Since China’s reform and opening-up,the growing disparity between urban and rural areas and regions has led to massive migration.With China’s Rural Revitalization Strategy and the industrial transfer from the easter...Since China’s reform and opening-up,the growing disparity between urban and rural areas and regions has led to massive migration.With China’s Rural Revitalization Strategy and the industrial transfer from the eastern coastal areas to the inland,the migration direction and pattern of the floating population have undergone certain changes.Using the 2017 China Migrants Dynamic Survey(CMDS),excluding Hong Kong,Macao,and Taiwan regions of China,organized by China’s National Health Commission,the relationship matrix of the floating population is constructed according to the inflow place of the interviewees and their outflow place(the location of the registered residence)in the questionnaire survey.We then apply the complex network model to analyze the migration direction and network pattern of China’s floating population from the city scale.The migration network shows an obvious hierarchical agglomeration.The first-,second-,third-and fourth-tier distribution cities are municipalities directly under the central government,provincial capital cities,major cities in the central and western regions and ordinary cities in all provinces,respectively.The migration trend is from the central and western regions to the eastern coastal areas.The migration network has‘small world’characteristics,forming nine communities.It shows that most node cities in the same community are closely linked and geographically close,indicating that the migration network of floating population is still affected by geographical proximity.Narrowing the urban-rural and regional differences will promote the rational distribution this population.It is necessary to strengthen the reform of the registered residence system,so that the floating population can enjoy urban public services comparable to other populations,and allow migrants to live and work in peace.展开更多
Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we cl...Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.展开更多
Objective To evaluate the community-based health promotion effect of physical activity. Methods The residents aged 28 and above from two communities in Gongshu District of Hangzhou City, Zhejiang province, were random...Objective To evaluate the community-based health promotion effect of physical activity. Methods The residents aged 28 and above from two communities in Gongshu District of Hangzhou City, Zhejiang province, were randomly selected and recruited for the multi-strategy and comprehensive physical activity intervention. Questionnaire survey, physical check up and blood biochemistry were conducted. Results After this two-year intervention, the time of the participant spent on weekly physical activity of moderate intensity increased from 464 min to 542 min (P〈0.05), with an average increase of 78 min. Time spent in walking every week increased from 533 min to 678 min (P〈0.05), with an average increase of 245 min. The body weight, waistline, blood pressure and heart rate all reduced significantly (P〈0.05); the vital capacity increased significantly (P〈0.05); and the related biochemical indicators were also improved. Conclusion Comprehensive and evidence-based physical activity interventions targeting community population can improve the levels of physical activity, related body measurement and biochemical indicators.展开更多
Isolated, relic populations of Acer grandidentatum (bigtooth maple, Sapindaceae) were found in deep canyons in central Texas. Associated with them on hilltops were communities of Juniperus ashei (ash juniper). We dete...Isolated, relic populations of Acer grandidentatum (bigtooth maple, Sapindaceae) were found in deep canyons in central Texas. Associated with them on hilltops were communities of Juniperus ashei (ash juniper). We determined the structure of relic A. grandidentatum populations and compared them to adjacent J. ashei populations. The overstory and understory density was counted and basal area was determined for all woody species in both communities using the quadrat procedure. Acer grandidentatum was the highest density (788 ± 964 or 52%) and basal area (29 ± 35 or 52%) overstory species in the canyon communities while J. ashei had the highest density (1589 ± 146 or 92%) and basal area (51 ± 13 or 88%) in the hilltop communities. In the understory of the canyon communities, there were five juvenile tree species including A. grandidentatum which had the fourth highest density (13% or 176 ± 110 plants/ha). In the hilltop communities, J. ashei was the high density understory tree species (52% or 994 ± 400 plants/ha). There were no A. Grandidentatum overstory or understory plants in the hilltop Juniperus communities. Acer grandidentatum had an inverse quadratic size distribution with few juveniles. Although we counted a number of seedlings, there was little recruitment over the last 16 years and very little potential recruitment in the previous 20 years. Juniperus ashei had an inverse exponential size distribution with many understory plants and considerable recruitment. Weibull age/size distributions showed one A. grandidentatum established in the 1670’s and 2 in the 1760’s, with peak establishment in the 1970’s. Causes of the lack of recent recruitment are uncertain, but it could be episodic due to changes in herbivory, management or other environmental conditions.展开更多
This paper deals with the distribution pattern type,aggregative intensity,pattern scaleand dynamics of plant populations of Rhizophora stylosa community in Yingluo Bay of Guangxi.The measured results show that R.stylo...This paper deals with the distribution pattern type,aggregative intensity,pattern scaleand dynamics of plant populations of Rhizophora stylosa community in Yingluo Bay of Guangxi.The measured results show that R.stylosa population is an aggregated distribution,while thepopulations of Kandelia candel,Bruguiera gymnorrhiza and Aegiceras corniculatum appear asrandom distribution.The plant population distribution pattern changes,along with the populationdevelopment and the succession of the community.展开更多
The structures of bacterial communities in the brown planthopper (BPH) Nilaparvata lugens (St^l) from different geographic and resistant virulent populations were analyzed by using denatured gradient gel electroph...The structures of bacterial communities in the brown planthopper (BPH) Nilaparvata lugens (St^l) from different geographic and resistant virulent populations were analyzed by using denatured gradient gel electrophoresis (DGGE). Results showed that the bacterial communities in BPH nymph from the first to the fifth instars varied with nymphal growth and development. The bacterial communities in the first-instar BPH nymph were similar to those in adults. Nine geographic BPH populations were divided into three groups based on the cluster analysis of DGGE fingerprint. The first group was from the Philippines; the second group was from Thailand and Hainan, Yunnan and Zhejiang provinces of China; and the third group was from Vietnam and Guangxi, Hunan and Jiangxi provinces of China. BPH populations adapted to different resistant rice varieties. The BPH populations from Mudgo (with resistant gene Bphl) and ASD7 (with resistant gene bph2) differed with those of the susceptible rice variety TNI.展开更多
Local communities depend on Kalinzu Forest Reserve (KFR) for plant resources. This resource utilization affects the population of tree species in the forest. This study set out to estimate the population of ten tree s...Local communities depend on Kalinzu Forest Reserve (KFR) for plant resources. This resource utilization affects the population of tree species in the forest. This study set out to estimate the population of ten tree species in the forest. Results of this study are hoped to provide a basis for studying future changes in population dynamics of the species. The ten species selected were: Newtonia buchananii, Cynometra alexandrei, Teclea nobilis, Prunus africana, Entandrophragma exelsum, Sapium ellipticum, Diospyros abyssinica, Zanthoxylum gilletii, Rytiginia kigeziensis and Spathodea nilotica. Their selection was based on the results of a study (Aine-Omucunguzi et al., 2010) about utilization of plant resources by the local people around KFR. Species with high demand from the local people were selected. Alternate nested quadrants along five line transects, were used to estimate the population. The plants were categorized into three classes as trees (>5 cm diameter at breast height), saplings (2 cm root collar diameter-5 cm diameter at breast height) and wildings (<2 cm root collar diameter). Population, population density, relative density, frequency, and relative frequency of each species were determined. Generally, the number of wildings, saplings and trees of each species increased away from the forest edge inwards. For all the species, wildings had the highest population density followed by saplings and then trees. Teclea nobilis had the highest number of individual per hectare, followed by Newtonia buchananii, while Rytiginia kigeziensis and Spathodea nilotica had the lowest number of individuals per hectare.展开更多
Evaluating the presence of fresh water snails in a location is germane in establishing a snail-borne disease control program.The purpose of the study was to see how physicochemical parameters influenced the population...Evaluating the presence of fresh water snails in a location is germane in establishing a snail-borne disease control program.The purpose of the study was to see how physicochemical parameters influenced the population distribution of four fresh water snails(Lymnaea natalensis,Bulinus globosus,Biomphalaria pfeiffer,and Melanoides spp.)in the Amassoma community and Niger Delta University between March,2021 and May 2021.Snails were gathered by plucking and scooping them by hand.Snail was identified using standard pictorial keys.Physicochemical of the water of the snail habitat were measured using standard in-situ apparatus across eight sites Physico chemical measured were temperature,pH,conductivity,BOD,turbidity,salinity,and alkalinity.A total of 258 snails were gathered from the eight(8)different sites.In all sites,Lymnaea natalensis was more abundant.Bulinus globosus,Biomphalaria pfeiffer,and Melanoides spp.were among the other snails discovered.Lymnaea had negative correlation with pH,conductivity,BOD,and alkalinity and a positive correlation with salinity and temperature.Bulinus had a positive relationship with pH,salinity,and conductivity and a negative correlation with temperature,turbidity,BOD,and alkalinity.Biomphalaria had a positive correlation with temperature,pH,salinity,turbidity,and alkalinity Melanoides had positive correlations with Temperature,pH,salinity,BOD,and alkalinity and a negative correlation with turbidity and concentration.The was correlation between snails and snails.The presence of these snails suggests that the Amassoma village and Niger Delta University campuses are potential hotspots for a variety of snail-borne diseases.展开更多
The suppression of overwintering population is essential in integrated pest management,but little is known about the biological mortality factors that reduce the overwintering density of Chilo suppressalis.Here,we exa...The suppression of overwintering population is essential in integrated pest management,but little is known about the biological mortality factors that reduce the overwintering density of Chilo suppressalis.Here,we examine the parasitism of overwintering larvae,and assume that key parasitoids strengthen the over-wintering population suppression.The natural parasitism incidence and related dominant parasitoids in overwintering larvae were investigated in two successive winters,in 2015-2016 and 2016-2017.Parasitism rates were also assessed in larvae collected from 15 different counties in 2016.The results showed that the parasitism incidence and dominant parasitoids in overwintering C.suppressalis larvae were significantly different for different sampling dates and sites.Overwintering larvae of C.suppressalis were mainly parasitized by Cotesia chilonis,and less often by Eriborus sinicus and Microgaster russata.Regression analysis indicated that the natural incidence of parasites in overwintering C.suppressalis larvae was positively correlated with the over-wintering larval density.The current work provides support for overwintering pest management strategies by showing the effectiveness of parasitoid communities as a bio-mortality factor for suppressing overwintering density.展开更多
Pakistan is declared a cirrhotic state by WHO because of high prevalence of Hepatitis C virus(HCV). It is proposed that there are more than 10 million infected individuals in Pakistan. Keeping in mind the scenario, on...Pakistan is declared a cirrhotic state by WHO because of high prevalence of Hepatitis C virus(HCV). It is proposed that there are more than 10 million infected individuals in Pakistan. Keeping in mind the scenario, one should expect to have proper surveillance system for HCV monitoring across the country not only for high risk groups but also for general population as well. Monitoring the general population is of considerable help to identify the hot spots for infection spread and will help in designing effective strategies. In this study the current available data from last 6 years is analyzed. The results showed that the range of HCV seroprevalence in general population in Pakistan varied from 3.13%-23.83%. Similarly year wise HCV prevalence showed great variation and the prevalence was 9.57%, 6.04%, 7.46%, 4.9% and 11.04% in 2010, 2011, 2012, 2013 and 2014 respectively. The current analysis declared that available data is not sufficient and is not presenting the original picture of the situation. On these basis, a proper surveillance system is proposed across the country to get an actual picture of the infection for better management in future and massive community education programmes should be warranted in identified hot spots across the country.展开更多
The community characteristics of mangroves in the Futian Nature Reserve, Shenzhen, China are given based on surveying of 33 quadrats in 4 transects which stretch from the higher tidal zone to the lower tidal zone. The...The community characteristics of mangroves in the Futian Nature Reserve, Shenzhen, China are given based on surveying of 33 quadrats in 4 transects which stretch from the higher tidal zone to the lower tidal zone. The results show that there are 6 community types in this area: Kandelia candel association, Avicennia marina association, Aegiceras corniculatum association, Kandelia candel + Aegiceras corniculatum association, Aegiceras corniculatum + Kandelia candel association and Acanthus ilicifolius association. Kandelia candel, Aegiceras corniculatum and Avicennia marina dominate the typical quadrats. Kandelia candel can be seen at almost all quadrats, Aegiceras corniculatum distributes mostly toward the estuary and the higher tidal zone, Avicennia marina distributes mostly toward the bay and the lower tidal zone, Bruguiera gymnorrhiza occasionally occurs toward the Estuary with one or several individuals, Acanthus ilicifolius was common toward the higher tidal zone, as an accompanying species, Derris trifoliata was common in many mature quadrats. Totally, 6 species of mangrove plants and 3 species of semi-mangrove plants appear in this research area. From the higher tidal zone to the lower tidal zone, the average diameter and basal area of mangrove trees increase gradually. According to the results, the Avicennia marina dominates in average diameter and basal area, and the Aegiceras corniculatum trees are on the contrary. From the transect 1 to the transect 4, the importance value of Avicennia marina, Bruguiera gymnorrhiza and Kandelia candel decreases, and Aegiceras corniculatum increases. In this area, the Kandelia candel population and Aegiceras corniculatum population are developing populations with many seedlings and saplings, but the Avicennia marina population is in a mature stage with few seedlings and not so many total individuals. According to this research, we suppose that Aegiceras corniculatum should be developed toward the estuary and the Avicennia marina association should be protected.展开更多
This article reveals the data about two coenopopulation of </span><i><span style="font-family:Verdana;">Tulipa</span></i> <i><span style="font-family:Verdana;"...This article reveals the data about two coenopopulation of </span><i><span style="font-family:Verdana;">Tulipa</span></i> <i><span style="font-family:Verdana;">fosteriana</span></i><span style="font-family:Verdana;"> in Zeravshan mountain ridge in the vicinity of the Takhta-Karachi pass in the border of Kashkadarya basin. Thus, the studied coenopopulation of </span><i><span style="font-family:Verdana;">T</span></i><span style="font-family:Verdana;">.</span></span><span style="font-family:""> </span><i><span style="font-family:Verdana;">fosteriana</span></i><span style="font-family:Verdana;"> is normal, incomplete. The absence of senile individuals in the examined coenopopulation is associated with the biological characteristic of the species. In tulips, as in many geophytes, most individuals complete</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> finish their large life cycles in a generative state. The ontogenetic spectra of the studied coenopopulation coincide with the characteristic ones, and thereby reflect the biological characteristics of the species.展开更多
The progressive aging of society is expected to lead to the development of effective integrated community-based care system considering the characteristics based on community environments. However, the COVID-19 pandem...The progressive aging of society is expected to lead to the development of effective integrated community-based care system considering the characteristics based on community environments. However, the COVID-19 pandemic has influenced population health worldwide. This study aimed to examine disparities in population health and health-related factors between rural and urban communities during the COVID-19 pandemic. A literature search was conducted using PubMed, Medline, and CINAHL for articles published up to September 2022 with the following search terms: community health, rural, urban, and COVID-19. A total of 105 articles were identified, of which three articles with a cross-sectional quantitative research design met the inclusion criteria. Two articles focused on mental health, and among them, one recognized a significant disparity between rural and urban areas. Four health-related factors in view of the COVID-19 pandemic in rural and urban areas were perceived, including knowledge, behavior, lifestyle, and social support. And, two factors: health-related knowledge and health-related behavior, were perceived as the significant disparities between rural and urban during the COVID-19 pandemic. The further efforts will be needed to pursue effective integrated community-based care system during and post-COVID-19, taking into account community environment at both community and individual levels.展开更多
Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession ...Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.展开更多
Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem fu...Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem functions,especially in nutrient-limited ecosystems.However,as the key propagule pool of perennial grasslands,how belowground bud bank and its relationship with aboveground vegetation respond to short-term changes in soil nutrients was still unclear.In this study,we conducted a short-term(2021–2022)soil fertilization experiment with N addition(10 g N m^(-2) yr^(-1))and P addition(5 g N m^(-2) yr^(-1))in the meadow steppe of Inner Mongolia,China,to explore the responses of belowground bud bank,aboveground shoot population and their relationships(represented by the ratio of bud to shoot density-meristem limitation index(MLI))for the whole community and three plant functional groups(perennial rhizomatous grasses-PR,perennial bunchgrasses-PB,and perennial forbs-PF)to nutrient addition.The short-term nutrient addition had no significant influences on belowground bud density,aboveground shoot density,and MLI of the whole plant community.Plant functional groups showed different responses to soil fertilization.Specifically,N addition significantly increased the bud density and shoot density of PR,especially in combination with P addition.N addition reduced the shoot density of PF but had no influence on its bud density and MLI.Nutrient addition had significant effects on the three indicators of PB.Our study indicates that the belowground bud bank and its relationship with aboveground vegetation in temperate meadow steppe are insensitive to short-term soil fertilization,but plant functional groups exhibit specific responses in terms of population regeneration,which implies that plant community composition and ecosystem functions will be changed under the ongoing global change.展开更多
This study aims to investigate the seasonal variations in copepod community structure and prosome length of dominant species from March 2009 to January 2010 around artificial reefs in Xiaoshi Island, Yellow Sea, Weiha...This study aims to investigate the seasonal variations in copepod community structure and prosome length of dominant species from March 2009 to January 2010 around artificial reefs in Xiaoshi Island, Yellow Sea, Weihai, China. Samples were collected using two types of plankton net (Model I and Model II) for different-sized copepods. The number of taxon was calculated from the data of both the net types, while the copepod abundance was done using the samples from Model II only. Sixteen species of planktonic copepods, including 5 dominant species, were recorded. Results reveal that Oithona similis was the first dominant species from March to June, and was replaced by Paracalanus parvus in September; both dominated the copepod community in January. Acartia hongi was the second dominant species from March to September. Centropages abdominalis was the third dominant species from March to June, and was replaced by O. sirnilis in September and Corycaeus aJfinis in January. C. affinis was the fourth dominant species in September. Population density of the dominant copepods was compared with that of other similar regions. We found that the dominant species were mostly small copepods (〈1 mm) except for adult Centrapages abdominalis. Seasonal variation in prosome length of O. similis, C. abdominalis, and C. affinis, and their copepodites were studied for the first time in China. For P. parvus and A. hongi, seasonal trends in prosome length variation were similar with those in Jiaozhou Bay, Yellow Sea, Qingdao, China, in a similar temperate domain. The results are helpful for future calculation of copepod biomass and production, and for investigation of the relationship between copepods and fish resources.展开更多
China's ageing, the service for elderly pension is become a serious problem, and the traditional way of pension is not enough to meet the needs of existing. In this case, the community endowment to its unique advanta...China's ageing, the service for elderly pension is become a serious problem, and the traditional way of pension is not enough to meet the needs of existing. In this case, the community endowment to its unique advantages to be the new choice to solve the problem of China's pension. Taiyuan city, Shanxi Province in China based on as the breakthrough point, to study the community endowment service of Taiyuan city. For multiple community in Taiyuan city by using the method of field survey and some residents to investigate analyze the present situation of Taiyuan city community endowment. Through the research that Taiyuan city community endowment exists does not reach the designated position on propaganda, unbalanced development, lack of funds, community service and social participation is not high, and even the poor community health care can't satisfy the elderly need to all sorts of problems. Put forward the corresponding suggestion, according to the issues can be solved through policy support, strengthen the propaganda, broaden the sources of funding, training and service team, strengthening community health service and diversified development, community service projects, so that the community endowment in China better development.展开更多
Tremendous progress has been made in the past decade surrounding the underlying mechanisms and treatment of neuropsychiatric disease. Technological advancements and a broadened research paradigm have contributed to th...Tremendous progress has been made in the past decade surrounding the underlying mechanisms and treatment of neuropsychiatric disease. Technological advancements and a broadened research paradigm have contributed to the understanding of the neurochemistry, brain function and brain circuitry involved in neuropsychiatric disorders. The predominant area of unmet medical need in the United States is major psychiatric disorders, and major depressive disorder is the leading cause of disability for ages 15-44. Total spending on research and development by the pharmaceutical industry has grown exponentially during the past decade, but fewer new molecular entities(NME) for the treatment of major psychiatric disorders have received regulatory approvals compared to other therapeutic areas. Though significant expansion has occurred during the "decade of the brain", the translation of clinical trials outcomes into the community mental health setting is deficient. Randomized controlled trials(RCTs) have been the standard approach to clinical evaluation of the safety and efficacy of NMEs for the past 60 years; however, there are significant barriers and skepticism in the implementation of evidence-based outcomes into clinical practice. Recruitment of patients, shortages of experiencedclinical researchers, regulatory requirements and later translation of outcomes into clinical practice are ever growing problems faced by investigators. The community mental health setting presents particular barriers in the replication of therapeutic outcomes from RCTs. The diagnostic complexity of major psychiatric diseases and the highly selective patient populations involved in clinical trials lend to the gap in translation from the "bench to the bedside". The community mental health setting lends to a diverse patient population with numerous co-morbidities and environmental factors that are unaccounted in the average RCT. While we acknowledge the enormous complexity in developing novel and innovative treatments for major psychiatric disorders, we must continue to improve the translatability of clinical trials to real world settings. Progress has been rather slow but as the gap in treatment effectiveness is reduced, so will costs and barriers in community mental health.展开更多
Using plant community analysis methods, we analyzed the floristic characteristics, species composition, community structure, population structure, and spatial distribution patterns of a Betula dahurica forest on the ...Using plant community analysis methods, we analyzed the floristic characteristics, species composition, community structure, population structure, and spatial distribution patterns of a Betula dahurica forest on the "1238" mountain of Badaling in Beijing, China. The results show that: 1) There are 33 plant species in the B. dahurica community, including 18 woody plant species. The B. dahurica forest is a monodominant community with 75.9% dominance. 2) Based on diameter at breast height (DBH) size class distribution, the population structure of B. dahurica and Acer mono--two heliophyllous and pioneer tree species-is cascade-type, with both in an increasing stage. The population structure of Ella mandshurica and T. mongolica, two shade-tolerant tree species, is inverse-J type, and they have more young seedling individuals and regenerate more stably. They are associated species of the pioneer tree species. The population structure of Quercus mongolica, as the associated species of climax species in the community, is sporadic, and its regeneration is fluctuating and random. Fraxinus rhynchophylla is a shade-tolerant tree species which has a unibar population structure and climax characteristics of pioneer tree species. The relative frequency of young seedlings reached 0.4. 3) The dominant species B. dahurica is still in an increasing stage, and the regeneration of other species is steady or partly influences the community, putting the community in the pioneer species stage. From the population structure and distribution frequency ofF. rhynchophylla, the B. dahurica forest will approach to a climax state in the future.展开更多
At present, the world's aging population is developing at an unprecedented rate, how to deal with the community service for the elderly has become a top priority. For it not only relates to the community's harmony b...At present, the world's aging population is developing at an unprecedented rate, how to deal with the community service for the elderly has become a top priority. For it not only relates to the community's harmony but also to the whole social's stability. This paper summarized some experiences and practices from some typical foreign countries on their community endowment, such as the British community care model, the Japan's aged care at home, the PACE mode of United States, the Germany's long-term care services, the Australian's old-age community security. On the basis of a comparative analysis, this paper concluded some experience and enlightenment of serving the old in abroad urban community, this include: Give full play to the function and role of the community in the pension, take law as safeguard on the implementation of community endowment, professional services, government-led and multiple subject participation, provide comprehensive and diversified service, etc. Combined with China's national conditions, this paper puts forward some countermeasures and suggestions in the end to further perfect China's elderly community service.展开更多
基金Under the auspices of the Fund of Social Sciences Research,Ministry of Education of China(No.17YJA840011)。
文摘Since China’s reform and opening-up,the growing disparity between urban and rural areas and regions has led to massive migration.With China’s Rural Revitalization Strategy and the industrial transfer from the eastern coastal areas to the inland,the migration direction and pattern of the floating population have undergone certain changes.Using the 2017 China Migrants Dynamic Survey(CMDS),excluding Hong Kong,Macao,and Taiwan regions of China,organized by China’s National Health Commission,the relationship matrix of the floating population is constructed according to the inflow place of the interviewees and their outflow place(the location of the registered residence)in the questionnaire survey.We then apply the complex network model to analyze the migration direction and network pattern of China’s floating population from the city scale.The migration network shows an obvious hierarchical agglomeration.The first-,second-,third-and fourth-tier distribution cities are municipalities directly under the central government,provincial capital cities,major cities in the central and western regions and ordinary cities in all provinces,respectively.The migration trend is from the central and western regions to the eastern coastal areas.The migration network has‘small world’characteristics,forming nine communities.It shows that most node cities in the same community are closely linked and geographically close,indicating that the migration network of floating population is still affected by geographical proximity.Narrowing the urban-rural and regional differences will promote the rational distribution this population.It is necessary to strengthen the reform of the registered residence system,so that the floating population can enjoy urban public services comparable to other populations,and allow migrants to live and work in peace.
基金This study received financial support from the Science and Technology Department of Yunnan University,China(2019YNU002)Major Program for Basic Research Project of Yunnan Province,China(202101BC070002)the Special Foundation for National Science and Technology Basic Resources Investigation of China(2019FY202300).
文摘Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.
文摘Objective To evaluate the community-based health promotion effect of physical activity. Methods The residents aged 28 and above from two communities in Gongshu District of Hangzhou City, Zhejiang province, were randomly selected and recruited for the multi-strategy and comprehensive physical activity intervention. Questionnaire survey, physical check up and blood biochemistry were conducted. Results After this two-year intervention, the time of the participant spent on weekly physical activity of moderate intensity increased from 464 min to 542 min (P〈0.05), with an average increase of 78 min. Time spent in walking every week increased from 533 min to 678 min (P〈0.05), with an average increase of 245 min. The body weight, waistline, blood pressure and heart rate all reduced significantly (P〈0.05); the vital capacity increased significantly (P〈0.05); and the related biochemical indicators were also improved. Conclusion Comprehensive and evidence-based physical activity interventions targeting community population can improve the levels of physical activity, related body measurement and biochemical indicators.
文摘Isolated, relic populations of Acer grandidentatum (bigtooth maple, Sapindaceae) were found in deep canyons in central Texas. Associated with them on hilltops were communities of Juniperus ashei (ash juniper). We determined the structure of relic A. grandidentatum populations and compared them to adjacent J. ashei populations. The overstory and understory density was counted and basal area was determined for all woody species in both communities using the quadrat procedure. Acer grandidentatum was the highest density (788 ± 964 or 52%) and basal area (29 ± 35 or 52%) overstory species in the canyon communities while J. ashei had the highest density (1589 ± 146 or 92%) and basal area (51 ± 13 or 88%) in the hilltop communities. In the understory of the canyon communities, there were five juvenile tree species including A. grandidentatum which had the fourth highest density (13% or 176 ± 110 plants/ha). In the hilltop communities, J. ashei was the high density understory tree species (52% or 994 ± 400 plants/ha). There were no A. Grandidentatum overstory or understory plants in the hilltop Juniperus communities. Acer grandidentatum had an inverse quadratic size distribution with few juveniles. Although we counted a number of seedlings, there was little recruitment over the last 16 years and very little potential recruitment in the previous 20 years. Juniperus ashei had an inverse exponential size distribution with many understory plants and considerable recruitment. Weibull age/size distributions showed one A. grandidentatum established in the 1670’s and 2 in the 1760’s, with peak establishment in the 1970’s. Causes of the lack of recent recruitment are uncertain, but it could be episodic due to changes in herbivory, management or other environmental conditions.
文摘This paper deals with the distribution pattern type,aggregative intensity,pattern scaleand dynamics of plant populations of Rhizophora stylosa community in Yingluo Bay of Guangxi.The measured results show that R.stylosa population is an aggregated distribution,while thepopulations of Kandelia candel,Bruguiera gymnorrhiza and Aegiceras corniculatum appear asrandom distribution.The plant population distribution pattern changes,along with the populationdevelopment and the succession of the community.
基金funded by the National Basic Research Program of China (973, Grant No. 2010CB126202)the Agro-Industry R & D Special Fund of China (Grant No. 201003031)
文摘The structures of bacterial communities in the brown planthopper (BPH) Nilaparvata lugens (St^l) from different geographic and resistant virulent populations were analyzed by using denatured gradient gel electrophoresis (DGGE). Results showed that the bacterial communities in BPH nymph from the first to the fifth instars varied with nymphal growth and development. The bacterial communities in the first-instar BPH nymph were similar to those in adults. Nine geographic BPH populations were divided into three groups based on the cluster analysis of DGGE fingerprint. The first group was from the Philippines; the second group was from Thailand and Hainan, Yunnan and Zhejiang provinces of China; and the third group was from Vietnam and Guangxi, Hunan and Jiangxi provinces of China. BPH populations adapted to different resistant rice varieties. The BPH populations from Mudgo (with resistant gene Bphl) and ASD7 (with resistant gene bph2) differed with those of the susceptible rice variety TNI.
文摘Local communities depend on Kalinzu Forest Reserve (KFR) for plant resources. This resource utilization affects the population of tree species in the forest. This study set out to estimate the population of ten tree species in the forest. Results of this study are hoped to provide a basis for studying future changes in population dynamics of the species. The ten species selected were: Newtonia buchananii, Cynometra alexandrei, Teclea nobilis, Prunus africana, Entandrophragma exelsum, Sapium ellipticum, Diospyros abyssinica, Zanthoxylum gilletii, Rytiginia kigeziensis and Spathodea nilotica. Their selection was based on the results of a study (Aine-Omucunguzi et al., 2010) about utilization of plant resources by the local people around KFR. Species with high demand from the local people were selected. Alternate nested quadrants along five line transects, were used to estimate the population. The plants were categorized into three classes as trees (>5 cm diameter at breast height), saplings (2 cm root collar diameter-5 cm diameter at breast height) and wildings (<2 cm root collar diameter). Population, population density, relative density, frequency, and relative frequency of each species were determined. Generally, the number of wildings, saplings and trees of each species increased away from the forest edge inwards. For all the species, wildings had the highest population density followed by saplings and then trees. Teclea nobilis had the highest number of individual per hectare, followed by Newtonia buchananii, while Rytiginia kigeziensis and Spathodea nilotica had the lowest number of individuals per hectare.
文摘Evaluating the presence of fresh water snails in a location is germane in establishing a snail-borne disease control program.The purpose of the study was to see how physicochemical parameters influenced the population distribution of four fresh water snails(Lymnaea natalensis,Bulinus globosus,Biomphalaria pfeiffer,and Melanoides spp.)in the Amassoma community and Niger Delta University between March,2021 and May 2021.Snails were gathered by plucking and scooping them by hand.Snail was identified using standard pictorial keys.Physicochemical of the water of the snail habitat were measured using standard in-situ apparatus across eight sites Physico chemical measured were temperature,pH,conductivity,BOD,turbidity,salinity,and alkalinity.A total of 258 snails were gathered from the eight(8)different sites.In all sites,Lymnaea natalensis was more abundant.Bulinus globosus,Biomphalaria pfeiffer,and Melanoides spp.were among the other snails discovered.Lymnaea had negative correlation with pH,conductivity,BOD,and alkalinity and a positive correlation with salinity and temperature.Bulinus had a positive relationship with pH,salinity,and conductivity and a negative correlation with temperature,turbidity,BOD,and alkalinity.Biomphalaria had a positive correlation with temperature,pH,salinity,turbidity,and alkalinity Melanoides had positive correlations with Temperature,pH,salinity,BOD,and alkalinity and a negative correlation with turbidity and concentration.The was correlation between snails and snails.The presence of these snails suggests that the Amassoma village and Niger Delta University campuses are potential hotspots for a variety of snail-borne diseases.
基金funded by a grant from the National Natural Science Foundation of China (31872929)
文摘The suppression of overwintering population is essential in integrated pest management,but little is known about the biological mortality factors that reduce the overwintering density of Chilo suppressalis.Here,we examine the parasitism of overwintering larvae,and assume that key parasitoids strengthen the over-wintering population suppression.The natural parasitism incidence and related dominant parasitoids in overwintering larvae were investigated in two successive winters,in 2015-2016 and 2016-2017.Parasitism rates were also assessed in larvae collected from 15 different counties in 2016.The results showed that the parasitism incidence and dominant parasitoids in overwintering C.suppressalis larvae were significantly different for different sampling dates and sites.Overwintering larvae of C.suppressalis were mainly parasitized by Cotesia chilonis,and less often by Eriborus sinicus and Microgaster russata.Regression analysis indicated that the natural incidence of parasites in overwintering C.suppressalis larvae was positively correlated with the over-wintering larval density.The current work provides support for overwintering pest management strategies by showing the effectiveness of parasitoid communities as a bio-mortality factor for suppressing overwintering density.
文摘Pakistan is declared a cirrhotic state by WHO because of high prevalence of Hepatitis C virus(HCV). It is proposed that there are more than 10 million infected individuals in Pakistan. Keeping in mind the scenario, one should expect to have proper surveillance system for HCV monitoring across the country not only for high risk groups but also for general population as well. Monitoring the general population is of considerable help to identify the hot spots for infection spread and will help in designing effective strategies. In this study the current available data from last 6 years is analyzed. The results showed that the range of HCV seroprevalence in general population in Pakistan varied from 3.13%-23.83%. Similarly year wise HCV prevalence showed great variation and the prevalence was 9.57%, 6.04%, 7.46%, 4.9% and 11.04% in 2010, 2011, 2012, 2013 and 2014 respectively. The current analysis declared that available data is not sufficient and is not presenting the original picture of the situation. On these basis, a proper surveillance system is proposed across the country to get an actual picture of the infection for better management in future and massive community education programmes should be warranted in identified hot spots across the country.
文摘The community characteristics of mangroves in the Futian Nature Reserve, Shenzhen, China are given based on surveying of 33 quadrats in 4 transects which stretch from the higher tidal zone to the lower tidal zone. The results show that there are 6 community types in this area: Kandelia candel association, Avicennia marina association, Aegiceras corniculatum association, Kandelia candel + Aegiceras corniculatum association, Aegiceras corniculatum + Kandelia candel association and Acanthus ilicifolius association. Kandelia candel, Aegiceras corniculatum and Avicennia marina dominate the typical quadrats. Kandelia candel can be seen at almost all quadrats, Aegiceras corniculatum distributes mostly toward the estuary and the higher tidal zone, Avicennia marina distributes mostly toward the bay and the lower tidal zone, Bruguiera gymnorrhiza occasionally occurs toward the Estuary with one or several individuals, Acanthus ilicifolius was common toward the higher tidal zone, as an accompanying species, Derris trifoliata was common in many mature quadrats. Totally, 6 species of mangrove plants and 3 species of semi-mangrove plants appear in this research area. From the higher tidal zone to the lower tidal zone, the average diameter and basal area of mangrove trees increase gradually. According to the results, the Avicennia marina dominates in average diameter and basal area, and the Aegiceras corniculatum trees are on the contrary. From the transect 1 to the transect 4, the importance value of Avicennia marina, Bruguiera gymnorrhiza and Kandelia candel decreases, and Aegiceras corniculatum increases. In this area, the Kandelia candel population and Aegiceras corniculatum population are developing populations with many seedlings and saplings, but the Avicennia marina population is in a mature stage with few seedlings and not so many total individuals. According to this research, we suppose that Aegiceras corniculatum should be developed toward the estuary and the Avicennia marina association should be protected.
文摘This article reveals the data about two coenopopulation of </span><i><span style="font-family:Verdana;">Tulipa</span></i> <i><span style="font-family:Verdana;">fosteriana</span></i><span style="font-family:Verdana;"> in Zeravshan mountain ridge in the vicinity of the Takhta-Karachi pass in the border of Kashkadarya basin. Thus, the studied coenopopulation of </span><i><span style="font-family:Verdana;">T</span></i><span style="font-family:Verdana;">.</span></span><span style="font-family:""> </span><i><span style="font-family:Verdana;">fosteriana</span></i><span style="font-family:Verdana;"> is normal, incomplete. The absence of senile individuals in the examined coenopopulation is associated with the biological characteristic of the species. In tulips, as in many geophytes, most individuals complete</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> finish their large life cycles in a generative state. The ontogenetic spectra of the studied coenopopulation coincide with the characteristic ones, and thereby reflect the biological characteristics of the species.
文摘The progressive aging of society is expected to lead to the development of effective integrated community-based care system considering the characteristics based on community environments. However, the COVID-19 pandemic has influenced population health worldwide. This study aimed to examine disparities in population health and health-related factors between rural and urban communities during the COVID-19 pandemic. A literature search was conducted using PubMed, Medline, and CINAHL for articles published up to September 2022 with the following search terms: community health, rural, urban, and COVID-19. A total of 105 articles were identified, of which three articles with a cross-sectional quantitative research design met the inclusion criteria. Two articles focused on mental health, and among them, one recognized a significant disparity between rural and urban areas. Four health-related factors in view of the COVID-19 pandemic in rural and urban areas were perceived, including knowledge, behavior, lifestyle, and social support. And, two factors: health-related knowledge and health-related behavior, were perceived as the significant disparities between rural and urban during the COVID-19 pandemic. The further efforts will be needed to pursue effective integrated community-based care system during and post-COVID-19, taking into account community environment at both community and individual levels.
基金TheNationalNaturalScienceFoundationofChina (No .39670 1 36) PhDFund (No .980 5580 8)ofMinistryofEducationP .R .China Center
文摘Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.
基金support from the National Natural Science Foundation of China(41877542).
文摘Human activities and industrialization have significantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem functions,especially in nutrient-limited ecosystems.However,as the key propagule pool of perennial grasslands,how belowground bud bank and its relationship with aboveground vegetation respond to short-term changes in soil nutrients was still unclear.In this study,we conducted a short-term(2021–2022)soil fertilization experiment with N addition(10 g N m^(-2) yr^(-1))and P addition(5 g N m^(-2) yr^(-1))in the meadow steppe of Inner Mongolia,China,to explore the responses of belowground bud bank,aboveground shoot population and their relationships(represented by the ratio of bud to shoot density-meristem limitation index(MLI))for the whole community and three plant functional groups(perennial rhizomatous grasses-PR,perennial bunchgrasses-PB,and perennial forbs-PF)to nutrient addition.The short-term nutrient addition had no significant influences on belowground bud density,aboveground shoot density,and MLI of the whole plant community.Plant functional groups showed different responses to soil fertilization.Specifically,N addition significantly increased the bud density and shoot density of PR,especially in combination with P addition.N addition reduced the shoot density of PF but had no influence on its bud density and MLI.Nutrient addition had significant effects on the three indicators of PB.Our study indicates that the belowground bud bank and its relationship with aboveground vegetation in temperate meadow steppe are insensitive to short-term soil fertilization,but plant functional groups exhibit specific responses in terms of population regeneration,which implies that plant community composition and ecosystem functions will be changed under the ongoing global change.
基金Supported by the National Natural Science Foundation of China(No.41106133)the Shandong University Independent Innovation Foundation(No.2011ZRYQ005)the Program of Academy of Marine Research in Weihai(No.000041342080)
文摘This study aims to investigate the seasonal variations in copepod community structure and prosome length of dominant species from March 2009 to January 2010 around artificial reefs in Xiaoshi Island, Yellow Sea, Weihai, China. Samples were collected using two types of plankton net (Model I and Model II) for different-sized copepods. The number of taxon was calculated from the data of both the net types, while the copepod abundance was done using the samples from Model II only. Sixteen species of planktonic copepods, including 5 dominant species, were recorded. Results reveal that Oithona similis was the first dominant species from March to June, and was replaced by Paracalanus parvus in September; both dominated the copepod community in January. Acartia hongi was the second dominant species from March to September. Centropages abdominalis was the third dominant species from March to June, and was replaced by O. sirnilis in September and Corycaeus aJfinis in January. C. affinis was the fourth dominant species in September. Population density of the dominant copepods was compared with that of other similar regions. We found that the dominant species were mostly small copepods (〈1 mm) except for adult Centrapages abdominalis. Seasonal variation in prosome length of O. similis, C. abdominalis, and C. affinis, and their copepodites were studied for the first time in China. For P. parvus and A. hongi, seasonal trends in prosome length variation were similar with those in Jiaozhou Bay, Yellow Sea, Qingdao, China, in a similar temperate domain. The results are helpful for future calculation of copepod biomass and production, and for investigation of the relationship between copepods and fish resources.
文摘China's ageing, the service for elderly pension is become a serious problem, and the traditional way of pension is not enough to meet the needs of existing. In this case, the community endowment to its unique advantages to be the new choice to solve the problem of China's pension. Taiyuan city, Shanxi Province in China based on as the breakthrough point, to study the community endowment service of Taiyuan city. For multiple community in Taiyuan city by using the method of field survey and some residents to investigate analyze the present situation of Taiyuan city community endowment. Through the research that Taiyuan city community endowment exists does not reach the designated position on propaganda, unbalanced development, lack of funds, community service and social participation is not high, and even the poor community health care can't satisfy the elderly need to all sorts of problems. Put forward the corresponding suggestion, according to the issues can be solved through policy support, strengthen the propaganda, broaden the sources of funding, training and service team, strengthening community health service and diversified development, community service projects, so that the community endowment in China better development.
文摘Tremendous progress has been made in the past decade surrounding the underlying mechanisms and treatment of neuropsychiatric disease. Technological advancements and a broadened research paradigm have contributed to the understanding of the neurochemistry, brain function and brain circuitry involved in neuropsychiatric disorders. The predominant area of unmet medical need in the United States is major psychiatric disorders, and major depressive disorder is the leading cause of disability for ages 15-44. Total spending on research and development by the pharmaceutical industry has grown exponentially during the past decade, but fewer new molecular entities(NME) for the treatment of major psychiatric disorders have received regulatory approvals compared to other therapeutic areas. Though significant expansion has occurred during the "decade of the brain", the translation of clinical trials outcomes into the community mental health setting is deficient. Randomized controlled trials(RCTs) have been the standard approach to clinical evaluation of the safety and efficacy of NMEs for the past 60 years; however, there are significant barriers and skepticism in the implementation of evidence-based outcomes into clinical practice. Recruitment of patients, shortages of experiencedclinical researchers, regulatory requirements and later translation of outcomes into clinical practice are ever growing problems faced by investigators. The community mental health setting presents particular barriers in the replication of therapeutic outcomes from RCTs. The diagnostic complexity of major psychiatric diseases and the highly selective patient populations involved in clinical trials lend to the gap in translation from the "bench to the bedside". The community mental health setting lends to a diverse patient population with numerous co-morbidities and environmental factors that are unaccounted in the average RCT. While we acknowledge the enormous complexity in developing novel and innovative treatments for major psychiatric disorders, we must continue to improve the translatability of clinical trials to real world settings. Progress has been rather slow but as the gap in treatment effectiveness is reduced, so will costs and barriers in community mental health.
文摘Using plant community analysis methods, we analyzed the floristic characteristics, species composition, community structure, population structure, and spatial distribution patterns of a Betula dahurica forest on the "1238" mountain of Badaling in Beijing, China. The results show that: 1) There are 33 plant species in the B. dahurica community, including 18 woody plant species. The B. dahurica forest is a monodominant community with 75.9% dominance. 2) Based on diameter at breast height (DBH) size class distribution, the population structure of B. dahurica and Acer mono--two heliophyllous and pioneer tree species-is cascade-type, with both in an increasing stage. The population structure of Ella mandshurica and T. mongolica, two shade-tolerant tree species, is inverse-J type, and they have more young seedling individuals and regenerate more stably. They are associated species of the pioneer tree species. The population structure of Quercus mongolica, as the associated species of climax species in the community, is sporadic, and its regeneration is fluctuating and random. Fraxinus rhynchophylla is a shade-tolerant tree species which has a unibar population structure and climax characteristics of pioneer tree species. The relative frequency of young seedlings reached 0.4. 3) The dominant species B. dahurica is still in an increasing stage, and the regeneration of other species is steady or partly influences the community, putting the community in the pioneer species stage. From the population structure and distribution frequency ofF. rhynchophylla, the B. dahurica forest will approach to a climax state in the future.
文摘At present, the world's aging population is developing at an unprecedented rate, how to deal with the community service for the elderly has become a top priority. For it not only relates to the community's harmony but also to the whole social's stability. This paper summarized some experiences and practices from some typical foreign countries on their community endowment, such as the British community care model, the Japan's aged care at home, the PACE mode of United States, the Germany's long-term care services, the Australian's old-age community security. On the basis of a comparative analysis, this paper concluded some experience and enlightenment of serving the old in abroad urban community, this include: Give full play to the function and role of the community in the pension, take law as safeguard on the implementation of community endowment, professional services, government-led and multiple subject participation, provide comprehensive and diversified service, etc. Combined with China's national conditions, this paper puts forward some countermeasures and suggestions in the end to further perfect China's elderly community service.