Warm-wet climatic conditions are widely regarded as conducive to remarkable tree growth,alleviating climatic pressures.However,the notable decline in tree growth observed in the southern edge of boreal forests has hei...Warm-wet climatic conditions are widely regarded as conducive to remarkable tree growth,alleviating climatic pressures.However,the notable decline in tree growth observed in the southern edge of boreal forests has heightened concerns over the spatial-temporal dynamics of forest decline.Currently,attaining a comprehensive grasp of the underlying patterns and their propelling factors remains a formidable challenge.We collected tree ring samples from a network of 50 sites across the Greater Xing'an Mountains.These samples were subsequently grouped into two distinct clusters,designated as Groups A and B.The percentage change of growth(GC,%)and the proportion of declining sites were utilized to assess forest decline.The decline in tree growth within Larix gmelinii forests exhibits significant regional variation,accompanied by temporal fluctuations even within a given region.Group A exhibited a pronounced increase in frequency(59.26%)of occurrences and encountered more severe declines(21.65%)in tree growth subsequent to the 1990s,contrasting sharply with Group B,which observed lower frequencies(20.00%)and relatively less severe declines(21.02%)prior to the 1980s.The primary impetus underlying the opposite radial growth increments observed in Larix gmelinii trees from the interplay between their differential response to temperatures and wetter climatic conditions,which is significantly influenced by varying stand densities.In cold-dry conditions,low-density forests may experience soil water freezing,exacerbating drought conditions and thereby inhibiting tree growth,in Group B.Trees growth in high-density stands is restrained by warm-wet conditions,in Group A.These results provide new insights into the variability at the southern edge of the boreal forest biome with different responses to density and climate.展开更多
Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts o...Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes.展开更多
Recently,the China Textile Industry Association held 2011 textile and economic operation analysis meeting.The meeting held that the 2011 overall economic operation of China’s textile industry was stable,the indicator...Recently,the China Textile Industry Association held 2011 textile and economic operation analysis meeting.The meeting held that the 2011 overall economic operation of China’s textile industry was stable,the indicators are normal,but various types of risk faced by the operation was展开更多
In order to establish the immune procedure for Actinobacillus pleuropneumonia and to determine the date for the first immunization on piglets, the growth and decline law of A. pleuropneumonia material antibodies in th...In order to establish the immune procedure for Actinobacillus pleuropneumonia and to determine the date for the first immunization on piglets, the growth and decline law of A. pleuropneumonia material antibodies in the piglets borne by cows inoculated with A. pleuropneumonia vaccines （type I, II, and VII） before delivery was detected. The results showed that type I, II, and VII maternal antibodies in piglets decreased gradually with the age growing overall, and was at the critical protection value at the ages of 42-50 days （type I） and 28 days （type VII）, lower than the quantification rate; and the antibodies all turned to be negative until the ages of 70 days （type I）, 60 days （type VII） and 35 days （type II）. The first immunization should be carried out at the age of 42-50 days using type I A. pleuropneumonia vaccine, and at the age of 28 days using type VII A. pleuropneumonia vaccine. However, type II A. pleuropneumonia maternal antibody had lower level and positive rate and could not well protect piglets, so the various A. pleuropneumonia vaccines differed in the date for the first immunization. In order to achieve a better immunization effect, A. pleuropneumonia vaccines with different valences should be further researched and developed.展开更多
A decline in tree growth has occurred in numerous regions over recent decades and is associated with enhanced water deficits driven by climate warming.This phenomenon may be more noticeable at lower latitudes with hig...A decline in tree growth has occurred in numerous regions over recent decades and is associated with enhanced water deficits driven by climate warming.This phenomenon may be more noticeable at lower latitudes with higher temperatures.However,the process by which these elevated temperatures alter growth performance is not well understood.In this study,by combining tree-ring data(including 340 increment cores)and remotely sensed vegetation index data,we investigated the long-term growth performance of Pinus sylvestris var.mongolica Litv.(Mongolian pine),an important species for afforestation in northern China,in response to environmental factors in an area of introduction(lower latitude)and its native range(higher latitude).More notable decreases in both tree-ring width index(RWI)and basal area increment at breast height coincided with lower values and larger variations in the satellite-derived vegetation index in the area of introduction.The RWI showed stronger negative correlations with temperature and positive correlations with the self-calibrating Palmer drought severity index during most months in the introduction area.These results indicate that enhanced drought stress caused by elevated temperatures in lower latitudes might be a key factor for the growth decline in Mongolian pine plantations.The negative impact of increased temperatures on tree growth through exacerbating drought stress at lower latitudes with water deficit highlights the need to reduce water stress in forest management in such areas under climate warming-driven aridification.展开更多
One of the main contemporary problems requiring urgent attention since its present and future repercussions on particular countries is the decrease of population and related problems of population ageing. The populati...One of the main contemporary problems requiring urgent attention since its present and future repercussions on particular countries is the decrease of population and related problems of population ageing. The population ageing is not a worldwide problem yet, it concerns mostly world developed countries. On the other hand, it is a known fact that the population ageing in developing countries will culminate in few decades and will be more dramatic as the current population ageing in the developed world. In the developed countries, the population ageing is cause by the prolonged human life and the decrease of natality. This trend is resulting from many factors that are related to the modernization of the society which caused the decrease in fertility and natality. The health care improvement resulted in the prolonged life expectancy and a better health condition of the population. The science advance prolonged the average life expectancy which is the main reason for the population ageing.展开更多
[Objective]The paper was to investigate the occurrence of Lithocolletis ringoniella adults in aged and new apple orchards in Shijiazhuang area.[Method]The growth and decline dynamics of L.ringoniella adults in 3a appl...[Objective]The paper was to investigate the occurrence of Lithocolletis ringoniella adults in aged and new apple orchards in Shijiazhuang area.[Method]The growth and decline dynamics of L.ringoniella adults in 3a apple orchard and 17a apple orchard in Shijiazhuang were monitored by sex attractant trapping method.Meantime,the trapping effects of sex attractant on L.ringoniella were compared with that of sweet-sour liquor.[Result]L.ringoniella occurred five generations annually in Shijiazhuang area.The adults emerged in April,and entered into peak occurrence period during May and June,with overlapping generations.Comparison between sex attractant and sweet-sour liquor tests showed that the trapping effect of sweet-sour liquor received little effect,but was expensive.Therefore,it is not recommended to use sweet-sour liquor for prevention and treatment of L.ringoniella in production.[Conclusion]In the actual production,sex attractant trapping should be combined with appropriate agricultural control measures to control the damage of L.ringoniella.展开更多
基金National Nature Science Foundation of China(No.32371871)。
文摘Warm-wet climatic conditions are widely regarded as conducive to remarkable tree growth,alleviating climatic pressures.However,the notable decline in tree growth observed in the southern edge of boreal forests has heightened concerns over the spatial-temporal dynamics of forest decline.Currently,attaining a comprehensive grasp of the underlying patterns and their propelling factors remains a formidable challenge.We collected tree ring samples from a network of 50 sites across the Greater Xing'an Mountains.These samples were subsequently grouped into two distinct clusters,designated as Groups A and B.The percentage change of growth(GC,%)and the proportion of declining sites were utilized to assess forest decline.The decline in tree growth within Larix gmelinii forests exhibits significant regional variation,accompanied by temporal fluctuations even within a given region.Group A exhibited a pronounced increase in frequency(59.26%)of occurrences and encountered more severe declines(21.65%)in tree growth subsequent to the 1990s,contrasting sharply with Group B,which observed lower frequencies(20.00%)and relatively less severe declines(21.02%)prior to the 1980s.The primary impetus underlying the opposite radial growth increments observed in Larix gmelinii trees from the interplay between their differential response to temperatures and wetter climatic conditions,which is significantly influenced by varying stand densities.In cold-dry conditions,low-density forests may experience soil water freezing,exacerbating drought conditions and thereby inhibiting tree growth,in Group B.Trees growth in high-density stands is restrained by warm-wet conditions,in Group A.These results provide new insights into the variability at the southern edge of the boreal forest biome with different responses to density and climate.
基金funded by the National Key Research and Development Plan of China(No.2022YFE0127900)the National Natural Science Foundation of China(Nos.32071558,32171559)+2 种基金the Natural Science Foundation Key Project of Inner Mongolia Autonomous Region,China(No.2023ZD23)the Hulunbuir Science and Technology Plan Project(No.SF2022001)the Fundamental Research Funds of CAF(CAFYBB2023ZA002).
文摘Increasing temperatures and severe droughts threaten forest vitality globally.Prediction of forest response to climate change requires knowledge of the spatiotemporal patterns of monthly or seasonal climatic impacts on the growth of tree species,likely driven by local climatic aridity,climate trends,edaphic conditions,and the climatic adaption of tree species.The ability of tree species to cope with changing climate and the effects of environmental variables on growth trends and growth-climate relationships across diverse bioclimatic regions are still poorly understood for many species.This study investigated radial growth trends,interannual growth variability,and growth-climate sensitivity of two dominant tree species,Pinus tabulaeformis(PT)and Pinus sylvestris var.mongolica(PS),across a broad climatic gradient with a variety of soil properties in temperate Northern China.Using a network of 83 tree ring chronologies(54 for PT and 29 for PS)from 1971 to 2010,we documented that both species maintained constant growth trends at wet sites,while both displayed rapid declines at dry sites.We reported the species-specific drivers of spatial heterogeneity in growth trends,interannual growth variability,and growth-climate relationships.Calculated climatic variables and soil properties were identified as the most critical factors affecting the growth trends and growth-climate relationships.However,climatic variables play more essential roles than soil properties in determining the spatial heterogeneity of the growth-climate relationship.Lower clay content and higher soil nutrient regimes can exacerbate the moisture-related susceptibility of tree growth.Our findings highlight that soil properties emerged as important modulating factors to predict the drought vulnerability of forests in addition to climatic variables.Considering the continued climate warmingdrying trend in the future,both pines will face a more severe growth decline and increase in drought vulnerability at drier sites with lower clayed soil or higher nutrient regimes.
文摘Recently,the China Textile Industry Association held 2011 textile and economic operation analysis meeting.The meeting held that the 2011 overall economic operation of China’s textile industry was stable,the indicators are normal,but various types of risk faced by the operation was
基金Supported by National Natural Science Foundation of China(31560696)Development Fund for Scientific Research Institutes in Hainan Province(KYYS-2014-32)Special Fund for Integration of Production,Learning and Research of Hainan Province(cxy20150008)
文摘In order to establish the immune procedure for Actinobacillus pleuropneumonia and to determine the date for the first immunization on piglets, the growth and decline law of A. pleuropneumonia material antibodies in the piglets borne by cows inoculated with A. pleuropneumonia vaccines （type I, II, and VII） before delivery was detected. The results showed that type I, II, and VII maternal antibodies in piglets decreased gradually with the age growing overall, and was at the critical protection value at the ages of 42-50 days （type I） and 28 days （type VII）, lower than the quantification rate; and the antibodies all turned to be negative until the ages of 70 days （type I）, 60 days （type VII） and 35 days （type II）. The first immunization should be carried out at the age of 42-50 days using type I A. pleuropneumonia vaccine, and at the age of 28 days using type VII A. pleuropneumonia vaccine. However, type II A. pleuropneumonia maternal antibody had lower level and positive rate and could not well protect piglets, so the various A. pleuropneumonia vaccines differed in the date for the first immunization. In order to achieve a better immunization effect, A. pleuropneumonia vaccines with different valences should be further researched and developed.
基金supported by the National Natural Science Foundation of China(grants number 32220103010,32192431,31722013,32101587,32271571)the National Key R&D Program of China(2020YFA0608100)+1 种基金the Major Program of Institute of Applied Ecology,Chinese Academy of Sciences(IAEMP202201)Liaoning Provincial Science and Technology Major Project(2023JH1/10400001).
文摘A decline in tree growth has occurred in numerous regions over recent decades and is associated with enhanced water deficits driven by climate warming.This phenomenon may be more noticeable at lower latitudes with higher temperatures.However,the process by which these elevated temperatures alter growth performance is not well understood.In this study,by combining tree-ring data(including 340 increment cores)and remotely sensed vegetation index data,we investigated the long-term growth performance of Pinus sylvestris var.mongolica Litv.(Mongolian pine),an important species for afforestation in northern China,in response to environmental factors in an area of introduction(lower latitude)and its native range(higher latitude).More notable decreases in both tree-ring width index(RWI)and basal area increment at breast height coincided with lower values and larger variations in the satellite-derived vegetation index in the area of introduction.The RWI showed stronger negative correlations with temperature and positive correlations with the self-calibrating Palmer drought severity index during most months in the introduction area.These results indicate that enhanced drought stress caused by elevated temperatures in lower latitudes might be a key factor for the growth decline in Mongolian pine plantations.The negative impact of increased temperatures on tree growth through exacerbating drought stress at lower latitudes with water deficit highlights the need to reduce water stress in forest management in such areas under climate warming-driven aridification.
文摘One of the main contemporary problems requiring urgent attention since its present and future repercussions on particular countries is the decrease of population and related problems of population ageing. The population ageing is not a worldwide problem yet, it concerns mostly world developed countries. On the other hand, it is a known fact that the population ageing in developing countries will culminate in few decades and will be more dramatic as the current population ageing in the developed world. In the developed countries, the population ageing is cause by the prolonged human life and the decrease of natality. This trend is resulting from many factors that are related to the modernization of the society which caused the decrease in fertility and natality. The health care improvement resulted in the prolonged life expectancy and a better health condition of the population. The science advance prolonged the average life expectancy which is the main reason for the population ageing.
文摘[Objective]The paper was to investigate the occurrence of Lithocolletis ringoniella adults in aged and new apple orchards in Shijiazhuang area.[Method]The growth and decline dynamics of L.ringoniella adults in 3a apple orchard and 17a apple orchard in Shijiazhuang were monitored by sex attractant trapping method.Meantime,the trapping effects of sex attractant on L.ringoniella were compared with that of sweet-sour liquor.[Result]L.ringoniella occurred five generations annually in Shijiazhuang area.The adults emerged in April,and entered into peak occurrence period during May and June,with overlapping generations.Comparison between sex attractant and sweet-sour liquor tests showed that the trapping effect of sweet-sour liquor received little effect,but was expensive.Therefore,it is not recommended to use sweet-sour liquor for prevention and treatment of L.ringoniella in production.[Conclusion]In the actual production,sex attractant trapping should be combined with appropriate agricultural control measures to control the damage of L.ringoniella.
