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A review on light response model of photosynthesis under different environmental conditions WANG Fubiao, YANG Xiaolong, KANG Huajing, YE Zipiao Chinese Journal of Applied Ecology    2023, 34 (7): 1995-2005.   DOI: 10.13287/j.1001-9332.202307.003 Abstract （92）      PDF（pc） （1224KB）（76）       Knowledge map    Save Light response curve of photosynthesis (An-I curve) is a useful modeling tool to investigate how photosynthesis reacts with different abiotic factors, which would help quantify the response of photosynthetic rate to photosynthetically active radiation. Based on the mathematical characteristics of photosynthesis An-I models, we reviewed the advantages of using these model in practice and the potential caveats. We proposed the development of new mechanistic photosynthesis An-I models based on the primary light response and discussed its advantages in the field of plant ecology and physiology. Photosynthesis has three main steps, including the primary reaction, the assimilatory power forms, and the carbon assimilation. Changes in each step could directly affect the photochemical efficiency and carbon assimilation in photosynthesis. The primary reaction consists of a series of physical processes that are related to light energy absorption and utilization, including the absorption of light energy, the change of quantum state, and the transfer and de-excitation of exciton resonance of light-trapping pigment molecules. How-ever, the empirical photosynthesis An-I models can not explain some scenarios. For example, the non-photochemical quenching in plants increases with increasing light intensity in a non-linear manner. Further, the life-time of singlet chlorophyll molecules can be extended when plant light-harvesting pigment molecules absorb excessive light energy but would not be immediately used for the photochemical reaction. Meanwhile, the parameters obtained by fitting the mechanistic An-I curve model can not only reflect the primary photochemical reaction characteristics of plants, but also describe the physical characteristics of plant light harvesting pigment molecules, such as the number of light harvesting pigment molecules in the excited state (Nk) and effective light energy absorption cross-section (σik′). This can be used to further investigate the physical characteristics of light harvesting pigment molecules, including the light-response of Nk and σik′ and the average life time of light harvesting pigment molecules in the lowest exciting state (τmin). In addition, it would be necessary to determine how to incorporate abiotic factors, such as temperature and CO2 concentration, into the mechanistic An-I curve model, as well as to determine the association between the abiotic factors and light harvesting pigment molecules, such as Nk, σik′, and τmin. Reference | Related Articles | Metrics | Comments（0）

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Discussing the basic ecological relations of sand dune vegetation process LIU Zhimin, YU Haibin, WANG Haiyang Chinese Journal of Applied Ecology    2024, 35 (1): 1-7.   DOI: 10.13287/j.1001-9332.202401.029 Abstract （41）      PDF（pc） （3625KB）（69）       Knowledge map    Save Dune is often considered as a degraded ecosystem. Natural vegetation restoration and stable artificial vegetation construction are the basic means restoring dune ecosystem. Based on long-term study of dune ecosystem, by taking into consideration both the philosophical principles of unity of opposites and dynamic change, and related ecological theories, we put forward some ecological relations that should be paid attention to in the study of vegetation assembly from the perspective of the uniqueness of dune ecosystem. We discussed the necessity of coupling relationships of scale-pattern-process and the transformation of synergy-tradeoff relationships, interpreted the importance of distinguishing sand dune stabilized and shifting phases, disturbance and stress, wind erosion and sand burial in the study of vegetation process. We further explored the applied value of niche law or neutral law in the study of dune vegetation process. Finally, we discussed the issues that should be paid attention to in the study of dune vegetation process from the aspects of adaptability to aeolian activities and drought tolerance, physiological and reproductive process, sexual and asexual reproduction of plants. This study would provide theoretical supports for vegetation restoration and stable vegetation construction of dune ecosystem. Reference | Related Articles | Metrics | Comments（0）

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Multidimensional climatic niche conservatism and invasion risk of Phenacoccus solenopsis ZHANG Huisheng, XU Lin, LYU Weiwei, ZHOU Yu, WANG Weifeng, GAO Ruihe, CUI Shaopeng, ZHANG Zhiwei Chinese Journal of Applied Ecology    2023, 34 (6): 1649-1658.   DOI: 10.13287/j.1001-9332.202306.018 Abstract （78）      PDF（pc） （1901KB）（67）       Knowledge map    Save The cotton mealybug Phenacoccus solenopsis, a globally invasive insect, is listed as a national quarantine pest in agriculture and forestry, which seriously threatens biological safety of China. Niche conservatism is a key assumption of species distribution model. An evaluation of the applicability of using ecological niche models to assess the invasion risk of cotton mealybug, and further optimizing model complexity, are of both theoretical and practical significance. Based on 706 occurrence records and key bioclimatic variables, we used n-dimensional hypervolume niche analysis method to quantify the climatic niche hypervolumes of this pest in both native and invasive sites, and further tested the niche conservatism hypothesis. MaxEnt model parameters were optimized to predict the invasion risk of the mealybug under current and future climate scenarios in China. The results showed that four climatic variables (annual mean temperature, mean temperature of wettest quarter, mean temperature of warmest quarter, and precipitation of driest quarter) were the key climate factors affecting the distribution of cotton mealybug. Compared with native climatic niche (hypervolume volume, HV=40.43), the niche hypervolume of cotton mealybug in the invasive areas was significantly reduced (HV=6.04). Niche contraction (the net differences between the amount of space enclosed by each hypervolume was 0.84) explained 98.8% of niche differentiation, whereas niche shift (the replacement of space between hypervolumes was 0.01) contributed less than 2%. The direction of climatic niche contraction of the pest in different invasive areas was not exactly consistent. The default parameters of MaxEnt model were unreliable (ΔAICc=14.27), and the optimal parameter combination was obtained as follows: feature combination was linear-quadratic-hinge-product and regularization multiplier was 0.5. The most suitable habitats of cotton mealybug were concentrated in the south of Huaihe River-Qinling Mountains line, and the north-central provinces contained a large area of low suitable habitat. The increase of suitable habitat was not significant at the end of 21 century (SSP1-2.6: 1.7%, SSP5-8.5: 0.7%). The multidimensional climatic niche of P. solenopsis was highly conservative. The species distribution model was suitable for analyzing its invasion risk. The northward spread was obvious, and climate change had less impact on the pest. Reference | Related Articles | Metrics | Comments（0）

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Advances in the research of transformation and stabilization of soil organic carbon from plant and microbe YANG Yang, WANG Baorong, DOU Yanxing, XUE Zhijing, SUN Hui, WANG Yunqiang, LIANG Chao, AN Shaoshan Chinese Journal of Applied Ecology    2024, 35 (1): 111-123.   DOI: 10.13287/j.1001-9332.202401.011 Abstract （65）      PDF（pc） （2449KB）（63）       Knowledge map    Save Soil organic carbon (SOC) is the core component of terrestrial carbon (C) sink. Exploring the transformation and stabilization mechanism of SOC is key to understand the function of terrestrial C sink which copes with climate change. The traditional perspective is that plant residues are the initial source of SOC. The new concept of “soil microbial C pump” emphasizes that the synthesized products of soil microbial assimilation are important contributors to the stable SOC. This provides a new insight to the sequestration mechanism of SOC. Due to the complex and variable decomposition process of plant residues and the high heterogeneity of microbial residues, the transformation and stabilization mechanism of plant residues and microbial residues into SOC is still unclear. We reviewed research progress in plant and microbial residues, and introduced the characterization methods of quantification and transformation of plant residues and microbial residues, and also summarized the new findings on the transformation of plant and microbial residues into SOC. We further discussed the contribution and driving factors of microbial and plant-derived C to SOC. Finally, we prospected the future development direction and research focus in this field. This review would provide the scientific reference for the research of soil C sequestration in terrestrial ecosystem. Reference | Related Articles | Metrics | Comments（0）

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Spatial distribution pattern and correlation of dominant species in the arbor layer at a 25 hm2 forest plot in Lushan Mountain, China WANG Jingxuan, ZHANG Jiaxin, XIANG Zeyu, ZHANG Zhaochen, XI Dan, WAN Huilin, PENG Yansong, ZHOU Saixia Chinese Journal of Applied Ecology    2023, 34 (6): 1491-1499.   DOI: 10.13287/j.1001-9332.202306.001 Abstract （73）      PDF（pc） （5103KB）（56）       Knowledge map    Save To explore the spatial pattern of zonal tree species in the subtropical subalpine mountain area on Lushan Mountain, a 25 hm2 forest plot was established in Yangtianping area of Lushan Mountain following the technical specification of CTFS in 2021. We classified these species into evergreen conifer species, deciduous broad-leaved species and evergreen broad-leaved species based on their leaf shape and deciduous or not to analyze the spatial pattern of dominant species of different types by spatial point pattern method. The results showed that Pinus taiwanensis, Cornus kousa subsp. chinensis, Platycarya strobilacea, Castanea henryi, Quercus serrata, Cornus controversa, Eurya muricata, Litsea elongata, and Eurya hebeclados were dominant species. Among these species, P. taiwanensis was the constructive one. The spatial pattern of dominant species was clustered at a certain scale, and gradually became to randomly distribution with the increases of scales. Evergreen conifer species was independent with deci-duous broad-leaved species and evergreen broad-leaved species at small scales, but was negatively correlated with them at large scales. Deciduous broad-leaved species and evergreen broad-leaved species were obviously negatively correlated with each other. Deciduous broad-leaved species were positively correlated or independent with each other at small scales, but were negatively correlated with each other at large scales. Evergreen broad-leaved species were positively correlated at small scales, independent at medium scales, and negatively correlated with each other at large scales. Reference | Related Articles | Metrics | Comments（0）

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Effects of long-term fertilization patterns on bacterial community structure and soil nutrients in dryland of yellow soil XIONG Han, LIU Yanling, LI Yu, ZHANG Yarong, HUANG Xingcheng, YANG Yehua, ZHU Huaqing, JIANG Taiming Chinese Journal of Applied Ecology    2023, 34 (7): 1949-1956.   DOI: 10.13287/j.1001-9332.202307.011 Abstract （81）      PDF（pc） （1865KB）（53）       Knowledge map    Save Understanding the responses of soil bacterial community to long-term fertilization in dryland of yellow soil could provide theoretical basis for establishing scientific fertilization system and cultivating healthy soil. Based on a 25-year long-term fertilization experiment on yellow soil, we collected soil samples from 0-20 cm layer under different fertilization treatments: no fertilization (CK), balanced application of N, P and K fertilizers (NPK), single application of organic fertilizer (M), combined application of constant organic and inorganic fertilizer (MNPK), and 1/2 organic fertilizer instead of 1/2 chemical fertilizer (MNP). Illumina MiSeq high-throughput sequencing technology was used to examine the effects of different fertilization patterns on soil bacterial community structure and soil nutrient content. The main driving factors of soil bacterial community were explored. The results showed that soil pH and organic matter content under treatments with organic fertilizer increased by 11.4%-13.5% and 28.8%-52.0%, respectively, compared to that under NPK treatment. Long-term fertilization did not affect soil bacterial α diversity, but significantly affected soil bacterial β diversity. Compared with CK and NPK treatment, treatments of M, MNP, and MNPK significantly changed soil bacterial community structure, and increased the relative abundance of Fusobacteria and Anaerobes. Four fertilization treatments increased the relative abundance of Bacteroidetes, and decreased the relative abundance of Actinomyces and Campylobacter, compared to CK. Soil pH was the most important factor affecting soil bacterial community structure. Fertilization-stimulated rare microbial taxa (Pumilomyces and Anaerobes) were more sensitive to changes in different environmental factors and were the main drivers of the formation of community versatility. In conclusion, organic fertilizer improved soil properties and fertility and changed soil bacterial community structure, which are conducive to cultivating healthy soil. Reference | Related Articles | Metrics | Comments（0）

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Research advance on quantitative assessment methods of ecosystem water conservation service functions LIU Yisheng, HOU Peng, WANG Ping, ZHU Jian Chinese Journal of Applied Ecology    2024, 35 (1): 275-288.   DOI: 10.13287/j.1001-9332.202401.022 Abstract （33）      PDF（pc） （1288KB）（50）       Knowledge map    Save The water conservation service function, which is one of the most important ecological service function in the regional system, directly reflects the regulation role of a region in precipitation, the redistribution function of precipitation, and the ecohydrological value. With the development of the comprehensive evaluation method and the deepening of research on water conservation service function, relevant evaluation calculation process has changed significantly. Nowadays, in the assessment of the water conservation service function, it is necessary not only to calculate and evaluate relevant indicators, but also to localize specific parameters in the model and analyze the effectiveness of the overall model for specific study areas. However, the current literature review lacks systematic summaries of model evaluation methods. Meanwhile, the review is also insufficient on model validity verification and significance analysis methods, the result verification and applicability analysis methods such as parameter localization in water conservation studies. We reviewed the research advance on typical ecosystem water conservation ser-vice assessment methods with a specific focus on the model assessment methods that have developed rapidly in recent years. At the same time, we summarized methods commonly used for parameter localization, as well as validity testing and sensitivity analysis of simulation results, and discussed existing problems and future directions in this field. Reference | Related Articles | Metrics | Comments（0）

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Temporal and spatial patterns of habitat of Nipponia nippon in China under the background of climate change XIA Zhuoyi, SU Jie, YIN Haiwei, KONG Fanhua Chinese Journal of Applied Ecology    2023, 34 (6): 1467-1473.   DOI: 10.13287/j.1001-9332.202306.008 Abstract （86）      PDF（pc） （3240KB）（49）       Knowledge map    Save Crested ibis (Nipponia nippon) is one of the endangered species in the International Union for Conservation of Nature. It is of great significance to pay attention to the changes of its suitable habitat in the context of climate change. Based on the geographical distribution data of crested ibis, the MaxEnt model was used to predict the suitable habitat of crested ibis under current scenario and future climate change. The results showed that the prediction accuracy of MaxEnt model was high, with an AUC value of 0.989. The minimum temperature of the coldest month, the mean temperature of the coldest quarter, and the mean annual rainfall were the dominant environmental factors affecting the habitat of crested ibis. Under current climate scenario, the area of moderately and highly suitable area of Chinese crested ibis was 10.65×104 km2, mainly distributed in Shaanxi, Sichuan, Hubei, Henan, and Gansu. In the future, the suitable habitat area of crested ibis would increase significantly under climate change, mainly distributed in Anhui, Chongqing, Guizhou, Jiangsu, Hunan, Shandong, Shaanxi, Jiangxi, Taiwan, Yunnan, Liaoning, and Fujian. In the SSP126 scenario from 2041 to 2060, the suitable habitat area of crested ibis would reach the maximum, being 139.53×104 km2 higher than that of the current climate scenario, accounting for 19.6% of the land area. This study could provide a basis for policy making on the conservation of crested ibis under global climate change. Reference | Related Articles | Metrics | Comments（0）

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Suitable overwintering habitat simulation and the drivers of their population expansion for Siberian cranes (Grus leucogeranus) in China SHAO Mingqin, WANG Jianying, DING Hongxiu Chinese Journal of Applied Ecology    2023, 34 (6): 1639-1648.   DOI: 10.13287/j.1001-9332.202306.023 Abstract （59）      PDF（pc） （2052KB）（48）       Knowledge map    Save To gain a more comprehensive understanding of habitat preferences, potential wintering area distribution and drivers of population expansion of Grus leucogeranus, we selected 70 geographical distribution points and 11 environmental variables in its wintering period from 2015-2022. We modeled suitable habitat patterns for G. leucogeranus in China using MaxEnt model, and analyzed the relationship between suitable habitat distribution and environmental factors. The results showed that the dominant factors affecting the overwintering distribution of G. leucogeranus were distance to mudflats, elevation, average precipitation in February, distance to water sources, minimum temperature in December, and land use type, with a cumulative contribution rate of 94.6%. The wintering ground of G. leucogeranus in China was mainly distributed in the middle and lower reaches of the Yangtze Plain and the Yellow River Delta of the North China Plain. In these regions, the area of high-, medium- and low-suitability habitat were 17685, 60787 and 60747 km2, respectively. A total of 40 protected areas had been established in the high-suitability wintering range of G. leucogeranus in China, whereas 12 high-suitability wetlands such as Qili Lake in Anhui, Liangzi Lake in Hubei and Chenjia Lake in Jiangxi were still unprotected. The wintering grounds had shown a trend of expansion to the northeast and southeast since 2015. Considering the large-scale habitat shifts of G. leucogeranus in recent years and the frequent new wintering records in various places, we suggested that the shortage of food resources in natural habitats was the main factor driving the expansion of G. leucogeranus’ wintering range. To protect G. leucogeranus more effectively, we should strengthen the restoration of natural habitats and the management of farmland habitats. Reference | Related Articles | Metrics | Comments（0）

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Carbon emission reduction potential assessment in food transportation by urban agriculture: A case study of main urban area of Nanjing, China SUN Yibing, SU Jie, YIN Haiwei, SUN Hui, KONG Fanhua Chinese Journal of Applied Ecology    2023, 34 (6): 1441-1449.   DOI: 10.13287/j.1001-9332.202306.021 Abstract （79）      PDF（pc） （3898KB）（46）       Knowledge map    Save As an emerging urban green infrastructure and continuous productive urban landscape, urban agriculture can increase the resilience of urban food systems and reduce carbon emission in food transportation. However, there are few studies in China on the potential of urban agriculture and its role in carbon emission reduction. With semantic segmentation and spatial analysis method to identify urban agricultural potential spaces on the ground and rooftops based on satellite images and Lidar point cloud data in the main urban area of Nanjing, we estimated their potential in vegetable production and the CO2 emission reduction effect in food transportation. The results showed that there were 2904.39 hm2 of ground and 2976.96 hm2 of rooftops in the study area with the potential to be used for urban agriculture. Under a scenario with 80% potential space utilization, it could produce approximately 225000 t of vegetables per year, which equated to 43.6% of annual vegetable consumption in the study area. Meanwhile, it would reduce CO2 emission in long distance food transportation by 63700 t per year. Reference | Related Articles | Metrics | Comments（0）

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Impacts and prediction of land use change on ecosystem carbon sequestration in Zhejiang Province, China XU Caiyao, REN Yan, KONG Fanbin Chinese Journal of Applied Ecology    2023, 34 (6): 1610-1620.   DOI: 10.13287/j.1001-9332.202306.024 Abstract （80）      PDF（pc） （4660KB）（45）       Knowledge map    Save It is crucial to clarify the impact of land use change on ecosystem carbon sequestration service for exploring natural-based carbon neutral solutions. We used InVEST and FLUS models to analyze land use change and its impacts on ecosystem carbon sequestration service in Zhejiang Province from 2000 to 2021, and predict ecosystem carbon sequestration service potential and its economic value of land use pattern in 2035 and 2050 under three scenarios of natural development, ecological protection, and cultivated land protection. The results showed that the area of cultivated land, forest, grassland, and water was continuously reducing and the area of construction land was continuously increasing from 2000 to 2021 in Zhejiang Province. The total amount of ecosystem carbon sequestration service decreased by 29.9658 million t, and the net income of carbon sequestrqtion service was -170.7184 million dollars. The distribution of ecosystem carbon sequestration services showed a spatial pattern of high in the southwest and low in the northeast. In the future, the total amount of ecosystem carbon sequestration services in Zhejiang Province would be the highest under the ecological protection scenario, followed by the cultivated land protection scenario, and the lowest under the natural development scenario. From 2021 to 2035 and 2050, ecosystem carbon sequestration services in Zhejiang Province would increase by 3.2326 million and 4.73 million t respectively under the ecological protection scenario, generating carbon sequestration service benefits of 77.0786 million and 111.8391 million dollars, respectively. Under the cultivated land protection scenario, it would be reduced by 10.1318 million and 16.1611 million t, and the net loss of carbon sequestration service value would be 241.3849 million and 381.9109 million dollars, respectively. Under the natural development scenario, it would be reduced by 11.6490 million and 16.1651 million t, resulting in a net loss of carbon sequestration service value of 277.5393 million and 382.0063 million dollars, respectively. In the context of actively addressing climate change and striving to achieve the goal of carbon neutrality, Zhejiang Province should focus on protecting ecological land such as woodlands, grasslands, and water, expand the scale of ecological land, optimize the spatial structure of ecological land, and continuously enhance carbon sequestration and sink enhancement functions of ecological land. Reference | Related Articles | Metrics | Comments（0）

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Responses of root-associated fungal community structure of mycorrhizal plants to nitrogen and/or phosphorus addition in a subtropical forest LIU Shanshan, WANG Quancheng, SHI Jiamian, LIU Zikai, SHEN Jupei, HE Jizheng, ZHENG Yong Chinese Journal of Applied Ecology    2023, 34 (6): 1547-1554.   DOI: 10.13287/j.1001-9332.202306.017 Abstract （76）      PDF（pc） （1563KB）（42）       Knowledge map    Save Root-associated fungi play a vital role in maintaining nutrient absorption and health of host plants. To compare the responses of root-associated fungal community structures to nitrogen (N) and/or phosphorus (P) additions across differential mycorrhizal types, we collected roots of nine plant species belonging to three mycorrhizal types (arbuscular mycorrhiza, ectomycorrhiza, and ericoid mycorrhiza) under control and N and/or P addition treatments from a subtropical forest, and detected the diversity and community composition of fungi inhabiting roots through the high-throughput sequencing technique. The results showed that root-associated fungal communities of all nine plant species were mainly composed of Basidiomycota and Ascomycota. The relative abundance of Ascomycota and Basidiomycota was significantly lower and higher under the P addition than that under control, respectively. The relative abundance of Ascomycota of ericoid mycorrhizal trees was significantly higher than those of arbuscular mycorrhizal and ectomycorrhizal trees, while the relative abundance of Basidiomycota was significantly lower than the other two mycorrhizal types. Compared with the control, P addition significantly reduced the α-diversity and changed community composition of root-associated fungi across different mycorrhizal plant types, while no effect of N addition or mycorrhizal type was observed. Compared with the control and N addition treatments, NP addition caused root-associated fungal communities of all plants becoming integrally divergent. In addition, the fungal communities of ectomycorrhizal mycorrhizal trees became apparently convergent in comparison with those of arbuscular and ericoid mycorrhizal trees under the NP addition. Collectively, our results highlighted that P was a critical factor influencing community structures of tree root-associated fungi in subtropical forest soils. This study would enhance our understanding of the responses and maintenance mechanisms of plant root-associated fungal diversity under global environmental changes in the subtropical region. Reference | Related Articles | Metrics | Comments（0）

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Spatio-temporal distribution and overlap of Naemorhedus griseus and Capricornis milneedwardsii in Gongga Mountain, Sichuan, China LIU Wei, LI Xuqin, LI Zhonglun, LI Ying, YOU Zhiyuan, JIANG Yong, RUAN Guanghua, LU Bigeng, YANG Nan Chinese Journal of Applied Ecology    2023, 34 (6): 1630-1638.   DOI: 10.13287/j.1001-9332.202306.031 Abstract （55）      PDF（pc） （2058KB）（42）       Knowledge map    Save Clarifying the distribution pattern and overlapping relationship of sympatric relative species in the spatio-temporal niche is important for our understanding of the behavioral relationship between species and the integrated management of multi-species habitats. Based on the infrared camera monitoring data from 2012 to 2021, we investigted the spatio-temporal distribution characteristics of the national secondary-class key protected animals Naemorhedus griseus and Capricornis milneedwardsii in the Gongga Mountain National Nature Reserve, Sichuan Province. We analyzed the distribution of N. griseuss and C. milneedwardsiis in the reserve using the MaxEnt model, based on 72 and 108 occurrence data of the two species, respectively, obtained by infrared cameras from 2016 to 2021, combined with 12 environmental factors potentially affecting their spatial distribution. Then, based on 1312 occurrence data of N. griseus and 1889 occurrence data of C. milneedwardsii collected by infrared camera from 2012 to 2021, we estimated their daily activity rhythms by using the kernel density estimation to understand the distribution pattern and overlap of the two species in the temporal niche. The results showed that the area of suitable habitats for N. griseus and C. milneedwardsii was 731.95 km2 and 1220.46 km2, respectively. The overlapping area was 697.17 km2. The main environmental factors had similar effects on the habitat selection of the two species. The daily activity of both species peaked in the early morning and evening. The utilization of the interval and intensity of the morning and evening time periods were different for the two species. The morning and evening activity peaks of C. milneedwardsii were earlier and later, respectively, than that of N. griseus. C. milneedwardsii had a higher utilization intensity during the nocturnal period. In general, high degree of spatial overlap and low degree of overlap in the temporal niche dimension contribute to the long-term coexistence of the two species. Reference | Related Articles | Metrics | Comments（0）

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Effects of mixed broadleaved tree species with pure Pinus massoniana plantation on soil microbial necromass carbon and organic carbon fractions QIN Zhenkai, LIU Runhong, HE Peng, WANG Cong, NIE Yanxia, SHEN Weijun Chinese Journal of Applied Ecology    2024, 35 (1): 141-152.   DOI: 10.13287/j.1001-9332.202401.015 Abstract （40）      PDF（pc） （2157KB）（41）       Knowledge map    Save Mixing native broadleaved tree species is a widely used method for renovating Pinus massoniana plantations. Soil microbial necromass carbon and organic carbon fractions are important parameters for evaluating the impacts of tree species mixing and soil organic carbon (SOC) stability. However, their responses to the mixing and renovation of P. massoniana plantation has not been understood yet. Here, we selected a pure P. massoniana plantation (PP) and a mixed P. massoniana and Castanopsis hystrix plantation, with ages of 16 (MP16) and 38 years (MP38), respectively, as the research objects. We quantified soil physical and chemical properties, microbial necromass carbon content, and organic carbon components at different soil layers to reveal whether and how the introduction of C. hystrix into P. massoniana plantation affected soil microbial necromass carbon and organic carbon components. The results showed that the mixed P. massoniana and C. hystrix plantation significantly reduced fungal necromass carbon content and the ratio of fungal/bacterial necromass carbon in the 0-20 cm and 20-40 cm soil layers. There were no significant differences in microbial necromass carbon contents, bacterial necromass carbon contents, and their contributions to SOC among the different plantations. The contribution of fungal necromass carbon to SOC was higher than that of bacterial necromass carbon in all plantation types. The contribution of soil mineral-associated organic carbon (MAOC) to SOC was higher than that of occluded particulate organic carbon (oPOC) and light-free particulate organic carbon (fPOC) for all plantation types. Mixing the precious broadleaved tree species (i.e., C. hystrix) with coniferous species (P. massoniana) significantly increased MAOC content and the contribution of MAOC, oPOC, and fPOC to SOC in the 0-20 cm and 20-40 cm soil layers. The MAOC of MP38 was significantly higher than that of PP in all soil layers and the MAOC of MP38 stands were significantly higher than MP16 stands in the 20-40 cm, 40-60 cm, and 60-100 cm soil layers, indicating that hybridization enhanced SOC stability and that the SOC of MP38 stands were more stable than MP16 stands. SOC and total nitrogen contents were the main environmental factors driving the changes in soil microbial necromass carbon, while soil total nitrogen and organically complexed Fe-Al oxides were the primary factors affecting organic carbon fraction. Therefore, SOC stability can be enhanced by introducing native broadleaved species, such as C. hystrix, during the management of the P. massoniana plantation. Reference | Related Articles | Metrics | Comments（0）

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Short-term legacy effects of long-term nitrogen and water addition on soil chemical properties and micro-bial characteristics in a temperate grassland DAI Zecheng, LIU Yuexiu, DANG Ning, WANG Zhirui, CAI Jiangping, ZHANG Yuge, SONG Yongbo, LI Hui, JIANG Yong Chinese Journal of Applied Ecology    2023, 34 (7): 1834-1844.   DOI: 10.13287/j.1001-9332.202307.016 Abstract （82）      PDF（pc） （2285KB）（40）       Knowledge map    Save Nitrogen deposition and summer precipitation in eastern Inner Mongolia are predicted to increase in recent decades. However, such increases in nitrogen inputs and precipitation may not be continuous under the future new patterns of global change, with the direction and magnitude of which may change or weaken. The legacy effects of nitrogen and water addition after cessation on ecosystems are still unclear. Based on a 13-year nitrogen and water addition experiment in temperate grassland of northern China, we examined the short-term (2 years) legacy effects of historical nitrogen and water addition on soil physicochemical properties and microbial properties after the cessation of nitrogen and water addition in the 14th year. The results showed that the positive effects of historical nitrogen addition on most of soil nutrient variables diminished after two years of cessation, including ammonium nitrogen, nitrate nitrogen, dissolved organic carbon and nitrogen, and Olsen-P concentrations. In contrast, there were legacy effects on soil microbial characteristics. For example, the historical nitrogen input of 15 g N·m-2·a-1 reduced microbial biomass carbon, respiration, and alkaline phosphomonoesterase activity by 73.3%, 81.9%, and 70.3% respectively. It implied that microbial parameters restored slowly in comparison with soil nutrients, showing a hysteresis effect. Results of Pearson’s correlation and redundancy analysis showed that the legacy effects of historical nitrogen addition on microbial parameters could be attributed to the negative effects of nitrogen addition on soil pH. Historical water addition showed significant legacy effects on soil pH, ammonium nitrogen, dissolved organic carbon and nitrogen, respiration, and soil enzyme activities, which significantly interacted with historical nitrogen addition. These results are of great significance to predict the changes in grassland ecosystem functions and services under the local environmental improvement conditions, and to reveal the restoration mechanism of degraded grassland. Reference | Related Articles | Metrics | Comments（0）

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Effects of warming on fine root lifespan of forests: A review LIU Yuanhao, DU Xulong, HUANG Jinxue, XIONG Decheng Chinese Journal of Applied Ecology    2023, 34 (6): 1693-1702.   DOI: 10.13287/j.1001-9332.202306.007 Abstract （70）      PDF（pc） （1217KB）（39）       Knowledge map    Save As an important parameter of forests growth, fine root lifespan plays an important role in plant water and nutrient absorption, and affects underground distribution of photosynthetic products and forest ecosystem carbon cycling. The impact of climate warming on fine root lifespan has become a hot issue under the context of global change. The responses of fine root lifespan to global warming will affect ecosystem carbon balance. We reviewed the research progress of the response characteristics and mechanism of fine root lifespan of trees to warming. Most stu-dies proposed that warming would affect fine root lifespan by changing rhizosphere soil environment, fine root morphology, and tree phenology. However, the growth and death of fine roots were affected by lots of factors, leading to differences in the research results on fine root lifespan due to natural environment of the study area, the way of warming, and the research objects. Therefore, it is of importance to comprehensively analyze the responses of fine root lifespan in forests under the background of climate warming to study the underground ecological process. In the future, the following research should be strengthened: 1) Combining multiple methods to warming underground and aboveground simutaneously, and explore more accurate and effective non-destructive observation methods. 2) Combining multiple observations to study the effects of warming on fine root lifespan. 3) Carrying out research on the effect of warming on fine root lifespan of different tree species, and deeply understand the response mechanism of fine root lifespan of different trees to warming. 4) A comprehensive analysis of the effects of warming on fine root lifespan from various perspectives, and an investigation into the mechanism of the combined effects of various factors on fine root lifespan. 5) The interaction between warming and other environmental factors fine root lifespan. 6) The effect of root architecture on the fine root lifespan after warming. 7) The effects of rhizosphere microorganisms (bacteria and fungi) on fine root lifespan after warming. Reference | Related Articles | Metrics | Comments（0）

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Soil microbial community characteristics and the influencing factors at different elevations on the eastern slope of Helan Mountain, Northwest China PANG Danbo, WU Mengyao, ZHAO Yaru, YANG Juan, DONG Liguo, WU Xudong, CHEN Lin, LI Xuebin, NI Xilu, LI Jingyao, LIANG Yongliang Chinese Journal of Applied Ecology    2023, 34 (7): 1957-1967.   DOI: 10.13287/j.1001-9332.202307.031 Abstract （93）      PDF（pc） （2255KB）（38）       Knowledge map    Save As an important bridge connecting aboveground communities and belowground biological processes, soil microorganisms play an important role in regulating belowground ecological processes. The altitudinal changes and driving factors of soil microbial community in mountain ecosystem in arid region are still unclear. We measured soil physicochemical properties at seven altitudes in the range of 1300-2800 m in Helan Mountains, and investigated the understory community composition, soil physicochemical properties, and soil microbial community. The driving factor for soil microbial community was explored by variance partitioning analysis and redundancy analysis. The results showed that the total amount of soil microorganisms and bacterial biomass first increased and then decreased with the increases of altitude, fungi, actinomyces, arbuscular mycorrhizal fungi, Gram-positive bacteria, and Gram-negative bacteria groups showed a gradual increase. The variation of fungal-to-bacterial ratio (F/B) along the altitude showed that the cumulative ability of soil bacteria was stronger than that of fungi at low altitudes, while the pattern is opposite at high altitudes. The ratio of Gram-positive bacteria to Gram-negative bacteria (GP/GN) showed an overall decreasing trend with the increases of altitude, indicating that soil bacteria and organic carbon availability changed from “oligotrophic” to “eutrophication” and from “low” to “high” transition as the altitude increased. Vegetation properties, soil physical and chemical properties jointly accounted for 95.7% of the variation in soil microbial community. Soil organic carbon (SOC), soil water content (SWC), and total nitrogen (TN) were significantly correlated with soil microbial community composition. Our results revealed the distribution pattern and driving factors of soil microbial communities at different elevations on the eastern slope of Helan Mountain, which would provide theoretical basis and data support for further understanding the interaction between plant-soil-microorganisms in arid areas. Reference | Related Articles | Metrics | Comments（0）

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Effects of grazing on soil water recharge of rehabilitated grassland under natural rainfall on the Loess Pla-teau, Northwest China MING Jiao, YANG Guang, ZHAO Yunge, MA Xinxin, SUN Hui, QIAO Yu Chinese Journal of Applied Ecology    2023, 34 (6): 1555-1562.   DOI: 10.13287/j.1001-9332.202306.011 Abstract （62）      PDF（pc） （1525KB）（38）       Knowledge map    Save Rainfall is critical to the regulation of slope runoff and soil water recharge. Grazing affects land cover and soil structure, with consequence on slope runoff generation and soil water recharge. Little attention has been paid to the effects of rainfall on soil water recharge caused by grazing. In this study, we examined land covers and soil water contents under different grazing intensities (G1-G5: 2.2, 3.0, 4.2, 6.7, 16.7 sheep·hm-2) and no grazing sites (NG), aiming to analyze soil water recharge under natural rainfall conditions after grazing. The results showed that grazing exerted significant effects on vegetation and biocrust coverage. The vegetation coverage was decreased by 8.3%-16.4% under G1-G5 grazing, while the biocrust coverage was increased by 106.9% under G2 grazing compared to NG. The soil surface roughness under G1-G5 grazing was increased by 53.1%-152.5%, and the thickness of biocrust was decreased by 24.1% under G5. Soil wetting front velocity decreased with increasing rainfall intensity, and that of 0-5 cm layer under the G2 grazing intensity decreased by 60.0% to 83.3% under rainfall between 18.0 mm and 70.3 mm compared to NG. The effect of grazing on soil wetting front velocity was significantly related to biocrust coverage and soil bulk density of 0-5 cm soil layer. Generally, grazing did not affect soil water recharge rates of the slope grassland on the Loess Plateau. G2 grazing may prolong the migration time of soil water in the surface layer by increasing the coverage of cyanobacteria biocrusts, which may be beneficial to the restoration of soil microenvironment. Our results provided scientific basis for water management in the enclosure grassland of the Loess Plateau in the “post-conversion era”. Reference | Related Articles | Metrics | Comments（0）

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Effects of sowing patterns on nitrogen utilization and yield formation of winter wheat in the western Huang-Huai-Hai region YANG Yixuan, CHEN Yingzhi, TANG Peng, LIN Wen, SUN Min, GAO Zhiqiang Chinese Journal of Applied Ecology    2023, 34 (6): 1572-1582.   DOI: 10.13287/j.1001-9332.202306.016 Abstract （68）      PDF（pc） （1805KB）（38）       Knowledge map    Save To examine the differences of three improved sowing methods in winter wheat yield and nitrogen efficiency and reveal the characteristics responsible for such differences, we conducted field experiments in the Jinnan area of the western Huang-Huai-Hai wheat region for three consecutive seasons from 2016 to 2019. The three improved sowing methods were wide space sowing (WSS), furrow sowing in moisture soil (FS), and three-dimensional uniform sowing (TDUS), with conventional drilling sowing (CDS) as the control. The results showed that meteorological factors such as accumulated temperature, solar radiation, and precipitation in the growing seasons from 2016 to 2019 showed great intra- and inter-annual variations. Compared with CDS, the improved sowing methods (WSS, FS, and TDUS) enhanced spike number per unit area and increased grain yield in three growing seasons by 18.3%-55.5%, 8.6%-22.2%, and 10.9%-39.5%, respectively. The three methods increased nitrogen uptake efficiency (NEup) by 5.8%-57.1%, pre-flowering nitrogen transfer ratio (Np/Nt) by 3.0%-15.3%, and nitrogen efficiency by 7.9%-35.7%, respectively. We developed a structural equation model (SEM) by integrating meteorological factors and experimental variables. The results showed that the three improved sowing methods could reduce the effects of extreme low temperature on wheat plant population, increase NEup and Np/Nt, and provide sufficient nitrogen supply to the grains of high-spike number wheat population for high yield and high nitrogen efficiency. In summary, our results demonstrated that WSS, FS, and TDUS all improved NEup and Np/Nt in the 2016-2017 season when meteorological conditions were favorable for wheat growth, and enhanced yield components with high SN, leading to high yield and high nitrogen efficiency. In contrast, in both 2017-2018 and 2018-2019 seasons with extremely low temperature and uneven distribution of meteorological conditions, WSS had a higher number of tillers at the jointing stage and enhanced pre-flowering nitrogen uptake and translocation, whereas TDUS had a relatively stable nitrogen uptake rate, leading to a stable grain yield. Reference | Related Articles | Metrics | Comments（0）

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Niche and interspecific association of dominant tree species in karst forest of Junzi Mountain, Eastern Yunnan, China LIU Yuting, HOU Manfu, HE Luyan, TANG Wei, ZHAO Jun Chinese Journal of Applied Ecology    2023, 34 (7): 1771-1778.   DOI: 10.13287/j.1001-9332.202307.006 Abstract （73）      PDF（pc） （1453KB）（37）       Knowledge map    Save To understand the interspecific relationships of tree species in the karst forest of Junzi Mountain in Eas-tern Yunnan, we evaluated the niche and interspecific association of dominant tree species based on field survey plot data with the combining approaches of niche determination, χ2 test, association coefficient (AC), and Spearman rank correlation test. The results showed that the niche breadth of Quercus glaucoides was the largest and that of Juglans mandshurica was the smallest. The ranking of niche breadth was more consistent with the ranking of frequency than with that of importance values. The degree of niche overlap was generally low, with a mean value of 0.21, suggesting a low similarity in resource utilization among tree species. The overall association of dominant tree species was significantly positive, and the ratio of positive and negative association was 1.07, indicating that the communities were at a relatively stable and the late succession stage. The χ2 test and Spearman rank correlation test for tree dominant species showed that 65.3% species pairs were not significantly associated with each other, indicating a weak interspecific association. Both association coefficient (AC) and Spearman rank correlation coefficient showed significantly positive correlations with the corresponding niche overlap index. The species pairs of Q. glaucoides-Rhamnella martini, Viburnum propinquum-Zanthoxylum myriacanthum, Cladrastis delavayi-Carrierea calycina, Z. myriacanthum-C. delavayi had strong interspecific associations and wide ecological niches, thus may have potential application value in ecological restoration of karst region in eastern Yunnan and the vicinity areas. Reference | Related Articles | Metrics | Comments（0）