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Deposition of water-soluble inorganic ions in PM_(2.5) in a typical forestry system in beijing,China

Forest Ecosystems 2018年第4期5卷 486-497页

作者： Junqi Ding Xiaoxiu Lun Weifang Ma Lu Zhao Yingying Cao Fengbin Sun Renna Li College of Environmental Science and Engineering Beijing Forestry University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Academy of Environmental Sciences School of Soil and Water Conservation Beijing Forestry University

Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and ***: Samples were taken from two sites in beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron ***: The total deposition flux and total deposition velocity during the daytime were higher than those at *** showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest ***: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry sy

关键词： Fine particle Water-soluble inorganics Forest Dry deposition Deposition velocity

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Sugarcane bagasse amendment improves the quality of green waste vermicompost and the growth of Eisenia fetida

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Frontiers of Environmental Science & Engineering 2020年第4期14卷 65-75页

作者： Linlin Cai Xiangyang Sun Dan Hao Suyan Li Xiaoqiang Gong Hao Ding Kefei Yu College of forestry Beijing Forestry UniversityBeijing 100083China

Vermicomposting is a feasible method for disposing of lignocellulosic waste while generating a useful *** current study assessed the potential of vermicomposting green waste mixed with sugarcane bagasse in proportions of 25%,50%,and 75%(v:v,based on dry weight).The suitability was evaluated based on the agrochemical properties,earthworm biomass,and *** final vermicomposts exhibited near-neutral pH values(7.1-7.6),and lower EC values(0.43-0.72 mS/cm)and C:N ratios(14.1-19.9).The content of available nutrients and CEC for all the vermicomposts exceeded those of the control compost(without earthworms).For vermicomposts,the average values of NO3-N,AP,AK,and CEC were 53,517,1362 mg/kg,and 158 cmol/kg,*** total contents of heavy metals increased in all vermicompost treatments compared to control composts with the following average final percentages:Zn(2.0%),Cr(15.5%),Pb(23.4%),and Cu(44.3%),but these amounts were safe for application in *** addition of sugarcane bagasse to green waste significantly increased the content of total humic substance,humic acid and urease activity,acid and alkaline phosphatase activity,and Eisenia fetida *** addition of 25%sugarcane bagasse to green waste decreased the toxicity to germinating *** results revealed that vermicomposting is a feasible way to degrade green waste into a value-added chemical product.

关键词： Green waste Earthworms Sugarcane bagasse Vermicomposting Nutrient recovery

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Effects of organic mulching on soil aggregate stability and aggregate binding agents in an urban forest in beijing, China

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Journal of forestry Research 2022年第3期33卷 1083-1094页

作者： Wei Zhou Xiangyang Sun Suyan Li Tiantian Du Yi Zheng Zhihui Fan College of forestry Beijing Forestry UniversityBeijing100083People’s Republic of China

Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability through organic mulching in urban forest soils. Three treatments were applied in Jiufeng National Forest Park, beijing: (1) no organic mulch (control);(2) wood chips alone (5 cm thickness);and, (3) wood chips + wood compost (This mulch was divided into two layers, the upper layer of wood chips (2.5 cm), the lower layer wood compost (2.5 cm)). Soil samples were collected from the surface 10- cm soil layer and fraction into four aggregates. Glomalin-related soil protein and soil organic carbon were measured in bulk soil and the four aggregates. The results show that wood chips + wood compost increased the proportion of large and small macroaggregates, mean weight diameter and geometric mean diameter. The total and easily extractable glomalin-related soil protein were higher in the wood chips + wood compost. However, soil organic carbon was lower in the wood chips alone application compared to the controls and wood chips + wood compost. Easily extractable / total glomalin-related soil protein and glomalin-related soil protein / soil organic carbon ratios of wood chips alone and wood chips + wood compost had increased trend compared to the controls but did not reach significant levels (p > 0.05). Mean weight diameter and geometric mean diameter correlated positively with total and easily extractable glomalin-related soil protein but were not positively correlated with soil organic carbon, the ratios of easily extractable and total glomalin-related soil protein, and the ratios of glomalin-related soil protein and soil organic carbon. Redundancy analysis revealed that total glomalin-related soil protein was the most important driver for soil aggregate stability, especially the total glomalin-related soil protein of small macroaggregates. The results suggest tha

关键词： Organic mulching Soil aggregate stability Soil binding agents Glomalin-related soil protein(GRSP) Soil organic carbon(SOC)

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Understory seedlings of Quercus mongolica survive by phenological escape

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Forest Ecosystems 2024年第2期11卷 236-246页

作者： Shixiong Wu Ying Liu Lulu He Wei Zeng Qijing Liu College of forestry Beijing Forestry UniversityBeijing100083China

Understanding understory seedling regeneration mechanisms is important for the sustainable development of temperate primary forests in the context of increasingly intense climate warming *** poor regeneration of dominant tree species,however,is one of the biggest challenges it faces at the ***,the regeneration of the shade-intolerant Quercus mongolica seedling is difficult in primary forests,which contrasts with the extreme abundance of understory seedlings in secondary *** mechanism behind the interesting phenomenon is still *** study used in-situ monitoring and nursery-controlled experiment to investigate the survival rate,growth performance,as well as nonstructural carbohydrate (NSC) concentrations and pools of various organ tissues of seedlings for two consecutive years,further analyze the understory light availability and simulate the foliage carbon (C) gain in the secondary and primary *** suggested that seedlings in the secondary forest had greater biomass allocation aboveground,height and specific leaf area (SLA) in summer,which allowed the seedling to survive longer in the canopy closure *** light availability and positive C gain in early spring and late autumn are key factors affecting the growth and survival of understory seedlings in the secondary forest,whereas seedlings in the primary forest had annual negative carbon *** the growing season,the total NSC concentrations of seedlings gradually decreased,whereas those of seedlings in the secondary forest increased significantly in autumn,and were mainly stored in roots for winter consumption and the following year's summer shade period,which was verified by the nursery-controlled experiment that simulated autumn enhanced light availability improved seedling survival rate and NSC *** conclusion,our results revealed the survival trade-off strategies of Quercus mongolica seedlings and highlighted the necessity of high light availability d

关键词： Carbon gain Nonstructural carbohydrate Recruitment Trade-off Biomass allocation

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Long-term response of living forest biomass to extensive logging in subtropical China

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Journal of forestry Research 2019年第5期30卷 1679-1687页

作者： Hua Zhou Shengwang Meng Qijing Liu forestry College Beijing Forestry University

Forest disturbance and recovery are critical ecosystem processes,but the temporal patterns of disturbance have not been studied in subtropical *** a tree-ring analysis approach,we studied post-logging above-ground(ABG)biomass recovery dynamics over a 26-year period in four plots with different degrees of logging *** logging,the ABG biomass ranged from 291 to 309 t *** after logging,the plots in primary forest,secondary forest,mixed forest and singlespecies forest had lost 33,91,90 and 100%of their initial ABG biomass,***-six years after logging,the plots had regained 147,62,80 and 92%of their original ABG biomass,*** the 26 years following logging,the mean CAI(Current annual increment)were 10.1,5.5,6.4 and 10.8 t ha^-1 a^-1 and the average MAI(Mean annual increment)8.7,2.5,5.6 and 7.8 t ha^-1 a^-1 for the four forest types,*** results indicate that subtropical forests subjected to moderate logging or disturbances do not require intensive management and single-species plantings can rapidly restore the above-ground biomass to levels prior to heavy logging.

关键词： Biomass Forest management Harvest intensity Subtropical evergreen broad-leaved forest Jiulianshan Nature Reserve

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Larix olgensis growth-climate response between lower and upper elevation limits:an intensive study along the eastern slope of the Changbai Mountains,northeastern China

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Journal of forestry Research 2020年第1期31卷 231-244页

作者： Jian Yu Qijing Liu forestry College Beijing Forestry University

Larix olgensis is a dominant tree species in the forest ecosystems of the Changbai Mountains of northeast *** assess the growth response of this species to global climate change,we developed three tree-ring width and biomass chronologies across a range of elevations in the subalpine forests on the eastern slope of the Changbai *** used dendroclimatic analyses to study key factors limiting radial growth in *** and its variation with *** statistical characteristics of chronologies suggested that elevation is a determinant of tree growth patterns in the study *** function analysis of chronologies with climate factors indicated that climate–growth relationships changed with increasing elevation:tree growth at high elevation was strongly limited by June temperatures of the previous year,and as elevation decreases,the importance of temperature decreased;tree radial growth at mid-elevation was mainly controlled by precipitation towards the end of the growing season of the current *** chronologies reflected a stronger climatic signal than tree-ring width *** correlation with gridded climate data revealed that our chronologies contained a strong regional temperature signal for northeast *** growing below timberline appeared to be more sensitive to climate,thus optimal sites for examining growth trends as a function of climate variation are considered to be just below *** study objective was to provide information for more accurate prediction of the growth response of *** to future climate change on the eastern slope of the Changbai Mountains,and to provide information for future climate reconstructions using this tree species in humid and semi humid regions.

关键词： Tree-ring width Dendrochronology Changbai Mountains Elevation gradient Timberline Larix olgensis

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Neutral and accumulator species in determining the spatial structure of tree species at different spatial scales

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Journal of forestry Research 2019年第6期30卷 2175-2183页

作者： Jie Gao Chengyu Lü Yanhong Liu forestry College of beijing forestry university

In 2014,a 40-ha undisturbed plot was established in the beijing Songshan Nature *** spatial distribution and spatial associations of five dominant tree species of different height classes were examined using spatial point pattern analysis and the effects of these species on local community diversity assemblages were examined using the ISAR *** dominant species were characterized by an aggregated distribution at spatial scales of 0–50 *** smaller spatial scales,trees in larger height classes had significant positive and negative effects on the diversity of the lower height ***,at larger spatial scales this effect was *** small scales(0–10 m),accumulator species had positive effects on species diversity,maintained an over-representative proportion of diversity in their proximity,and supported the ecological niche *** the larger scale(10–50 m),neutral species were dominant and had positive effects on species diversity,though repeller species,which had negative effects on species diversity,also contributed to *** and accumulator species together determined local species diversity,but the relative importance of the two was closely related to spatial scale.A combination of the ecological niche theory and neutral processes together determines species coexistence and biodiversity of an undisturbed pine forest.

关键词： The 40-ha natural Chinese pine forest Spatial scale ISAR model Species coexistence Neutral and accumulator species

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Efficient proton conduction in porous and crystalline covalent-organic frameworks(COFs)

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Journal of Energy Chemistry 2023年第7期82卷 198-218,I0005页

作者： Liyu Zhu Huatai Zhu Luying Wang Jiandu Lei Jing Liu beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing 100083China MOE Engineering Research Center of forestry Biomass Materials and Bioenergy Beijing Forestry UniversityBeijing 100083China

To attain the objectives of carbon peaking and carbon neutrality,the development of stable and highperformance ion-conducting materials holds enormous relevance in various energy storage and conversion ***,crystalline porous materials possessing built-in ordered nanochannels exhibit remarkable superiority in comprehending the ion transfer mechanisms with *** this regard,covalent organic frameworks(COFs)are highly regarded as a promising alternative due to their preeminent structural tunability,accessible well-defined pores,and excellent thermal/chemical stability under hydrous/anhydrous *** the availability of organic units and the diversity of topologies and connections,advances in COFs have been increasing rapidly over the last decade and they have emerged as a new field of proton-conducting ***,a comprehensive summary and discussion are urgently needed to provide an"at a glance"understanding of the prospects and challenges in the development of proton-conducting *** this review,we target a comprehensive review of COFs in the field of proton conductivity from the aspects of design strategies,the proton conducting mechanism/features,the relationships of structure-function,and the application of *** relevant content of theoretical simulation,advanced structural characterizations,prospects,and challenges are also presented elaborately and *** importantly,we sincerely hope that this progress report will form a consistent view of this field and provide inspiration for future research.

关键词： Covalent-organic frameworks Proton conduction mechanism Proton exchange membrane Fuel cells

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Recent advanced development of stabilizing sodium metal anodes

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Green Energy & Environment 2023年第5期8卷 1279-1307页

作者： Liyu Zhu Yucheng Li Jingyang Zhao Jing Liu Luying Wang Jiandu Lei beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China MOE Engineering Research Center of forestry Biomass Materials and Bioenergy Beijing Forestry UniversityBeijing100083China

As the application of next-generation energy storage systems continues to expand,rechargeable secondary batteries with enhanced energy density and safety are imperative for energy ***-ion batteries(SIBs)have attracted extensive attention and are recognized as ideal candidates for large-scale energy storage due to the abundant sodium resources and low *** metal anodes(SMAs)have been considered as one of the most attractive anode materials for SIBs owing to their high specific capacity(1166 mAh g^(-1)),low redox potential,and abundant natural ***,the uncontrollable dendrite growth and inevitable side reactions on SMA lead to the continuous deterioration of the electrochemical performance,causing serious safety concerns and limiting their practical application in the ***,the construction of stable dendrite-free SMAs is a pressing problem for advanced sodium metal batteries(SMBs).In this review,we comprehensively summarize the research progress in suppressing the formation of sodium dendrite,including artificial solid electrolyte interphase(SEI),liquid electrolyte modification,three-dimensional(3D)host materials,and solid-state ***,key aspects and prospects of future research directions for SMAs are *** hope that this timely review can provide an overall picture of sodium protection strategies and stimulate more research in the future.

关键词： Sodium-metal battery Sodium metal anode Dendrite growth Artificial solid electrolyte interphases Electrolyte engineering

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Influencing factors and growth state classification of a natural Metasequoia population

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Journal of forestry Research 2019年第1期30卷 337-345页

作者： Mu Liu Zhongke Feng Chenghui Ma Liyan Yang Accuracy forestry Key Laboratory of beijing Beijing Forestry University The Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry University Northeast forestry university

By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a natural Metasequoia glyptostroboides Hu and W.C. Cheng population. We studied 2817 M. glyptostroboides trees over 100 years old and analyzed their growth state by measuring 15 factors from stumpage, site condition, and environmental data. The dimensionality of all factors were reduced using the random forest algorithm, and we classified the remaining factors using the following algorithms: random forest, back-propagation(BP) neural networks, and support vector machine(SVM). The applicability of each sorting algorithm was analyzed. When all the d factors are used for classification and modeling, the model's overall accuracy,kappa coefficient and test accuracy were 85.5%, 0.739 and 85.8%, respectively. By reducing the dimensionality of the factors using the random forest algorithm, 11 factors most strongly influenced the classifications of the growth state of the Metasequoia population: diameter at breast height,height, crown width, age from stumpage data; longitude,latitude, elevation, slope aspect, gradient and slope position from the site condition data; and the edge of the field from the environmental data. For classifying the Metasequoia population, the random forest algorithm has the highest overall accuracy at 87.2%, which is 3.4 and 2.3% higher than the BP neural networks and SVM algorithms,respectively. The SVM algorithm is superior to the random forest algorithm with respect to classifying the state of mortality. The combination of the random forest and SVM algorithms and their combined information can be used to classify and predict the growth state of this natural *** population to provide a scientific basis for its effective protection.

关键词： Metasequoia glyptostroboides Growth state Random forest Support vector machine(SVM) Influencing factor

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