Table of Content

18 March 2026, Volume 37 Issue 3

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Policy research on agriculture, rural areas, and farmers (“Sannong”)based on landscape sustainability science: Scientific foundations and core research directions

HUANG Lu, WANG Yuhai, ZHANG Fan, FANG Lu, WU Jianguo

2026, 37(3):  647-656.  doi:10.13287/j.1001-9332.202603.032

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Research on “Sannong” policies has long been dominated by agricultural economics and other social sciences. However, the “Sannong” issue is an integrative sustainable development challenge involving agricultural activities, the rural environment, and farmers' livelihoods. It is characterized by multidimensionality, complexity, and uncertainty. Understanding such a complex issue demands an integrated scientific paradigm that transcends traditional disciplinary boundaries. Sustainability science aims to understand and improve the dynamic relationship between people and the environment, through merging natural sciences, social sciences, and the humanities, as well as integrating theoretical explorations with on-the-ground applications. Emphasizing spatially explicit analysis and synthesis, landscape sustainability science (LSS) deepens and expands sustainability science by focusing on the dynamic relationships among climate change and socioeconomic-technological drivers, landscape pattern, ecosystem services, human well-being, and landscape planning and governance at the local and regional landscape scales. We reviewed research on “Sannong” policies, elucidated the core framework of LSS (i.e., the inner and outer feedback loops that center on the “golden triangle” of landscape pattern, ecosystem services, and human well-being), proposed a LSS-based research approach for advancing the studies of “Sannong” policies, and further identified three key research directions: urban-rural integration and spatial optimization, synergistic mechanisms for food and ecological security, and adaptive transformations of rural social-ecological systems. This review aimed to enhance the scientific foundation and applications of “Sannong” policy research from three dimensions: multi-scale perspectives, spatial explicitness, and dynamic processes. By fostering interdisciplinary knowledge integration and scenario-based simulation, it established an adaptive management loop of “analysis-decision-adjustment”, thereby providing scientific support for achieving the sustainable development goals of strong agriculture, beautiful countryside, and prosperous farmers.

Special Features of Urban Climate and Urban Design (Guest Editors: HE Baojie, KONG Fanhua)

Construction of a new type of urban high-temperature resilience infrastructure with “blue-green-grey-smart” synergy: Theoretical framework, implementation challenge, and practical approach

WANG Feng, MAO Yao, HE Baojie

2026, 37(3):  657-670.  doi:10.13287/j.1001-9332.202603.021

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The coupling of global warming and accelerated urbanization has led to frequent and severe extreme heat events, threatening urban ecological stability, public health, and sustainable development. Actively responding to the risks of high temperatures and enhancing the heat resilience of cities are urgent needs to ensure urban safety and high-quality development. Infrastructure is a key carrier of the adaptive capacity and ecological service functions of urban and rural systems, as well as an important approach to address climate risks through infrastructure innovation and implement the resilient city strategy. Grasping the core direction of the national infrastructure system reform, we constructed a new infrastructure system for urban heat resilience by taking information networks as the foundation, technological integration and innovation as the key, and digitalization as the framework, with the goal of empowering “blue-green-gray” infrastructure to undergo smart and ecological transformation in response to high-temperature risks. We defined the theoretical and methodological connotations of the construction of new infrastructure for heat resilience, proposed a “blue-green-gray-smart” collaborative framework, analyzed the implementation challenges, such as insufficient coordination of green infrastructure, weak support of blue infrastructure, lagging transformation of gray infrastructure, and insufficient empowerment of smart infrastructure. We further delved into the four root causes of functional protection, survival support, carrier support, and quality improvement and efficiency enhancement, and proposed an implementation path for the construction of new infrastructure for heat resilience based on a collaborative adaptation system, a people-oriented governance system, and a full-chain guarantee mechanism. This study would provide core support for the implementation of smart infrastructure and the construction of heat-resilient cities, and could offer theoretical and practical references for urban high-temperature risk response and ecological resilience enhancement.

Comparison of methods for exploring spatiotemporal variations of urban heat island effect: With Wuhan Metropolitan Development Area as an example

LI Qiqi, LI Miao, LIU Huimin

2026, 37(3):  671-682.  doi:10.13287/j.1001-9332.202603.050

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In the context of global climate change, the urban heat island effect (UHI) poses a severe threat to the health and life quality of residents. Explorations of the spatiotemporal variations of intra-urban heat island effect present as a key foundation for identifying the impacts of diversified and differential construction modes on the thermal environment, as well as testing the implementation effect of relevant planning interventions. However, the spatio-temporal variability of UHI manifests as highly dynamic and stochastic, governed by the nonlinear coupling between built environment and climate system. Such intrinsic volatility poses a critical challenge for precise diagnostic assessment in urban planning. To distill actionable insights from this complexity, two classes of “sequential reduction” strategies have emerged. The “time-space” approach prioritizes temporal trend extraction before spatial partitioning based on trend similarity, while the “space-time” approach clusters spatial units by trajectory similarity prior to trend analysis. Yet, despite their proliferation, a systematic critique regarding their core rationales, methodological protocols, and distinct domains of applicability remains conspicuously absent. To fill this gap, we utilized 11 periods of land surface temperature data by Landsat satellites for Wuhan from 2000 to 2024 to systematically compare the two methods in terms of analytical capabilities and applicability in planning evaluations. Results showed that the “time-space” method, relying on the trend test of independent pixels, identified 10 types of spatial zones, which could be further summarized into three major patterns, including persistent warming pattern, significantly mitigated pattern, and balanced-stable pattern. Among them, persistent warming pattern accounted for 21.9% of the area, while significant mitigation pattern accounted for 0.1%. Those results indicated that this method was highly sensitive to local subtle changes and was therefore more suitable for meso-micro assessment oriented to urban detailed planning and urban renewal. The “space-time” method was based on temporal clustering to preferentially identify homogeneous spatial units. It identified 13 types of spatial zones with consistent upward trends, which could be further summarized into three major patterns, including persistent warming pattern, stable high-temperature pattern, and stable low-temperature pattern. Among them, persistent warming pattern accounted for 26.6% of the area. This method emphasized the identification of the overall continuous spatial pattern and was hence more suitable for city-level assessment through master plans for improved spatial patterns of urban thermal environments. Overall, both categories of methods revealed a shared pattern in the spatiotemporal variations of the UHI in Wuhan's metropolitan development area: “overall intensification and core shift”. However, distinct differences in the logic and strategies used to handle spatiotemporal complexity had led to significant discrepancies in the assessment results, indicating an urgent need for further methodological innovation.

Seasonal effects of urban morphology on surface temperature within Beijing's Fourth Ring Road at different grid scales

DUO Linghua, DUAN Yaqing, WANG Junqi

2026, 37(3):  683-694.  doi:10.13287/j.1001-9332.202603.022

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With the intensified urbanization, urban morphology has a significant impact on land surface temperature (LST). Although the influence of urban morphology on the thermal environment has been widely recognized, further investigation is required in terms of multi-scale grid-based analyses and seasonal comparisons. Taking the area within Beijing's Fourth Ring Road as the study area, we employed a random forest model to quantify the inpact of urban morphology factors on LST. We investigated the seasonal effects of different urban morphology factors on LST across multiple grid scales, and examined the spatial correlation between urban morphology factors and the spatial distribution of LST using bivariate spatial autocorrelation analysis. The results showed that within the grid scale range of 180-360 m, the goodness of fit between urban morphology factors and LST generally exhibited an increasing-decreasing trend with increasing grid size. Among these, the optimal model performance was achieved at the 300 m grid scale, suggesting that this scale could be applied in urban planning to mitigate the urban heat island effect. The effects of urban morphology on LST exhibited seasonal differences. The influence of building height was the strongest in spring, with a relative importance value of 3.36. The effect of the density of built-up land peaked in summer and autumn, with relative importance values of 4.21 and 4.39, respectively. The influence of urban vegetation cover was more pronounced in winter, with a relative importance value of 2.15. Among the urban morphology factors, normalized difference built-up index was positively correlated with LST, while normalized difference vegetation index, building height, building volume, and sky view factor were negatively correlated with LST. All urban morphology factors and LST exhibited a certain degree of local spatial correlation. By taking urban morphology as the analytical entry point, this study would advance the understanding of the multi-scale and seasonal variation patterns of LST, reveal its spatial heterogeneity, and provide scientific support for climate-adaptive urban planning and the development of differentiated thermal environment regulation strategies.

Impacts of land use on spatiotemporal patterns of urban heat islands in Nanjing City, China

SONG Xiaomeng, TIAN Congrong

2026, 37(3):  695-706.  doi:10.13287/j.1001-9332.202603.024

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Urban environments have undergone significant changes under the background of rapid urbanization, with pronounced urban heat island (UHI) effect. It is important to understand the UHI and identify their relationships with the land use changes, which can provide reasonable suggestions for alleviating UHI and building an effective ecologically livable city. We used 1 km daily MODIS surface temperature data from 2002 to 2022, 30 m summer Landsat imagery, and land use data to retrieve land surface temperature (LST) using the atmospheric correction method. By incorporating the definition of UHI intensity and employing a mean-standard deviation classification approach, we systematically analyzed the spatiotemporal variations of UHI in Nanjing and evaluated the impact of land use patterns on UHI. The results showed that there were significant differences in the spatial distribution of LST, with higher temperatures in urban areas than rural regions. There were significant diurnal differences in LST among different land types, among which the diurnal temperature difference of water body was the most significant. The diurnal and seasonal UHI intensity exhibited significant variations, with the maximum value occurring during day-time in summer (1.52 ℃) and night-time in winter (0.80 ℃). The day-time UHI intensity showed an increasing trend in winter but decreased in summer, while the night-time UHI intensity was increased in all seasons. The areas of UHI steadily increased during 2002-2022, especially for the strong heat island area, which was highly coincident with the urban construction land. The LST in the urban core area was consistent with the normalized building index. The heat island level of grassland and cultivated land was mainly in the middle zone, accounting for 58.0% and 52.8% of their respective land types. Forest and water body were mainly in the cold island zone, accounting for 64.7% and 94.3% of respective land types.

Construction of urban ventilation corridor based on computational fluid dynamics and circuit theory: A case study of Nanjing central urban area

GAO Shumeng, SU Jie, YIN Haiwei, KONG Fanhua

2026, 37(3):  707-717.  doi:10.13287/j.1001-9332.202603.025

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Ventilation corridors play an important role in alleviating the urban heat island effect and promoting air circulation, which is of great significance for improving the urban wind and heat environment and enhancing the quality of life of residents. However, the available methods for constructing ventilation corridors have limitations in terms of the balance among computational cost, spatial accuracy and research scope, as well as the identification of multiple air flow paths. Moreover, those methods mostly simplify air flow by using macroscopic wind direction and external fixed entrances and exits, overlooking the potential of internal urban wind sources and the spatial heterogeneity of the wind environment. In response to the above issues, we proposed a new technical framework for the construction of ventilation corridors and took Nanjing central urban area as an example to elaborate its implementation process. Firstly, we used the computational fluid dynamics (CFD) simulation to obtain the near-ground wind field, and carried out the multi-factor comprehensive evaluation of urban ventilation corridor construction suitability. Then, we identified the urban ventilation corridor by combining circuit theory with the land surface thermal environment. Finally, we constructed an urban ventilation corridor system composed of wind sources, corridors, and restoration zones. To test the effectiveness of this framework and evaluate its advantages, we conducted a comparative analysis using the least cost path method based on the frontal area index (FAI-LCP method). The results based on the technical frame work of this study showed that there were 6 core wind sources, 19 secondary wind sources, 9 primary ventilation corridors and 10 secondary corridors in the urban ventilation corridor system of Nanjing central urban area. Based on the normalized current flow results obtained from circuit theory, 14 restoration zones of the ventilation corridor system were identified, mainly distributed in the downwind areas of the internal wind sources and the areas with a higher frontal area index in the secondary ventilation corridors. Compared with the FAI-LCP method, our technical framework could achieve the identification of internal wind sources, the characterization of corridor width and the discrimination of ventilation obstruction points, which would be conducive to enhancing the systematicness of ventilation corridor planning.

Original Articles

Prediction models for tree height and height to crown base of individual trees in valuable hardwood broad-leaved forests of Northeast China based on terrestrial laser scanning data

XIE Mingrui, JIA Weiwei, WANG Fan, WANG Yidong, LI Pengyu, HE Yulong

2026, 37(3):  718-730.  doi:10.13287/j.1001-9332.202603.003

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Tree height and height to crown base are key parameters for the monitoring of forest growth and sustainable forest management. Accurate prediction of these variables is essential for the conservation and efficient utilization of valuable hardwood broad-leaved forests. In this study, we developed prediction models for tree height and height to crown base of Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense in the Zhuan-shan Experimental Forest Farm of Heilongjiang Province, to by combining terrestrial laser scanning (TLS) point cloud data with field-measured data. First, optimal basic models were screened, and generalized models were then constructed by introducing individual-tree factors (height to crown base), competition factors (relative diameter and basal area of trees larger than the subject tree), stand structure variables (dominant diameter and Gini coefficient of diameter), and species diversity indices (mingling index and Pielou evenness index). Finally, mixed-effects models were established by incorporating plot-level random effects. The results showed that the overall fitness for individual trees reached 96%, and the coefficients of determination (R²) between TLS-derived tree height, height to crown base, and diameter at breast height and field measurements were 0.80, 0.75, and 0.98, respectively, with corresponding root mean square error (RMSE) values of 2.00 m, 1.96 m and 0.93 cm. The optimal basic models for tree height and height to crown base were the exponential reciprocal model (R²=0.637, RMSE=2.739 m) and the bivariate interaction model (R²=0.373, RMSE=2.981 m), respectively. The introduction of multiple variables in the generalized models significantly improved prediction accuracy, with R² increasing by 24.2% and 20.9% and RMSE decreasing by 39.4% and 6.3% for tree height and height to crown base models, respectively. The mixed-effects models considering plot-level random effects performed the best, with R² further increasing by 11.8% and 7.1% and RMSE decreasing by 29.1% and 3.8% for tree height and height to crown base models, respectively, compared with the corresponding generalized models. Overall, mixed-effects modeling combining TLS data with multi-level ecological factors effectively improved the prediction accuracy of vertical structural parameters in valuable hardwood broad-leaved forests, which could provide reliable technical support for precision forest management and dynamic monitoring in Northeast China.

Tree height-diameter modeling of Larix olgensis plantations based on generalized additive mixed models

LI Zhichao, MEI Xuesong, DONG Lingbo

2026, 37(3):  731-740.  doi:10.13287/j.1001-9332.202603.002

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Based on data from 71 permanent plots established in the Maoershan Experimental Forest Farm of Northeast Forestry University and the Shengli Experimental Forest Farm in Harbin City, we developed three types of height-diameter models for Larix olgensis plantations. A generalized additive model (GAM) included only the main effects of either the stand density index (SDI) or the site index (SI). A generalized additive mixed model (GAMM) incorporated the interaction between SDI and SI. A varying-coefficient generalized additive mixed model (VC-GAMM) adjusted the slope by the logarithm of diameter at breast height (logD). Model selection was based on the Akaike information criterion (AIC) and Bayesian information criterion (BIC). Model performance was evaluated using the adjusted coefficient of determination (R_adj²), root mean square error percentage (RMSE), and mean absolute error percentage (MAE). The effects of stand density, site conditions, and their interaction on individual-tree height-diameter curves of L. olgensis plantations were quantified to provide a theoretical basis for sustainable plantation management. The results showed that the VC-GAMM was the optimal height-diameter model, with a R_adj² value of 0.733, representing an improvement of 9.6%-13.6% over the GAM models and 0.14% over the GAMM model, while its RMSE and MAE were 12.4% and 9.7%, respectively, which were the lowest among all kinds of models. Marginal effect analysis showed that under extremely poor site conditions (standardized site index SI_s=-1.89), a one-standard-deviation increase in the standardized stand density index (SDI_s) increased tree height by only 0.34 m, whereas under excellent site conditions (SI_s=+2.15), tree height increased by 0.78 m, corresponding to 1.9% difference in relative height gain. The maximum tree height occurred in regions characterized by moderate SDI_s and relatively high SI_s. The interaction between stand density and site conditions was strongest at the small-diameter stage (25th percentile of DBH), where the relative variation in tree height was 5% higher than that at the medium- and large-diameter stages. There was a significant interaction between stand density and site conditions, and their combined explanatory power for tree height variation exceeded that of either factor alone. Increasing stand density promoted height growth under favorable site conditions. Under poor site conditions, high stand density intensified competition and suppressed height growth, with tree height being more sensitive to this interaction during the early developmental stages of the stand.

Responses of radial growth and leaf physiology to drought in Cunninghamia lanceolata and Quercus acutissima

LI Jiangkai, LIU Qiang, JIANG Jiang, GUO Jiangyan, LIU Ziqiang

2026, 37(3):  741-750.  doi:10.13287/j.1001-9332.202603.004

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Cunninghamia lanceolata and Quercus acutissima are common plantation species in the hilly regions of southern China. To understand the responses of radial growth to drought under the background of climate warming, we analyzed the radial growth and intrinsic water use efficiency (iWUE) of both species from 1968 to 2024, ecolo-gical resilience indices during the 1994-1995 drought event, and physiological strategies under the 2024 drought in Mopanshan Forest Farm, Jurong City, Jiangsu Province. Several variables related with dendrochronology and leaf physiological processes were measured. The results showed that: 1) The radial growth level of C. lanceolata was higher than that of Q. acutissima in the young forest stage (1973-1981), with the standard chronology index reaching a maximum of 1.7, after which it stabilized between 0.9 and 1.1, and was surpassed by Q. acutissima multiple times in the mature forest stage (after 2010). 2) In all the years except 1978, the iWUE of C. lanceolata was consistently higher than that of Q. acutissima. The sensitivity of radial growth and iWUE to climatic factors was higher in C. lanceolata than in Q. acutissima. The iWUE of C. lanceolata showed significant positive correlations with the mean temperature from the previous September-October and the current February-June, the mean maximum temperature from the previous September and the current February-April, as well as the annual mean minimum temperature, indicating that its iWUE was driven by rising temperature. 3) In historical drought events, the resistance of both species was less than 1 and recovery was greater than 1. The resilience of C. lanceolata was greater than 1 while that of Q. acutissima was less than 1, indicating that the ecological resilience of C. lanceolata was superior to that of Q. acutissima. 4) Under drought conditions, C. lanceolata sustained low stomatal conductance and transpiration rates to maintain stable photosynthesis, whereas Q. acutissima adopted a more aggressive physiological strategy, with photosynthetic rate declining rapidly under high temperatures and strong light at noon. In summary, C. lanceolata maintained stronger hydraulic safety and ecological resilience through a conservative water use strategy, while the aggressive strategy of Q. acutissima, increased drought risks. Water use strategy was the primary factor leading to the differences in radial growth and drought response between the two species.

Effects of aridity level on the maximum density lines of Larix spp. plantations in Northeast China

DONG Lingbo, ZHANG Nengneng, LIU Zhaogang

2026, 37(3):  751-757.  doi:10.13287/j.1001-9332.202603.006

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Based on data from 389 plots of Larix spp. plantations in Northeast China collected from the Seventh National Forest Inventory of China, we used the De Martonne aridity index (MAI) to quantify aridity conditions, and classified the aridity levels into five categories: Ⅰ ∈ (0, 40], Ⅱ ∈ (40, 50], Ⅲ ∈ (50, 60], Ⅳ ∈ (60, 70], and Ⅴ ∈ (70, ∞). We further employed quantile regression to develop the maximum stand density line models under different aridity levels, and simulated the effects of aridity level on the maximum stand density, stand volume, and carbon sequestration, which could provide a basis for precision management of Larix plantations in the region. The results showed that when aridity levels were not considered, the maximum stand density line slope for Larix spp. plantations in the region were -1.421, higher than Reineke's recommended value (-1.605). When aridity levels were considered, the slope generally increased with increasing MAI values, and there were significant differences in the response of maximum stand density to the aridity index across different growth stages of Larix spp. plantations. When the average stand diameter was less than 12 cm, the carrying capacity of the maximum stand density decreased with increasing MAI values. However, when the average diameter exceeded this threshold, the carrying capacity increased with increasing MAI values. At an average stand diameter of 40 cm, the maximum stand density under aridity level Ⅰ (144 trees·hm^-2) was significantly lower than the unclassified value, leading to a reduction in stand volume and carbon sequestration by 137.76 m³·hm^-2 and 55.68 t·hm^-2, respectively. In contrast, the maximum stand density under aridity levels Ⅱ to Ⅴ was significantly increased by approximately 80 to 211 trees·hm^-2, with corresponding increases in stand volume and carbon sequestration by 91.84 to 242.23 m³·hm^-2 and 37.12 to 97.91 t·hm^-2, respectively. Aridity conditions significantly affected the maximum density carrying capacity of Larix plantations. Therefore, reasonable stand density control tables should be developed based on the MAI values and growth stages to maximize stand volume and carbon sequestration benefits.

Monitoring aboveground biomass in Larix olgensis plantations using bi-temporal unmanned aerial vehicle laser scanning data

XIAO Xiang, LIU Xin, DONG Lihu, HAO Yuanshuo

2026, 37(3):  758-768.  doi:10.13287/j.1001-9332.202603.005

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This study aimed to accurately monitor plantation biomass change, support the assessment of forest carbon dynamics, and improve forest resource management. We focused on Larix olgensis plantations from three age groups at the Mengjiagang Forest Farm, Heilongjiang Province. By using dual-temporal UAV LiDAR point cloud data, we constructed canopy height models to extract canopy height statistics, canopy cover, and vertical volume occupied by the canopy for both periods. The Weibull function was used to fit the height distribution of the canopy surface, obtaining threshold, scale, and shape parameters. A comparative analysis was conducted on the accuracy and applicability of two biomass change estimation methods: the direct method (modeling biomass change directly using the difference between two periods' features) and the indirect method (predicting biomass for each period separately and calculating the difference). The results showed that the indirect method achieved high fitting accuracy for biomass [R²=0.94, relative root mean square error (rRMSE)=9.2%], and the indirectly derived biomass change also exhibited high estimation accuracy [Bias=-0.16 Mg·hm^-2, mean absolute error (MAE)=4.78 Mg·hm^-2]. The canopy volume and the Weibull threshold parameter were identified as key predictors. In contrast, the direct method showed lower fitting accuracy for biomass change (R²=0.60, rRMSE=26.2%) and correspondingly lower prediction accuracy (Bias=0.37 Mg·hm^-2, MAE=4.95 Mg·hm^-2). Predictions based on the indirect method indicated that young forest of the Mengjiagang Forest Farm had the fastest biomass growth (mean stand biomass change rate was 6.48 Mg·hm^-2·a^-1), followed by middle-aged forests (5.29 Mg·hm^-2·a^-1), while near-mature forests showed the slowest growth (3.75 Mg·hm^-2·a^-1). This study validated the effectiveness of bi-temporal UAV LiDAR data in plantation biomass monitoring and offered a technical and methodological reference for forest biomass monitoring and carbon stock assessment.

Effects of of Tamarix chinensis plantation restoration duration on soil aggregate stability and extracellular polymeric substances in an inland salt marsh

WANG Jiwei, WANG Bingjie, LI Jiayi, LI Xinwang, TANG Xiaowei

2026, 37(3):  769-778.  doi:10.13287/j.1001-9332.202603.011

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Soil water-stable aggregates and extracellular polymeric substances (EPS) strongly affect soil processes and functions, serving as important indicators of soil structure and quality. However, the changing patterns and internal correlations of both factors under artificial vegetation restoration are not well understood. In Qinwangchuan National Wetland Park of central Gansu Province, we measured soil aggregate composition and EPS content in the 0-20 cm layer across Tamarix chinensis plantations of different restoration years (3-, 7-, and 11-year-old) and an adjacent piece of secondary bare land (CK), and assessed the effects of T. chinensis plantation restoration on soil aggregate stability and EPS. The results showed that 1) planting T. chinensis generally improved soil aggregate structure and stability. Compared to the CK, the content of >0.25 mm water-stable aggregates, mean weight diameter (MWD), and geometric mean diameter (GMD) were all significantly increased in the plantation soils, showing a trend of initial increase followed by a decrease with stand age and peaking in the 7-year-old plantation. 2) Extracellular polysaccharide and protein contents increased consistently with restoration years, being 10.7 and 4.6 times higher in the 11-year plantation than in the CK, respectively. This result indicated that artificial vegetation restoration effectively promoted microbial metabolic activities. 3) MWD and GMD showed significantly positive correlations with the contents of >1 mm aggregates, 0.5-1 mm aggregates, extracellular polysaccharides, extracellular proteins, soil organic carbon (SOC), and litter biomass, but were negatively correlated with soil pH and electrical conductivity (EC). The EPS contents were significantly positively correlated with SOC, litter biomass, and cation exchange capacity, while were significantly negatively correlated with soil pH and EC. 4) Redundancy analysis showed that the contents of >1 mm aggregates, 0.5-1 mm aggregates, SOC, and EC were the core factors influencing soil aggregate stability (69.1% explanation), while EC and pH were the key environmental variables regulating EPS content (57.8% explanation). This study elucidated the evolutionary patterns and influencing factors of soil aggregate stability and EPS during the restoration of T. chinensis plantations, and thereby provided a scientific basis for restoring degraded salt marshes in arid and semi-arid China.

Differences in soil fungal and bacterial necromass carbon accumulation between subtropical Cunninghamia lanceolata and Castanopsis carlesii plantations

WU Zhenjie, TAN Siyi, WU Fuzhong, XIE Rongzhang, ZHU Jingjing, NI Xiangyin

2026, 37(3):  779-786.  doi:10.13287/j.1001-9332.202603.015

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Cunninghamia lanceolata is a major tree species for afforestation in southern China. Compared with native evergreen broadleaved tree species, C. lanceolata produces litter with low-quality carbon substrates, which may change the accumulation of microbial necromass carbon by controlling microbial community and biomass turnover, but the underlying mechanisms remain poorly understood. In this study, we evaluated the differences in microbial necromass carbon in soil organic matter (SOM), particulate (POM) and mineral-associated organic matter (MAOM) between a C. lanceolata plantation and a Castanopsis carlesii plantation. The results showed that soil microbial necromass carbon was significantly higher in C. lanceolata plantation than that in C. carlesii plantation. The average carbon content of fungal and bacterial residues in the SOM of C. lanceolata plantations was 32.8% and 28.9% higher than that in C. carlesii plantations, respectively. For POM, it was 19.7% and 31.4% higher, and for MAOM, it was 48.2% and 37.0% higher. The MAOM in the soil of C. lanceolata plantations exhibited higher microbial residue carbon accumulation efficiency and was significantly correlated with soil organic carbon, C/N ratio, and microbial biomass carbon, whereas the microbial residue carbon in the soil of C. carlesii plantations was primarily accumulated in the POM. Compared to the dominant endemic tree species C. carlesii, more microbial residue carbon in the soil of C. lanceolata plantations entered the MAOM, forming relatively stable soil organic matter to maintain soil fertility.

Spatiotemporal pattern of the endangered Hainania trichosperma population in a karst seasonal rainforest of Guangxi, Southwest China

ZHAO Zhongke, WANG Bin, LI Dongxing, LU Fang, TAO Wanglan, WANG Yanping, XIANG Wusheng, LI Xiankun

2026, 37(3):  787-796.  doi:10.13287/j.1001-9332.202603.007

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We investigated the spatiotemporal pattern of an endangered Hainania trichosperma population in a 15 hm² permanent plot in the karst seasonal rainforest of southwestern Guangxi. Using spatial point pattern analysis and zero-inflated models, we analyzed population size and spatial distribution of H. trichosperma in 2011, 2016, and 2021, aiming to elucidate its spatiotemporal patterns and key habitat characteristics. We found a decline in population size (from 1978 to 1142 individuals), with the diameter-class structure shifting from an “inverted-J” to a “bell-shaped” distribution over the past decade. Spatially, the population showed distinct topographic differentiation, primarily aggregating on the midslopes with a southwestern aspect. In all the three years, individuals of different developmental stages aggregated at the 0-50 m scale, but randomly or uniformly distributed at larger spatial scales. The intensity of aggregation at the 0-50 m scale increased significantly over the study period, mainly due to the shifts in the spatial pattern of saplings. The species distribution range was significantly influenced by slope aspect, soil water content, and soil potassium concentration. While the abundance was primarily associated with altitude, soil bulk density, soil phosphorus and total potassium. Habitat preferences differed markedly between developmental stages. Adult trees favored upperslope positions with higher soil water content, phosphorus but lower potassium, whereas saplings preferred midslope habitats rich in phosphorus, low in calcium, and with lower soil pH. Taken together, H. trichosperma population, despite being in a protected area, displayed a declining trajectory. Therefore, conservation efforts should prioritize the protection of unstable small diameter individuals and consider stage-specific habitat preferences in future population reinforcement or restoration programs to mitigate further decline.

Evaluation of conservation priority and identification of hotspots for key protected wild plants on the Loess Plateau, China

ZHANG Yinbo, HAN Yixuan, SUN Weiduo, ZHANG Xin, WANG Xiangyu, QIN Hao, ZHANG Xiaolong

2026, 37(3):  797-804.  doi:10.13287/j.1001-9332.202603.001

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The key protected wild plants are critical resources for human sustainable development, and play an irreplaceable role in maintaining biodiversity. The flora of the Loess Plateau occupies an important position in China's flora, but are facing severe challenges due to the fragile ecological environment in this region. Based on the species lists and geographical distribution database, we constructed a quantitative evaluation system for conservation priority with four evaluation indicators, including the degree of endangerment, protection level, genetic value, and distribution range. We quantitatively evaluated the conservation priority of key protected wild plants on the Loess Plateau. We further identified hotspots of key protected wild plants according to the regional species richness and species importance. The results showed that there were 93 species of key protected wild plants on the Loess Plateau, belonging to 67 genera and 39 families. According to the conservation priority values, the protected plants could be classified into 4 levels of conservation priority, among which 14 species were key protection, 29 species were priority protection, 16 species were sub-priority protection, and 34 species were general protection. The protected plants were distributed in 213 county-level administrative units, and were concentrated in some counties and districts in the southern and western parts of the Loess Plateau. Among them, Meixian County (33 species) and Zhouzhi County (21 species) in Shaanxi Province, as well as Lingbao City (21 species) in Henan Province, had the highest species richness. The species richness of the four conservation priority levels showed high spatial variations. A total of 7 hotspots and 36 sub-hotspots for key protected wild plants on the Loess Plateau were identified, which could meet the dual conservation goals of species richness and species importance.

Spatiotemporal variations of normalized difference vegetation index in the Mu Us Sandy Land and the dri-ving forces: A case study of Uxin Banner, Inner Mongolia, China

LIU Yidan, HUANG Haiguang, LI Xiaolan, LI Xuehua

2026, 37(3):  805-813.  doi:10.13287/j.1001-9332.202603.060

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The Mu Us Sandy Land is a crucial component of China's northern ecological barrier. It is of paramount importance to clarify the spatiotemporal variations of the impacts of climate change and human activities on the normalized difference vegetation index (NDVI). Based on remote sensing imagery and meteorological data from 1990 to 2023, we analyzed the variations of NDVI and its response to meteorological factors in Uxin Banner, Inner Mongolia, and quantitatively delineated the spatiotemporal patterns for the impacts of climate change and human activities on NDVI. The results showed that the NDVI in Uxin Banner showed a overall significant increasing trend [0.03·(10 a)^-1]. The vegetation showed a predominance of moderate improvement (71.6%), but areas with low vegetation cover dominated (90.5%). Pixels with slight decline accounted for 28.4%, highly overlapping with the extremely low NDVI zones (<0.1) in the northwestern central region. Annual precipitation and mean annual temperature in Uxin Banner increased with rates of 49.40 mm·(10 a)^-1 and 0.37 ℃·(10 a)^-1, respectively, both showing significant positive correlation with NDVI. Relative importance analysis showed that mean annual temperature was the dominant climatic factor affecting NDVI, followed by annual precipitation, with relative importance contribution of 74.9% and 18.4%. Both climate change and human activities drove NDVI increases in the vast majority of the region (98.9%), with their relative contribution rates exhibiting distinct spatially differentiated and complementary characteristics. Climate change contributed 60%-80% to NDVI increases in localized areas of south-central Uxin Banner, while human activities contributed 60%-80% in the northern part. This study could provide scientific evidence for the ecological restoration and sustainable management of the core area in the central Mu Us Sandy Land.

Spatial zoning of forest in Zixi County, Jiangxi Province based on carbon sink enhancement targets

YAN Yuqian, ZHANG Haotian, ZHU Meiqing, HUANG Hongsheng

2026, 37(3):  814-824.  doi:10.13287/j.1001-9332.202603.028

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Forests are the largest carbon sink in terrestrial ecosystem. Territorial spatial planning is an important carrier for the management of carbon sinks in forest vegetation. Exploring the spatial zoning of forest based on the goal of carbon sink increase is of great practical significance for achieving China's carbon neutrality goal. With Zixi County from Jiangxi Province as an example, based on the volume-biomass equation and the improved Carnegie-Ames-Stanford Approach (CASA) model, we analyzed the spatio-temporal variations of vegetation carbon storage and net primary productivity (NPP) of different forest types from 2009 to 2020. Combined with forest age and the results of the “three spatial control lines” demarcation in the national spatial planning, we conducted a multi-attribute comprehensive evaluation and spatial zoning at the township scale. The results showed that the overall land-use structure of the county remained relatively stable from 2009 to 2020, while structural changes in forestland had a significant impact on vegetation carbon storage. Broad-leaved forests were the dominant contributors to vegetation carbon storage, accounting for 78.8% and 80.4% of the total in 2009 and 2020, respectively. By 2020, vegetation carbon storage of forest in Zixi County had increased by 13.4% compared with 2009. With increasing forest age, vegetation carbon storage in most forestlands exhibited an inverted U-shaped pattern, reflecting the constraining effects of forest aging on carbon sink functions. From 2009 to 2020, forest vegetation NPP decreased by 7.3% overall, primarily due to anthropogenic disturbances and stand aging. Based on carbon sink characteristics and territorial spatial regulation constraints, we classified the 12 townships (including forest farms) in Zixi County into three functional zones: carbon sink growth zone, carbon sink conservation zone, and carbon sink renewal zone. Corresponding management strategies included prioritizing protection in growth zones, promoting rational utilization in conservation zones, and implementing orderly adjustment in renewal zones.

Synergistic improvement strategy of spring maize yield and water use efficiency under shallow buried drip irrigation in semi-arid areas

LIU Yongqi, GU Jian, YIN Guanghua, WANG Weishu, MA Ningning, LI Hang, SUN Shijun

2026, 37(3):  825-835.  doi:10.13287/j.1001-9332.202603.016

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To elucidate the mechanisms by which shallow buried drip irrigation enhances water saving and yield in semi-arid areas, and to develop an irrigation regime that synergistically improves spring maize yield and water use efficiency (WUE), we conducted a two-year completely randomized block experiment in the semi-arid area of western Liaoning from 2023 to 2024. There were three irrigation frequencies (F₁-F₃, irrigation every 7, 14, and 21 days, respectively) and four irrigation quotas (I₁-I₄, corresponding to 60%, 80%, 100%, and 120% of crop evapotranspiration (ET_c), respectively). We investigated the effects of these two factors on maize root-breeding sap flow, dry matter accumulation, net photosynthetic rate (P_n), yield, and WUE. The results showed that under the same irrigation quota, compared with F₁ and F₃, the F₂ treatment significantly increased the root-breeding sap flow and dry matter accumulation during the seedling stage by 16.3%-24.4% and 18.7%-27.4%, respectively, leading to a 4.3%-8.0% increase in WUE, and exhibited a higher P_n at 8:00 and 16:00 during the tasseling stage. Under the same irrigation frequency, compared with I₁, I₃, and I₄, the I₂ treatment increased root-breeding sap flow and dry matter accumulation across all growth stages (except during the jointing stage) by 11.6%-43.3% and 6.5%-21.5%, respectively, resulting in a 4.0%-18.0% increase in yield; it also showed a higher P_n at 8:00, 14:00, and 16:00. Considering the interactive effects of those two factors, the F₂I₂ treatment significantly promoted root-breeding sap flow and dry matter accumulation during the milky stage. Path analysis showed that root sap flow and dry matter accumulation during the milky stage, and P_n at 8:00 and 16:00 during the tasseling stage, were the key factors driving the synergistic improvement in maize yield and WUE. In summary, an irrigation frequency of once every 14 days combined with an irrigation quota of 80% ET_c is the optimal irrigation strategy for spring maize under shallow buried drip irrigation in semi-arid areas.

Effects of foliar spraying brassinolide on low-temperature tolerance in different organs of wheat during the booting stage

DONG Yongwen, ZHANG Yuman, JIANG Xue, ZHAO Can, WANG Weiling, LI Guohui, GUO Baowei, XU Ke, HUO Zhongyang

2026, 37(3):  836-842.  doi:10.13287/j.1001-9332.202603.017

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Late spring coldness constitutes a significant meteorological threat to the production of winter wheat in China. We simulated late spring coldness under controlled conditions in artificial climate chambers and examined the regulatory effects of foliar-applied 2,4-epibrassinolide (EBR) on low-temperature tolerance across different wheat organs (leaf, stem, and spike) at the booting stage by using the winter wheat cultivar Ningmai 13 as experimental material. The results showed that under low-temperature stress, EBR treatment significantly increased grains per spike, 1000-grain weight, and grain yield by 15.0%, 11.8%, and 29.1%, respectively, compared with the water-treated control. Additionally, EBR treatment enhanced whole-plant dry matter accumulation and promoted the allocation of dry matter to spikes by 27.4%. EBR markedly elevated the activities of key antioxidant enzymes. The activities of catalase and glutathione reductase in leaves increased by 23.1% and 14.1%, respectively. The activities of superoxide dismutase, peroxidase, catalase, and glutathione reductase in stems increased by 22.6%, 18.7%, 20.0%, and 30.1%, respectively. The activities of peroxidase, catalase, and ascorbate peroxidase in spikes increased by 18.7%, 20.2%, and 82.1%, respectively. These responses effectively alleviated membrane lipid peroxidation across all organs, reducing malondialdehyde content in leaves, stems, and spikes by 11.9%, 32.2%, and 27.3%, respectively. Furthermore, EBR treatment significantly increased the content of osmotic adjustment substances. In leaves and spikes, total soluble sugar, soluble protein, and free proline increased by 8.2%, 18.1%, 36.5% and 3.9%, 31.0%, 10.7%, respectively, while stems exhibited increases of 4.0% in total soluble sugar and 72.9% in soluble protein content. In summary, foliar EBR application significantly enhanced the antioxidant and osmotic adjustment capacities of leaves, stems, and spikes under low-temperature stress, systematically improved low-temperature tolerance at the booting stage, promoted dry matter accumulation and its translocation from source to sink organs, thereby effectively mitigating yield losses induced by low-temperature stress.

Characteristics of nitrogen accumulation and utilization in nitrogen-efficient rice under different ecological conditions

SONG Wenwen, ZHOU Wei, XIA Haixiao, ZHU Li, LI Guiyong, ZHU Shilin, DENG Qiqi, TAO Youfeng, HU Jianfeng, REN Wanjun

2026, 37(3):  843-854.  doi:10.13287/j.1001-9332.202603.014

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Clarifying nitrogen accumulation and utilization in nitrogen-efficient rice under different ecological conditions can provide a theoretical basis for breeding such rice varieties and optimizing fertilizer management. We conducted a two-factor split-plot field experiment under two contrasting light conditions: low-light and overcast conditions in Dayi, Sichuan, and sufficient-light conditions in Yongsheng, Yunnan. The main plot factor consisted of three nitrogen application levels: no nitrogen application (N₀), reduced nitrogen (120 kg·hm^-2, N₁₂₀), and conventional nitrogen (180 kg·hm^-2, N₁₈₀). The subplot factor included 10 rice varieties classified into three nitrogen efficiency types: low-nitrogen high-efficiency type, high-nitrogen high-efficiency type, and other type. We quantified nitrogen accumulation, allocation, translocation, and utilization characteristics by measuring plant dry matter weight and nitrogen content at the full heading and maturity stages. The results showed that nitrogen uptake, accumulation, and utilization in rice are jointly influenced by rice variety, nitrogen fertilizer level, and their interaction effect. Under the ecological conditions of Dayi, low-nitrogen high-efficiency rice performed optimally under the N₁₂₀ treatment, exhibiting the highest nitrogen content in various organs at maturity. Specifically, leaf nitrogen content was 68.8% higher than that of high-nitrogen high-efficiency rice and 6.8% higher than that of other type. Compared to other type, low-nitrogen high-efficiency rice showed increases of 27.3%-37.7% in pre-heading nitrogen accumulation in stem-sheaths and leaves, and 16.7%-44.4% in the contribution of pre-heading stem-sheath and leaf nitrogen to grains, ultimately leading to a 14.4%-18.9% increase in total nitrogen accumulation. In Yongsheng, high-nitrogen high-efficiency rice performed outstandingly under the N₁₈₀ treatment, with higher nitrogen content in various organs than other type, showing an average increase of 13.1% at the full heading stage and 8.5% at the maturity stage, respectively. At the maturity stage, nitrogen allocation to panicles increased by 5.2% compared to other type. The nitrogen translocation contribution rate of pre-heading leaves increased by 19.0%-27.5% compared to the other two rice types, ultimately raising total plant nitrogen accumulation by 13.3%-23.8%. In Dayi, the low-nitrogen high-efficiency rice, and in Yongsheng, the high-nitrogen high-efficiency rice, exhibited significantly higher nitrogen fertilizer partial productivity, nitrogen agronomic utilization efficiency, and nitrogen fertilizer recovery efficiency compared to other type. In summary, low-nitrogen high-efficiency rice combined with reduced nitrogen application (N₁₂₀) is suitable for regions with low-light and overcast conditions such as Dayi, while high-nitrogen high-efficiency rice combined with conventional nitrogen application (N₁₈₀) is applicable to regions with sufficient light and temperature like Yongsheng.

Effects of light quality on growth and photosynthesis of broccoli at different reproductive periods

WANG Xiaohan, DIAO Lixin, QIN Xiaohan, GONG Jimin, ZHANG Xiaowei, AI Xizhen, BI Huangai

2026, 37(3):  855-864.  doi:10.13287/j.1001-9332.202603.013

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To understand the light requirements of broccoli, we investigated the effects of different light qualities on the growth and photosynthesis in the ‘Naihanyouxiu' cultivar at various growth stages in an experiment. There were four light treatments, white-to-red light ratio 4:1 (WR), white-to-blue light ratio 4:1 (WB), white-purple light ratio of 4:1 (WP), and white-green light ratio of 4:1 (WG), with the white light as control (CK). Results showed that all light quality treatments reduced broccoli germination rate but did not affect the growth during the germination stage. During the seedling, rosette and heading stages, WR treatment increased plant height, leaf length, leaf width, leaf spread, relative chlorophyll content, and net photosynthetic rate (P_n), and promoted the accumulation of dry matter. Moreover, the single head weight of WR treatment increased by 15.5%, 16.2%, 66.6%, and 42.7% compared to CK, WB, WP, and WG, respectively. Plants treated with WB showed similar growth and P_n to CK, while that of WP and WG both exhibited significantly lower growth and P_n. Compared to CK, WR treatment increased total sugar, starch, and nitrogen content, followed by WB treatment though the difference was not significant, and WP and WG treatments showed no difference or a significant decrease compared to CK during the rosette stage. In summary, supplementing 20% red light to white light could enhance photosynthetic capacity, increase the accumulation of dry matter, and then promote the growth and head formation of broccoli. Supplementing blue light showed no impact, while supplementing purple and green light significantly inhibited growth. These findings could provide theoretical support for light quality regulation during different growth stages of broccoli.

Spatiotemporal variation and driving factor of ecological enviornment quality in the Markam Yunnan Snub-nosed Monkey National Nature Reserve, Tibet, China

REN Yuhang, ZHANG Tong, LIAO Ziyan, PAN Junjie, LIU Huangcheng, LI Jinjie, PAN Kaiwen, ZHANG Lin, WU Xiaogang

2026, 37(3):  865-875.  doi:10.13287/j.1001-9332.202602.029

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Rhinopithecus bieti is a rare and endangered species unique to China, and habitat ecological environment quality would affect its population persistence. Taking the Markam Yunnan Snub-nosed Monkey National Nature Reserve in Tibet as the study area, we calculated a remote sensing ecological index (RSEI) based on Landsat imagery from 2000 to 2024. We further analyzed the spatiotemporal variations and driving factors of ecological environmental quality using trend analysis methods, including the Theil-Sen median estimator, in combination with XGBoost and SHAP models. From 2000 to 2024, the RSEI of the study area exhibited an overall fluctuating upward trend and peaked in 2024. Spatially, it showed a distribution pattern characterized by stable core areas and degraded marginal areas. Areas with significant RSEI improvement were mainly distributed in the central-eastern part of the reserve and some high-altitude regions in the west area, while markedly degraded areas were concentrated along the western marginal zone. About 42% of the reserve area was predicted to face potential ecological degradation risks in the future. Land use was the dominant factor influencing RSEI variation, and its interaction effects with elevation, mean annual temperature, and snow cover ratio on RSEI were significant. The impacts of all driving factors on RSEI exhibited pronounced nonlinear characteristics. This study would provide a scientific basis for assessing the ecological environmental quality of habitats of rare and endangered species and offer important references for ecological monitoring and sustainable development of protected areas located in high-altitude regions.

Spatiotemporal variations and driving factors of ecological environmental quality in Shanxi Province based on the PLS-SEM model

BI Xu, LI Jian, SHI Kailong, FU Yongyong, ZHANG Yushuo, SHI Lailiang, BAN Fengmei

2026, 37(3):  876-888.  doi:10.13287/j.1001-9332.202603.023

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Shanxi Province is located in the eastern part of the Loess Plateau in China, characterized by natural geographic spatial heterogeneity and fragile ecological environments. Understanding the spatiotemporal distribution variations of ecological environment quality and their driving factors is crucial for promoting ecological conservation and coordinated socio-economic development in Shanxi. We constructed a remote sensing ecological index (RSEI) on the Google Earth Engine platform and analyzed the spatiotemporal variations in ecological environment quality in Shanxi from 2000 to 2020. Methods such as Theil-Sen median trend analysis, Mann-Kendall test, and Hurst index were employed to assess the trends and sustainability of RSEI changes. Additionally, geographic detectors, partial least squares structural equation modeling (PLS-SEM), and mediation analysis were introduced to explore interactions among factors and their direct and indirect effects on RSEI. The results showed that the mean RSEI fluctuated between 0.44 and 0.68 from 2000 to 2020, showing an overall upward trend with spatial distribution patterns of mountainous areas outperforming basins and southeastern regions outperforming northwestern ones. The ecological environment quality exhibited a significant improvement trend, with 81.6% of the area showing enhancement. The Hurst index suggested uncertainties and potential reversal risks in future trends. Geographic detector analysis revealed that elevation, potential evapotranspiration, and land use intensity were the primary factors driving spatial differentiation in RSEI, with the explanatory power of multi-factor interactions significantly exceeding that of single-factor. PLS-SEM and mediation analysis demonstrated that potential evapotranspiration weakened the positive effect of precipitation on RSEI by intensifying climatic stress, while the nighttime light index amplified the negative combined effects of urbanization and resource exploitation on RSEI. Our results deepened the understanding of ecological environment quality evolution mechanisms and could provide methodological support and policy insights for ecological governance and sustainable transformation in resource-dependent regions.

Auto detection on morphological characteristics of termite legs based on deep learning

SHI Wenwen, LIU Shijian, ZOU Zheng, WANG Dingyi

2026, 37(3):  889-896.  doi:10.13287/j.1001-9332.202603.033

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The legs of termites follow the standard segmentation pattern of insect appendages. Focusing on the lengths of the femur, tibia, tarsus, and related derived characteristics, we developed a deep learning-based automatic detection and analysis software for termite leg morphology, with a key point detection model for leg segments as the core component to calculate quantitative indicators such as lengths. The results showed that the software could accurately measure the femur, tibia, and tarsus of termite legs, with a mean absolute error of 0.07 mm, a mean relative error of 18.7%, and a root mean square error of 0.09 mm, and could address issues such as occlusion. The positive correlation between hindleg length and body length (Pearson correlation coefficient was 0.413) was higher than that between foreleg length-body length and midleg length-body length, which was consistent with the ecological function of hindlegs. By statistically analyzing the proportional relationships of segment lengths among the foreleg, midleg, and hindleg, we verified the rationality of conventionally using hind tibia length as an indicator for termite leg measurements in morphological studies. This research filled the application gap of deep learning in the field of automatic and accurate measurement of termite leg morphology. Our findings could be extended to studies on other insects with appendage structures.

Effect of yak and Tibetan sheep dung decomposition on the nutrient of soil-plant system in the Qinghai Lake Region

LI Mengqi, DONG Quanmin, LIU Yuzhen, LYU Weidong, SUN Caicai, XU Wei, LIU Wenting, JI Haiming, YANG Xiaoxia

2026, 37(3):  897-906.  doi:10.13287/j.1001-9332.202603.018

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The decomposition of yak dung (YD) and Tibetan sheep dung (SD) affects nutrient cycling in alpine grasslands, but the mechanisms underlying the differences in their impacts on plant-soil nutrient cycling remain unclear. In this study, a 270 day decomposition experiment using fresh YD and SD was conducted in an alpine grassland near the Qinghai Lake. By measuring nutrient contents in dung, soil, and plants at different decomposition stages, we analyzed the effects of the two dung types on nutrient transfer along the soil-plant continuum. The results showed that: 1) The decomposition rate of YD was significantly higher than that of SD. Total carbon (TC), total nitrogen (TN), and total phosphorus (TP) in YD decreased linearly over time (TC declined from 333.39 g·kg^-1 to 211.24 g·kg^-1), with TN consistently higher in YD than in SD. After 90 days of decomposition, nitrate (NO₃^--N) and available phosphorus (AP) contents were significantly higher in YD than in SD. 2) Changes in soil TN and TP were mainly influenced by dung type, accounting for 57.1% and 71.5% of the variance, respectively. Soil NO₃^--N and AP under YD treatment remained significantly higher than those under SD throughout the 90 day decomposition period. 3) Plant nutrient uptake showed functional group specificity. Plant functional group was the key factor driving variation in plant TN, explaining 40.2% of the variance. The TN of grasses responded more rapidly under YD treatment than under SD treatment. 4) Structural equation modeling revealed that dung affected plant nutrient uptake mainly through the indirect pathway “dung total nutrients → soil available nutrients”, with soil available nutrients acting as the critical mediator. In summary, yak dung decomposed faster, favoring early release of available nutrients and grass nitrogen utilization, whereas Tibetan sheep dung decomposed more slowly, leading to a more prolonged nutrient release process. This study clarified key processes through which different livestock dung types drive soil-plant nutrient cycling and could provide a scientific basis for optimizing grazing management in alpine grasslands.

Spatial variations of carbon stock in tidal flat sediments of Zhoushan Archipelago

WANG Haoran, LIU Mingzhi, JIANG Rijin, XIAO Zeyu, SHEN Jiarong, ZHAO Peng, YIN Rui, LI Pengfei, SONG Jianhui

2026, 37(3):  907-916.  doi:10.13287/j.1001-9332.202603.031

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Tidal flats, a type of blue carbon ecosystems, play a crucial role in enhancing carbon storage capacity of natural ecosystems and addressing climate change. The organic carbon stored in tidal flat sediments is a key component of their carbon sequestration function but is dependent on habitat factors such as topographic features and depositional environments. To investigate the spatial variations of carbon storage in tidal flat sediments and their primary regulating factors at the regional scale, we selected six typical islands in the Zhoushan Archipelago as research areas, systematically analyzed the spatial distribution characteristics of sedimentary organic carbon storage and quantified the impact of sediment physicochemical factors on carbon storage capacity using the Absolute Principal Component Score-Multiple Linear Regression (APCS-MLR) model. The results showed that there was significant spatial heterogeneity in sedimentary carbon storage among sampling sites, with the highest carbon storage value being recorded on Daishan Island (68.96 Mg C·hm^-2) and the lowest on Liuheng Island (50.96 Mg C·hm^-2). Most sampling sites showed no significant differences in organic carbon storage between the surface layer (0-30 cm), intermediate layer (30-60 cm), and bottom layer (>60 cm). The APCS-MLR model identified three principal components, with particle size structure, sedimentary state, and salinity-alkalinity characteristics contributing 37.0%, 29.0%, and 20.0% to the carbon storage capacity of tidal flat sediments in the Zhoushan Archipelago, respectively. Particle size structure and sedimentary depth exhibited significant correlations with carbon storage, while there was no relationship between sedimentary state and salinity-alkalinity characteristics and carbon storage. This study would enhance understanding of carbon storage mechanisms in tidal flat sediments and provide scientific support and decision-making for regional blue carbon estimation and coastal carbon sink management.

Impacts of climate change on the potential suitable habitats of Pontederia crassipes in the middle and lower reaches of the Yangtze River, China

XIE Hanqi, ZHANG Qingji, MA Xiaoxue, TIAN Linlin

2026, 37(3):  917-925.  doi:10.13287/j.1001-9332.202603.035

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Pontederia crassipes is one of the most invasive aquatic plants, which threatens the ecological stability of the middle and lower reaches of the Yangtze River. To assess the potential spread trends of water hyacinth under climate change, we employed the MaxEnt model and ArcGIS spatial analysis techniques to analyze the dominant environmental factors influencing the spread of P. crassipes in the middle and lower reaches of the Yangtze River. We evaluated the potential suitable habitat during 1970-2000 and under different climate scenarios (SSP245 and SSP585) during 2041-2100. The results showed high predictive accuracy of the model, with the mean AUC of the training dataset reaching 0.954. The key environmental factors determining the distribution of P. crassipes were isothermality, elevation, and temperature seasonality, with a cumulative contribution of 82.9%. Dissolved oxygen affected the distribution of P. crassipes. During 1970-2000, the total potential suitable habitat area was 5.77×10⁴ km², primarily concentrated in the Jianghan Plain area, Poyang Lake, the Jiangsu-Anhui Yangtze River Plain, and the Yangtze River Delta, regions with dense river networks. During 2041-2100, the potential suitable habitat was projected to initially expand and then contract, centered mainly around Taihu Lake, Poyang Lake, and Dongting Lake, with new highly suitable areas emerging in the northwestern part of the study region. Under the different climate scenarios (SSP245 and SSP585) during 2041-2100, the total area of potential suitable habitat for P. crassipes reached its maximum, at 8.11×10⁴ and 6.81×10⁴ km², respectively. The area of suitable habitats wowld decrease after 2060, and experience substantial shrinkage by 2081-2100. In the long term, the SSP245 scenario would suppress the spread of P. crassipes.

Impact of climate change on the potentially suitable habitat distribution of Pygoscelis penguins in Antarctica

WANG Jinrui, HU Ailian, YANG Juan

2026, 37(3):  926-932.  doi:10.13287/j.1001-9332.202603.037

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Penguins play a crucial role in maintaining the energy flow of the Antarctic ecosystem and serve as important indicator species for ecosystem health. In this study, we collected the distribution records for Pygoscelis penguins from the Ocean Biogeographic Information System (OBIS). Using the MaxEnt model and marine environmental datasets during 2010-2020 and 2090-2100 under SSP5-8.5 climate conditions, we simulated the potentially suitable habitat distributions and changes for Pygoscelis adeliae, P. antarctica, and P. papua during those two periods. The results showed that sea surface temperature and ice coverage were key environmental variables influencing the distribution of penguins. In the first period, the potentially suitable habitats of the Pygoscelis species exhibited distinct spatial segregation. The potentially suitable habitats for P. adeliae were sporadically distributed along the coasts and adjacent waters of the Antarctic continent between 60° S and 75° S. The potentially suitable habitats for P. papua were concentrated along the coast where the Antarctic continent extends into the ocean and on offshore islands distant from the mainland. The potentially suitable habitats for P. antarctica were similar to those of P. papua, primarily concentrated along distant coasts and islands. Under the future SSP5-8.5 climate scenario, the habitats for all three species were projected to shrink. The area of potentially suitable habitat for P. adeliae was projected to a decrease of 10.2×10⁶ km², for P. papua of 0.47×10⁶ km², and for P. antarctica of 1.66×10⁶ km².

Reviews

Research progress on soil organic carbon sequestration processes driven by plant-microbe interactions in agroforestry systems

WANG Minghao, DANG Long, WANG Xiuyuan, TANG Lei, HUANGFU Leiming, YAN Zhaogui, HE Wei, WANG Pengcheng

2026, 37(3):  933-944.  doi:10.13287/j.1001-9332.202603.012

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Addressing global climate change and achieving China's “Dual Carbon” strategic goals require enhancing the soil carbon sink function of terrestrial ecosystems. Agroforestry, as a sustainable land management practice, promotes soil organic carbon (SOC) sequestration and soil carbon storage potential by strengthening plant-microbe interactions. However, the specific mechanisms through which plant-microbe interactions regulate the input, transformation, and stabilization of SOC remain poorly understood. Focusing on the “input-transformation-protection” pathway of soil carbon, we systematically elucidated recent advances in understanding how plant-microbe interactions regulate SOC in agroforestry systems. At the input stage, diverse plant species combinations in agroforestry systems optimize the supply of plant-derived carbon. At the transformation stage, rhizosphere microenvironment drives the changes in microbial community structure, metabolic function, and ecological strategy, and thereby enhancies carbon transformation and stabilization efficiency via the microbial carbon pump (MCP). At the protection stage, roots and fungi synergistically promote the formation of soil aggregate structures that protect newly formed carbon. Microbes play a vital role in mediating plant-soil carbon sequestration. Future efforts should strengthen long-term monitoring on deep soil carbon dynamics, deepen the understanding of complex feedback mechanisms among plants, microbes, and soil, and integrate ecological models with multi-omics technologies, which together would provide a theoretical foundation for optimizing carbon management strategies in agroforestry systems under global climate change.

Changes of oceanic dissolved inorganic carbon and the regulation of ocean carbon sink

LEI Demin, SONG Jinming, ZHONG Guorong, LI Xuegang, LIU Shanshan, YUAN Huamao

2026, 37(3):  945-954.  doi:10.13287/j.1001-9332.202603.036

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Dissolved inorganic carbon (DIC) constitutes a major component of carbon reservoir in ocean and plays a pivotal role in regulating global carbon cycle. However, the distribution of DIC in global ocean exhibits pronounced spatial and temporal variations. Vertically, the concentration of DIC increases gradually from the surface to the depth; horizontally, surface DIC exhibits a pattern characterized by lower concentrations in low-latitude regions and higher concentrations in high-latitude oceans, with upwelling regions presenting elevated concentrations. Temporally, DIC exhibits significant seasonal, interannual, and decadal variations. Since the Industrial Revolution, the global concentration of DIC has risen at a rate of 1.5±0.3 μmol·kg^-1·a^-1, resulting in a net annual increase of 2.9±0.4 Pg C, which has altered the marine carbonate system and biological communities. Currently, due to the reliance on direct ocean surveys for DIC data, there is limited temporal and spatial coverage. DIC gridded datasets based on field observations and machine-learning algorithms can be used for studying the global-scale temporal and spatial variations of DIC and ocean carbon sinks. Under the background of global change, regional DIC trends are increasingly complex and require further investigations. We propose to enhance the ocean carbon sink by regulating DIC, which would hold significant scientific importance and potential applications.

Impacts of artificial light at night on birds: A review of behavioral, physiological, and population-level effects

KANG Yuan, LUAN Haolian, WANG Lirui, YIN Peng

2026, 37(3):  955-964.  doi:10.13287/j.1001-9332.202603.034

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Artificial light at night (ALAN), as a novel and increasingly widespread ecological stressor with global reach, is substantially altering nocturnal environments and posing multiple threats to the survival and fitness of wild birds. We summarized and proposed a three-level cascade effect framework of ALAN on the “behavior physiology population” of birds by systematically searching and screening 80 articles from the core databases of China National Knowledge Infrastructure (CNKI) and Web of Science (WoS) from 2004 to 2024 with bibliometric methods. We systematically analyzed the research hotspots and development trends in this field, and summarized the pathways and linkage mechanisms of ALAN on birds. We further analyzed the significant imbalanced characteristics of current research in geographical distribution and species identities. In the context of ecological civilization construction in China, we proposed four research- and management-oriented recommendations: 1) strengthening studies on the sensitivity of endemic bird species in China to ALAN; 2) conducting ecological risk assessments based on large-scale in situ field monitoring; 3) developing ecologically friendly (“avian-friendly”) lighting technologies adapted to native birds and local biodiversity; and 4) incorporating the prevention and control of ALAN pollution into protected-area management frameworks. This framework would provide a basis for clarifying the ecological effects of ALAN and formulating targeted conservation strategies, thereby promoting the coordination of urban development and biodiversity conservation.

Application of sniffer dog detection in the prevention and control of biological invasions: Principles, practices, and prospects

LI Suxiong, ZHENG Jilong, YANG Yuxiang, WANG Ruohan

2026, 37(3):  965-974.  doi:10.13287/j.1001-9332.202603.038

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Biological invasions, as a long-term and latent biological threat, pose significant hazards. There is global consensus on the importance of early detection and targeted control measures for invasive species. Traditional detection methods have certain limitations and often fail to meet the requirement of rapid and accurate identification. As an emerging detection technique, sniffer dog technology can, to some extent, overcome these shortcomings and provide crucial support for early detection and rapid response to biological invasions. It also offers valuable leads and evidence for the judicial prevention and control of crimes related to invasive species. We explored the principles of using sniffer dogs to detect invasive animals, plants, and microorganisms, systematically elaborated on the practical applications and advantages of this technology in terms of universality, sensitivity, accuracy, cost, and efficiency, and highlighted the main challenges. Furthermore, we proposed recommendations such as strengthening risk assessment for invasive species, establishing odor sample databases, improving training techniques for detection dogs, and developing standardized protocols, with the aim of providing a reference for the wider adoption and application of this technology in China