservation, and tourism development. We used Spearman correlation analysis and K-means clustering to identify trade-offs and synergies among ESs, delineate the functional structure of ES bundles, and examine their dynamics. The results showed that different ESs exhibited distinct evolutionary trends from 2020 to 2050. Recreational services remained relatively stable overall. Water yield, soil conservation, and habitat quality showed declining trends, with the most significant reductions under the tourism development scenario by 359769.00 mm, 28388.70 t, and 0.11, respectively. Carbon storage increased significantly only under the ecological conservation scenario, with a gain of 102096.71 t. Relationships among ESs under different scenarios were predominantly synergistic and showed notable changes. Under the natural development and tourism development scenarios, trade-offs weakened while synergies strengthened. The relationship between carbon storage and water yield shifted from trade-off to synergy. Under the ecological conservation scenario, trade-offs and synergies remained largely unchanged. Based on K-means clustering of ecosystem service trade-offs and synergies, four distinct types of ES bundles were identified: strict protection, science education and recreation, community livelihood, and ecological restoration. The spatial patterns of ES bundles showed minimal variation and remained relatively stable across different scenarios. Based on the distribution patterns and internal characteristics of different ES bundles, we proposed corresponding ecological management strategies to provide a scientific basis for the holistic conservation of national park ecosystems.

Microplastics are formed during the degradation of plastic products under the action of environmental factors such as light, high temperature and mechanical friction, which are widely used in agricultural production. These microplastics would threaten human health through the accumulation of the food chain, which has become a global pollution problem. Traditional plastic waste disposal methods (landfilling, incineration, mechanical recycling) have obvious limitations in both environmental benefits and economic feasibility. In contrast, emerging plastic carbonization technology holds potential for achieving harmless transformation of pollutants and resource utilization. Through techniques like co-thermal decomposition, hydrothermal carbonization, and catalytic carbonization, plastics can be synergistically converted into high-value carbon materials (biochar, hydrothermal carbon, and carbon nanomaterials), effectively reducing plastic pollution. These materials also exhibit promising applications in microplastic adsorption, soil remediation, and integrated pollutant treatment of pollutants. However, challenges including unclear reaction mechanisms, inconsistent product properties, high energy consumption, scalability difficulties, and a lack of policy support, hinder industrial application and the development of value-added products. We reviewed the mechanisms, application scenarios, and limitations of three plastic carbonization technologies, including co-thermal decomposition, hydrothermal carbonization, and catalytic carbonization. Future efforts should integrate life cycle assessment and multi-technology strategies to further validate their environmental and economic sustainability, facilitating the transition from theory to practice.

The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is one of China's largest urban agglomera-tions in terms of economic aggregate. However, accelerated urbanization have led to a series of ecological problems, including ecosystem fragmentation and imbalances in ecosystem functions. The precise identification and optimization of key ecological restoration areas are critical pathways for conducting territorial spatial ecological restoration, holding significant value for safeguarding the ecological security of the GBA. We integrated the MSPA-InVEST model with circuit theory to assess habitat quality of GBA and construct an ecological network, with which we identified key regions for ecological restoration. Based on the findings, we proposed optimization strategies for territorial spatial ecological restoration in the GBA. The results showed that the average habitat quality value across the GBA was 0.69 in 2023, indicating an overall favorable level of habitat quality. Extremely high-quality habitat areas covered 26431.8 km², while extremely low-quality habitat areas spanned 8662.9 km². By integrating ecological network construction and habitat quality assessment, we identified 41 ecological source optimization zones (total area: 742.8 km²), 151 ecological pinch point improvement zones (total area: 12.4 km²), and 499 ecological barrier restoration zones (total area: 158.5 km²). We proposed targeted measures for territorial spatial ecological restoration in the GBA, including structural optimization of ecological source, functional enhancement of ecological pinch point, and systematic restoration of ecological barrier areas at the regional-plot level. Our results would provide a scientific basis and practical guidance for territorial spatial ecological restoration in the GBA.

Species invasion in marine has increased the frequency of security incidents at coastal nuclear power plants, posing serious threats to the cooling water intake. To systematically identify the risk organisms in nuclear power cooling water sources and clarify their distribution pattern, we established a risk identification and assessment framework for marine organisms in cooling water intake areas. Based on field investigation conducted in the summer of 2024 in the adjacent waters of a nuclear power plant in northern China, we categorized marine organisms into five types: phytoplankton, zooplankton, swimming animals, benthic animals, and selected intertidal organisms. Trophic level, habitat layer, body size, body length, and density were used as evaluation criteria. These indices were combined with type-specific traits (e.g., migratory behavior and reproduction mode) to develop a scoring system, with each indicator being assigned a maximum score of 10 points. Scores were determined based on the potential risk of each biological trait to clogging the water intake, and a spatial weight based on the distance from sampling points to the intake was incorporated to calculate the total risk score for each species. We classified risk levels into low, medium, and high according to thresholds set at 30% and 80% of the total possible score. Results showed that a total of 40 phytoplankton, 28 zooplankton, 27 swimming animals, 62 benthic animals, and 43 intertidal species were recorded. Through multi-indicator integration and spatial weighting analysis-balancing field data authenticity and theoretical traits of species, Loligo sp., Charybdis japonica, and Konosirus punctatus were identified as high-risk species. Moreover, there was a higher density of high-risk organisms in the northern area near the water intake. By integrating functional traits and measured data into a comprehensive evaluation framework, this study could provide a scientific basis for risk organism identification, early warning, and the development of prevention and control strategies for cooling water systems near nuclear power plants.

Under the ongoing strategic advancement of biodiversity conservation, the delineation of the proposed Asian Elephant National Park progressively entered the phase of spatial identification. Identifying the habitat network of regional flagship and umbrella species served as a critical prerequisite and scientific basis for defining spatial extent of the park. This study focused on the key distribution areas of Asian elephants (Elephas maximus) in Xishuangbanna, Pu'er, and Lincang. We integrated the InVEST model with morphological spatial pattern analysis (MSPA) to identify habitat sources, selected six ecological resistance factors and determined their weights using the entropy weight method to construct a resistance surface. We applied the Linkage Mapper tool to extract habitat corridors, ecological barrier points and pinch points, thereby building the habitat network for Asian elephant acti-vity areas. The results showed that a total of 158 habitat sources were identified, covering approximately 23000 km², with primary and secondary sources together accounting for 18000 km²(20.5% of the study area). There was a spatial pattern of "high density in the central region, sparse distribution at both ends, and north-south connecti-vity", forming a continuous and ecologically valuable core habitat source areas along the Xishuangbanna-Pu'er boundary. We extracted 439 habitat corridors with a combined length of 4616.58 km, which displayed a pattern of "denser in the south, sparser in the north, connecting patches, and forming corridor belts", and effectively supported regional-scale elephant movement. The ecological barrier points in Asian elephant migration paths are predominantly distributed in areas of dense road disturbance and fragmented habitats in Lincang City and central-eastern Pu'er. The ecological pinch points are mainly concentrated in Menghai County and the Menglun area of Xishuangbanna Prefecture, as well as in central-southern Pu'er. Clarifying the differentiated management needs corresponding to various source areas within the core zones of Asian elephants and prioritizing the protection of highly sensitive regions such as ecological barriers and ecological pinch points could enhance the overall connectivity and stability of the regional habitat network, thereby expanding its umbrella effect on biodiversity conservation.

We measured the contents of starch, soluble sugars, and non-starch carbohydrates (NSC) in leaves of 60 common plant species (trees, shrubs, and herbaceous plants) from Betula platyphylla secondary forests across an altitude gradient (950, 1150, 1350, 1550, and 1750 m) in the northern Hebei mountainous region and analyzed their relationships with environmental factors. The results showed that both trees and shrubs exhibited significantly higher soluble sugar and NSC contents than herbaceous plants, while the starch-to-soluble sugar ratio (SC/SSC) was significantly lower in woody species, indicating a tendency to maintain higher carbon storage levels. With increasing altitude, NSC contents in trees first decreased and then increased, shifting from carbon limitation to growth limitation as a response to environmental stress, demonstrating a flexible trade-off strategy between 'growth' and 'energy storage'. In contrast, NSC in shrubs and herbaceous plants increased significantly with altitude, dominated by growth limitation, reflecting a conservative strategy focused on carbon accumulation under low-temperature stress. The mixed-effects model revealed that altitude was the key driver of NSC variation, with interspecific differences being the primary source of leaf NSC variation. Redundancy analysis indicated that the first two principal components explained 87.6%, 79.9%, and 93.1% of the cumulative variance for trees, shrubs, and herbaceous plants, respectively. The main influencing factors were soil moisture and total nitrogen for trees; soil pH, available phosphorus, and mean temperature of the growing season for shrubs; and, mean temperature of the growing season, soil moisture, and pH for herbaceous plants. This study revealed the differential regulation of hydrothermal conditions and nutrient supply on carbon balance of different plant life forms, and clarified that life form is a key dimension to explain the diversity of plant adaptation strategies to altitude gradient.

Soil microbial carbon use efficiency (CUE), defined as the proportion of assimilated carbon allocated to microbial growth versus maintenance, is a key parameter regulating terrestrial soil organic carbon (SOC) storage. The response of CUE to climate change and its feedbacks profoundly affect global carbon cycle and soil carbon sequestration. At present, there are substantial uncertainties regarding the mechanisms underlying the responses of CUE to climate change and the ecological consequences. We synthesized research progress on soil microbial CUE over the past 20 years. First, we clarified the basic concept and computational approaches of CUE, and compared the principles, strengths, and limitations of three mainstream measurement techniques (isotope labeling method, stoichiometric model, and thermodynamic efficiency method). Second, we summarized the key biotic and abiotic factors influencing CUE. Focused on the mechanisms underlying the main and interactive effects of elevated atmospheric CO₂ concentration, climate warming, and altered precipitation patterns on microbial CUE, and based on a "resource-cost trade-off" framework, we discussed the potential mechanisms underlying the heterogeneous responses of CUE across different ecosystems, and summarized the bottlenecks and challenges that still existed in current research regarding methodological standardization, the analysis of deep soil processes, the quantification of multi-factor interaction effects, and the application of CUE in earth system models (ESMs). We proposed an integrative research framework spanning from micro-scale metabolic mechanisms to macro-scale carbon cycling patterns, emphasizing the need for methodological innovation, multi-scale networked observations, and model-experiment integration, to thoroughly reveal the dynamics and adaptive mechanisms of CUE under climate change.

Nature reserves are of great significance in maintaining the supply of ecosystem services and sustaining development of local livelihoods. It is important to understand the perceptions of community residents on the importance and satisfaction with ecosystem services in protected areas, which is helpful for prioritizing ecosystem services and coordinating the relationship between ecological protection and resident livelihood development. With Wolong Nature Reserve as a case, we used the participatory rural appraisal method to the perceptions of community residents regarding the importance and satisfaction of ecosystem services. We further employed the importance-satisfaction analysis and multiple regression analysis to examine the differences in their perceptions of various ecosystem services and the influencing factors. The results showed that there were significant differences between the importance and satisfaction for the all types of ecosystem services, except for the regulating service of air purification. Importance-satisfaction analysis indicated that six ecosystem services (freshwater provision, natural disaster prevention, soil fertility maintenance, pest control, scientific knowledge and environmental education, and recreational tourism) were identified as high importance-low satisfaction, which requires high priority in reserve management. Local perceptions of ecosystem services were influenced significantly by the educational level, livelihood type, and geographical location. Residents with different education levels, livelihood types, and geographical locations exhibited different perceptions of the importance and satisfaction with ecosystem services. Among these, livelihood type and geographic location jointly affected residents' perception of importance and satisfaction, while educational level only had a significant impact on satisfaction perception.