Table of Content

10 September 2025, Volume 44 Issue 9

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Effects of spatial dimensions on species abundance patterns of natural forests in different successional stages in the Khingan Mountains.

SU Wenhao, WANG Xiaonan, DONG Lingbo

2025, 44(9):  2817-2825.  doi:10.13292/j.1000-4890.202509.020

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Based on the data from 100 m×100 m fixed plots in Cuigang Forest Farm of Xinlin Forestry Bureau, we investigated the impacts of horizontal and vertical dimensions on community assembly processes and species abundance at different successional stages in the Greater Khingan Mountains. These plots were established in communities at three different successional stages, including Betula platyphylla forest, Larix gmelinii-Betula platyphylla mixed forest, and Larix gmelinii forest. Different species abundance models were used to fit species abundance distributions of large tree layer, sapling layer, and regeneration layer at each successional stage and under different sampling scales (ranging from 100 to 10000 m²). The χ² test was employed to determine the optimal model, and then the community assembly mechanisms of each community under different spatial dimensions were quantified. The results showed that: (1) The optimal species abundance models varied under different spatial and temporal dimensions. The Niche Preemption Model and the Zipf-Mandelbrot Model exhibited the best fitting effects. (2) The neutral processes in the local communities were relatively strong. As the sampling scale increased, the neutral processes weakened while the ecological processes strengthened. The species abundance patterns of the large tree layer in the Betula platyphylla forest and the mixed forest were less affected by the sampling scale. As the forest layer became smaller, the influence of the sampling scale on it gradually increased. The species abundance pattern of the large tree layer in the Larix gmelinii forest was greatly affected by the scale, while the species abundance pattern of the regeneration layer was less affected by the scale. (3) The larger the forest layer in the community, the stronger the ecological processes of community assembly and the weaker the neutral processes.





Effects of nitrogen and phosphorus addition on carbon, nitrogen, and phosphorus stoichiometry of leaf-litter-soil in different stand types of Machilus pauhoi.

ZHOU Yunruo, ZHONG Quanlin, ZOU Yuxing, ZHANG Xue, CHENG Dongliang, XU Chaobin, LIU Yao1, ZHENG Xinjie

2025, 44(9):  2826-2836.  doi:10.13292/j.1000-4890.202509.029

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Clarifying the ecological stoichiometry of “leaf-litter-soil” continuum of Machulus pauhoi under the influence of nitrogen (N) and phosphorus (P) addition can provide scientific basis for revealing the nutrient limitations and adaptation strategies of M. pauhoi plantations. A four-year experiment was conducted with control (CT), N addition (+N), P addition (+P), and co-addition of N and P (+NP) to investigate the effects of N and P addition on C, N, and P concentrations and their stoichiometric characteristics of leaf, leaf litter, and soil of M. pauhoi in a pure plantation of M. pauhoi and a mixed plantation of M. pauhoi and Cunninghamia lanceolata. The results showed that: (1) +N significantly affected leaf litter P concentration and C∶P in pure stand, and soil P concentration and its C∶P of mixed stand. +P significantly affected leaf litter N and P concentration of pure stand, and leaf N concentration and C∶N of mixed stand. +NP significantly affected leaf litter N and P concentration, C∶N, and C∶P of pure stand, as well as leaf litter C and N concentration and soil P concentration and its N∶P and C∶P of mixed stand (P<0.05). (2) Compared with the pure stand, +N significantly affected leaf N concentration and C∶N of M. pauhoi, and soil N concentration, C∶N, and N∶P. +P significantly affected leaf litter P concentration and its C∶P, and soil N concentration and C∶N. +NP significantly affected leaf N concentration, leaf litter N concentration, C∶N and N∶P, and soil N concentration, C∶N, and N∶P in the mixed stand (P<0.05). (3) +P and +NP increased N resorption efficiency in pure stand and decreased that in mixed stand, while +N improved P resorption efficiency in pure stand. This result indicated that mixed stand may be more effective in N use, while the N-limitation in pure stand was stronger than that of mixed stand. Young forest of M. pauhoi was jointly limited by N and P in the study area. (4) The relationships between leaf-litter-soil nutrients and stoichiometric ratios were significantly affected by stand type. Specifically, the correlation between fresh leaf and leaf litter was stronger in pure stand, but the correlation between leaf litter and soil was relatively weak in mixed forest. Collectively, this study revealed the effects of N and P addition on the ecological stoichiometry characteristics of the “leaf-litter-soil” continuum in different stand types of M. pauhoi, providing an important theoretical basis for the efficient management of M. pauhoi plantations, as well as the nutrient management.





Spatial patterns and driving mechanisms of net primary productivity and precipitation use efficiency in global evergreen broadleaved forests.

LI Xiaozhen, HU Ying, WEI Yu, LIAO Jiapei, FU Ruiyu, XU Sheng, ZAHNG Zijia, HU Zhongmin, YANG Yue

2025, 44(9):  2837-2845.  doi:10.13292/j.1000-4890.202509.026

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Evergreen broadleaved forests (EBFs) play a crucial role in maintaining biodiversity and ecosystem functions, which are highly sensitive to climate change and human activities. However, global spatial distributions and the underlying mechanisms of net primary productivity (NPP) and precipitation use efficiency (PUE) in EBFs remain poorly understood. Here, we integrated measured NPP data from 272 EBFs sites worldwide with a random forest model to predict global NPP and PUE patterns and to evaluate climatic and edaphic drivers. The results showed that the predicted global NPP values ranged from 909.08 to 3213.11 g C·m^-2·a^-1, while PUE varied from 0.22 to 5.79 g C m^-2·mm^-1. NPP and PUE exhibited similar global distribution patterns, both increasing at forests below an elevation of 400 m and then declining above this threshold. Temperature and precipitation were the principal determinants of NPP and PUE variations, whereas soil physical properties played a relatively minor role. We identified the threshold effects in these relationships, including a shift in the NPPprecipitation relationship at 1200 mm, with precipitation exerting a stronger influence on NPP at temperatures below 19 ℃. PUE displayed threshold responses to temperature and precipitation, with higher values being observed at precipitations below 2500 mm or temperatures below 24 ℃. The combined effects of precipitation and temperature on both NPP and PUE depend on their interactive influence rather than the isolated effects. These findings provide critical parameters for carbon-water cycle models in EBFs and enhance the predictive capabilities under future climate change scenarios.





Effects of soil nutrients on nutrient resorption of four plant species used for soil and water conservation.

WANG Hongshuang, PAN Li, GU Huiyan, WANG Xiuwei

2025, 44(9):  2846-2854.  doi:10.13292/j.1000-4890.202509.038

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Nutrient resorption is an important nutrient conservation strategy for plants to reduce their dependence on environmental nutrients. We examined the responses of nutrient resorption of four common plant species used for soil and water conservation to soil nutrient changes, namely, Populus × xiaohei, Larix gmelinii, Bromus inermis and Amorpha fruticosa. Soil degradation levels of natural conditions were simulated by soil stripping. The results showed that there were significant differences in N and P contents of fresh and senesced leaves under different soil degradation levels. The differences in the N and P resorption efficiency were not significant but the differences in the resorption proficiency (i.e., the N and P contents of senesced leaves) were significant across different soil degradation levels. N and P resorption were significantly correlated with foliar N and P contents. The nutrient contents in leaves and soil nutrient factors were important factors affecting the nutrient resorption, explaining 61%-96% of the variation in N and P resorption efficiency and resorption proficiency. Nutrient resorption proficiency was more sensitive to soil nutrients than resorption efficiency. Leaf nutrient content was the main factor regulating nutrient resorption. There were differences in the resorption capacity of different species. Bromus inermis had the highest resorption proficiency, with a strong nutrient conservation capacity to minimize its dependence on soil nutrients. By contrast, Populus × xiaohei had lower resorption proficiency but higher quality of senesced leaves, which allowed more nutrients to be returned through the senesced leaves.





Effects of elevated CO₂ concentration on the accumulation and translocation of non-structural carbohydrates in seedlings of different Chinese fir families.

GUO Zhijuan, ZOU Xianhua, WU Xi, LI Yanmin, QIN Yi, YANG Mengjia, PENG Zhiyuan, ZHU Liqin, HUANG Rongzhen

2025, 44(9):  2855-2863.  doi:10.13292/j.1000-4890.202509.027

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To provide theoretical support for the selection and promotion of Chinese fir (Cunninghamia lanceolata) families adapted to changing climate, we investigated how elevated atmospheric CO₂ concentration influenced photosynthetic carbon allocation in one-year-old seedlings of two Chinese fir families (NO.020 and NO.061). Using a ¹³C isotope pulse-labeling approach, we established three CO₂ concentration treatments, i.e. ambient (400±50 μmol·mol^-1), elevated (800±50 μmol·mol^-1), and super-elevated (1000±50 μmol·mol^-1), to trace the fixation and distribution of carbon across different plant tissues. We analyzed the differences of total carbon uptake, non-structural carbohydrate (NSC) dynamics (including soluble sugars and starch), and biomass allocation across treatments and families. Results showed that both families increased total ¹³C accumulation and NSC content with rising CO₂ levels, with the highest values being observed under the 1000 μmol·mol^-1 treatment (C1000). Family NO.020 exhibited rapid ¹³C assimilation within the first 5 days after labeling, particularly under C800 and C1000, followed by a decline over time, suggesting an initial burst of metabolic activity. In contrast, NO.061 displayed a more gradual but sustained increase in ¹³C accumulation, indicating a conservative carbon-use strategy. After 30 days, the aboveground soluble sugar content in NO.020 under C800 and C1000 decreased by 40% and 26.1%, respectively, whereas the aboveground starch content increased by 32.8% and 85.3% compared to ambient CO₂ (C400). In NO.020, root NSC levels consistently followed the order C1000>C800>C400. Under C1000, soluble sugar content in the aboveground tissues of NO.061 increased by 54.5% at 15 days post-treatment (P<0.05), while the starch content increased 10% compared to C400 at 30 days. Elevated CO₂ stimulated growth, as it increased biomass and plant height in both families. However, the two families had distinct adaptive strategies to elevated CO₂. NO.020 demonstrated a faster rate of carbon uptake and metabolism, accompanied by a greater translocation of carbon from aboveground tissues to roots, which promoted root development. In contrast, NO.061 maintained higher NSC reserves in aboveground parts and prioritized shoot growth, likely optimizing resource capture under enhanced carbon availability. These findings reveal distinct carbon allocation strategies among Chinese fir families, highlighting the significance of family-specific responses in adapting to elevated CO₂ and supporting climate-resilient reforestation.





Effects of phosphorus addition on growth and non-structural carbohydrate content of Pinus massoniana seedlings.

ZENG Tingting, ZHANG Shaochun, HE Zhihang, WU Miaolan, WANG Yiying, MO Qifeng

2025, 44(9):  2864-2872.  doi:10.13292/j.1000-4890.202509.019

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The acceleration of nitrogen (N) deposition may aggravate phosphorus (P) limitation of subtropical tree species. We explored the response of 1-year-old Pinus massoniana seedlings to different P addition levels \[(without P fertilization, CK), low P (50 kg P·hm^-2·a^-1, LP) and high P (100 kg P·hm^-2·a^-1, HP)\]. The effects of different P addition levels on growth, biomass accumulation, non-structural carbohydrate (NSC), and root morphological indexes of P. massoniana seedlings were analyzed. The results showed that: (1) P addition promoted biomass accumulation in various organs of P. massoniana seedlings. HP treatment led to significant increases of 531%, 210%, 355%, 187%, and 321% in leaf, stem, coarse root, fine root biomass, and total biomass, respectively. Moreover, the proportion of leaf biomass increased in response to changes in soil P concentrations. (2) P addition significantly increased the NSC content in various organs of P. massoniana seedlings, and the NSC proportion in leaves gradually increased while that in stems gradually decreased with increasing in P addition. Root proportion showed a trend of first decreasing then increasing with increasing in P addition, but was lower than that in CK. (3) P addition significantly increased length, surface area, and volume of both coarse and fine roots, while root diameter was insensitive to P addition. Under conditions of P addition, fine roots adopted a resource utilization strategy. Our results indicated that P. massoniana seedlings responded to exogenous P addition by increasing the biomass and NSC content of each organ and increasing the proportion of leaves in biomass and NSC content. There was a trade-off between aboveground and underground parts in NSC distribution. P addition promoted the growth of seedling roots, while the coarse roots had certain internal stability in response to external changes. Therefore, P addition stimulated the growth of P. massoniana seedlings.





Structural diversity dynamics of oak secondary forest in Xiaolong Mountains.

ZHANG Ganggang, ZHANG Qing, LIU Qiao, JIANG Yuxin, LIU Wenzhen, LV Xun

2025, 44(9):  2873-2879.  doi:10.13292/j.1000-4890.202509.021

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Quantitatively describing forest structural diversity is the foundation and key to the dynamic regulation of forest structure and the precise improvement of forest quality. Quercus aliena var. acuteserrata secondary forest was surveyed in four periods (2008, 2013, 2018 and 2023). The bivariate distributions of diameter at breast height (DBH) class and spatial structure parameter were used to quantify structure dynamics. The differences of size differentiation and spatial structure among these periods were quantified. The results showed that DBH class distributions of trees were well mixed, and that spatial distribution patterns or dominance degrees were significantly different at different periods (P<0.05). Tree size was positively correlated with dominance status across different periods. The diversity of tree size structure was relatively poor and exhibited slight temporal fluctuations. The forest spatial heterogeneity generally showed a slight inverted U-shaped trend, but the spatial diversity tended to be favorable. Therefore, tree size differentiation in Q. aliena var. acuteserrata secondary forest was pronounced under different spatial structures. Both tree size and spatial structure diversity exhibited a certain degree of volatility. It is suggested that management techniques and measures targeting the distribution pattern and competitive micro-environment should be prioritized to provide references for dynamic optimization of forest structure and precise improvement of forest quality.





Plant diversity and community stability in different habitats in the upper reaches of Tarim River, Xinjiang.

ZENG Yong, Maireziya Wumaierjiang, Abuduhelili Imin, Aikebaier Nulimaimaiti, LIANG Yuejia, LIU Yaxuan

2025, 44(9):  2880-2886.  doi:10.13292/j.1000-4890.202509.025

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The upper reaches of the Tarim River are a typical arid and fragile ecosystem. Plant diversity and community stability play an important role in ecosystem balance and sustainable development. We explored species diversity and community stability in different habitats (riverbank, transition zone, and desert margin) in the upper reaches of the Tarim River Basin, as well as the influencing factors. The results showed that Phragmites australis, Populus euphratica, and Halogeton arachnoideus were the dominant species in the habitats of riverbank, transition zone, and desert margin, respectively. Along the riverbank-transition zone-desert margin, species diversity increased first and then decreased. The community stability in different habitats was manifested as follows: desert margin > transition zone > riverbank. The results of PCA showed that species diversity was positively correlated with soil organic matter and was negatively correlated with groundwater depth, soil pH, and total salt content. Structural equation modeling revealed that total salt content and species diversity were negatively correlated with community stability. These results provide a theoretical basis for further research on ecosystem stability and sustainability in the upper reaches of the Tarim River.





Resilience response of radial growth of Betula platyphylla, Picea asperata, and Larix principis-rupprechtii to extreme drought events.

HAN Jiaxuan, SUN Haokang, ZHANG Zihang, JIA Jianheng, GUO Mingming

2025, 44(9):  2887-2894.  doi:10.13292/j.1000-4890.202509.023

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s temperature continues to rise in northern China, extreme drought events are occurring more frequently and with greater intensity. We examined the response of radial growth of different tree species to extreme drought events in the natural forests of Betula platyphylla, . and Larix principis-ruprechtii. in Mulan Weichang National Forest Farm, Chengde, Hebei. Based on tree ring sampling and measurement, we analyzed their resistance, recovery, and resilience to extreme drought events. The results showed that: (1) The radial growth of B. platyphylla was significantly positively correlated with the average and minimum temperature in February of the current year. The radial growth of P. asperata was significantly positively correlated with the precipitation from April to June and the standardized precipitation evapotranspiration index in May. There was a significant positive correlation between the radial growth of L. principis rupprechtii and the precipitation in June of the current year. (2) The resistance and resilience of B. platyphylla to extreme drought events were significantly greater than that of L. principis-rupprechtii and P. asperata. The recovery of P. asperata was significantly greater than that of B. platyphylla and L. principis-rupprechtii, while there was no significant difference between the latter two. In summary, P. asperata was more susceptible to extreme drought, followed by L. principis-rupprechtii and B. platyphylla. This study can provide theoretical reference for predicting the ecological adaptability and development trends of B. platyphylla, P. asperata, and L. principis rupprechtii in Mulan Weichang National Forest Farm under future climate change.





Physiological response and salt tolerance evaluation of Quercus virginiana under salt stress.

YANG Ning, LIAN Huiwen, WANG Yangdong, CHEN Yicun, SHI Xiang

2025, 44(9):  2895-2906.  doi:10.13292/j.1000-4890.202509.012

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To identify superior salt-tolerant families of Quercus virginiana, we evaluated the physiological and biochemical characteristics of various families under salt stress by examining the response mechanisms of nonstructural carbohydrate (NSC) content and the stoichiometry of carbon, nitrogen, and phosphorus. The experiment involved three treatments, with 0.4% and 0.8% of soil dry mass as low and moderate salt stress treatments and deionized water as a control. Growth characteristics, antioxidant enzyme activity, osmotic adjustment substance content, chlorophyll fluorescence parameters, as well as the carbon (C), nitrogen (N), and phosphorus (P) content and their stoichiometric ratios of different families were measured. The results showed that salt stress significantly reduced the growth across the four families. The levels of membrane lipid peroxide malondialdehyde, proline content, and antioxidant enzyme activity significantly increased, while soluble protein content markedly decreased. Under salt stress, the actual photosynthetic efficiency of leaves (Y(II)), apparent electron transfer rate (ETR), and photochemical quenching coefficient (q_P) were reduced, whereas the non-photochemical quenching coefficient (q_N) significantly increased. Soluble sugar and NSC content increased, while starch content decreased. The C, N, and P contents of each family exhibited varying degrees of decrease. N∶P ratios ranged from 14 to 16, suggesting that the plants were co-limited by N and P. There were significant or extremely significant correlations among the various indicators. Furthermore, gray correlation analysis identified malondialdehyde, leaf length growth, non-structural carbohydrate, actual photosynthetic efficiency, and N/P ratio as key indicators for assessing salt tolerance. Principal component analysis and a comprehensive evaluation of membership functions both indicated that the salt tolerance order of the four families was as follows: WL1 > WL5 > WL2 > WL3. Notably, the WL1 family exhibited the highest level of salt tolerance and should be prioritized in future promotion trials of salt-tolerant varieties.





Soil fungal community structure dynamics and its relationship with soil organic carbon stability during ecological restoration of tropical secondary forests.

YANG Meiqiu, DENG Danting, SUN Yanfei, LONG Wenxing

2025, 44(9):  2907-2918.  doi:10.13292/j.1000-4890.202509.015

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Changes in soil organic carbon in tropical secondary forests are critical to global carbon balance, with soil fungi playing a key role in soil carbon decomposition. However, the effect of soil fungal communities on the stability of soil organic carbon during the restoration of tropical secondary forests remains unclear. We investigated the secondary forests at the early (<30 years), middle (>40 years), and late (>70 years) stages of restoration and the old-growth forests (>300 years) in the Bawangling Branch of National Park of Hainan Tropical Rainforest, Hainan Island, China. Soil samples were collected from the humus (Ah) and eluvial (E) horizons. The chemical composition of soil organic carbon was analyzed using Fourier transform infrared spectroscopy. We further examined the relationships of fungal community diversity, composition, and network stability with organic carbon chemical stability. The results showed that total organic carbon content remained stable during forest restoration. However, polysaccharide carbon and aromatic carbon contents increased initially and then decreased, whereas aliphatic carbon showed an opposite trend. The chemical stability of soil organic carbon was highest in the middle-stage secondary forests. The Ah horizon exhibited significantly higher total organic carbon and its chemical fractions than the E horizon. While secondary forest restoration did not affect soil fungal alpha diversity, fungal richness declined markedly with increasing soil depth. Molecular ecological network analysis showed that the stability of the fungal community network increased with forest restoration and soil depth. Keystone fungal species were primarily ectomycorrhizal and saprophytic fungi, including Russula, Inocybe, Sebacina, Entoloma, Penicillium, Aspergillus, and Mortierella. Structural equation modeling demonstrated that the restoration of tropical secondary forests mainly regulated the stability of organic carbon by influencing the keystone fungal species. These findings provide insights into the microbial mechanisms regulating soil organic carbon dynamics during tropical secondary forest restoration and provide theoretical support for the ecological management of tropical secondary forests.





Soil organic carbon fractions and enzyme activities in different forest types on northern and southern mountains of Lanzhou City.

ZHANG Jianpeng, SU Shiping, LIU Xiaoe, ZHANG Wanyu, XU Ning

2025, 44(9):  2919-2929.  doi:10.13292/j.1000-4890.202509.016

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Clarifying the characteristics of soil organic carbon and its fractions and enzyme activities across different forest types can provide the reference for ecological restoration and soil quality improvement. In this study, we investigated the distribution patterns of soil organic carbon, its fractions, and enzyme activities as well as their relationships in the 0-40 cm soil layer in five different types of plantations (Populus alba var. pyramidalis stand, Robinia pseudoacacia stand, Platycladus orientalis stand, a mixed stand of Populus alba var. pyramidalis and Robinia pseudoacacia, and a mixed stand of Platycladus orientalis and Robinia pseudoacacia) on the southern and northern mountains of Lanzhou City. Among the five stand types, Platycladus orientalis stand had the highest average soil organic carbon and light and heavy fraction organic carbon, followed by R. pseudoacacia stand. The highest average soil organic carbon and light and heavy fraction organic carbon were recorded in May. Soil organic carbon and light and heavy fraction organic carbon at 0-20 cm layer in Platycladus orientalis stand were higher than those in R. pseudoacacia stand. At 20-40 cm layer, they showed fluctuating changes among different forest stand types. The highest average soil invertase, amylase, and cellobiase activities were found in the Populus alba var. pyramidalis and R. pseudoacacia mixed stand. Soil enzyme activities of each stand were highest in June. The activities of soil enzymes in the 0-20 cm soil layer showed Populus alba var. pyramidalis and Robinia pseudoacacia mixed stand > Platycladus orientalis and R. pseudoacacia mixed stand. In the 20-40 cm soil layer, the activities of the three soil enzymes were pure forest > mixed forest. There were significant differences in soil enzyme activities among different forest types. The contents of soil organic carbon and its fractions and soil enzyme activities of different forest stand types all showed a significant downward trend with increasing soil depth (P<0.05). Soil organic carbon and its fractions were extremely significantly correlated with soil invertase activity (P<0.01). Soil organic carbon and its fractions as well as soil enzyme activities were affected by forest stand types, with the highest levels in the Platycladus orientalis stand and Populus alba var. pyramidalis and R. pseudoacacia mixed stand, respectively, indicating that the establishment of coniferous forests and mixed forests is of great significance for ecological restoration.





Response of soil microbial activity to grazing intensity in alpine grassland of Qinghai-Tibet Plateau.

SUN Caicai, AN Haitao, DONG Quanmin, LIU Wenting, LYU Weidong, YANG Xiaoxia

2025, 44(9):  2930-2937.  doi:10.13292/j.1000-4890.202509.033

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Soil microorganisms play an important role in grassland ecosystems. Understanding the changes of soil microbial activity under different grazing conditions is of great significance for evaluating the variations of soil quality. We examined the changes of soil microbial activity under different grazing intensities (no grazing, light grazing, moderate grazing and heavy grazing) in alpine grassland of Qinghai-Tibet Plateau. We measured the soil physical and chemical properties (organic carbon, pH, ammonium nitrogen, nitrate nitrogen, and available phosphorus) and microbial activities (microbial biomass carbon, microbial biomass nitrogen, microbial entropy, soil basal respiration, and microbial quotient) under different grazing intensities by combining laboratory analysis with field sampling. The results showed that: (1) Grazing decreased soil organic carbon and soil ammonium nitrogen contents, but increased soil pH in the 0-10 cm soil layer. (2) Soil microbial biomass carbon, biomass nitrogen and microbial entropy showed a decreasing trend with increasing grazing intensity. The contents of microbial biomass carbon and nitrogen were the highest in the 0-10 cm layer, which ranged from 404.44-748.49 and 101.73-173.78 mg·kg^-1, respectively. (3) Soil basal respiration gradually decreased with the intensification of grazing intensity, while microbial quotient gradually increased. (4) Soil organic carbon, pH, and ammonium were important factors affecting soil microbial activity. In summary, soil microbial biomass carbon, microbial biomass nitrogen, microbial entropy, and soil basal respiration tended to decrease with increasing grazing intensity and soil depth, while microbial quotient tended to increase.





Effects of a novel bio-inhibitor on soil nitrogen transformation and functional microbial and enzyme activities.

ZHANG Kun, LI Jie, WANG Shuai, WANG Wenyu, WANG Wei, LI Yaqun, LIU Kai, LI Jinyuan, LI Dongwei, LIAN Ruiyuan

2025, 44(9):  2938-2947.  doi:10.13292/j.1000-4890.202509.008

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In this study, we carried out a maize field experiment with four treatments, including control (CK), urea application alone (U), urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and nitrification inhibitor dicyandiamide (DCD) with urea (NBPT+DCD+U), and cyclopentanone (CCO) with urea (CCO+U), to investigate the responses of soil nitrogen transformation, the activities of nitrogen cycling-related enzymes, the abundance of nitrogen cycling-related functional genes and related microorganisms to the application of CCO, a novel bio-inhibitor. Compared with the NBPT+DCD+U treatment, the NH₄⁺-N content was increased by 12.5%-73.7% in the first 16 days, while the NO₃^--N content was reduced by 11.7%-47.4% in the CCO+U treatment from 20 to 85 days. Compared with the U treatment, the CCO+U treatment effectively delayed urea hydrolysis and significantly reduced soil urease activity by 52.5%-82.3%. CCO+U treatment significantly reduced soil nitrification potential and denitrifying enzyme activities (NR and NiR) during the maize reproductive period, suppressed the functional activities of both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), and reduced the abundance of functional genes for denitrification (nir-S and nir-K). Results of thermogram and SEM analyses indicated that CCO improved crop yield by reducing the abundance of AOA amo-A, nir-S, and nir-K gene abundance. In summary, CCO improves crop yield by inhibiting hydrolysis, nitrification and denitrificationrelated enzyme activities and reducing the abundance of functional genes of nitrifying and denitrifying microorganisms.





Effects of biochar application on nitrous oxide emissions from tobacco-planted soils.

WANG Chen, BAO Peipei, JI Yu, SUN Qiao, LI Qingshan, YU Haiyang, ZHANG Zhen

2025, 44(9):  2948-2955.  doi:10.13292/j.1000-4890.202509.014

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We investigated the effects of biochar application on nitrous oxide (N₂O) emission in tobaccoplanted soils by laboratory incubation experiment and meta-analysis. There were six treatments in the incubation experiment: no nitrogen fertilizer and no biochar application (N0B0), no nitrogen fertilizer but biochar application (N0B100), nitrogen fertilizer but no biochar application (N100B0), reducing nitrogen fertilizer by 20% and no biochar application (N80B0), nitrogen fertilizer and biochar application (N100B100), and reducing nitrogen fertilizer by 20% and biochar application (N80B100). N₂O fluxes, ammonium (NH₄⁺) and nitrate (NO₃^-) contents were measured. Furthermore, a meta-analysis was performed to explore the optimal fertilization and biochar application rates to reduce N₂O emissions from tobacco-planted soils using data from 10 peer-reviewed papers. Results showed that: (1) N₂O fluxes of each treatment decreased rapidly and tended to be stable during the incubation duration. Compared with N0B0 treatment, nitrogen fertilization significantly increased cumulative N₂O emissions. Compared with N100B0 (or N100B100) treatment, N80B0 (or N80B100) treatment significantly reduced the cumulative N₂O emission. (2) During the whole incubation period, biochar application significantly reduced N₂O emission under the same nitrogen fertilizer application level. (3) N₂O emissions positively correlated with NH₄⁺ content, and negatively correlated with NO₃^- content. (4) Compared with other crop systems, N²O emission factors (EFs) in the tobacco-planted system are relatively smaller. Nitrogen fertilizer reduction and biochar application could significantly mitigate N₂O emission from tobacco-planted soils. These findings provide a theoretical basis for optimizing fertilization strategies and biochar implementation to reduce N₂O emissions from tobacco-planted systems, with important significance for realizing carbon neutrality and sustainable agricultural development in agricultural ecosystems.





Effects of pavements on the vertical distribution of soil bacterial community under urban greening trees.

YU Weiwei, YANG Yunjiang, WANG Yachen, TIAN Panli, WANG Xiaoke

2025, 44(9):  2956-2965.  doi:10.13292/j.1000-4890.202509.011

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Pavements change the structure and function of soil microbial community, which is adverse to soil bacterial community. To evaluate the effects of pavements on the vertical distribution of soil bacterial communities, an experiment was conducted to simulate the in-situ conditions of pervious pavement (PP), impervious pavement (IPP), and non-pavement (NP) by planting typical greening tree species in Beijing (Pinus tabuliformis, Fraxinus chinensis, and Acer truncatum). Soil samples were collected from five layers (0-20, 20-40, 40-60, 60-80, 80-100 cm) and the composition and diversity of soil bacterial community were determined by 16S amplicon sequencing method. The results showed that: (1) PP decreased the relative abundance of Acidobacteria in 0-60 cm soil layer. IPP increased the relative abundance of Gemmatimonadetes and Acidobacteria in 0-20 cm soil layer and Proteobacteria in 60-100 cm soil layer. (2) The effects of pavement on α diversity of the three tree species were as follows: Pinus tabuliformis <Fraxinus chinensis < Acer truncatum, with greater effects on the deep soil across all the species. Both PP and IPP significantly decreased the diversity of bacterial Chao1 in the 40-60 cm soil layer under Fraxinus chinensis and 20-40 cm soil layer under Acer truncatum. PP significantly decreased Shannon index in 60-100 cm soil layer under Pinus tabuliformis, 20-40 and 80-100 cm soil layer under Acer truncatum, and decreased Chao1 diversity in 80-100 cm soil layer of Acer truncatum. IPP significantly increased Chao1 diversity in 80-100 cm soil layer of Acer truncatum. (3) Soil bacterial community under pavements was positively correlated with soil pH, total carbon, total nitrogen, ammonium, available phosphorus and available potassium. Soil bacterial α diversity was positively correlated with ammonium and available phosphorus in 20-60 cm soil layer, while Shannon index was positively correlated with soil total carbon in 80-100 cm soil layer. The α diversity of soil bacteria was negatively correlated with total nitrogen, organic matter, nitrate and available potassium in the 60-100 cm soil layer, while the diversity of soil bacteria Chao1 was negatively correlated with ammonium nitrogen in the 0-20 cm soil layer. Overall, pavements had a negative effect on soil bacteria, with the effect in the deep layer being greater than that in the surface soil. PP could alleviate the negative effect to a certain extent. Our results can provide a theoretical basis for reasonably evaluating soil ecosystem function of urban green space.





Spatial distribution and influencing factors of inorganic sulfur species in coastal wetland sediments.

QIAO Manrong, LANG Yunchao, HAN Xiaokun, LA Wei, DING Hu, LIU Congqiang

2025, 44(9):  2966-2975.  doi:10.13292/j.1000-4890.202509.031

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Sulfur cycle is an important component of fundamental biogeochemical cycles, which deeply affects the cycles of carbon, iron, phosphorus and other elements as well as the ecological function of coastal wetlands. In this study, we measured the content of acid volatile sulfide (AVS), elemental sulfur (ES), pyrite sulfur (FeS₂), organic carbon, and active iron in the sediment cores collected from the Beidagang wetland (in Tianjin) with different salinity, to better understand the migration and transformation processes of sulfur in coastal wetland sediments. The vertical distribution characteristics of sulfur species, active iron, and organic carbon in the wetlands with different salinity were clarified. The influencing factors of sulfur migration and transformation in different forms were examined. The results showed that AVS was the main reduced inorganic sulfur in the sediments of mesohaline and polyhaline wetlands, followed by FeS₂ and ES. The relative contributions of AVS to reduced inorganic sulfur (RIS) were 71.45% ± 18.97% and 58.96% ± 28.88% for the mesohaline and polyhaline wetland sediments, respectively. However, the content of FeS₂ was the highest inorganic sulfur in the sediments of oligohaline wetland, with an average content of 83.41 ± 33.03 μmol·g^-1, which accounted for 71.98% ± 13.01% of RIS in the sediments. These results indicated that the spatial distribution of reduced inorganic sulfur species in wetland sediments highly depended on salinity. Furthermore, the high sulfate concentration in the water of mesohaline and polyhaline wetlands led to an enhanced sulfate reduction driven by methane and organic matter in the sediments, producing more AVS. The formation of pyrite in the mesohaline and polyhaline wetlands was mainly limited by the content of active iron and ES, while the accumulation of FeS₂ in the sediments of oligohaline wetland may be mainly affected by the reservoir retention effect, particle input, and high sulfur content. Our results contribute to the restoration and management of ecological environment in wetlands.





Dynamics of carbon sink capacity in young northward-afforested mangroves in southern Zhejiang Province.

BAO Mingyan, LI Xiuzhen, CHEN Xuechu, DU Minghui, LI Changda, CHEN Yahui, YANG Hualei

2025, 44(9):  2976-2982.  doi:10.13292/j.1000-4890.202509.010

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As an important blue carbon ecosystem, mangrove forests are among the most effective natural systems for carbon sequestration in combating climate change. Climate change provides an opportunity for the northward expansion of mangroves. Yet, their capacity of carbon sequestration is poorly understood. With long-term eddy covariance technique, we investigated the daily and seasonal dynamics of net ecosystem exchange (NEE) of young northward-afforested mangroves in southern Zhejiang Province and explored the main driving factors. The results showed that NEE of the northward-afforested mangroves demonstrated a U-shaped pattern on diurnal scale. There was a strong seasonality of NEE, which peaked in summer and decreased as temperature cools. NEE was strongly positively correlated with photosynthetically active radiation and wind speed, but was negatively correlated with air pressure and vapor pressure deficit. Based on the annual cumulative data of eddy NEE, the carbon sequestration capacity of the young northward-afforested mangroves (3 years old) was 291 g C·m^-2·a^-1, reflecting its potential as a carbon sink.





Spatial identification of habitat restoration projects for the key protected wild animal Meles meles in Shanghai.

2025, 44(9):  2983-2991.  doi:10.13292/j.1000-4890.202509.003

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Habitat restoration for wildlife and recovery of extremely small populations are crucial measures for enhancing biodiversity and integral components of ecological civilization construction. Identifying potential ecological spaces as wildlife habitats and initiating habitat restoration projects represent effective strategies to adapt wildlife conservation management to the new era. There are many difficulties in site selection and inadequate integration of project areas with urban ecological spatial planning in the wildlife habitat construction projects promoted by the Shanghai Forestry Bureau. Taking the Eurasian badger (Meles meles) as an example, analyzing data from the Third National Land Use Survey, and fully avoiding urban development boundaries and permanently protected basic farmland, this study closely aligned with the “Special Planning of Shanghai Ecological Space” and the “Planning of Shanghai Basic Ecological Network”. We further took into account the integrated and optimized scope of nature reserves and potential afforestation spaces to delineate the priority ecological space for selecting wildlife habitat restoration projects in Shanghai. Using identification strategies based on key indicators such as landscape characteristics, human disturbance, and ecological location, we innovatively developed a method for rapidly screening and establishing a project reserve database for wildlife habitat restoration in highly urbanized areas. The results showed that the priority ecological space for selecting wildlife habitat restoration projects in Shanghai covered a total area of 3388.7925 km², encompassing various land use types such as cultivated land, gardens, forests, grasslands, wetlands, and water areas. Based on the rapid screening method, we identified eight spaces for Meles meles habitat restoration projects, located in Changxing Island of Chongming, Zhujiajiao of Qingpu, Jinhui of Fengxian, Xinchang of Pudong, Lvxiang of Jinshan, Guangfulin of Songjiang, Waigang of Jiading, and Shenya of Fengxian. These results provide robust scientific support for key decisions regarding the selection, quantity, and spatial configuration of habitat protection and restoration projects under the context of urbanization. This study offers significant insights for guiding ecological protection practices in future urban construction and management.





Infrared camera monitoring of birds and mammals in Hebei Wulingshan National Nature Reserve.

PANG Dingwei, CUI Hualei, CHEN Yiyan, LU Yan, LI Linxi, GAO Jianxin, FAN Xiaoliang

2025, 44(9):  2992-2998.  doi:10.13292/j.1000-4890.202509.007

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Wildlife resource baseline surveys play a crucial role in the protection and assessment of endangered species and serve as the foundation for research work in nature reserves. From October 2022 to October 2023, 60 infrared cameras were set up in the Hebei Wuling Mountain National Nature Reserve to observe wildlife, with a total of 10985 camera days. A total of 4405 independent and effective photos were obtained. A total of 16 species from 5 orders and 10 families of mammals, and 24 species from 5 orders and 10 families of birds were recorded. Five new recording species records were found in the reserve. Nine species were among the wildlife under national protection. Moreover, four species were rated “vulnerable (VU)” by the International Union for Conservation of Nature (IUCN) Red List. The species with the highest relative abundance index (RAI) and grid occupancy (GO) for mammals was roe deer (Capreolus pygargus), with RAI=146.57 and GO=72.5%, respectively. For birds, the species with the highest RAI and GO was the koklass pheasant (Pucrasia macrolopha), with RAI=6.92 and GO=22.5%, respectively. The results will help more comprehensively understand the diversity and distribution pattern of birds and mammals in the protected area, providing data support for ecological research and conservation management.





The structure and distribution characteristics of fish communities in the Suwalong to Hutiaoxia section of the upper reaches of Jinsha River.

WANG Zhongmin, ZHANG Dengcheng, CHEN Feng, YANG Hanyun

2025, 44(9):  2999-3007.  doi:10.13292/j.1000-4890.202509.005

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We conducted a survey on the structure and distribution of fish communities in the Suwalong to Hutiaoxia section of Jinsha River in October-November 2012, May-June 2013, May-June and October-November 2019. The results showed that 17 fish species were distributed in the study area, of which 11 species were indigenous and six species were exotic. Schizothorax wangchiachii, Schizothorax dolichonema, Schizothorax kozlovi, and Euchiloglanis kishinouyei were mainly distributed in the main stream of Jinsha River, while Schizopygopsis malacanthus, Gymnocypris potanini firmispinatus, and Triplophysa sp. were more frequently found in the tributaries. The Shannon diversity index, Pielou evenness index, and Margalef richness index of fish species across sampling points ranged from 0.20 to 0.75, 0.18 to 0.39, and 1.44 to 3.37, respectively. Overall, the diversity indices of sampling points in the main stream section of the Jinsha River were higher than that in the tributary section. The fish communities from 2012 to 2013 could be divided into two groups at a level of 70% Bray-Curtis similarity. When the Bray-Curtis similarity reached 55%, fish communities in 2019 could be divided into three groups. Euchiloglanis kishinouyei, Schizothorax dolichonema, and Jinshaia sinensis tended to occur in rapid or torrent sections with high flow rates, while Triplophysa sp. more occurred in slow flowing sections with low flow rates. Schizothorax kozlovi and Schizopygopsis malacanthus tended to occur in wide valley streams. Based on the community structure and distribution characteristics of fish species, we proposed the following measures to protect fish resources, including strengthening the control of alien species, strengthening the planning and design of environmental protection measures for hydropower projects, carrying out habitat restoration, and strengthening aquatic ecological monitoring.





Effect of coexisting saline-alkaline ions on copper adsorption behavior at hematite and magnetite/water interface.

YANG Jiali, CHEN Xingyu, ZHANG Ling, WANG Ying, ZHANG Danni

2025, 44(9):  3008-3018.  doi:10.13292/j.1000-4890.202509.028

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Irrigation with untreated sewage is one of the important causes of heavy metal copper (Cu) pollution in farmland soil in the drylands of Northwest China. Soil pH and the types and concentrations of saline-alkali ions have profound influence on the speciation and mobility of Cu in the saline-alkali soil. We investigated the adsorption behavior and interfacial reaction of Cu at hematite and magnetite/water interface in the presence of four ions including sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), and magnesium (Mg²⁺) based on simulated batch experiments. Scanning electron microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy were used for characterization. The adsorption capacities of the two iron oxides to Cu increased in the presence of Ca²⁺ but reduced the adsorption rate, indicating that the adsorption affinity between iron oxides and Cu increased in the presence of Ca²⁺. The influence of the four ions on the adsorption capacity of Cu at hematite and magnetite surface varied, with an order of Mg²⁺>Ca²⁺>Na⁺>K⁺, which might be due to the differences of the hydration radius of the four ions. The adsorption capacities of Cu on the surface of the two iron oxides increased with increasing soil pH. The results of XRD, FTIR, and Raman spectroscopy characterization showed that Cu adsorbed on the surface of the two iron oxides could form complicated precipitates through complexation reaction in the coexisting ion system.





Coupling effect of acid deposition and nano-ZnO on decomposition function of aquatic fungi.

YUAN Shuaikang, TAO Tianying, GUO Ruili, WANG Xilin, ZHANG Yuyan, XU Yuanqian, CAO Xia, ZHANG Hongzhong, DU Jingjing

2025, 44(9):  3019-3025.  doi:10.13292/j.1000-4890.202509.034

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To explore the effect of acid deposition and nano-ZnO on functional microorganisms in leaf litter decomposition, we assessed effects of the interaction of those two factors on the growth and function of two dominant aquatic fungi, Geotrichum candidum and Mucor circinelloides. Results showed that the coupling effect of those two factors significantly promoted the growth of G. candidum, but inhibited its enzyme activities compared to the effect of each single factor. For M. circinelloides, the coupling effect showed inhibitory role on fungal growth and enzyme activities. Therefore, G. candidum was more tolerant to the coupling effect of acid deposition and nano-ZnO, whereas M. circinelloides was more sensitive with decreases in water absorption capacity, material synthesis, and extracellular enzyme activities. The inhibitory effect would influence the role of M. circinelloides in leaf litter decomposition. The results improve our understanding of the coupling effect of acid deposition and nano-ZnO on the decomposition function of aquatic fungi.





Effects of  oil shale residue on growth and stoichiometry of Medicago sativa.

WANG Zhengwei, WANG Kai, LIU Chang, LYU Linyou

2025, 44(9):  3026-3035.  doi:10.13292/j.1000-4890.202509.006

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To assess the feasibility of utilizing oil shale residue to increase Medicago sativa yield and ensure edible safety, we measured the biomass, carbon (C), nitrogen (N), phosphorus (P) stoichiometry, and heavy metal enrichment in different organs (leaf, stem, and root) of M. sativa under four levels of oil shale residue addition (0, 3, 6, and 9 kg·m^-2). The results showed that, with increasing oil shale residue addition level, a pattern of initial increase and then decrease was found in plant height, basal diameter, number of roots and nodules, biomasses and total N concentrations in each organ, and root N∶P at seedling and flowering stages, and C concentrations in leaves and roots at mature stage. Moreover, a pattern of first decrease and subsequent increase was found in specific root length and specific root area, and the concentrations of copper and chromium in various organs increased, being higher in roots than in leaves and stems. Compared with the control, plant height increased by 36%, 23% and 26%, basal diameter increased by 56%, 16% and 20%, and total biomass increased by 130%, 135% and 30% at seedling, flowering, and mature stages, respectively, while heavy metal concentrations in the aboveground parts did not exceed the standard under oil shale residue addition of 6 kg·m^-2. Therefore, 6 kg·m^-2 oil shale residue addition was optimal for M. sativa, which effectively promoted plant growth and alleviated N limitation.





Time-lag effects of climate and the influence of anthropogenic activities on vegetation of the Loess Plateau.

GUO Famiao, PENG Daoli, SU Yanfang, ZHAO Yabing, WANG Yin

2025, 44(9):  3036-3043.  doi:10.13292/j.1000-4890.202509.001

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Understanding the influences of climate change and anthropogenic activities on vegetation is of great significance for restoring vegetation and maintaining ecological balance. The time-lag impact of climate changes on vegetation is usually overlooked, which would underestimate the impacts of climate change on vegetation changes. We analyzed the spatiotemporal variations of vegetation on the Loess Plateau from 2000 to 2019, explored the time-lagged response of vegetation to climate change, proposed a modified residual analysis method considering the climate time-lag effect, and revealed the impacts of climate change and human activities on vegetation. The results showed that the Normalized Difference Vegetation Index (NDVI) of the vegetation on the Loess Plateau increased significantly from 2000 to 2019, with an annual growth rate of 0.048·10 a^-1. Spatially, the NDVI of vegetation in most areas of the Loess Plateau was increasing, with the increases in 76.6% of the area being statistically significant. Temperature had an obvious time-lag effect on the changes of NDVI, with the optimal lag time being 1 month, while precipitation had no lag effect. The time-lag effect of vegetation was the same for different land use types, but the correlation varied. The contributions of climate change and human activities to the changes of NDVI were 0.01·10 a^-1  and 0.03·10 a^-1, respectively. Their combined effect was the main reason for the changes of NDVI on the Loess Plateau in the past nearly 20 years, accounting for 58.3% of the area. The independent effect of human activities is greater than that of climate change.





Quantitative characteristics of Coptis chinensis var. brevisepala populations in Guangdong Province and prediction of its potential distribution area in China based on MaxEnt.

XU Yida, XIE Dan, DONG Shupeng, NING Zulin

2025, 44(9):  3044-3053.  doi:10.13292/j.1000-4890.202509.022

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Understanding the current status of species populations and the changes of their potential distribution area under climate change is crucial for elucidating the mechanisms of species endangerment and carrying out conservation practices. Coptis chinensis var. brevisepala is a perennial herb endemic to China, which is ranked as second-class in the List of National Key Protected Wild Plants. In this study, the wild C. chinensis var. brevisepala populations in Guangdong Province were investigated, and MaxEnt combined with ArcGIS were used to analyze the potential distribution area under different shared socioeconomic pathways (SSP126, SSP245, SSP585) in three different periods (1970-2000, 2021-2040 and 2041-2060) based on 60 distribution records and 11 environmental variables. The results showed that C. chinensis var. brevisepala were mainly distributed in the eastern and northern regions of Guangdong Province. Most populations were characterized by a small number of individuals and incomplete age structure. Precipitation in the coldest quarter (63%) and elevation (21.1%) were the two environmental factors with the strongest impact on the habitat adaptability of C. chinensis var. brevisepala. The potential distribution area of C. chinensis var. brevisepala will generally expand in the periods of 2021-2040 and 2041-2060. However, the large emission of greenhouse gases could still have a negative impact on their habitat adaptability. The Tianmu Mountains-Yandang Mountains area and the eastern region of the Nanling Mountains-Xuefeng Mountains were the hotspots for the future changes in distribution area, and the conservation works there should be prioritized. During the period of 1970-2000, about 43.1% of the area of moderately and highly suitable areas in Guangdong were directly covered by natural reserves. It is suggested that measures should be taken in the planning of nature reserves to further expand the protected area in Guangdong. In addition, germplasm resource gardens should be established in the northern part of Guangdong, and artificial propagation and cultivation should be strengthened to protect and rationally develop and utilize the wild population resources.





Spatiotemporal patterns of eco-environmental vulnerability in the Yellow River Basin, China.

TAO Jian, LIN Yuchen, WANG Bingxin, CONG Nan, XIE Yujie, ZHU Juntao

2025, 44(9):  3054-3064.  doi:10.13292/j.1000-4890.202509.036

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Vulnerable eco-environment restricts the high-quality development of the Yellow River Basin. The assessment of eco-environment vulnerability is an important foundation for the coordinated advancement of large-scale governance in the Yellow River Basin. Taking 410 counties in the Yellow River Basin as the objects, we assessed spatiotemporal patterns of eco-environmental vulnerability in the basin by integrating Big Earth Data with socio-economic statistic records during 2001-2020 and using Exposure-Sensitivity-Adaptability model. The results showed that: (1) The eco-environment of the basin was generally vulnerable. Counties with moderate-level or higher eco-environmental vulnerability indices (EVIs) accounted for 57.02% of the total area of the basin. EVIs showed a pattern of high in the north and lower reaches while low in the west. (2) Over the past 20 years, the EVIs in the central and downstream counties had been intensified, with obvious high-high agglomeration. The EVIs in the western and eastern counties in the middle reaches had been weakened, with obvious low-low agglomeration. (3) Spatial pattern of EVIs was correlated with urban agglomeration development and ecosystem vulnerability. The conflicts and competitions caused by administrative barriers and fragmented management led to the lagging governance effectiveness. In particular, EVIs in the junction of Inner Mongolia, Shanxi, and Shaanxi provinces and the junction of Shandong and Henan provinces increased. The contradictions among ecology, economy, and society at the junction of Inner Mongolia, Shanxi, and Shaanxi provinces were prominent. The sharp increase in water demand caused by population growth and urbanization, as well as the destruction of the eco-environment, had exacerbated the eco-environment vulnerability. In the county-level industries within Henan Province at the junction of Shandong and Henan, the water and energy consumption was high, and the uncoordinated relationship between the eco-environment and socio-economic development was prominent. Cross-regional, cross-sector, and multi-subject collaborations are an important starting point to promote the great governance of the basin.





Land use optimization framework and application for the maintenance and improvement of ecosystem services: Taking the Yangtze River Delta Ecological Greening Development Demonstration Area as an example.

SUN Xiaohui, FENG Ziwen, MA Qun, WANG Menghan, ZHANG Naijie, KONG Lingqiang

2025, 44(9):  3065-3082.  doi:10.13292/j.1000-4890.202509.017

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Land use optimization strategies for maintaining and improving ecosystem services are crucial for improving landscape sustainability. As current research primarily focuses on case studies, a universal land use optimization framework based on ecosystem services is lacking. To fill this knowledge gap, we proposed a land-use optimization framework for the maintenance and improvement of ecosystem services within different ecosystem services bundles. This framework involves first identifying priority protected areas, then determining key improvement types and the influencing factors, and finally integrating local land use/ecological protection policies. We tested the feasibility of the framework with the Yangtze River Delta Ecological Greening Development Demonstration Area as a study area. The results showed that: (1) From 1980 to 2020, food production, water production, and recreational opportunities in the study area increased by 60.35%, 30.59%, and 17.56%, respectively. In contrast, air purification, carbon sequestration, and habitat quality showed decreased by 10.75%, 5.10%, and 32.25%, respectively. (2) This framework can effectively protect the high-value ecosystem service areas within each bundle and improve the degraded ecosystem services. The priority protection areas for ecosystem services were mainly concentrated in the central part of the study area, accounting for 53.10% of the total area. The ecological multi-functional service bundle should focus on improving habitat quality services, while the food supply-oriented service bundle and the urban built environment-oriented service bundle need to improve the services of air purification, carbon sequestration, and habitat quality. (3) Among the three bundles, NDVI and patch density were positively correlated with air purification, whereas population density was negatively correlated with habitat quality. However, there were certain differences in the influencing factors among different bundles. (4) Compared with the situation before optimization, the comprehensive ecosystem services of the three bundles increased by 0.47%, 15.59%, and 12.62%, respectively. This study provides a scientific basis for land spatial planning in the Yangtze River Delta and offers a conceptual framework and methodological reference for land use optimization in other regions around the world.





The coupling between ecosystem services and rural development level in ecologically fragile areas: A case study of Shenmu City, Shaanxi Province.

YANG Yue, YUAN Xuefeng, MA Chaoqun, ZHAO Yu

2025, 44(9):  3083-3093.  doi:10.13292/j.1000-4890.202509.002

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Clarifying the coupling between ecosystem services and rural development levels is important for promoting rural revitalization, advancing ecological civilization construction, and achieving a balanced coexistence between humans and the Earth in ecologically fragile areas. With the InVEST model, we quantified five ecosystem services (food production, water yield, carbon storage, soil conservation, and habitat quality) in Shenmu City, Shaanxi Province. The level of rural development was evaluated from five dimensions, including resource endowment, human capital, industrial foundation, facility security, and location conditions. The coupling between ecosystem services and the level of rural development was analyzed using a coupling coordination model and a relative development model. The spatial heterogeneity of the factors influencing the level of coupling coordination was analyzed using a geographically weighted regression model. The results showed that the level of rural development in the northern townships of Shenmu City was generally higher than that in the southern townships. Apart from grain output, water production, carbon sequestration, soil conservation, and habitat quality in Shenmu City had shown an upward trend. The coordination between ecosystem services and rural development levels was generally dysfunctional or antagonistic, with ecosystem services lagging behind the level of rural development in the northern townships and exceeding it in the southern townships. There was spatial heterogeneity in the influence of natural and socio-economic factors on the degree of coupling between ecosystem services and the level of rural development. In the future development process, it is suggested to promote ecological civilization construction and the rural revitalization strategy based on the differences in natural and socio-economic conditions.





Patterns of ecosystem service supply and demand and ecological management zoning in the Gaoligong Mountain region.

CHEN Yuyang, LI Yungang

2025, 44(9):  3094-3105.  doi:10.13292/j.1000-4890.202509.013

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Ecological management zoning from the perspective of ecosystem service supply and demand patterns aids in the sustainable ecosystem management. With Gaoligong Mountain region (GMR) as a case, we measured the supply and demand of ecosystem services by the equivalent factor method and a three-dimensional ecological footprint model, respectively. The spatial and temporal variations of the relationships between ecosystem service supply and demand were analyzed. The results showed that: (1) From 2010 to 2020, the supply of ecosystem services showed an increasing trend, with changes in standard equivalent factors having a greater impact on ecosystem services value than land use changes. (2) The demand for ecosystem services was higher in the south than in the north, primarily influenced by factors such as per capita GDP, urban and rural per capita disposable income, retail sales of consumer goods, the added value of the tertiary industry, and urbanization. (3) There were three main types of supply-demand matches: high supply-low demand, low supply-low demand, and low supply-high demand. Based on these matches, the GMR was divided into ecological protection, improvement, control, and reconstruction zones, with differentiated ecological management strategies proposed. This study provides a scientific basis for formulating ecological management policies in the GMR.





Multi-scale ecosystem services and the driving mechanisms in multiple scales: A case study of Shanxi Province.

CHEN Xiaoping, LI Xuan, XU Ruofan, MA Hang, WANG Ben, HUANG Chunbo

2025, 44(9):  3106-3115.  doi:10.13292/j.1000-4890.202509.018

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Clarifying the scale effects of ecosystem services and the driving mechanisms is of great importance for improving regional ecological governance and sustainable development. With Shanxi Province as the research area, we calculated the values of four typical ecosystem services (carbon sequestration, soil conservation, food production, and recreational services). We used correlation analysis to clarify the trade-off and synergy relationships among the four ecosystem services, and used PLS-SEM model to analyze the driving mechanisms of four ecosystem services at four different spatial scales (1 km×1 km, 5 km×5 km, 10 km×10 km, and 15 km×15 km). The results showed that: (1) The spatial distribution of the four ecosystem services exhibited obvious spatial differentiation, which tended to become more uniform with increasing scales. Carbon sequestration, soil conservation, and recreational services showed similar distributional patterns, with high values concentrated in mountainous areas with extensive vegetation coverage, while low values were observed in urban areas with intensive human activities. The high value areas of food production service were mostly distributed in cultivated areas, while the low value areas were located in mountainous and urban areas. (2) Trade-offs and synergies relationships among ecosystem services were significantly influenced by spatial scale, and the direction did not change with increasing scale, but the intensity varied greatly. (3) Terrain was the main factor influencing the four types of ecosystem services. The relationship among ecosystem services and drivers also changed with scales. This study can provide theoretical basis for hierarchical ecosystem management and landscape pattern regulation.





Research progress on response mechanisms, models and applications of forest canopy conductance to climate change.

GAO Juneng, WANG Weifeng, LI Li, SU Menglin

2025, 44(9):  3116-3125.  doi:10.13292/j.1000-4890.202509.009

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Canopy conductance is a key ecological parameter characterizing gas exchange process between plants and the atmosphere, playing a crucial role in regulating material and energy balance of terrestrial ecosystems. Under the context of global change, canopy conductance, as a core regulatory factor in the carbon-water coupled cycle, holds important scientific value for clarifying the adaptive mechanisms of forest canopy in response to climate change. We reviewed the response characteristics of forest canopy conductance to environmental factors such as photosynthetic radiation, temperature, air humidity, and CO₂ concentration, and then explored the mechanisms by which stomatal behaviors regulate plant growth and physiological processes. We further evaluated the applicability of existing forest canopy conductance calculation methods including the Penman-Monteith equation, up-scaling approaches, and remote sensing techniques. Despite the significant progress in these calculation methods in recent years, limitations remain in terms of their applicability under extreme climate conditions and universality across different developmental stages of forests. Future research should focus on the dynamic stress mechanisms of extreme climate events on canopy conductance and the effects of stand age. By integrating multi-source remote sensing data and optimizing the parameter scheme with the process-based models, a cross-scale canopy conductance simulation framework can be constructed. This review provides theoretical support for improving the carbon-water coupled cycle simulation framework and offers scientific evidence for forest management strategies under climate change.





Research progress on vegetation restoration and regeneration after forest fire disturbance and the influencing factors of species diversity.

YUE Yongjie, JIA Wenjie, ZHANG Zetao, ZHAO Pengwu, ZHOU Mei, SHU Yang

2025, 44(9):  3126-4134.  doi:10.13292/j.1000-4890.202509.024

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Forest fire is one of the most critical disturbance factors in forests, which damages ecosystem stability and exerts significant regulatory control over vegetation recovery, regeneration, and succession. Here, we summarized research progress on the effects of forest fires on vegetation restoration, regeneration, and species diversity, focusing on factors such as fire intensity, frequency, burnt wood management practices and recovery time. The intensity and frequency of fires, recovery periods, and different methods for managing burnt wood had shortor longterm impacts on vegetation recovery and species diversity, altering forest structure and function. Additionally, natural regeneration and artificial restoration can lead to distinct processes of vegetation recovery, renewal, and succession. Future research should focus on: (1) strengthening the long-term monitoring of post-fire vegetation restoration; (2) identifying the key driving factors in post-fire processes; (3) developing predictive models for vegetation regeneration trajectories. This study clarifies the effects of forest fires on vegetation recovery and species diversity, providing guidance for the restoration and management of forest ecosystems after fire.





Research progress on the preparation and application of biochar from sludge source in municipal sewage plants.

YU Liming, DING Xin, CHEN Kun, YUAN Yanfei, LIU Qiang, ZHENG Hao

2025, 44(9):  3135-3142.  doi:10.13292/j.1000-4890.202509.030

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The resource utilization of municipal sewage plant sludge is an important initiative to achieve the synergistic targets of pollution reduction and carbon emission mitigation in the sewage treatment industry for the goal of building a beautiful China. Converting sewage sludge to sewage sludge derived biochars (SSBCs) with pyrolysis techniques is a promising way to achieve resource utilization of sewage sludge. SSBCs have excellent properties of high aromaticity, high stability, rich pore structure, large specific surface area and strong adsorption capacity, making them highly applicable for soil quality improvement and carbon sequestration. However, there is a lack of summary on the preparation methods, modification technologies, and soil improvement research progress of SSBCs, which greatly limits the improvement of the performance and application of SSBCs. We reviewed the advantages and disadvantages of the current preparation methods and modification technology of SSBCs, as well as the future development trend, and summarized the application and possible mechanisms of SSBCs in soil quality improvement and pollution remediation. Finally, we summarized the problems in the preparation and application of SSBCs, and put forward the prospects for the application mode in soil improvement, particularly in salt-affected soil. This review will provide a theoretical basis for the development of soil improvement and remediation technologies based on carbon sequestration materials SSBCs, and contribute to the synergy of pollution reduction and carbon emission reduction in the sewage treatment industry.





Degradation of enrofloxacin by a low-temperature resistant immobilized Alcaligenes.

ZHANG Si, WANG Yinggang, XUE Chenyang, LI Xiaojun

2025, 44(9):  3143-3151.  doi:10.13292/j.1000-4890.202509.032

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Antibiotics are difficult to degrade under low temperature in cold regions of northern China. To improve the adaptability of low-temperature degrading bacteria to the environment with low temperature and enhance recycling rate and removal effect on pollutants, enrofloxacin (ENR), a common antibiotic in the environment, was taken as the target pollutant. A low-temperature resistant immobilized bactericide was prepared using the developed process. We examined the adaptability of this immobilized bactericide to environmental conditions and its degradation ability on ENR. The results showed that: (1) The mechanical strength of the immobilized particles was increased by the addition of low-temperature resistant materials. The highest value of the mechanical strength was 113.7 N, being 256.7 times that of the conventional sodium alginate particles. (2) The immobilized bactericide weakened the influence of low temperature. The removal rate of ENR was significantly improved even at 4 and 8 ℃, with the removal rate being 11.6% and 11.9% higher than that of free-living bacteria. (3) The immobilized bactericide has a stronger adaptability to pH, and can achieve better degradation effect in slightly alkaline and acidic environments. At pH=8.0, the removal rate of ENR by immobilized bacteria was 22.9% higher than that by free-living bacteria. The immobilized bactericides further improved the adaptability and function of cryogenic bacteria to the low temperature. Our results could provide a reference for the efficient degradation of antibiotics under low temperature conditions in the northern region of China.





Application of amphiphilic porous hydrogel for the solar distillation of phenol wastewater.

LAN Yaru, ZHAO Liyan, ZHANG Xuejiao

2025, 44(9):  3152-3160.  doi:10.13292/j.1000-4890.202509.035

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Solar distillation is widely used for seawater desalination and fresh water production because of low cost and low energy demand. When the temperature at the air-water interface reaches 40-70 ℃, however, volatile organic compounds (VOCs) will evaporate with water vapor and enrich in distilled water. To solve this problem, amphiphilic porous hydrogels were prepared by Pickering emulsion template method and applied in solar distillation process. We examined the performance of the hydrogel in solar distillation, including water evaporation rate, photothermal conversion efficiency and removal efficiency of phenol during wastewater treatment. The results showed that the PPC-5 hydrogel exhibited a water evaporation rate of 1.62 kg·m^-2·h^-1, a photothermal conversion efficiency of 96.8%, and a phenol removal efficiency of 71.3%. Our results indicate that the amphiphilic porous hydrogel provides an effective way for the treatment of phenol-contaminated wastewater and offers a new idea for solving the difficulty in removing VOCs in the process of solar distilled water treatment.





Assessing fish diversity in the Nanjing section of the Yangtze River by fish larvae survey and eDNA technology.

LI Tianyou, WU Siran, ZHAO Huali, TANG Yue, LIU Baoxing, FANG Di’an

2025, 44(9):  3161-3168.  doi:10.13292/j.1000-4890.202509.004

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The traditional fishery resources survey is difficult to implement under the ecological background of “the Yangtze River Protection”. Fishery environmental DNA (eDNA) technology has been widely used in fishery resources monitoring because of its advantages of non-invasiveness and high sensitivity. Fish larvae survey can reflect fisheries resource status and diversity. To assess the present situation of fish resources in the Nanjing section of the Yangtze River, we analyzed fish species composition and diversity using the traditional fish larvae survey method and eDNA technology from June to August 2023. The results showed that 39 fish species were detected in the Nanjing section of the Yangtze River with the two methods, which belong to 6 genera and 11 families. The traditional fish survey identified 6 orders, 9 families, 30 species, and the eDNA method identified 5 orders, 9 families, 30 species, among them, 21 fish species were both detected by the two methods. The common dominant species detected by the two methods are Coilia nasus, Hemiculter bleekeri, and Pseudolaubuca sinensis. Furthermore, the Shannon diversity index calculated by traditional fish larvae survey and eDNA method was 1.89±0.22 and 1.86±0.15, respectively, and the Pielou evenness index was 0.63±0.08 and 0.56±0.04, respectively. The fish diversity in the Nanjing section of the Yangtze River was at a high level and showed a recovery trend. This study revealed the feasibility and application prospects of fish larvae survey and eDNA technology in fishery resource monitoring, providing basic information and scientific basis for the protection and restoration of fish resources in the Nanjing section of the Yangtze River.