Table of Content

10 July 2025, Volume 44 Issue 7

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Community structure and functional traits of epiphytic algae on the surface of aquatic macrophytes in Qingshan Lake.

HUANG Yimin, LIU Kunyu, YANG Yi, XU Nuo, GUO Jishu, ZHANG Yun, LI Jin

2025, 44(7):  2113-2122.  doi:10.13292/j.1000-4890.202507.007

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To analyze the changes of community structure and functional traits of phytoalgae on leaf surface of aquatic plants in different growing seasons, we collected samples of epiphytic algae from 10 macrophyte species in Qingshan Lake of Huangshi City in autumn (November 2022) and the following spring (May 2023). The results showed that 393 species (or variants) of epiphytic algae on the surface of the 10 macrophytes were identified, including the most diverse phylum, Bacillariophyta (199 species), followed by Chlorophyta (120 species) and Cyanobacteria (49 species). Results from both the Canonical Analysis of Principal Coordinates (CAP) and Analysis of Similarity (ANOSIM) showed significant differences in the community structure between growing seasons and across different macrophyte species. The density of epiphytic algae was the highest on submerged macrophytes, followed by emergent macrophytes and floating-leaved macrophytes. In terms of functional traits, the relative abundance of small, prostrate/adnate, non-attached, and unicellular algae was relatively high on most macrophytes. As for ecological guilds, high-profile epiphytic algae were more abundant on submerged macrophytes, whereas low-profile epiphytic algae were more abundant on floating-leaved macrophytes. In terms of the diversity of epiphytic algae, both species and functional diversity were the highest on submerged macrophytes and lowest on floating-leaved macrophytes. Higher diversity was found on macrophytes with higher leaf complexity. This study supports an understanding of the ecological functions of epiphytic algae on the surface of aquatic macrophytes with basic data, and provides references for monitoring the effectiveness of ecological restoration in Qingshan Lake.





Phytoplankton community structure and its driving factors in Hulun Lake.

ZHANG Yi, BAI Kai, SHI Liping, LI Liang, BAI Yongquan, YIN Xuwang, BAI Haifeng

2025, 44(7):  2123-2131. 

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Understanding the seasonal variations of plankton community and the driving factors can provide basis for scientific protection of lakes. We examined the characteristics of phytoplankton community and its response to environmental changes in Hulun Lake with index method and correlation analysis method. The results showed that a total of 178 phytoplankton species belonging to 8 phyla were identified. The phytoplankton species composition was diatomic-green algae type, with Anabaena circinalis, Anabaena azotica, Cyclotella meneghiniana, and Microcystis wesenbergii as the dominant species. Seasonal variation of phytoplankton species followed a pattern of spring > summer > autumn. The average phytoplankton density and biomass was 810.140×10⁴ cells·L^-1 and 4.010 mg·L^-1, respectively. The density and biomass varied significantly across seasons. The average Shannon diversity index and Pielou evenness index of phytoplankton were 2.73 and 0.58, respectively, and both indices varied significantly among seasons. Based on the biodiversity index and comprehensive trophic level index (TLI), the water quality of Hulun Lake was at the level of mild eutrophication and the divers level is “good”. Redundancy analysis showed that total phosphorus, electrical conductivity, chemical oxygen demand, turbidity, chlorophyll a, and ammonium nitrogen were the main environmental factors affecting the distribution of phytoplankton community, and those influencing factors were different with seasons. Our results could provide a data reference for aquatic ecological restoration and water environmental protection in Hulun Lake.





Macrobenthos community structure and its relationship with environmental factors in Ulungur Lake.

DOU Qianming, WANG Le, ZHAO Zhangguo, YAO Yanling, WANG Huibo, SONG Dan, HUANG Xiaoli, HUO Tangbin

2025, 44(7):  2132-2141. 

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To understand the community structure of benthos and its relationship with environmental factors in Ulungur Lake, six surveys were conducted on benthos and environmental factors at 28 sampling sites in five sites of Ulungur Lake from 2019 to 2021. A total of 68 species of benthos belonging to 4 phyla, 14 orders and 21 families were collected. Chironomus larvae and oligochaetes dominated the community, while Chironomus salinarius, Chironomus sp. and Procladius sp. were the dominant species throughout the year. There were significant temporal and spatial variations of environmental factors (P<0.05). The density and biomass of benthos exhibited variations across both time and space. The average density and biomass of benthos in spring, summer, and autumn were 851, 529, 669 and·m^-2 and 19.52, 14.60, and 13.39 g·m^-2, respectively. The density and biomass in spring were mainly concentrated in the middle of the Buluntuohai Lake (987 ind·m^-2, 24.29 g·m^-2) and the south of Jili Lake (1040 ind·m^-2, 21.32 g·m^-2). Summer density and biomass mainly concentrated in Luotuobozi Lake (896 ind·m^-2, 30.12 g·m^-2). Autumn density was mainly concentrated in the southern part of Jili Lake (808 ind·m^-2) and Luotuobozi Lake (864 ind·m^-2). The biomass in autumn was concentrated in the southern part of Jili Lake (16.07 g·m^-2) and Luotuobozi Lake (14.81 g·m^-2), as well as in the 73 km Xiaohaizi Lake (15.74 g·m^-2). Principal component analysis and similarity analysis showed that the benthos community structure had significant spatiotemporal variations (P<0.01). The significant indicator species differed in different lakes. Redundancy analysis showed that salinity, total nitrogen, and electrical conductivity were important factors affecting the community structure of benthos across different seasons. These factors exhibited significant positive correlations with oligochaetes and chironomid larvae, while significant negative correlation with most benthos. Water salinity, nutrients, and organic pollutants were the main threats to the ecological environment of Ulungur Lake. Both climate change and human activities have exerted considerable stress on the structure of benthos community.





Diversity and floristic characteristics of invasive plants in Yuncheng Salt Lake wetland.

LI Peirong, FAN Qingzhuo, LI Rongrong, GUO Donggang, ZHANG Quanxi

2025, 44(7):  2142-2149.  doi:10.13292/j.1000-4890.202507.040

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The impacts of invasive plants on ecosystem have become a focus in the field of ecology. We investigated the number and ecological characteristics of invasive plants in Yuncheng Salt Lake wetland, aiming to provide scientific basis for the rational utilization and ecological restoration of wetland ecosystems. Based on the survey data of 385 plots, the species of invasive plants in this area were listed, and their quantitative and ecological characteristics, floristic characteristics, dominance and niche characteristics were analyzed. The results showed that: (1) There were 35 invasive plant species from 13 families and 30 genera in Yuncheng Salt Lake wetland. Asteraceae and Fabaceae were the dominant families, and annual herb was the dominant growth type. (2) Among the 35 invasive species, 13 species were classified as Ⅰ and Ⅱ hazard species, accounting for 37.14% of the total. Among them, five species, such as Amaranthus retroflexus and Erigeron canadensis, had caused malignant invasion hazards. (3) The origin of invasive plants is mainly in America. The invasive species from the American continent have strong adaptability and diffusion in this region. (4) In terms of floristic composition, the genera and families of the world distribution types of invasive plants occupy the dominant position. (5) The dominance degree and niche breaths of Lolium perenne, Cosmos bipinnatus and Erigeron canadensis were relatively large. The potential causes of plant invasion in Yuncheng Salt Lake wetland are early development time, long history of salt mining, and fragile ecological environment. Measures combining artificial control and reasonable ecological restoration that considering the differences of habitat types should be taken to control the spread of invasive species.





Population spatial pattern and intraspecific correlation of the rare and endangered aquatic plant Ottelia acuminata var. jingxiensis.

LI Junfeng, GAO Hongcan, YIN Genshen, LIANG Ziyu, YANG Xiaohong, ZHAI Shuhua

2025, 44(7):  2150-2156.  doi:10.13292/j.1000-4890.202507.008

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We investigated population dynamics, viability, and environmental adaptation of the rare and endangered aquatic plant Ottelia acuminata var. jingxiensis, distributed in the Chengjiang River in Hechi and the Equan River in Jingsi, Baise. Point pattern analysis was used to examine the spatial pattern and spatial correlation of the population at different levels. The results showed that the proportion of class III clusters was higher than that of class I and class II clusters in both sampling sites. The karst landscape’s water environment has resulted in a unique distribution pattern for the population. At small scales, both sampling sites exhibited an aggregated distribution, which transitions from aggregation to random or uniform distribution as the scale increases. Class I, Class II, and Class III clusters in both sampling plots exhibited a positive correlation at small scales, which shifted to negative at larger scales. The number of young plants in the populations was insufficient, with population renewal currently in a negative growth phase. At small scales, the population exhibited an aggregated distribution. The interdependence among different classes was an adaptation strategy of Ottelia acuminata var. jingxiensis populations.





The seasonal variations of nitrogen and phosphorus removal in a large northern wetland.

CHEN Tiezhu, ZHOU Rixiu, TIAN Hangfei, YANG Haiyang, LIAO Minhui, AN Shuqing, XIN Fei, LI Qiming

2025, 44(7):  2157-2163.  doi:10.13292/j.1000-4890.202507.005

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Excessive nitrogen and phosphorus affect water quality and pose a threat to urban water safety. Purifying river water and enhancing the ecological functions of rivers are essential for restoring the ecological integrity of urban watersheds. To address ecological issues such as water pollution in urban areas, projects for wetland water quality purification have been initiated. In this study, we analyzed the seasonal variations in nitrogen and phosphorus removal efficiency of a large wetland water purification project in northern China. The results showed that the project effectively removed nitrogen and phosphorus from the influent during the summer (wet season). However, in spring and winter (normal and dry seasons), low temperatures and substantial plant residues and bird excretion led to lower removal efficiency. Overall, the wetland project demonstrated a positive effect on nitrogen removal across different seasons, with the three areas-pre-sedimentation ecological ponds, subsurface flow constructed wetland areas, and aquatic plant ponds-working synergistically and complementarily. To enhance nitrogen and phosphorus removal during the less effective seasons, it is recommended to implement management measures such as plant harvesting, membrane insulation, adding carbon sources, and extending hydraulic residence time.





Population characteristics of harmful organisms and their terrain influencing factors in the alpine meadow of Guoluo Prefecture, Qinghai Province.

YANG Liyan, SONG Meiling, WANG Yuqin, WANG Hongsheng, ZHOU Rui

2025, 44(7):  2164-2173.  doi:10.13292/j.1000-4890.202507.012

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To clarify the influence of topographic factors on population density of pests in alpine meadows, we combined field surveys and geographic information technology to analyze the population characteristics of primary pests in alpine meadows in Guoluo Prefecture, Qinghai Province. These pests included Eospalax baileyi, Ochotona curzoniae, Gynaephora qinghaiensis, and Ligularia virgaurea. Using geographical detector analysis, we examined the impact of topographic factors on the population density of major pests in alpine meadows. Results showed that population densities of O. curzoniae, E. baileyi, and G. qinghaiensis exhibited a trend of initial increasing and then decreasing with elevation, with the highest densities observed at 4360-4470, 3980-4080, and 3950-3990 m, respectively. The population density of L. virgaure increased along the elevation gradient, peaking at 4070-4110 and 4280-4620 m. The densities of O. curzoniae and G. qinghaiensis on slopes above 6° were significantly higher than that on 0°-5° gentle slopes, while E. baileyi density was highest on 0°-5° slopes. The L. virgaurea population showed peak density on slopes of 0°-5° and 16°-25°. There was no significant difference in pest population density across different aspects. Geographic detector analysis indicated that elevation had the greatest influence on population densities of O. curzoniae (0.0674) and E. baileyi (0.2052), while slope had the greatest impact on G. qinghaiensis (0.2362) and L. virgaure (0.0776). The interactions between any two topographic factors primarily showed dual enhancement and nonlinear enhancement, with elevation and aspect exhibiting the highest interacting interpretability for O. curzoniae, and elevation and slope showing the highest interacting interpretability for E. baileyi, G. qinghaiensis, and L. virgaure. In summary, the population density of different pests has different responses to topographic factors in alpine meadows. O. curzoniae and E. baileyi show significant responses to altitude, while G. qinghaiensis and L. virgaure are more sensitive to slope gradients.





Leaf functional trait response to environmental gradients and community assembly characteristics in semi-humid evergreen broad-leaved forests.

LI Xinrong, PENG Mingjun, PENG Mingchun, KANG Ya, FANG Shengquan, LAN Chunyan, ZHAO Biao, CHEN Dengpeng, LI Yun, WANG Chongyun

2025, 44(7):  2174-2184.  doi:10.13292/j.1000-4890.202507.025

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The mechanism of species coexistence, as a core theme in community ecology, is critical for understanding community structure features, as well as for predicting community dynamics. We examined community assembly characters and influencing factors through the integration of phylogenetic information and leaf functional traits in semi-humid evergreen broad-leaved forests (SEBFs) in Yunnan, China. Eight leaf functional traits of five dominant tree species of SEBFs were examined along with phylogenetic data. To quantify the effects of deterministic and stochastic processes on leaf functional traits, the factors were categorized into environmental and environmental + spatial variables (representing niche-based processes) and spatial variables (representing stochastic processes). Functional trait changes along environmental gradients were analyzed. Leaf structural traits exhibited phylogenetic signals (Blomberg’s K>1 for dry matter content, specific leaf area, leaf mass per area, and leaf thickness, with P=0.05 for dry matter content), suggesting their formation and development are primarily determined by genetic variation. Leaf chemical traits showed weak phylogenetic signals (K<1, P>0.05 for leaf nitrogen, leaf phosphorus, and carbon-to-nitrogen ratio), indicating the traits of different tree species maintain optimal performance by tradeoff strategies across different habitats. Community assembly in SEBFs is a result of the combined effects of deterministic and stochastic processes. Water conditions are pivotal environmental factors shaping leaf functional traits of dominant tree species. Wetness and aridity explained 19.1% and 10.8% variations of leaf functional trait, respectively. In areas with less precipitation, dominant species in SEBFs tend to increase specific leaf area to enhance water use efficiency and increase carbon storage.





Spatiotemporal variation of dust retention in the leaves of common greening tree species in Urumqi.

Enkaer Shadekebieke, Kailibinuer Nuermaimaiti, Aliya Baiduorela

2025, 44(7):  2185-2192.  doi:10.13292/j.1000-4890.202507.013

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We explored the spatiotemporal variations of different sized particulate matter (PM) contents in leaves of six common greening tree species located in different functional areas of Urumqi central urban region, i.e., traffic area (TA), residential area (RA), park area (PA), and landscape ecological forest (LA; different altitudes of Yamalik Mountain: 844, 869, 910, 930 and 960 m). The retention of different sized PMs (PM_0.2-3, PM_3-10, PM_>10 and PM_total) were measured, and the spatiotemporal variation patterns of retention were analyzed. There were significant interspecific differences in retention of different sized PM in leaves among the six species across the TA, RA, and PA functional areas (P<0.05), with a pattern of different life-form types being evergreen trees > deciduous shrubs > deciduous trees. The retention of PM_3-10 and PM_total of different green tree species showed Pinus sylvestris var. mongolica > Picea asperata > Ulmus pumila > Ligustrum obtusifolium > Ulmus densa > Fraxinus rhynchophylla. The PM_0.2-3 retention of Picea asperata was higher than that of Pinus sylvestris var. mongolica, and the PM_>10 retention of Ligustrum obtusifolium was higher than that of Ulmus pumila. Temporally, the retention of different sized PMs of different green tree species gradually increased with time, and the lowest value was obtained on day 3 and the highest value was obtained on day 23 after heavy rain (>20.4 mm). Spatially, the retention of different sized PMs of the six species in TA was the highest, medium in RA, and the lowest in PA. The retention of different sized PMs in Ulmus pumila in Yamalik Mountain varied significantly with altitudes. The retention of PM_0.2-3 and PM_3-10 by Ulmus pumila in Yamalik Mountain increased gradually with the altitude, while there was no significant change in the retention of PM_>10 and PM_total. In conclusion, the common green tree species in Urumqi showed spatial and temporal differences in PM retention. Therefore, reasonable selection and management of greening tree species under different polluted environments is helpful to effectively exert the ability of tree species to mitigate atmospheric particulate matter.





The impact of sowing dates on yield and quality of super-early maturing foxtail millet.

WANG Chenchen, LI Yajun, MA Cui, YANG Mingzhen, WANG Juanling, LI Hongying, ZHANG Yijuan

2025, 44(7):  2193-2199.  doi:10.13292/j.1000-4890.202507.002

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To assess the influence of sowing dates on the yield and quality of foxtail millet, an experiment was conducted in 2022 using three super-early maturing foxtail millet mutants, xiaomi1, xiaomi3, and xiaomi4. We examined the yield and quality of the three mutants under different sowing date treatments, D1 (April 11th), D2 (April 29th), and D3 (May 17th). The results showed that compared to the D1, the duration of the whole growth period, as well as the seedling stage, was shortened in the D2 and D3 treatments for all the three mutants. The duration of the jointing stage initially increased and then decreased, but without any change in the duration of the filling and maturity stages. Sowing date had a significant impact on the panicle length, panicle diameter, and panicle weight of the three super-early maturing foxtail millet mutants. The panicle length and weight under D3 significantly increased compared to that under D1 (P<0.05). Furthermore, fat content significantly increased, while protein content rose initially and then declined significantly, and the contents of amylose, flavonoids, and carotenoids significantly decreased in D2 and D3 compared to D1 (P<0.05). Panicle length and panicle weight were negatively correlated with fat and flavonoid contents, and positively correlated with protein content. Daily mean temperature, ultraviolet intensity, and sunshine duration significantly affected panicle length and weight of foxtail millet, while daily mean temperature, sunshine duration, total solar irradiance and ultraviolet intensity significantly affected the contents of fat, protein and amylose (P<0.05). Sowing in mid-April could improve the quality of foxtail millet, while sowing in mid-May could increase the panicle length and weight of foxtail millet.





Impacts of climate change and human activities on potato yield in Hebei Province.

XUE Sijia, WANG Pengpeng, WEI Ruijiang, YANG Mei, LIU Yuanyuan, LI fan

2025, 44(7):  2200-2206.  doi:10.13292/j.1000-4890.202507.001

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We examined the effects of climate change and human activities on potato yield by correlation analysis, path analysis and residual trend method based on the daily meteorological observation data of 20 meteorological stations, fertilizer application amount, effective irrigated area, and potato yield from 1982 to 2022 in Hebei Province. The results showed that daily average temperature, daily maximum temperature, daily minimum temperature, the temperature of 0 cm and 5 cm soil depth increased significantly, sunshine duration decreased significantly, the precipitation and air relative humidity did not change during potato growth period. The average fluctuation of potato meteorological yield was medium, with weak fluctuation during 2021-2022. The contribution rates of climate change and human activities to the increase of potato yield were 59.07% and 40.93%, respectively, indicating that climate change was the leading factor for the increases of potato yield.





Community compositions of arbuscular mycorrhizal fungi and the effects of different strains on the growth of maize seedlings in saline soils.

YANG Kaixin, YAN Junfen, WANG Zhikang, WANG Yongqi, BIAN Wenqing, FU Xiaoyu, YANG Jisong, WANG Xuehong, GUAN Bo, YU Junbao, CHEN Xin

2025, 44(7):  2207-2217.  doi:10.13292/j.1000-4890.202507.034

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Soil salinization seriously reduces crop growth. Arbuscular mycorrhizal (AM) fungi infect crop roots by forming mycorrhizal symbiosis which can promote crop growth by increasing soil nutrient and water acquisition and multi-stress tolerance. In this study, we collected rootzone soils of three widely distributed salt-tolerant plants (Phragmites australis, Tamarix chinensis, and Suaeda salsa) in the Yellow River Delta National Nature Reserve. The community composition of soil AM fungi was analyzed by high-throughput sequencing technology. The single spores of different AM fungi were isolated and identified by wet-sieving decanting-sucrose centrifugation, host propagation and 18S rRNA sequencing. The effects of different AM fungi on the growth and photosynthetic capacity of maize seedlings in saline soil were examined in pot experiment. The results showed that: (1) The AM fungal community composed of 32 species belonging to 10 families and 12 genera, dominated by Glomus, Claroideoglomus, and unclassified Glomeromytoca. The AM community composition was closely related to soil conductivity and TOC. (2) We isolated six AM fungal strains with strong infection and stable colonization in maize roots. Strain AM3 had closer phylogenetic relationships with the family Glomeraceae and Claroideoglomus, and AM1, AM5, AM6, AM8, and AM9 were closely related to the genus Paraglomus or Glomus. (3) All of the six AM fungi can alleviate the salt stress and promote maize seedling growth. Particularly, AM3 and AM5 strains significantly improved plant height, biomass, and leaf photosynthesis. Our results revealed the differences in AM fungal community compositions in rootzone soils of salt-tolerant plants in the Yellow River Delta and evaluated their salt tolerance and growth promotion in maize seedlings, providing a scientific reference for selecting and applying AM fungi to improve crop growth in saline-alkali agricultural fields in the Yellow River Delta.








The short-term impact of fertilization and smooth vetch cover on soil nitrous oxide emissions in citrus orchards and the driving factors.

YANG Hongbing, ZENG Lixiong, LEI Lei, YANG Xin, ZHANG Jiajia, HUANG Zhilin, XIAO Wenfa

2025, 44(7):  2218-2228.  doi:10.13292/j.1000-4890.202507.016

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The investigation of the relationship between soil nitrous oxide (N₂O) emission and environmental factors, as well as its response to management practices, is of great significance for estimating soil greenhouse gas emission potential, improving non-point source pollution, and optimizing citrus orchard management in the Three Gorges Reservoir Area of the Yangtze River. We explored the effects of management practices on the physicochemical properties of citrus orchard soils, N₂O emission fluxes, and microbial characteristics, along with the regulatory mechanisms behind N₂O emissions in the Three Gorges Reservoir Area. Soil samples from 0-10 cm depth were collected under three management practices: fertilization plus smooth vetch cover (V), fertilization plus grass clearing (T), and no fertilization plus smooth vetch cover (NF). The results showed that fertilization increased overall soil enzyme activity by 5.12% and reduced the water stability of soil aggregates by 14.84%. In contrast, the smooth vetch cover reduced overall soil enzyme activity by 10.31% but did not affect aggregate stability. Fertilization stimulated soil N₂O emission, whereas smooth vetch reduced it. There was a weak correlation between soil N₂O and other gas emission fluxes. Greenhouse gas and ammonia emission fluxes were influenced by the ratio of soil carbon to nitrogen and nitrate nitrogen content under T and NF treatments, and by soil pH and water content under V treatment. N₂O emission fluxes were significantly affected by soil total porosity, cation exchange capacity, and the threshold ratio of carbon to phosphorus. Soil microbial growth and metabolism were nitrogen-limited. Both fertilization and smooth vetch cover alleviated nitrogen-limitation. Furthermore, these practices regulated N₂O emission fluxes mainly through the direct effects of soil temperature on soil silt content, mean weight diameter of water-stable aggregates, and nitrate reductase activity, which collectively explained 98.7% of the variation. Implementing sustainable agricultural management strategies can enhance soil aggregate stability, thereby directly regulating soil N₂O emission fluxes.





Reducing nitrogen leaching loss from cucumbers-densely planted soil by water-nitrogen partially decoupled drip fertigation.

NIU Mingfen, HE Jing, MA Jian, QUAN Zhi, CHI Guangyu, LU Caiyan, HUANG Bin

2025, 44(7):  2229-2239.  doi:10.13292/j.1000-4890.202507.036

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Water-nitrogen partially decoupled drip fertigation (DF) was proposed to cut nitrate leaching loss often associated with conventional water-nitrogen coupled drip fertigation (CF) in greenhouse soils. To investigate the performance of DF in a silty loam soil (thickness 28 cm), the distance between drip irrigation loci, the relative ratio of irrigation or nitrogen fertilization on water-more-nitrogen-less (WM) and water-less-nitrogen-more (WL) rootzone soil were set at 15 cm, 2, and 0.67, respectively. The reduction in soil nitrogen leaching without the presence of plants was small at an average daily irrigation intensity of 12.8 mm (<10%) after a switch from CF to DF. With an average daily irrigation intensity of 22.2 mm and the presence of densely planted cucumbers (plant spacing 25 cm), such switch slightly reduced water leaching intensity (10.8%) but significantly reduced the content of nitrate-dominated (averagely 82.0%) dissolved nitrogen in leachate averagely by 35.6% (P<0.05), resulting in significant reduction in dissolved nitrogen leaching by 42.8% (P<0.05), significant increases in soil residual nitrate level and cucumber yield (16.1%; P<0.05). DF promoted water absorption from the WM rootzone soil to weaken the lateral diffusion of water and nitrate in opposite direction in soil, and subsequently reduced dissolved nitrogen content in leachate mainly derived from the WM rootzone soil to reduce the leaching loss of dissolved nitrogen without much change in water leaching.





Community structure and diversity of fungi in rhizosphere soil of the endangered plant Woonyoungia septentrionalis.

ZHAO Ruiye, YAO Weihao, FAN Yu, WANG Zenghui, JIN Qianwen, LIAO Senmeng, OU Jing

2025, 44(7):  2240-2247.  doi:10.13292/j.1000-4890.202507.014

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Woonyoungia septentrionalis is an endangered dioecious species in China and mainly distributed in the karst habitats. Soil fungi affect the growth, development and morphogenesis of male and female trees, as well as their interaction with neighbors. Studying the difference in the composition and diversity of rhizosphere soil fungi between male and female Woonyoungia septentrionalis can provide theoretical basis for revealing the maintenance mechanism of their population in diverse habitats of karst regions. Based on the sequencing platform of PacBio, single molecule real-time sequencing (SMRT Cell) was used to investigate the composition and diversity of fungal communities in the rhizosphere soil of female and male Woonyoungia septentrionalis in Guizhou Maolan National Nature Reserve and Guangxi Mulun National Nature Reserve. The results showed that: (1) A total of 2375 fungal amplicon sequence variants (ASVs) were obtained from soil samples, belonging to 8 phyla, 30 classes, 83 orders, 176 families and 344 genera. At the phylum level, Ascomycota, Basidiomycota and Rozellomycota were the dominant phyla in the female and male individuals of Woonyoungia septentrionalis, but the relative abundances of Basidiomycota in female Woonyoungia septentrionalis were significantly higher than those in male Woonyoungia septentrionalis, while the relative abundances of Ascomycota and Rozellomycota were lower than those in male Woonyoungia septentrionalis. There were significant differences in the abundance of Pleosporales, Pezizales, and Tetracladium between the male and female groups. (2) NMDS analysis showed that there were significant differences in fungal structure between male and female groups. (3) There was no significant difference in rhizosphere soil fungi diversity index (Chao1, ACE, Shannon and Simpson) between female and male Woonyoungia septentrionalis (P>0.05). The faith_pd index of rhizosphere soil fungi in Woonyoungia septentrionalis of Guangxi was significantly lower than that in Guizhou.





Effects of short-term nitrogen addition on soil respiration components in enclosed and mown grasslands in the Hui River Basin of Hulunbuir.

JIN Sanling, QU Yan, HAN Zichen, WANG Deping, RONG Yuping

2025, 44(7):  2248-2258.  doi:10.13292/j.1000-4890.202507.010

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Soil respiration, a pivotal process of the carbon cycle in terrestrial ecosystems, comprises autotrophic respiration (R_a) and heterotrophic respiration (R_h), and is influenced by land use patterns and environmental changes. However, the response of soil respiration to grassland utilization patterns under the background of nitrogen (N) deposition remains unclear. In this study, we examined the effects of N addition on the rates of soil respiration (R_s) and its components (R_a and R_h) in long-term enclosed and mown grasslands during the growing season in the Hui River Basin of Hulunbuir. There were four levels of N addition, including 0 (N0), 2 (N2), 5 (N5), and 10 g·m^-2·a^-1 (N10). The results showed that N addition and grassland utilization patterns did not alter the temporal dynamics of soil respiration rate, with peak values observed in July-August. Nitrogen addition and grassland utilization patterns significantly affected R_s, R_a, and R_h (P<0.05), while had no effects on the ratio of R_a/R_h (P>0.05). Furthermore, there was no interactive effect of N addition and grassland utilization patterns in affecting soil respiration rate (P>0.05). The N2 treatment did not affect R_s or R_a (P>0.05). However, the N5 treatment significantly increased R_s (by 13.8% and 13.1%) and R_a (by 29.8% and 28.3%) in both enclosed and mown grasslands, respectively (P<0.05). The N10 treatment significantly increased R_s (by 7.0%) in mown grassland (P<0.05). Additionally, N addition did not affect R_h in either enclosed or mown grasslands (P>0.05). Mowing significantly increased soil respiration rates (P<0.05). R_s in mown grassland was significantly higher than in enclosed grassland under the N0, N5, and N10 treatments, while R_a was significantly higher in mown grassland only under the N0 treatment (P<0.05). Soil moisture was the main regulator of soil respiration and its components under N addition, whereas grassland utilization patterns regulated soil respiration and its components primarily through altering soil temperature and belowground biomass. Compared to fencing, mowing increased the moisture and temperature sensitivity of R_h and R_a. Moreover, N addition in enclosed grasslands enhanced the moisture and temperature sensitivity of R_a and the moisture sensitivity of R_h, but decreased the temperature sensitivity of R_h. In mown grasslands, N addition increased the moisture sensitivity of R_a but decreased its temperature sensitivity. Our results enhance the mechanistic understanding of the responses of soil respiration and its components to N addition and grassland utilization patterns in meadow steppe, which can provide a theoretical basis for the scientific management of grassland ecosystems.





Effects of typical forest transformation on soil enzyme activities and microbial nutrient limitations in Xishuangbanna, China.

JIN Liya, ZHANG Zhiming, LIU Wenjie, YUAN Xia, LUO Yan, HUANG Shuifen, ZHU Xiai

2025, 44(7):  2259-2267.  doi:10.13292/j.1000-4890.202507.021

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Land use change (LUC) is a key driver of various ecosystem processes, eventually influencing ecosystem function and stability. Hence, the knowledge of the impact of various popular LUCs on ecosystem processes and functions is vital for land management. We investigated the responses of soil enzyme activities and microbial nutrient limitations to a typical tropical LUC sequence: tropical rain forest, rubber monoculture, and rubber and Amomum villosum agroforestry system. Activities of six soil enzymes related to carbon (C), nitrogen (N), and phosphorus (P) cycle were investigated, including β-glucosidase (BG), β-xylosidase (BX), cellobiohydrolase (CBH), β-1,4-N-acetyglucosaminidase (NAG), leucine aminopeptidase (LAP), and acid phosphatase (AP). The relationships between soil enzyme activities, enzymatic stoichiometry, soil nutrients, and microbial biomass C (MBC) and N (MBN) among different forest types were analyzed. The results showed that: (1) Soil physicochemical properties differed greatly among the three forest types (P<0.05). Soil total nitrogen (TN) and total phosphorus (TP) concentrations of the rubber monoculture were higher than those of the other two forest types. Available phosphorus (AP), ammonium nitrogen (NH₄⁺-N), organic carbon (SOC) and dissolved organic carbon (DOC) concentrations were the highest in the agroforestry system, while the other soil physicochemical indices were the highest in tropical rain forest. (2) Forest conversion significantly influenced BG, CBH, NAG, and AP activities. CEs:NEs (C/N ratio of extracellular enzymatic activities) and CEs:PEs (C/P ratio of extracellular enzymatic activities) of the rubber monoculture were significantly higher than that of the other two forest types. (3) Enzymatic stoichiometry showed that soil microorganisms were limited by C and N across the three forest types. Specifically, microbial C limitation in rubber monoculture and N limitation in tropical rainforest were the highest. Microbial C and N limitations were mitigated in the agroforestry system. The redundancy analysis showed that soil NH₄⁺-N, SOC, MBN, MBC, NO₃^--N, and DON were the main environmental factors affecting soil enzyme activity and stoichiometry. In conclusion, the conversion of tropical rainforest to rubber monoculture significantly aggravated microbial C limitation, while the intercropping practice of A. villosum alleviated microbial C and N limitations caused by rubber plantation. Therefore, A. villosum shows promise as an intercropping species for establishing sustainable rubber-based agroforestry systems and improving soil nutrient balance.





Ecological stoichiometric characteristics and rhizosphere effects of soil in mixed forests of Cunninghamia lanceolata and Phoebe bournei. 

HUANG Ao, JI Li, HE Gongxiu, NI Yanlin, YANG Lili, WANG Mingkun

2025, 44(7):  2268-2276.  doi:10.13292/j.1000-4890.202507.022

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The rhizosphere is an important site for the exchange of matter and energy between trees and the external environment. It is of great significance to explore rhizosphere soil microorganisms and their stoichiometric characteristics for understanding nutrient cycling in forest ecosystems. In this study, the contents of carbon (SOC), nitrogen (TN) and phosphorus (TP) in rhizosphere and bulk soil under dry and wet seasons were measured in 10-year-old pure forest of Cunninghamia lanceolata (PCL), pure forest of Phoebe bournei (PPB) and mixed forest of Cunninghamia lanceolata and Phoebe bournei (MCP), and the rhizosphere effects of ecological stoichiometry were analyzed. The results showed that the contents of SOC, TN, TP, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP) in rhizosphere soil under the three forest types were generally higher than those in bulk soil. The contents of SOC, TN, TP, MBC, MBN and MBP in rhizosphere soil of Cunninghamia lanceolata and Phoebe bournei in mixed forest were significantly lower than those of pure Cunninghamia lanceolata and Phoebe bournei plantations, respectively. Soil C∶N, C∶P and N∶P in PCL stand were significantly higher than those in PPB. The MBC∶MBN and MBC∶MBP of rhizosphere and bulk soils increased significantly in dry season after mixed with Phoebe bournei, and these ratios of rhizosphere and bulk soils of Phoebe bournei decreased significantly after mixing with Cunninghamia lanceolata. The activity of rhizosphere soil sucrase was higher in mixed forest than in pure forest in both seasons. The activity of catalase in mixed rhizosphere soil was significantly lower than that in bulk soil. Results of partial least squares path analysis showed that mixed planting had negative effects on soil microbial biomass and rhizosphere effect, with a greatest rhizosphere effect on MBP. Mixed cultivation had overall positive effect on soil pH.





Soil nutrient distributions in different habitats of the Ulanbuh Desert.

MU Ren, LI Xinle, XU Guangfu, HAN Jinfu, CUI Jian, YU Xiao, GUO Junting, XIN Zhiming

2025, 44(7):  2277-2284.  doi:10.13292/j.1000-4890.202507.032

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Clarifying the distribution of soil nutrients in different habitat types in the Ulanbuh Desert can provide scientific basis for revealing nutrient limitation patterns. The habitats in the Ulanbuh Desert were classified into five types: semi-mobile sand dune, fixed/semi-fixed sand land, Gobi, saline alkali land, and grassland. Soil physical and chemical properties of those five habitat types were measured and stoichiometric ratios were calculated. Results showed that: (1) In the Ulanbuh Desert, soil available nitrogen and total potassium exhibited high stability, with coefficients of variation (CV) being 8.17% and 9.44%, respectively. Habitat type was the principal factor influencing the levels of soil organic matter, available nitrogen, and available potassium. The levels of soil total nitrogen, total phosphorus, and available phosphorus were influenced by the parent material. (2) Soil available nitrogen in the 0-10 cm layer of grassland was 132.90% higher (P<0.05) than the 10-20 cm layer, the available phosphorus was 96.43% higher (P<0.05) compared to 20-40 cm, and the available potassium was 52.11% higher (P<0.05) compared to 40-60 cm, highlighting a pronounced phenomenon of nutrient enrichment in the surface layer. (3) Principal component analysis indicated that soil organic matter contributed the most to soil stoichiometry across different habitat types. Moreover, there were significant positive correlations (P<0.05 or P<0.01) between soil organic matter and total nitrogen, total phosphorus, and available phosphorus. Therefore, soil organic matter can be used as an indicator to evaluate soil nutrient limitations of different habitats in the Ulanbuh Desert. Our results are of great significance for clarifying the differences in soil physical and chemical properties, stoichiometric ratios, and regulatory factors in different habitats of the Ulanbuh Desert, providing scientific basis for the protection and restoration of desert ecosystems.





Effects of sludge compost and sludge vermicompost on physicochemical properties and heavy metal concentrations of aeolian sandy soil.

JIANG Xiaoyu, ZHOU Shuhui, LV Linyou, HE Miaomiao, TANG Jiaxi

2025, 44(7):  2285-2296.  doi:10.13292/j.1000-4890.202507.037

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The use of domestic sludge is an effective way of sludge disposal and has a good effect on the quality of nutrient-poor soil. In this study, municipal sludge was treated by aerobic composting and earthworm composting. The effect of sludge compost and sludge vermicompost on aeolian sandy soil in northwest Liaoning Province was examined in a 3-year field experiment. The physical and chemical properties of aeolian sandy soil and heavy metal content in different soil layers were analyzed. The results showed that the application of 30 t·hm^-2 of sludge compost and sludge vermicompost effectively improved moisture content and porosity of the aeolian sandy soil, and reduced the soil bulk density. The moisture content of the aeolian sandy soil applied with sludge compost was increased by 95.6%, and the porosity of soil applied with sludge vermicompost was increased by 8.0%. Sludge vermicompost application reduced soil bulk density by 11.4%. Meanwhile, soil fertility and soil nutrient content were improved. The contents of alkali-hydrolyzed nitrogen, available phosphorus and available potassium of the aeolian sandy soil applied with sludge compost increased by 19.0 times, 119.5 times and 6.1 times, while electrical conductivity of the aeolian sandy soil applied with sludge compost increased by 7.6 times. The maximum increase of cation exchange capacity of aeolian sandy soil applied with sludge compost was 9.7 times. When treated with sludge vermicompost, fresh weight of alfalfa leaves increased by 32.2%. Under both amendments, the concentrations of heavy metals in different layers of aeolian sandy soil were lower than the risk screening values in the “Standard for the Control of Soil Pollution Risk of Agricultural Land (Trial)” (GB 15618-2018). The results of single factor potential ecological risk and comprehensive potential ecological risk assessment of heavy metals are both in the safe range.





Musk secretion, appearance and muscone levels of captive forest musk deer in Zherong Musk Deer Farm in eastern Fujian Province, China.

LU Xiaoping, YI Simin, ZHENG Qintong, LIN Mingsheng, ZHANG Yanda, Vasili Shakun, Irena Solovej, ZENG Fangang, MENG Xiuxiang

2025, 44(7):  2297-2303.  doi:10.13292/j.1000-4890.202507.023

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Musk, widely used in the medicine and perfume industries, is secreted by adult male musk deer (Moschus spp.) and is one of the national strategic reserved materials in China. As musk deer (Moschidae) has been listed as the first class of national protected animals, it is explicitly prohibited to extract musk from the endangered wild musk deer. Musk deer farming has been one of the most important measures for the sustainable supply of natural musk and ex situ conservation of the endangered musk deer, of which the forest musk deer (M. berezovskii) is the most abundant. During November 1 to December 28 of 2023, the musk secretion of captive forest musk deer from the Zherong Musk Deer Farm in Fujian Province was monitored. Variables such as musk appearance, moisture content, and muscone levels were examined and compared based on the collected musk samples. The results showed that the overall extraction rate of forest musk deer in Fujian Zherong Musk Deer Farm was 100%, the effective extraction rate reached 85.07%, with musk secretion ranging 5.8-25.1 g per animal. The musk secretion of forest musk deer at the age of 1.5 years old was significantly lower than that of other age groups (P<0.01), and the highest musk secretion was recorded at the age of 2.5 years (16.91±5.36 g). The mean muscone content in mature musk secreted by captive forest musk deer was 1.66%±0.83% (n=57), without any difference among age groups (P>0.05). Muscone content was significantly correlated with musk appearance score (r=0.281, P<0.01). Our results suggest that musk secretion variables such as effective musk extraction rate and muscone content of captive forest musk deer in Zherong, Fujian Province were at a relatively favorable level compared with captive forest musk deer in other regions of China. In the practice of musk harvesting in musk deer farms, it is recommended that musk harvesting of male individuals secreting abnormal musk should be delayed to allow the musk to fully mature and increase musk production and quality. Since musk deer farming is currently the unique way to supply natural medicinal musk, it is recommended that the musk evaluation standards of the Chinese Pharmacopoeia should be revised accordingly, such as specifying standardized musk harvesting procedures.





Population status and habitat suitability evaluation of badger (Meles meles) in southern Laoyeling, Heilongjiang Province.

TIAN Xinmin, WANG Xinxue, GUO Wenliang, JI Xuyang, ZHOU Shaochun, ZHANG Zidong, LIU Lei, MENG Zijing, QI Qi, CHEN Hong

2025, 44(7):  2304-2311.  doi:10.13292/j.1000-4890.202507.020

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Understanding population status and habitat distribution is a fundamental aspect in biodiversity conservation. Laoyeling Mountains is considered a biodiversity hotspot in Heilongjiang Province. To determine the population status and habitat suitability of badgers (Meles meles) in this area, we collected photo, burrow, and footprint data by conducting large-plot surveys during the snow cover season, as well as camera trapping from 2021 to 2022. We analyzed population density, population size, and distribution within and outside the protected areas. Then, we evaluated the habitat suitability for this species based on occurrence datasets using maximum entropy (MaxEnt) modeling. The overall population density of badgers was 0.37±0.03 individuals·km^-2. Population densities were higher in protected areas, with 0.64±0.05 individuals·km^-2 in Laoyeling Amur Tiger National Nature Reserve and 0.42±0.03 individuals·km^-2 in Muling Japanese Yew National Nature Reserve, compared with a density of 0.23±0.02 individuals·km^-2 in the forest areas of Hanconghe and Liuqiaogou outside the reserves. The total population size was 1263-1483 individuals. The main environmental variables, including forest trails (30.9%), residential areas (21.5%), evergreen coniferous forests (10.7%), croplands (10.3%), rivers (6.1%), and grasslands (5.4%), had significant effects on the habitat suitability of badgers. The area of suitable habitat for M. meles was 395.06 km², accounting for 10.5% of the total area. 32.7% of the suitable habitats of the badger were within nature conservation network. A total of 265.82 km² suitable area need to be protected. To summarize, human disturbance had a considerable effect on habitat suitability of M. meles, mainly outside the reserves. Therefore, it is recommended to inhibit human activities such as poaching and resource harvesting in Taipingchuan, Wanbaowan, and Shuangning forest areas outside the reserves, and to strengthen the protection of the Nuanquan River, Zhongguliu, and Heping forest areas in the reserves.





Risk analysis of bird strike based on the records: A case study of Xi’an Xianyang International Airport.

ZHANG Xiaofeng, QU Xuejian, WANG Min, QIAN Tenghui, WANG Zhe, LIU Boye

2025, 44(7):  2312-2318.  doi:10.13292/j.1000-4890.202507.019

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Bird strike is one of the important factors threatening aviation safety. Extensive research has been carried out on bird strike risks of airports. However, earlier studies predominantly relied on bird community data obtained from line transect surveys, which led to some discrepancies compared to actual bird strike events. Few studies assessed the species-specific bird strike risk based on empirical data. In this study, we proposed a risk assessment model based on bird strike data, according to previous literature and work experience. The bird strike risk index was calculated based on the species identification data from bird strike residues collected at the Xi’an Xianyang International Airport from 2014 to 2022. The suitability of the model was evaluated based on the characteristics of bird species, including living habits, migration patterns, body size, clustering, and activities in and around the airport. This study provides new ideas and methods for the assessment of bird strike risk of airports.





Variations and niche driving factors of ground-dwelling spiders in Pinus tabuliformis forests of the Loess Plateau in Northern Shaanxi.

WU Zeyang, AI Ning, HUANG Lou, WANG Jie, YUAN Caixia, LIU Changhai

2025, 44(7):  2319-2329.  doi:10.13292/j.1000-4890.202507.024

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Spiders, as significant consumers, play a crucial role in maintaining biodiversity and ecosystem functions of pine plantations in arid and semi-arid regions. However, the diversity of ground-dwelling spiders in the Chinese pine forests in the areas where farmlands have been returned to forests of the Loess Plateau in northern Shaanxi remains poorly understood, limiting our understanding of the variations of spider community structure, ecological niches, and the maintenance mechanisms of spider diversity. In this study, four stands of Pinus tabuliformis with varying restoration ages were selected in Wuqi County, Yan’an City, along with an abandoned grassland as a control. Spider diversity was evaluated using the pitfall trapping method. One-way ANOVA and PCA were employed to compare species composition similarity, community diversity, and the niche characteristics of ground-dwelling spiders across different restoration years. The impacts of soil factors on spider diversity were analyzed. The results showed that: (1) The dominant ground-dwelling spider species in P. tabuliformis forests were Agroeca mongolica, Pardosa schenkeli, and Draconarius yananensis, which together accounted for over 50% of the total captures. (2) With increasing restoration years, the number of ground-dwelling spiders in P. tabuliformis forests gradually decreased. The species richness of spider communities did not significantly differ among restoration years, exhibiting a trend of initial decline followed by an increase. The evenness index and Shannon index initially increased, then decreased, and finally increased again. The Simpson index first decreased, then increased, and finally decreased again. The Jaccard similarity index among different habitats ranged from 0.39 to 0.72, indicating that ground-dwelling spider communities exhibited a moderate level of dissimilarity and similarity. (3) Among the spider species, Gnaphosa sinensis had the widest niche breadth and Gnaphosa songi had the narrowest. Niche overlap values for the primary ground-dwelling spiders varied from 0.33 to 1, with high overlap accounting for 37.88%, moderate overlap for 25.76%, and low overlap for 36.36%. The total niche response rate of the 12 main ground-dwelling spider species was positive, suggesting that they were in a developmental stage. (4) The key soil physicochemical factors influencing the distribution of ground-dwelling spiders in P. tabuliformis forests of varying restoration ages on the Loess Plateau included available potassium, capillary porosity, soil moisture, total nitrogen, pH, and alkaline hydrolyzable nitrogen. This study elucidates the variations and niche characteristics of ground-dwelling spiders in pine forests across different restoration years, thereby enhancing our understanding of spider population dynamics in artificial pine forests under the Grain for Green Program in northern Shaanxi.





Production mechanism and emission flux of nitrous oxide in surface waters of a small agricultural watershed in Sanjiang Plain.

ZHANG Hai, LIU Kaiming, LI Xia, BAI Li, WANG Mingguo, YANG Tao, LIU Xiaolong, LI Jun

2025, 44(7):  2330-2339. 

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Farmland drainage changes the hydrological process in the river-ditch-paddy field water networks and rebuilds the spatial distribution of nitrogen, with consequence on N₂O production. It is of great significance to explore the production and emission of N₂O in water from agricultural activities for improving the global N₂O budget and indirect emission factors. In this study, we explored the production mechanism of N₂O and source and sink effects of surface waters during the drainage period of farmlands in the Nongjiang River Basin in Sanjiang Plain. Headspace equilibrium gas chromatography was used to determine the concentration of N₂O in the water body. The boundary layer model was used to calculate the N₂O flux, and the physical and chemical indices in the water body were measured simultaneously. The results showed that surface waters were the source of atmospheric N₂O. The average N₂O fluxes in the Yalu River, the Nongjiang River, and ditches were 0.72, 0.20, and 0.34 μmol·m^-2·h^-1, respectively. The average emission factor (EF_5r) for rivers and ditches was 0.85% and 0.32%, respectively, which were higher than the recommended EF_5r values by the International Intergovernmental Panel on Climate Change (IPCC) and the average EF_5r values for world rivers. The significant positive correlation (P<0.05) between inorganic nitrogen (DIN) and N₂O concentration indicated that high levels of inorganic nitrogen can increase nitrification and denitrification rates, and thus stimulate the production of N₂O. The significant positive correlation (P<0.05) between dissolved organic nitrogen (DON) and N₂O concentration in Yalu River indicated that high concentration of DON will promote mineralization and affect the production of N₂O. The sink of N₂O in the mixed urban and agricultural watershed indicated that the lower denitrification rate may cause the consumption of N₂O.





Assessment of urban spatial layout and resilience in Liaodong Peninsula from the perspective of production-living-ecological space.

LIU Pudong, HUANG Li, LIU Jiantao, ZHUO Wei, WANG Yuanke

2025, 44(7):  2340-2349.  doi:10.13292/j.1000-4890.202507.017

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It is crucial to clarify the relationship between the spatial distribution of “production-living-ecological” space (PLES) and urban resilience for exploring the urban environmental situation caused by rapid urban expansion and intensified carbon emissions. Based on the perspective of PLES, we constructed an evaluation system for PLES and urban resilience by considering the carbon emissions, POI (point of interest) data, and nighttime light data. We further assessed the rationality of spatial patterns and urban risk tolerance according to the spatial coupling coordination degree and urban resilience measurement. The results showed that: (1) Between 2010 and 2022, the highvalue area of production space in the Liaodong Peninsula increased by 1228 km², ecological space decreased by 222 km², and living space increased by 449 km². (2) Between 2010 and 2022, the overall urban resilience showed a trend of first increasing and then decreasing, with a decline of 29.4% in production resilience, 10.29% in living resilience, and 14.16% in ecological resilience. Production resilience had a greater impact on the overall urban resilience, while ecological resilience had lesser effect on the overall urban. (3) The level of coupling coordination in most areas of the Liaodong Peninsula was predominantly highly positively correlated, exhibiting a spatial aggregation state. In terms of urban resilience, the aggregation degree of ecological resilience was higher than that of production resilience and living resilience. Therefore, the distribution of the PLES in the Liaodong Peninsula varied greatly, with ecological space gradually decreasing and production space rapidly expanding. The Liaodong Peninsula should enhance efforts in ecological environmental protection and balance the PLES pattern.





Variation and driving force of “production-living-ecological space” pattern in mountainous urban clusters: Taking Chongqing as an example.

LI Liangxin, WEI Xinping, YU Yuanxiu, LI Hui, CAI Yunli, CHEN Shidie, FENG Liuliu, LI Wenyan

2025, 44(7):  2350-2364.  doi:10.13292/j.1000-4890.202507.030

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Clarifying the spatial and temporal variations of land use pattern of “production-living-ecological space” in mountainous urban clusters can provide scientific basis for the utilization and rational planning of regional land resources. Based on the pattern of “one district and two clusters” in Chongqing and the remote sensing monitoring data of land use from 2000 to 2020, the dynamic degree model, transfer matrix, kernel density analysis and land use degree index were used to quantitatively analyze the spatial and temporal variations of “production-living-ecological space” land use in each urban cluster from two aspects of quantitative structure and spatial structure. The driving force of “production-living-ecological space” land use change at different temporal scales was analyzed by geographical detector. The results showed that land use change rate of the “production-living-ecological space” of each urban cluster accelerated and that the main urban metropolitan area was mainly converted from agricultural production land to forest ecological land, industrial and mining production land, and urban living land. The urban cluster in the Three Gorges Reservoir area in northeast Chongqing and the urban cluster in Wuling Mountain area in southeast Chongqing were mainly transformed from  agricultural production land to forest ecological land. In the past 20 years, the urban clusters as a whole were in a development period. The high-density area of agricultural production land was mainly distributed in the western part of Chongqing. The high-density core of urban living land was located in the main urban area. The high-density area of forest and grassland ecological land was concentrated in the Three Gorges Reservoir area of northeast Chongqing and the Wuling Mountain area of southeast Chongqing. The change of water area and other ecological lands was relatively stable. Socio-economic factors had a significant impact on land use change of each urban cluster, with population density as the dominant factor. The interaction between factors showed two-factor enhancement or non-linear enhancement. Our results provide reference for land use regulation and policy formulation of “production-living-ecological space” in mountainous areas.





Impact of road network pattern on landscape ecology of Altai Mountains Nature Reserve.

HOU Jinchao, HAN Fang, WANG Boli, XU Rui

2025, 44(7):  2365-2376.  doi:10.13292/j.1000-4890.202507.031

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Road network is one of the key factors driving the intensification of regional land use and landscape pattern change. How to measure the relationship between road network construction and ecological protection is a hot research topic. Based on road network data of various grades in 2000, 2010 and 2020, alongside land use data from the years 2000, 2010, and 2020 in the Altai Mountains Nature Reserve, we explored the relationship between land use and landscape patterns within different distances from the road network by using buffer zone analysis, dynamic land use change analysis, and landscape pattern analysis. The results showed that: (1) Over the past 20 years, roads of all grades intensified changes in land use types to varying degrees, with the changes being particularly pronounced alongside lowergrade roads. (2) From 2000 to 2020, forest lands and grasslands were the main sources of other land categories along roads of different grades. Forest lands and grasslands were major contributors to waters and unused lands along roads of provincial and national roads (>6.84%), while they were major contributors to residential lands and unused lands along county roads, township roads, and alternate roads (>6.15%). (3) In the past 20 years, there was an increase in both patch area and patch shape index within the buffer zones of roads of all grades. The growth rate of patch area in buffer zones of lowergrade roads was higher than that of highergrade roads. Moreover, patch shape was more complex and the landscape fragmentation was more significant. Our results indicate that land use types on both sides of the lower-grade road have changed significantly and that forest lands and grasslands were greatly affected by road construction. In the future, road network construction should not only assess its impact on the ecological environment along the roads in advance, reducing the negative impacts on the ecosystems of the Altai Mountains Nature Reserve before and after the construction of the road network, but also establish a long-term monitoring mechanism to ensure timely management and control of ecological environment changes.





Winter climate suitability for influenza A (H1N1) transmission in the Guangdong-Hong Kong-Macao Greater Bay Area and the spatiotemporal differentiation.

DUAN Hailai, LIU Chang, DU Yaodong

2025, 44(7):  2377-2382.  doi:10.13292/j.1000-4890.202507.004

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Based on the daily meteorological data and influenza A (H1N1) case data of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), a climate suitability model was used to calculate, evaluate, and predict the climate suitability and its spatiotemporal differences for the transmission of H1N1 in GBA during winter. The results showed that the climate suitability index for H1N1 transmission was relatively high from late December to next mid-February, with a small coefficient of variation. The suitability index peaked in late January, indicating the most suitable period for H1N1 transmission. Over the past 42 years, the climate suitability index for H1N1 transmission in GBA during winter showed a downward trend, with a significant decrease after 2015. From a monthly perspective, the climate suitability index in December and January showed a consistent increasing trend, but a significant decreasing trend in February. Moreover, the climate suitability for H1N1 transmission showed a spatial pattern of decreasing from northwest to southeast, with the suitability index in the northwest region being 1.5 to 2 times that in the southeastern coastal areas. In terms of variation trends, the suitability for H1N1 transmission was increasing in the eastern area of west side of the Pearl River Estuary and some regions of Huizhou, particularly in Foshan and Zhongshan, with an increase rate exceeding 1.0(10 a)^-1, while the coastal areas showed a downward trend, with a reduction rate of more than 0.05(10 a)^-1. In conclusion, the critical period for the H1N1 transmission was from the Winter Solstice to the Beginning of Spring of the following year, and the key areas of focus were the core cities of the west of the Pearl River Estuary.





A review on nitrogen fixation by symbiotic microorganisms in bryophytes and its ecological impacts.

LI Yi, XIANG Xing, SHEN Jiaheng, YANG Huan

2025, 44(7):  2383-2398.  doi:10.13292/j.1000-4890.202507.011

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As a milestone in plant evolution, bryophytes play a crucial role in carbon and nitrogen cycling in terrestrial ecosystems, and are sensitive to environmental changes. Nitrogen fixation by bryophyte-microbial symbionts shed new light on nitrogen and carbon cycles in terrestrial ecosystems. The nitrogen fixation process by sphagnum-microbial symbionts is particularly important in peatland ecosystems, which are one of the largest terrestrial carbon pools. We summarized microbial taxa symbiotic with bryophytes and the methods tracing the nitrogen fixation of symbiotic microorganisms. We focused on sphagnum-microbial nitrogen fixation in peatland ecosystems and discussed factors affecting nitrogen fixation by bryophyte-microbial symbioses as well as their ecological functions. Future studies should investigate the relationships, interactions, and co-evolutionary mechanisms between bryophytes and their symbiotic nitrogen-fixing microorganisms. Developing multiple proxies is also necessary to identify the identity and function of microorganisms fixing nitrogen in bryophytes. Additionally, the interaction between environment and nitrogen-fixing functions of the bryophyte-microbial symbioses should be explored as well.








Structure and physiological and ecological functions of root tissue of typical mangrove plants.

WANG Wenjing, YAO Qi, ZHAO Chunzhou, WANG Na, WANG Yan

2025, 44(7):  2399-2407.  doi:10.13292/j.1000-4890.202507.026

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Mangroves are one of the most carbon-rich ecosystems worldwide, with high ratio of below to above-ground biomass. Different types of mangrove roots and their physiological and ecological functions play an important role in the carbon budget of sediment layer. Except the absorptive roots in the sediment or soil layer, the aerial roots of mangrove plants exhibit many morphological variations to adapt to the complex environmental factors in the coastal zone, including prop/stilt roots, knee-like roots, plank roots, and pneumatophores. We reviewed the variations of different types of roots in structure, anatomy and other functional traits, and summarized their crucial roles in mangrove ecosystems, such as providing support for stem, gas exchange, maintaining biodiversity, as well as nutrient uptake. We also made an expectation on the development of the root researches, providing reference for future studies in mangrove root system.





A review of Rensch’s rule in amphibians and reptiles.

LIANG Tao, SHI Lei

2025, 44(7):  2408-2416.  doi:10.13292/j.1000-4890.202507.003

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Sexual size dimorphism is the phenomenon that conspecific males and females show different magnitudes or directions of body size variations at broad geographic and phylogenetic scales. The Rensch’s rule describes the patterns of sexual size dimorphism allometry, in that body sizes of males are larger than females in large-sized species and body sizes of females are larger than males in small-sized species. Sexual selection, fecundity selection, and sex-specific phenotypic plasticity hypothesis have been proposed to explain the Rensch’s rule or the inverse pattern. Amphibians and reptiles are widespread except Antarctica. They have abundant phenotypic traits, and exhibit a wide sexual size dimorphism, from marked male bias to strong female bias, which are excellent model organisms to test Rensch’s rule. We reviewed the research progress on Rensch’s rule in amphibians and reptiles, with the focus on the definitions, statistics, patterns, and mechanisms of this rule. We further proposed future research direction of Rensch’s rule.





Discussion on the concept and approach of roadside slope close-to-nature restoration.

LIN Sha, CHEN Jianye, KONG Yaping, TAO Shuangcheng

2025, 44(7):  2417-2424.  doi:10.13292/j.1000-4890.202507.015

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The protection of ecological environment along highways should be strengthend and the overall quality of roadside ecological restoration should be enhanced. There are several challenges in roadside slope restoration, including insufficient implementation of the concept of close-to-nature and unclear realization path. We introduced the concept of “close-to-nature” into the field of roadside ecological restoration, put forward a new concept of roadside slope close-to-nature restoration, accompanied by a deep analysis of its core theories, and established three basic principles for implementation. A comprehensive theoretical framework and practical approach for the roadside slope close-to-nature restoration were systematically developed, encompassing suitable habitat construction, vegetation restoration and reconstruction, as well as positive succession induction intervention. Furthermore, the key technologies of roadside slope ecological restoration at the current stage were sorted out and summarized, aiming to provide theoretical guidance and technical support for the roadside slope close-to-nature restoration, and promote the sustainable development of harmonious coexistence between highway construction and ecological environment.





Molecular composition and mineralization of sediment organic nitrogen in coastal area and their response to environmental changes: A review.

YANG Jia, WU Yunchao, LI Jinlong, LI Pengju, JIANG Zhijian, LIU Songlin, HUANG Xiaoping

2025, 44(7):  2425-2437.  doi:10.13292/j.1000-4890.202507.035

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Organic nitrogen is one of the primary forms of nitrogen in coastal sediments, playing a crucial role in biogeochemical cycles. The molecular composition and mineralization processes of organic nitrogen in coastal sediments exert significant influences on coastal eutrophication and the emission of major greenhouse gases (such as N₂O). We systematically review the molecular composition, sources, and mineralization processes of organic nitrogen in coastal sediments, summarize their responses to environmental changes, including human activities and climate changes. The molecular composition of coastal sediment organic nitrogen is complex and challenging to characterize. Conventional methods offer only preliminary insights, as they fail to provide detailed molecular composition information or track transformation processes. Our understanding is primarily confined to the metabolic processes of proteins and nucleic acids. Advanced techniques, particularly FTICR-MS, provide critical technical support for unraveling the molecular composition of sediment organic nitrogen. Factors such as eutrophication, warming, and acidification affect the mineralization processes of coastal sediment organic nitrogen. They influence the microbial communities involved in mineralization, which alters the characteristics of coastal sediment organic nitrogen (e.g., molecular composition and content). Considering the knowledge gaps, we propose three directions for future research of coastal sediment organic nitrogen: (1) employing new technologies and methods to further decipher the molecular composition and sources of sediment organic nitrogen, (2) using genomics, transcriptomics, and other omics techniques to delve deeper into the mineralization processes and pathways of sediment organic nitrogen, (3) investigating how sediment organic nitrogen mineralization responds to human activities and climate change, with a particular focus on its impact on the emission of N-related greenhouse gases.





Spatiotemporal variations and influencing factors of vegetation coverage in Sichuan Province.

LUO Xufu, DONG Zhengliang, SUN Yufang

2025, 44(7):  2438-2447.  doi:10.13292/j.1000-4890.202507.018

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Revealing the spatiotemporal variations in vegetation and the correlation with different factors provides a crucial basis for the quantitative assessment of regional ecological environment. Utilizing MODIS data from 2000 to 2020, we employed a pixel bipartite model to estimate fractional vegetation coverage (FVC) and analyzed the changes in vegetation coverage over the past 21 years in Sichuan Province. This analysis was conducted using the Sen+Mann-Kendall trend analysis, correlation coefficient method, and transfer matrix method, along with an exploration of the coupling changes with influencing factors. The results showed that: (1) The overall vegetation coverage in Sichuan Province was favorable, with medium to high coverage areas accounting for 85.31% of the total area. (2) Spatially, FVC was higher in eastern Sichuan than in the west, with lower coverage in the northwest and western regions, and higher coverage in the southern and northeastern parts. The overall growth and development status of vegetation were improved. (3) The correlations between temperature, precipitation, potential evapotranspiration, and FVC were significant in the central Sichuan Plain and northeastern regions. (4) There was a significant negative correlation between elevation and FVC across Sichuan Province. The elevation range with the highest average FVC was 1573-2302 m, with an average FVC value of 0.781. (5) Over the past 21 years, the areas of forest land, water bodies, unused land, and construction land had increased, while grassland and cultivated land had decreased. The conversion of cultivated land and grassland to construction land was the primary driver of FVC reduction. Overall, vegetation coverage in Sichuan Province showed an increasing trend from 2000 to 2020, with positive consequence on ecological environment improvement and protection.





Ecological quality assessment of Yellow River Delta based on DPSIR model.

YIN Yuanfeng, LIN Xingna, JIAO Shengwu, WU Ming

2025, 44(7):  2448-2455.  doi:10.13292/j.1000-4890.202507.033

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We assessed the ecological quality of four districts/counties in Dongying City (Dongying District, Hekou District, Kenli District and Lijin County) located in the Yellow River Delta. An ecological quality evaluation system was established with DPSIR model by identifying 14 indicators, including population density, sediment flux, and natural shore-line rate. The weight of each indicator was calculated by the entropy weight method. Using a comprehensive index approach, we analyzed the dynamics of ecological quality assessment index and its driving factors for each district/county from 2000 to 2020. The comprehensive index for ecological quality assessment of the modern Yellow River Delta decreased in 2000-2010 and increased in 2010-2020. Kenli District demonstrated superior ecological quality, while Dongying District showed inferior performance. Population density, area of wetland restoration, and wetland protection rate were key factors influencing the ecological quality. State, influence, and response indicators had significant impacts on wetland ecological quality. Different districts/counties exhibited different driving factors for improving ecological quality, such as population density for Dongying District and Lijin County, area of wetland restoration for Hekou District, and population density and wetland rate for Kenli District. Our results provide a scientific foundation for ecological protection and restoration in the Yellow River Delta.





Ecological suitability zoning of three Scutellaria species in Shanxi Province based on MaxEnt and ArcGIS.

JIANG Xia, ZHAO Junxi, SHI Panpan, PING Lili, DU Chenhui, ZHAN Haixian

2025, 44(7):  2456-2464.  doi:10.13292/j.1000-4890.202507.027

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Studies on the ecological suitability zoning of Scutellaria medicinal plants can provide scientific data for predicting the ecological suitability range and selecting suitable cultivation areas of medicinal plants in Scutellaria. We collected the distribution information of three widely distributed medicinal species of Scutellaria in Shanxi Province during the Fourth National Survey of Traditional Chinese Medicine Resources (including 421 samples of Scutellaria baicalensis Georgi, 87 samples of S. scordifolia Fisch. ex Schrank, and 14 samples of S. viscidula Bunge.), as well as data of 55 ecological factors. The Maximum Entropy Model (MaxEnt) and Geographic Information System (ArcGIS) were used to identify the key ecological factors affecting the distribution of suitable habitats for three Scutellaria species. The results showed that vegetation type, altitude, precipitation were the main factors affecting the distribution of suitable habitats for the three Scutellaria species. The critical factors affecting the ecological suitability varied among species. S. baicalensis and S. scordifolia had a wide distribution of potential suitable areas in Shanxi Province, with relatively large suitable distribution area in Xinzhou, Lvliang, Linfen, Changzhi, Jinzhong, Taiyuan, and Shuozhou. The potential distribution of S. viscidula in Shanxi Province was relatively small, mainly concentrated in Datong, Shuozhou, and Xinzhou (the northern regions of Shanxi Province). Our results provide references for the rational introduction and cultivation of S. baicalensis and its substitutes (S. scordifolia and S. viscidula), and will facilitate the standardized production of S. baicalensis in Shanxi Province.