Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tre...Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tree biomass within a fully censused 20 ha forest plot in a temperate forest of northern Alabama,USA.We evaluated the relationship between biomass and topography using ridge and valley landforms along with digitally derived moisture and solar radiation indices.Every live woody stem over 1 cm diameter at breast height within this plot was mapped,measured,and identified to species in 2019-2022,and diameter data were used along with speciesspecific wood density to map the aboveground biomass at the scale of 20 m×20 m quadrats.The aboveground tree biomass was 211 Mg·ha^(-1).Other than small stream areas that experienced recent natural disturbances,the total stand biomass was not associated with landform or topographic indices.Dominant species,in contrast,had strong associations with topography.American beech(Fagus grandifolia)and yellow-poplar(Liriodendron tulipfera)dominated the valley landform,with 37% and 54% greater biomass in the valley than their plot average,respectively.Three other dominant species,white oak(Quercus alba),southern shagbark hickory(Carya carolinaeseptentrionalis),and white ash(Fraxinus americana),were more abundant on slopes and benches,thus partitioning the site.Of the six dominant species,only sugar maple(Acer saccharum)was not associated with landform.Moreover,both topographic wetness and potential radiation indices were significant predictors of dominant species biomass within each of the landforms.The study highlights the need to consider species when examining forest productivity in a range of site conditions.展开更多
Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-cano...Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-canopy lichen(Cladonia spp.)woodlands have been observed in boreal forests of eastern Canada.It has been hypothesized that high severity of fires would be the cause of this change,but this is difficult to validate a posteriori on mature forest stands.Because charcoal properties are affected by fire severity,we have put forward the hypothesis that the amount and physicochemical properties of charcoal(C,N,H,O,ash,surface area)would be different and indicative of a greater fire severity for open-canopy forests compared to closed canopy ones.Our hypothesis was partly validated in that the amount of charcoal found on the ground of closed-canopy forests was greater than that of open-canopy forests.However,the physicochemical properties were not different,albeit a greater variability of charcoal properties for open canopy stands.These results do not allow us to fully validate or reject our hypothesis on the role of fire severity in the shift between open and closed canopy stands.However,they suggest that the variability in fire conditions as well as the amounts of charcoal produced are different between the two ecosystem types.Furthermore,considering the role that biochar may play in improving soil conditions and promoting vegetation restoration,our results suggest that charcoal may play a role in maintaining these two stable alternative ecosystem states.展开更多
Various types of vegetative cover,predominantly woodlands,shrublands,and grasslands,provide a range of habitats for urban organisms and are the main contributors to urban ecosystem services.The goal of this study was ...Various types of vegetative cover,predominantly woodlands,shrublands,and grasslands,provide a range of habitats for urban organisms and are the main contributors to urban ecosystem services.The goal of this study was to assess the potential of different vegetation types in maintaining and enhancing bryophyte diversity in urban areas.Bryophytes,small non-vascular plants,in woodlands,shrublands,and grasslands in Hefei city(eastern China)were investigated,and their species richness,abundance,community composition and relationships with habitat characteristics were analysed.The results show that urban woodlands had the highest species richness and abundance of bryophytes and a distinct community composition compared with the other vegetation types.Relative light intensity had a positive effect on species richness in urban woodlands,whereas litter cover had a negative effect on abundance.Shrub,grass and litter covers,and relative air humidity were the main factors driving the differences in bryophyte species composition between woodlands and other vegetation types.Therefore,owing to their high potential to maintain bryophyte diversity,woodlands should receive increased attention during the construction of urban green spaces.In addition,promoting structural heterogeneity and increasing light availability would be beneficial to bryophyte species diversity.展开更多
Objective:To investigate the osteogenic effects of polyphenol-rich extracts from Wisteria floribunda(Willd.)DC.(W.floribunda)flowers and elucidate the underlying mechanisms.Methods:Polyphenolic compounds of W.floribun...Objective:To investigate the osteogenic effects of polyphenol-rich extracts from Wisteria floribunda(Willd.)DC.(W.floribunda)flowers and elucidate the underlying mechanisms.Methods:Polyphenolic compounds of W.floribunda extracts were analyzed,including flavonoids and glucoside derivatives.Osteogenic activity was assessed in MC3T3-E1 preosteoblast cells by measurement of alkaline phosphatase(ALP)activity,alizarin red S staining,and the expression of osteogenic markers(RUNX2,SP7,and ALPL).In vivo effects were evaluated in zebrafish larvae by assessing skeletal development and expression of osteogenic genes(runx2a,sp7,and alpl).The role of mammalian target of rapamycin(mTOR)pathway was examined using rapamycin.Results:W.floribunda extracts significantly enhanced ALP activity,bone mineralization,and the expression of RUNX2,SP7,and ALPL in MC3T3-E1 cells.In zebrafish larvae,W.floribunda extracts improved vertebral mineralization and upregulated osteogenic genes.Mechanistically,the plant extract activated the mTOR pathway,and rapamycin treatment attenuated the extracts-induced ALP activity,mineralization,and vertebral formation in zebrafish,confirming mTOR involvement.Conclusions:W.floribunda extracts promote osteoblast differentiation and bone formation via mTOR pathway activation.These findings provide novel insights into the potential of W.floribunda extracts and support its further investigation as a natural therapeutic candidate for bone degenerative disorders such as osteoporosis.展开更多
Litterfall, which is influenced by physical and biological factors, is a major pathway for carbon and nutrient cycling in forest ecosystems. The purpose of this study was to investigate monthly litterfall production i...Litterfall, which is influenced by physical and biological factors, is a major pathway for carbon and nutrient cycling in forest ecosystems. The purpose of this study was to investigate monthly litterfall production in three forests in Jeju Island differentiated by forest composition and precipitation: Cheongsu(Quercus glauca as the dominant species;low precipitation), Seonheulb(Q. glauca as the dominant species;high precipitation), and Seonheulm(Q. glauca and Pinus thunbergii as the dominant species;high precipitation). Litterfall was collected monthly from April to December 2015 and divided into leaf litter, twig, bark, seeds, and unidentified materials.Seasonal patterns of litterfall production varied across stands according to their species composition. However,the amount of leaf litterfall and total litterfall were comparable among stands, ranging from 362 to 375 g m-2 for leaf litter and 524 g m-2 to 580 g m-2 for total litterfall.Oak leaf litter in May was the highest in all stands, while needle litter was the highest in December in Seonheulm.High twig litterfall in July may be attributable to high rainfall with strong winds and storms during the rainy season. Although forest type and climate factor had no influence on litterfall amounts in this study, the pattern of litterfall production was species dependent, suggesting diverse effects on carbon and nutrient cycling in these forests.展开更多
This study used the dynamic headspace adsorption(DHS) to collect volatile organic compounds(VOCs) released from the Fokienia hodginsii forest in summer, and analyzed the the composition and concentration of VOCs and t...This study used the dynamic headspace adsorption(DHS) to collect volatile organic compounds(VOCs) released from the Fokienia hodginsii forest in summer, and analyzed the the composition and concentration of VOCs and their correlation with environmental factors. The results showed that: there were 165 types of VOCs in the Fokienia hodginsii forest;the diurnal variation of the concentration of total volatile organic compounds(TVOCs) was "W"-shaped, the concentration reached its peak at 13:00–15:00 and its trough at 1:00–3:00;VOCs beneficial to human health mainly appeared at 13:00, while VOCs harmful to human health chiefly occurred at 11:00–19:00. The correlation analysis between the concentration of VOCs and climatic factors indicated that the concentration of VOCs was basically proportional to the temperature and illumination intensity and inversely proportional to the humidity and wind speed. In other words, the diurnal variation of the concentration was consistent with the diurnal variation of temperature and illumination intensity.展开更多
Innovation in forestry education is needed to address changing contexts of the positionality of forests.This is particularly signifi cant in the Asia–Pacifi c region,where deforestation and degradation are high.Howev...Innovation in forestry education is needed to address changing contexts of the positionality of forests.This is particularly signifi cant in the Asia–Pacifi c region,where deforestation and degradation are high.However,the accessibility of high-quality forestry education to address changing regional and global contexts is lacking.A series of innovative sustainable forest management(SFM)open education resource(OER)courses were developed and implemented to improve the accessibility of SFM education to enhance teaching quality,curriculum,and research capacity of universities in the Asia-Pacifi c Region.To evaluate the SFM-OER program in terms of student experiences,this study investigated student achievement,perceived success of the pedagogical approach and instructional design,and perceived eff ectiveness of the learning activities in promoting active and transformative learning through the assessment of a 1,191-course feedback survey between 2018 and 2020,including the global pandemic.This study revealed that the program attracted diverse student demographics,including a higher proportion of female students majoring in forestry,ecology,and other environmental studies.Their primary motivation to participate in the courses was to gain international experience,followed by the fl exibility of online learning,mandatory course requirements,and earning course credits.Students were satisfi ed with the Canvas learning management system.Most students spent less than 5 to 10 h of their weekly time in the course and agreed or strongly agreed that the workloads were manageable.Students refl ected positively on various learning activities and assignments,such as watching lecture videos,taking quizzes,reading and summarizing,having discussions,and peer review writing.However,they did not clearly prefer specifi c learning activities,signifying the importance of using diverse learning activities to satisfy diverse individual learning styles in online settings.This analysis contributes to the further development of student-centered pedagogical development for online learning and provides insight into the ways forward for online higher forestry education,while repurposing existing OER courses in a post-Covid-19 era.展开更多
Background： Growth and yield models are important tools for forest planning. Due to its geographic location, topology, and history of management, the forests of the Adirondacks Region of New York are unique and compl...Background： Growth and yield models are important tools for forest planning. Due to its geographic location, topology, and history of management, the forests of the Adirondacks Region of New York are unique and complex. However, only a relatively limited number of growth and yield models have been developed and/or can be reasonably extended to this region currently. Methods： in this analysis, 571 long-term continuous forest inventory plots with a total of 10 - 52 years of measurement data from four experimental forests maintained by the State University of New York College of Environmental Science and Forestry and one nonindustrial private forest were used to develop an individual tree growth model for the primary hardwood and softwood species in the region. Species-specific annualized static and dynamic equations were developed using the available data and the system was evaluated for long-term behavior. Results： Equivalence tests indicated that the Northeast Variant of the Forest Vegetation Simulator （FVS-NE） was biased in its estimation of tree total and bole height, diameter and height increment, and mortality for most species examined. In contrast, the developed static and annualized dynamic, species-specific equations performed quite well given the underlying variability in the data. Long-term model projections were consistent with the data and suggest a relatively robust system for prediction. Conclusions： Overall, the developed growth model showed reasonable behavior and is a significant improvement over existing models for the region. The model also highlighted the complexities of forest dynamics in the region and should help improve forest planning efforts there.展开更多
With the Fokienia hodginsii forest in Qishan National Forest Park as the object of study, this study observed the diurnal variation of concentrations of atmospheric aerosol particles inside and outside the forest, col...With the Fokienia hodginsii forest in Qishan National Forest Park as the object of study, this study observed the diurnal variation of concentrations of atmospheric aerosol particles inside and outside the forest, collected the data of microclimate factors, and analyzed their correlation with the particle concentration. The results showed that the diurnal variation curves of the particle concentration of the forest and the forest edge had two peaks and two troughs". There were two peaks throughout the day at 13:00 and 19:00 or 17:00 as well as two troughs at 7:00-9:00 and 15:00 or 17:00. The atmospheric aerosol particle in the forest was mainly fine particles, while the forest edge was dominated by coarse particles. For the forest and the forest edge, the diurnal variation trends of various atmospheric aerosol particles were similar. The particle concentration was positively correlated with temperature, relative humidity, and il umination intensity and negatively correlated with wind speed, and the particle concentration outside the forest was significantly negatively correlated with the wind speed.展开更多
positively or negatively depending on the condition.Vegetation has influence on the soil physico-chemical characteristics.Land use land cover changes are the main factors in the process of land resource degradation.Th...positively or negatively depending on the condition.Vegetation has influence on the soil physico-chemical characteristics.Land use land cover changes are the main factors in the process of land resource degradation.The objectives of this study were to define the soil texture,bulk density and extent of organic carbon in church forests and adjacent croplands and to compare the values.Transect lines of 100 meter apart and plots of 20 m×20 m were established to collect soil samples in the church forests and individual farm plots.The distance between plots was 100 m.Horizon based soil sampling was undertaken.Soil samples were collected on a diagonal position from 2 edges and the center from 2 soil horizons(H1 and H2)for soil texture and soil organic carbon(SOC)analysis.For bulk density(BD)soil core samplers were used.The data was analyzed using one way ANOVA in SPSS v20.Mean separation was undertaken by least significance difference.The results revealed the%clay content was significantly higher in croplands than church forests and the%sand was higher in church forests than croplands at(p<0.05).The SOC was significantly higher in H1 than H2 and in church forests than croplands at(p<0.05).The better soil characteristics were obtained in church forests than in croplands.Hence,it is recommended to conserve the natural forests as in the church forests to maintain better property of the soil through enhancing soil organic matter,soil organic carbon and by decreasing soil bulk density.展开更多
This study analyzed the microclimate factors and human comfort index of the inner and outer Fokienia hodginsii forests and of a city square.The results showed that:①In terms of the average daily temperature,the inner...This study analyzed the microclimate factors and human comfort index of the inner and outer Fokienia hodginsii forests and of a city square.The results showed that:①In terms of the average daily temperature,the inner and outer forests and the city square ranked as follows:square>outer forest>inner forest.The temperature of the inner forest was 8.21–11.73℃lower than that of the city square,and the temperature of the outer forest was 7.41–10.34℃lower than that of the city square.The inner forest was cooled by 24.21%and 1.37%respectively than the outer forest and the city square.②In terms of the average daily relative humidity,the inner and outer forests and the city square ranked as follows:square<outer forest<inner forest.The average daily relative humidity of the inner forest,the outer forest,and the city square was 68.57,84.91,and 88.27,respectively.③In terms of the average daily wind speed,the inner and outer forests and the city square ranked as:square>outer forest>inner forest.Their daily variation ranges were 0–0.75,0.18–0.43,and 0.12–0.31 m/s,respectively.④In terms of the daily average illumination intensity,the inner and outer forests and the square ranked as:square>outer forest>inner forest.Their average daily illumination intensities were 371.68,4,582.01,and 17,641.63 lux,respectively.展开更多
Taking the Phyllostachys heterocycla forest in Qishan National Forest Park of Fuzhou for example, this study observed the diurnal variation of atmospheric aerosol particles in the forest in the growing season.The resu...Taking the Phyllostachys heterocycla forest in Qishan National Forest Park of Fuzhou for example, this study observed the diurnal variation of atmospheric aerosol particles in the forest in the growing season.The results showed that:(1) The diurnal variation curves of the particle concentration of the forest and the forest edge had "two peaks and two troughs", but the peaks and troughs of the forest edge were advanced or delayed.The concentrations of the particles in the forest and at the forest edge had two peaks at 11:00–13:00 and 17:00–19:00 and two troughs at 7:00–9:00 and 15:00–17:00.(2) For the forest and the forest edge, the diurnal variation trends of the particles of different particle sizes were generally similar, except that the peaks and troughs of fine particles were slightly earlier or lagging than that of coarse particles.(3) The concentrations of the particles were positively correlated with temperature, humidity and light, and negatively correlated with wind speed, and the concentrations of the particles at the forest edge were significantly negatively correlated with wind speed.展开更多
This study analyzed the microclimate factors and human comfort index inside and outside the Phyl ostachys heterocycla forest of Qishan Natiional Forest Park in summer,and compared them with those of the city square.Th...This study analyzed the microclimate factors and human comfort index inside and outside the Phyl ostachys heterocycla forest of Qishan Natiional Forest Park in summer,and compared them with those of the city square.The results showed that:(1)In terms of the average daily temperature,the inner and outer forests and the city square ranked as follows:city square>outer forest>inner forest.The temperature of the inner forest was 5.41–10.31°C lower than that of the city square,and the temperature of the outer forest was 4.41–9.51°C lower than that of the city square.(2)In terms of the average daily relative humidity,the inner and outer forests and the city square ranked as follows:city square<outer forest<inner forest.Compared with the city sqaure,the inner forest had an increase of 8.21–31.51%in relative humidity,and the outer forest had an increase of 8.11–26.16%in relative humidity.(3)In terms of the average daily wind speed,the inner and outer forests and the city square ranked as follows:city square>outer forest>inner forest.The daily average value of the city square was 42%and 37%higher than that of the inner and outer forests,and the daily average value of the outer forest was 21%higher than that of the inner forest.(4)In terms of the daily average illumination intensity,the inner and outer forests and the square ranked as follows:city square>outer forest>inner forest.The daily average value of the city square was 97.38%and 74.33%higher than that of the inner and outer forests,and the daily average value of the outer forest was 89.78%higher than that of the inner forest.展开更多
This study observed the temperature,relative humidity,and wind speed of the inner and outer Fokienia hodginsii forests and the urban area in autumn,used the comprehensive comfort index to represent human comfort,compa...This study observed the temperature,relative humidity,and wind speed of the inner and outer Fokienia hodginsii forests and the urban area in autumn,used the comprehensive comfort index to represent human comfort,compared the differences in the microclimates between the inner and outer forests and the urban area,and evaluated the impacts of the 3 plots on the comfort level of people’s outdoor activities.The results showed that:The inner forest had a drop in temperature ranging 0.7℃to 1.5℃compared with the outer forest;the outer forest had a drop in temperature ranging 0.6℃to 3.5℃compared with the urban area;the relative humidity of the inner forest was 0.04–5%higher than that of the outer forest,and 21.7–37.1%higher than that of the urban area;the wind speed of the inner forest was 56%lower than that of the urban area,and 35%lower than that of the outer forest.In short,the inner forest,where people felt most comfortable,was a better place for developing outdoor activities in autumn.展开更多
基金supported in part by the intramural research program of the US Department of Agriculture,National Institute of Food and Agriculture,Evans-Allen#1024525,and Capacity Building Grant#006531supported in part by the US National Science Foundation RII Track 2 FEC:Leveraging Intelligent Informatics and Smart Data for Improved Understanding of Northern Forest Ecosystem Resiliency(INSPIRES)#1920908by The Lyndhurst Foundation.
文摘Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tree biomass within a fully censused 20 ha forest plot in a temperate forest of northern Alabama,USA.We evaluated the relationship between biomass and topography using ridge and valley landforms along with digitally derived moisture and solar radiation indices.Every live woody stem over 1 cm diameter at breast height within this plot was mapped,measured,and identified to species in 2019-2022,and diameter data were used along with speciesspecific wood density to map the aboveground biomass at the scale of 20 m×20 m quadrats.The aboveground tree biomass was 211 Mg·ha^(-1).Other than small stream areas that experienced recent natural disturbances,the total stand biomass was not associated with landform or topographic indices.Dominant species,in contrast,had strong associations with topography.American beech(Fagus grandifolia)and yellow-poplar(Liriodendron tulipfera)dominated the valley landform,with 37% and 54% greater biomass in the valley than their plot average,respectively.Three other dominant species,white oak(Quercus alba),southern shagbark hickory(Carya carolinaeseptentrionalis),and white ash(Fraxinus americana),were more abundant on slopes and benches,thus partitioning the site.Of the six dominant species,only sugar maple(Acer saccharum)was not associated with landform.Moreover,both topographic wetness and potential radiation indices were significant predictors of dominant species biomass within each of the landforms.The study highlights the need to consider species when examining forest productivity in a range of site conditions.
基金supported by the MITACS Accelerate grant with Greenfirst,industry partner in La Sarre,QC,Canada.
文摘Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-canopy lichen(Cladonia spp.)woodlands have been observed in boreal forests of eastern Canada.It has been hypothesized that high severity of fires would be the cause of this change,but this is difficult to validate a posteriori on mature forest stands.Because charcoal properties are affected by fire severity,we have put forward the hypothesis that the amount and physicochemical properties of charcoal(C,N,H,O,ash,surface area)would be different and indicative of a greater fire severity for open-canopy forests compared to closed canopy ones.Our hypothesis was partly validated in that the amount of charcoal found on the ground of closed-canopy forests was greater than that of open-canopy forests.However,the physicochemical properties were not different,albeit a greater variability of charcoal properties for open canopy stands.These results do not allow us to fully validate or reject our hypothesis on the role of fire severity in the shift between open and closed canopy stands.However,they suggest that the variability in fire conditions as well as the amounts of charcoal produced are different between the two ecosystem types.Furthermore,considering the role that biochar may play in improving soil conditions and promoting vegetation restoration,our results suggest that charcoal may play a role in maintaining these two stable alternative ecosystem states.
基金funded by the Scientific Research Project of Anhui Higher Education Institutions(2022AH050915)the Anhui Agricultural University Natural Science Foundation Youth Project(K2137004)the Anhui Agricultural University Introducing and Stabilizing Talent Project(rc372103).
文摘Various types of vegetative cover,predominantly woodlands,shrublands,and grasslands,provide a range of habitats for urban organisms and are the main contributors to urban ecosystem services.The goal of this study was to assess the potential of different vegetation types in maintaining and enhancing bryophyte diversity in urban areas.Bryophytes,small non-vascular plants,in woodlands,shrublands,and grasslands in Hefei city(eastern China)were investigated,and their species richness,abundance,community composition and relationships with habitat characteristics were analysed.The results show that urban woodlands had the highest species richness and abundance of bryophytes and a distinct community composition compared with the other vegetation types.Relative light intensity had a positive effect on species richness in urban woodlands,whereas litter cover had a negative effect on abundance.Shrub,grass and litter covers,and relative air humidity were the main factors driving the differences in bryophyte species composition between woodlands and other vegetation types.Therefore,owing to their high potential to maintain bryophyte diversity,woodlands should receive increased attention during the construction of urban green spaces.In addition,promoting structural heterogeneity and increasing light availability would be beneficial to bryophyte species diversity.
基金supported by the 2024 scientific promotion program funded by Jeju National University.
文摘Objective:To investigate the osteogenic effects of polyphenol-rich extracts from Wisteria floribunda(Willd.)DC.(W.floribunda)flowers and elucidate the underlying mechanisms.Methods:Polyphenolic compounds of W.floribunda extracts were analyzed,including flavonoids and glucoside derivatives.Osteogenic activity was assessed in MC3T3-E1 preosteoblast cells by measurement of alkaline phosphatase(ALP)activity,alizarin red S staining,and the expression of osteogenic markers(RUNX2,SP7,and ALPL).In vivo effects were evaluated in zebrafish larvae by assessing skeletal development and expression of osteogenic genes(runx2a,sp7,and alpl).The role of mammalian target of rapamycin(mTOR)pathway was examined using rapamycin.Results:W.floribunda extracts significantly enhanced ALP activity,bone mineralization,and the expression of RUNX2,SP7,and ALPL in MC3T3-E1 cells.In zebrafish larvae,W.floribunda extracts improved vertebral mineralization and upregulated osteogenic genes.Mechanistically,the plant extract activated the mTOR pathway,and rapamycin treatment attenuated the extracts-induced ALP activity,mineralization,and vertebral formation in zebrafish,confirming mTOR involvement.Conclusions:W.floribunda extracts promote osteoblast differentiation and bone formation via mTOR pathway activation.These findings provide novel insights into the potential of W.floribunda extracts and support its further investigation as a natural therapeutic candidate for bone degenerative disorders such as osteoporosis.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2018R1D1A3B07045079)。
文摘Litterfall, which is influenced by physical and biological factors, is a major pathway for carbon and nutrient cycling in forest ecosystems. The purpose of this study was to investigate monthly litterfall production in three forests in Jeju Island differentiated by forest composition and precipitation: Cheongsu(Quercus glauca as the dominant species;low precipitation), Seonheulb(Q. glauca as the dominant species;high precipitation), and Seonheulm(Q. glauca and Pinus thunbergii as the dominant species;high precipitation). Litterfall was collected monthly from April to December 2015 and divided into leaf litter, twig, bark, seeds, and unidentified materials.Seasonal patterns of litterfall production varied across stands according to their species composition. However,the amount of leaf litterfall and total litterfall were comparable among stands, ranging from 362 to 375 g m-2 for leaf litter and 524 g m-2 to 580 g m-2 for total litterfall.Oak leaf litter in May was the highest in all stands, while needle litter was the highest in December in Seonheulm.High twig litterfall in July may be attributable to high rainfall with strong winds and storms during the rainy season. Although forest type and climate factor had no influence on litterfall amounts in this study, the pattern of litterfall production was species dependent, suggesting diverse effects on carbon and nutrient cycling in these forests.
基金Sponsored by the Science and Technology Project of Beijing Municipal Administration Center of Parks(ZX2019,ZX2017)Beijing Science and Technology Plan Project(D171100001817001)
文摘This study used the dynamic headspace adsorption(DHS) to collect volatile organic compounds(VOCs) released from the Fokienia hodginsii forest in summer, and analyzed the the composition and concentration of VOCs and their correlation with environmental factors. The results showed that: there were 165 types of VOCs in the Fokienia hodginsii forest;the diurnal variation of the concentration of total volatile organic compounds(TVOCs) was "W"-shaped, the concentration reached its peak at 13:00–15:00 and its trough at 1:00–3:00;VOCs beneficial to human health mainly appeared at 13:00, while VOCs harmful to human health chiefly occurred at 11:00–19:00. The correlation analysis between the concentration of VOCs and climatic factors indicated that the concentration of VOCs was basically proportional to the temperature and illumination intensity and inversely proportional to the humidity and wind speed. In other words, the diurnal variation of the concentration was consistent with the diurnal variation of temperature and illumination intensity.
基金Asia-Pacifi c Network for Sustainable Forest Management and Rehabilitation SFM-ORE-2018。
文摘Innovation in forestry education is needed to address changing contexts of the positionality of forests.This is particularly signifi cant in the Asia–Pacifi c region,where deforestation and degradation are high.However,the accessibility of high-quality forestry education to address changing regional and global contexts is lacking.A series of innovative sustainable forest management(SFM)open education resource(OER)courses were developed and implemented to improve the accessibility of SFM education to enhance teaching quality,curriculum,and research capacity of universities in the Asia-Pacifi c Region.To evaluate the SFM-OER program in terms of student experiences,this study investigated student achievement,perceived success of the pedagogical approach and instructional design,and perceived eff ectiveness of the learning activities in promoting active and transformative learning through the assessment of a 1,191-course feedback survey between 2018 and 2020,including the global pandemic.This study revealed that the program attracted diverse student demographics,including a higher proportion of female students majoring in forestry,ecology,and other environmental studies.Their primary motivation to participate in the courses was to gain international experience,followed by the fl exibility of online learning,mandatory course requirements,and earning course credits.Students were satisfi ed with the Canvas learning management system.Most students spent less than 5 to 10 h of their weekly time in the course and agreed or strongly agreed that the workloads were manageable.Students refl ected positively on various learning activities and assignments,such as watching lecture videos,taking quizzes,reading and summarizing,having discussions,and peer review writing.However,they did not clearly prefer specifi c learning activities,signifying the importance of using diverse learning activities to satisfy diverse individual learning styles in online settings.This analysis contributes to the further development of student-centered pedagogical development for online learning and provides insight into the ways forward for online higher forestry education,while repurposing existing OER courses in a post-Covid-19 era.
文摘Background： Growth and yield models are important tools for forest planning. Due to its geographic location, topology, and history of management, the forests of the Adirondacks Region of New York are unique and complex. However, only a relatively limited number of growth and yield models have been developed and/or can be reasonably extended to this region currently. Methods： in this analysis, 571 long-term continuous forest inventory plots with a total of 10 - 52 years of measurement data from four experimental forests maintained by the State University of New York College of Environmental Science and Forestry and one nonindustrial private forest were used to develop an individual tree growth model for the primary hardwood and softwood species in the region. Species-specific annualized static and dynamic equations were developed using the available data and the system was evaluated for long-term behavior. Results： Equivalence tests indicated that the Northeast Variant of the Forest Vegetation Simulator （FVS-NE） was biased in its estimation of tree total and bole height, diameter and height increment, and mortality for most species examined. In contrast, the developed static and annualized dynamic, species-specific equations performed quite well given the underlying variability in the data. Long-term model projections were consistent with the data and suggest a relatively robust system for prediction. Conclusions： Overall, the developed growth model showed reasonable behavior and is a significant improvement over existing models for the region. The model also highlighted the complexities of forest dynamics in the region and should help improve forest planning efforts there.
基金Sponsored by the Science and Technology Project of Beijing Municipal Administration Center of Parks(ZX2019)Beijing Science and Technology Plan Project(D171100001817001)
文摘With the Fokienia hodginsii forest in Qishan National Forest Park as the object of study, this study observed the diurnal variation of concentrations of atmospheric aerosol particles inside and outside the forest, collected the data of microclimate factors, and analyzed their correlation with the particle concentration. The results showed that the diurnal variation curves of the particle concentration of the forest and the forest edge had two peaks and two troughs". There were two peaks throughout the day at 13:00 and 19:00 or 17:00 as well as two troughs at 7:00-9:00 and 15:00 or 17:00. The atmospheric aerosol particle in the forest was mainly fine particles, while the forest edge was dominated by coarse particles. For the forest and the forest edge, the diurnal variation trends of various atmospheric aerosol particles were similar. The particle concentration was positively correlated with temperature, relative humidity, and il umination intensity and negatively correlated with wind speed, and the particle concentration outside the forest was significantly negatively correlated with the wind speed.
基金My great thanks goes to my colegue Dr.Abdu Abdulkadir who gave me his valuable comments how to organize the manuscript.His inputs were very important for the work to proceed forward.I also thank my friend and colegue Mr.Nesibu Yaya for helping me in editing the map of the study area.
文摘positively or negatively depending on the condition.Vegetation has influence on the soil physico-chemical characteristics.Land use land cover changes are the main factors in the process of land resource degradation.The objectives of this study were to define the soil texture,bulk density and extent of organic carbon in church forests and adjacent croplands and to compare the values.Transect lines of 100 meter apart and plots of 20 m×20 m were established to collect soil samples in the church forests and individual farm plots.The distance between plots was 100 m.Horizon based soil sampling was undertaken.Soil samples were collected on a diagonal position from 2 edges and the center from 2 soil horizons(H1 and H2)for soil texture and soil organic carbon(SOC)analysis.For bulk density(BD)soil core samplers were used.The data was analyzed using one way ANOVA in SPSS v20.Mean separation was undertaken by least significance difference.The results revealed the%clay content was significantly higher in croplands than church forests and the%sand was higher in church forests than croplands at(p<0.05).The SOC was significantly higher in H1 than H2 and in church forests than croplands at(p<0.05).The better soil characteristics were obtained in church forests than in croplands.Hence,it is recommended to conserve the natural forests as in the church forests to maintain better property of the soil through enhancing soil organic matter,soil organic carbon and by decreasing soil bulk density.
基金Sponsored by the Science and Technology Project of Beijing Municipal Administration Center of Parks(ZX2019)Beijing Science and Technology Plan Project(D171100001817001)
文摘This study analyzed the microclimate factors and human comfort index of the inner and outer Fokienia hodginsii forests and of a city square.The results showed that:①In terms of the average daily temperature,the inner and outer forests and the city square ranked as follows:square>outer forest>inner forest.The temperature of the inner forest was 8.21–11.73℃lower than that of the city square,and the temperature of the outer forest was 7.41–10.34℃lower than that of the city square.The inner forest was cooled by 24.21%and 1.37%respectively than the outer forest and the city square.②In terms of the average daily relative humidity,the inner and outer forests and the city square ranked as follows:square<outer forest<inner forest.The average daily relative humidity of the inner forest,the outer forest,and the city square was 68.57,84.91,and 88.27,respectively.③In terms of the average daily wind speed,the inner and outer forests and the city square ranked as:square>outer forest>inner forest.Their daily variation ranges were 0–0.75,0.18–0.43,and 0.12–0.31 m/s,respectively.④In terms of the daily average illumination intensity,the inner and outer forests and the square ranked as:square>outer forest>inner forest.Their average daily illumination intensities were 371.68,4,582.01,and 17,641.63 lux,respectively.
基金Sponsored by the Science and Technology Project of Beijing Municipal Administration Center of Parks(ZX2019)Beijing Science and Technology Plan Project(D171100001817001)
文摘Taking the Phyllostachys heterocycla forest in Qishan National Forest Park of Fuzhou for example, this study observed the diurnal variation of atmospheric aerosol particles in the forest in the growing season.The results showed that:(1) The diurnal variation curves of the particle concentration of the forest and the forest edge had "two peaks and two troughs", but the peaks and troughs of the forest edge were advanced or delayed.The concentrations of the particles in the forest and at the forest edge had two peaks at 11:00–13:00 and 17:00–19:00 and two troughs at 7:00–9:00 and 15:00–17:00.(2) For the forest and the forest edge, the diurnal variation trends of the particles of different particle sizes were generally similar, except that the peaks and troughs of fine particles were slightly earlier or lagging than that of coarse particles.(3) The concentrations of the particles were positively correlated with temperature, humidity and light, and negatively correlated with wind speed, and the concentrations of the particles at the forest edge were significantly negatively correlated with wind speed.
基金Sponsored by the Science and Technology Project of Beijing Municipal Administration Center of Parks(ZX2019)Beijing Science and Technology Plan Project(D171100001817001)
文摘This study analyzed the microclimate factors and human comfort index inside and outside the Phyl ostachys heterocycla forest of Qishan Natiional Forest Park in summer,and compared them with those of the city square.The results showed that:(1)In terms of the average daily temperature,the inner and outer forests and the city square ranked as follows:city square>outer forest>inner forest.The temperature of the inner forest was 5.41–10.31°C lower than that of the city square,and the temperature of the outer forest was 4.41–9.51°C lower than that of the city square.(2)In terms of the average daily relative humidity,the inner and outer forests and the city square ranked as follows:city square<outer forest<inner forest.Compared with the city sqaure,the inner forest had an increase of 8.21–31.51%in relative humidity,and the outer forest had an increase of 8.11–26.16%in relative humidity.(3)In terms of the average daily wind speed,the inner and outer forests and the city square ranked as follows:city square>outer forest>inner forest.The daily average value of the city square was 42%and 37%higher than that of the inner and outer forests,and the daily average value of the outer forest was 21%higher than that of the inner forest.(4)In terms of the daily average illumination intensity,the inner and outer forests and the square ranked as follows:city square>outer forest>inner forest.The daily average value of the city square was 97.38%and 74.33%higher than that of the inner and outer forests,and the daily average value of the outer forest was 89.78%higher than that of the inner forest.
基金Sponsored by the Science and Technology Project of Beijing Municipal Administration Center of Parks(ZX2019,ZX2017)Beijing Science and Technology Plan Project(D171100001817001)
文摘This study observed the temperature,relative humidity,and wind speed of the inner and outer Fokienia hodginsii forests and the urban area in autumn,used the comprehensive comfort index to represent human comfort,compared the differences in the microclimates between the inner and outer forests and the urban area,and evaluated the impacts of the 3 plots on the comfort level of people’s outdoor activities.The results showed that:The inner forest had a drop in temperature ranging 0.7℃to 1.5℃compared with the outer forest;the outer forest had a drop in temperature ranging 0.6℃to 3.5℃compared with the urban area;the relative humidity of the inner forest was 0.04–5%higher than that of the outer forest,and 21.7–37.1%higher than that of the urban area;the wind speed of the inner forest was 56%lower than that of the urban area,and 35%lower than that of the outer forest.In short,the inner forest,where people felt most comfortable,was a better place for developing outdoor activities in autumn.
