[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were s...[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were set up to investigate the yield of Zhongzhu No.2,based on which we assessed the adaptability of Zhongzhu No.2 to various eco-regions and further analyzed the climatic factors causing the difference in eco-adaptability.[Result] Ramie yield varied largely among various experimental sites and the yield difference appeared to be well repeatable,with a differential value between the maximum and the minimum reaching 2.3 kg/20 m2.Analysis of the yield data,together with climatic factors in various ecological regions showed that yield of Zhongzhu No.2 was significantly correlated with rainfall,sunshine hours,relative humidity during its growing period.Of the climatic factors,sunshine hours and rainfall can positively promote yield increase,while relative humidity negatively regulate ramie yield.[Conclusion] The climatic indices,including rainfall,sunshine duration and relative humidity are a key factor causing yield difference in ramie among different regions of Yangtze Valley.展开更多
According to the distribution of arid and humid regions in China,the typical arid region (Erjina),the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) and the typical humid region (Poyang Lake basin...According to the distribution of arid and humid regions in China,the typical arid region (Erjina),the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) and the typical humid region (Poyang Lake basin) were selected as the study areas.Based on NDVI data from 1982 to 2000 and meteorological observing data of three study areas from 1981 to 2000,the interactions between vegetation NDVI and climatic factors (temperature and precipitation) in typical arid and humid regions were discussed in this study.The results showed that in the responses of vegetation to climatic factors,vegetation in the typical arid region (Erjina) was more sensitive to precipitation,while vegetation in the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) was more sensitive to both temperature and precipitation,and vegetation in the typical humid region (Poyang Lake basin) was more sensitive to temperature.As for effects of vegetation on climatic factors,there was a remarkable negative correlation between vegetation NDVI in the past winter and temperature in the present summer,and also a significant positive correlation between vegetation NDVI in the past winter and precipitation in the present summer.However,in the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau),there was a significant positive correlation between vegetation NDVI in the present spring and temperature in the present summer.展开更多
This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipit...This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipitation, wind speed, sunshine duration, and snow depth. Results show that annual mean temperature increased at a significant rate of 0.35℃ per decade, most notably in the Lesser Khingan Mountains and in winter. Annual rainfall had no obvious linear trend, while rainy days had a significant decreasing trend. So, the rain intensity increased. High-temperature days had a weak increasing trend, and low-temperature days and cold wave showed significant decreasing trends with rates of 3.9 d per decade and -0.64 times per decade, respectively. Frequency and spatial scope of low-temperature hazard reduced significantly. Warm days and warm nights significantly increased at 1.0 and 2.4 d per decade, while cold days and cold nights decreased significantly at -1.8 and -4.1 d per decade, respectively. The nighttime warming rate was much higher than that for daytime, indicating that nighttime warming had a greater contribution to the overall warming trend than daytime warming. The annual mean wind speed, gale days, and sunshine duration had significant decreasing trends at rates of-0.21 m s-1 per decade, -4.0 d per decade and -43.3 h per decade, respectively. The snow cover onset dates postponed at a rate of 1.2 d per decade, and the snow cover end date advanced at 1.5 d per decade, which leads to shorter snow cover duration by -2.7 d per decade. Meanwhile, the maximum snow depth decreased at -0.52 cm per decade. In addition, the snow cover duration shows a higher correlation with precipitation than with temperature, which suggests that precipitation plays a more important role in maintaining snow cover duration than temperature.展开更多
This study examined the temporal variation of the Normalized Difference Vegetation Index （NDVI） and its relationship with climatic factors in the Changbai Mountain Natural Reserve （CMNR） during 2000 - 2009. The re...This study examined the temporal variation of the Normalized Difference Vegetation Index （NDVI） and its relationship with climatic factors in the Changbai Mountain Natural Reserve （CMNR） during 2000 - 2009. The results showed as follows. The average NDVI values increased at a rate of 0.0024 year-1. The increase rate differed with vegetation types, such as 0.0034 year-1 for forest and 0.0017 year-1 for tundra. Trend analyses revealed a consistent NDVI increase at the start and end of the growing season but little variation or decrease observed in July during the study period. The NDVI in CMNR showed a stronger correlation with temperature than with precipitation, especially in spring and autumn. A stronger correlation was observed between NDVI and temperature in the tundra zone （2,000-2,600m） than in the coniferous forest （1,100-1,700m） and Korean pine-broadleaved mixed forest （7oo-1,1oom） zones. The results indicate that vegetation at higher elevations is more sensitive to temperature change. NDVI variation had a strong correlation with temperature change （r=0.7311, p〈0.01） but less significant correlation with precipitation change. The result indicates that temperature can serve as a main indicator of vegetation sensitivity in the CMNR.展开更多
Global climate change is a threat to animals in nearly all biomes and ecosystems, especially for ectotherm whose life activities highly depend on environmental thermal regime. Population genetic diversity which is ess...Global climate change is a threat to animals in nearly all biomes and ecosystems, especially for ectotherm whose life activities highly depend on environmental thermal regime. Population genetic diversity which is essential for adaptation to environmental change is a useful index for long-term species survival. In this paper, genetic diversity of eight Phrynocephalus forsythii population which distributed in Tarim Basin, China, were evaluated based on three mtDNA gene and its correlation with environment factors were investigated using RDA. Our result revealed that, the level of genetic diversity of P. forsythii populations was related to its location but there was no significant correlation between genetic distances and geographic distances in P. forsythii. However, we find that mtDNA of P. forsythii was subjected to selection pressure during evolution and population genetic diversity was significantly positively related to variation coefficient of rainfall(VCR) and altitude(AL), while significantly negatively related to longitude(N) and annual average temperature(AAT). Our result supported the previous prediction that excessive ambient heat is a threat to P. forsythii.展开更多
Panax wangianus （Syn. Panax pseudoginseng） S. C. Sun （Araliaceae） is a critically endangered, medicinal plant of North-East India. The objective of this study was to determine how plant size affects flowering phen...Panax wangianus （Syn. Panax pseudoginseng） S. C. Sun （Araliaceae） is a critically endangered, medicinal plant of North-East India. The objective of this study was to determine how plant size affects flowering phenology and to evaluate the effect of climatic factors on flowering, fruiting and seed production. Data on vegetative and repro- ductive characters were monitored from 2016 individuals of Panax wangianus population in Law Lyngdoh, Smit sacred grove in Nongkrem, Shillong, India. Leaflet area was measured by a planimeter. Size variables of both vegetative and reproductive traits in different age classes were measured. Climatic factors were recorded from 2007 to 2009. Age was recorded by counting the number of bud scale scars on the rhizome. Light intensity and relative humidity were measured using a photometer, LiCor Model LI-189 and thermohygrometer respectively. Different climatic variables are correlated with vegetative and reproductive phenological events. Statistical analysis revealed that a strong positive correlation was observed between the age versus vegetative and reproductive characters, except 1%–2% plants showed neoteny. Morphological variations were observed in natural conditions on the basis of the number of prong and carpellate conditions. Phenological status revealed that most of the individuals of the age class 35–50 years and above 50 years contributed the most to flowering, fruiting and seed production. Age class was significant to predict the size of the plant and its reproductive capacity. Climatic factors such as temperature, precipitation and relative humidity show synergistic effect on both the vegetative and reproductive phases in Panax wangianus in the undisturbed Nongkrem sacred grove. The color of flowers of P. wangianus also varied depending upon the sunlight intensity. Therefore, in the view of conservationand management, the age class of 35–50 years and above 50 years is the most important for population sustainability.展开更多
[Objective] The aim was to analyze the suitability of climatic factors for broad bean in Kunming. [Method] The suitability model of broad bean growth and development was established, involving temperature, rainfal , ...[Objective] The aim was to analyze the suitability of climatic factors for broad bean in Kunming. [Method] The suitability model of broad bean growth and development was established, involving temperature, rainfal , and sunshine, with consideration of bioecology characters of broad beans, in order to make further analysis of suitability of meteorological factors. [Result] Under average climate condition, temperature and sunshine suitability kept higher in the whole growth stage, but rainfal suitability was lower. Hence, lower temperature and insufficient rainfal are limiting factors of broad bean yield. Based on analysis of meteorological factors in 2013, it suggested that temperature and sunshine suitability kept higher in 2013, but rainfal suitability only reached over 0.6 in seedling stage, with rest below. [Conclusion] In the whole growth stage of broad bean in 2013, comprehensive meteorological factors kept middle or higher level and the suitability model reflects suitability of meteorological factors to crops in an objective way, which provides references for improving meteorological services.展开更多
Water scarcity has become a limiting factor for increasing crop production.Finding ways to improve water use efficiency(WUE)has become an urgent task for Chinese agriculture.To understand the response of different mai...Water scarcity has become a limiting factor for increasing crop production.Finding ways to improve water use efficiency(WUE)has become an urgent task for Chinese agriculture.To understand the response of different maize populations to changes in precipitation and the effects of changes in maize populations on WUE,this study conducted maize population experiments using maize hybrids with different plant types(compact and semi compact)and different planting densities at 25 locations across China.It was found that,as precipitation increased across different locations,maize grain yield first increased and then decreased,while WUE decreased significantly.Analyzing the relationship between WUE and the main climatic factors,this study found that WUE was significantly and negatively correlated with precipitation(R(daily mean precipitation)and R(accumulated precipitation))and was positively correlated with temperature(TM(daily mean maximum temperature),T_(M-m)(T_(m),daily mean minimum temperature)and GDD(growing degree days))and solar radiation(Ra(daily mean solar radiation)and Ra(accumulated solar radiation))over different growth periods.Significant differences in maize grain yield,WUE and precipitation were found at different planting densities.The population densities were ranked as follows according to maize grain yield and WUE based on the multi-site experiment data:60000 plants ha^(-1)(P_(2))>90000 plants ha^(-1)(P_(3))>30000 plants ha^(-1)(P_(1)).Further analysis showed that,as maize population increased,water consumption increased significantly while soil evaporation decreased significantly.Significant differences were found between the WUE of ZD958(compact type)and that of LD981(semi-compact type),as well as among the WUE values at different planting densities.In addition,choosing the optimum hybrid and planting density increased WUE by 21.70 and 14.92%,respectively,which showed that the hybrid played a more significant role than the planting density in improving WUE.Therefore,choosing drought-resistant hybrids could be more effective than increasing the planting density to increase maize grain yield and WUE in northern China.Comprehensive consideration of climatic impacts,drought-resistant hybrids(e.g.,ZD958)and planting density(e.g.,60000 plants ha^(-1))is an effective way to increase maize grain yield and WUE across different regions of China.展开更多
Sea ice has important effect on the marine ecosystem and people living in the surrounding regions in winter.However,the understanding on changes of sea ice in the Bohai and northern Huanghai Sea(BNHS),China is still l...Sea ice has important effect on the marine ecosystem and people living in the surrounding regions in winter.However,the understanding on changes of sea ice in the Bohai and northern Huanghai Sea(BNHS),China is still limited.Based on the images from Visible and InfraRed Radiometer(VIRR)onboard Chinese second generation polar-orbit meteorological series satellites FY-3A/B/C,the sea ice areas in the BNHS were extracted from December 2008 to March 2019,the spatio-temporal distribution charac-teristics of sea ice and the relationship between sea ice area and climatic factors were analyzed,then a preliminary sea ice forecast model based on the climatic factors was developed.The results showed that sea ice area in the BNHS in each December was relatively small and rather high sea ice occurrence probability appeared in the offshore areas in Liaodong Bay and northern Huanghai Sea.The sea ice area in January or February each year was the largest,and sea ice occurred in most of areas in Liaodong Bay and northern Huanghai Sea with rather high probability and in some areas in Bohai Bay and Laizhou Bay with relatively high probability.How-ever,the sea ice area in each March was the smallest,and sea ice was even melted completely occasionally,hence with relatively low occurrence probability in Liaodong Bay.As for the inter-annual variability of sea ice in the BNHS during the research period,the sea ice area was largest in winter 2010/11 and smallest in winter 2014/15,and annual sea ice area presented a decreasing trend.The at-mospheric temperature,western Pacific subtropical high(WPSH),Asia polar vortex(APV),Asian monsoon circulation(AMC)and Eurasian monsoon circulation(EMC)were very important climatic factors for sea ice formation and they had significant correlations with sea ice area.Therefore,a preliminary sea ice forecast model was constructed by using eight climatic factors including western Pacific subtropical high area index(WPSHAI),western Pacific subtropical high intensity index(WPSHII),western Pacific subtro-pical high northern boundary position index(WPSHNBPI),Asia polar vortex area index(APVAI),Asian zonal circulation index(AZCI),Asian meridional circulation index(AMCI),Eurasian zonal circulation index(EZCI)and mean minimum atmospheric tem-perature(MMAT).The model was confirmed to have a robust forecast effect by using F-test and validated sample data.The results are useful for monitoring sea ice with remote sensed data and forecasting sea ice conditions by climatic indices.展开更多
Climatic factor＇s effect was studied on the radial growth of teak （Tectona grandis L.F.） by using the stem analysis of 36 trees distributed in 6 plantations in Parakou and Tchaourou districts in northern Benin. The...Climatic factor＇s effect was studied on the radial growth of teak （Tectona grandis L.F.） by using the stem analysis of 36 trees distributed in 6 plantations in Parakou and Tchaourou districts in northern Benin. The results showed that the plantations of Parakou were in general more productive than those of Tchaourou. The annual average growth was estimated in the first five years at 0.86 cm/year for Parakou and 0.76 cm/year at Tchaourou. The analysis of the radial growth showed that a significant percentage of the variance was allotted to the growth model. It follows that a big part of the ring width was predetermined before the intervention of the other factors, in particular the climatic conditions. The percentage of the variance related to the climatic conditions was thus more reduced for the plantations of Tchaourou than those of Parakou. The radial growth was influenced by the conditions of humidity （evapotranspiration, humidity and rain） of February to May on the one hand and those from August to October on the other hand.展开更多
There are differing views regarding the climatic factors that limit radial growth of Qilian juniper （Juniperus przewalskii Kom.） at the upper treelines on the northeastern Tibetan Plateau. In this study, trees from ...There are differing views regarding the climatic factors that limit radial growth of Qilian juniper （Juniperus przewalskii Kom.） at the upper treelines on the northeastern Tibetan Plateau. In this study, trees from an upper tree northeastern Tibetan Plateau were selected to limits the radial growth of Qilian juniper. Using ine site in the Anyemaqen Mountains of the present new evidence that low temperature a signal-free regional curve standardization （SF-RCS） method, a ring-width chronology for Qilian juniper was developed extending from AD 1082 to 2010. The results of correlation analysis between tree-ring index and instrumental climatic variables showed that both winter （December in the previous year and January in the current year） and summer （July and August in the current year） temperatures were signifi- cantly and positively correlated with the tree-ring index. Precipitation in June was also significantly and positively correlated with the tree-ring index, but was not as important as low temperature in controlling tree growth. To test the key limiting climatic factor for tree radial growth at different altitudes, an indicator termed the ＂relative distance to upper treeline＂ （RDUT） was developed to quantify the representativeness of collected samples for the forest＇s upper treeline. The RDUT showed that the upper 20% of the forest belt may be an important boundary in terms of capturing the temperature signal from tree-ring width at the upper treelines on the northeastern Tibetan Plateau. Our findings enhance the existing understanding that temperature is the limiting factor at upper treelines on the northeastern Tibetan Plateau, and will be useful in the reconstruction of past temperature in future studies.展开更多
Taking Lancang County as a study area with a large area of eucalyptus introduction in Yunnan, spatiotemporal change characteristics of vegetation cover, as well as the relationships between Enhanced Vegetation Index（...Taking Lancang County as a study area with a large area of eucalyptus introduction in Yunnan, spatiotemporal change characteristics of vegetation cover, as well as the relationships between Enhanced Vegetation Index（EVl） and climatic factors （temperature and precipitation） were analyzed by using the data of MODIS-EVI from 2005 to 2010. The results indicated that： （1） The vegetation cover was overall good, and the annual average values of EVl were greater than 0.395 and showed a slow increasing trend from 2005 to 2010 in study area; the monthly average values of EVl ranged from 0.296 to 0.538, and seasonal variability was obvious. Monthly average values of EVl usually fell to the lowest level in February and March, and reached the peak in July and August. From the perspective of space, average EVl over the years significantly varied in different towns of Lancang County. During 2005 -2010, in 92.534% area of total, vegetation coverage change were not obvious; in 7.25% area of total, vegeta- tion becoming better; only in 0.02% area of total, vegetation cover were getting worse. （2） Monthly average values of EVl were significantly correlated with monthly average rainfall in Lancang County. The maxima of monthly average EVI and rainfall appeared in August on summer, while the minima of monthly average EVl and rainfall appeared in February and January on winter respectively. （3） Monthly average EVl was somewhat relative with monthly average temperature. The maxima of monthly average EVl and temperature appeared in June and August respectively, while the minima appeared in January and February respectively.展开更多
The use of Geographic Information System (GIS) has significantly helped managers provide optimal models of sustainable agricultural development, identify local features related to agricultural production and their pro...The use of Geographic Information System (GIS) has significantly helped managers provide optimal models of sustainable agricultural development, identify local features related to agricultural production and their proper zoning, identify agricultural needs and constraints and finally provide the appropriate structure of land use. The main purpose of this study was to determine areas capable of cultivating Pistachio according to the parameters affecting the Pistachio cultivation in Roshtkhar town. Statistics of meteorological stations of the town were taken from Meteorology Organization of Khorasan Razavi for the period of 1989-2010 in order to determine climatic parameters required to cultivate Pistachio. For mapping surface elevation, slope, aspect, and TIN of the geographic organization of armed forces with a scale of 1:250,000 topographic maps were used. For mapping vegetation and land use in the area under study, land capability map of the area on a scale of 1:250,000 from the institute of soil and water was used. Also information on cultivation and annual production of agricultural statistics, published by Agriculture was used. Finally, it was concluded that the northeast and southwest of Roshtkhar town are the most prone areas to cultivate Pistachio.展开更多
Dear Editor,Varicella,also known as chickenpox,is caused by the varicella-zoster virus(VZV),which has a genome comprising 125 kb of linear double-stranded DNA encoding approximately 71 proteins,is highly contagious,an...Dear Editor,Varicella,also known as chickenpox,is caused by the varicella-zoster virus(VZV),which has a genome comprising 125 kb of linear double-stranded DNA encoding approximately 71 proteins,is highly contagious,and spreads from person to person through direct contact with the rash or through contact with aerosolized droplets.Unsurprisingly,groups of people,social interaction,and urbanization have been positively correlated with an increased incidence of varicella.Viral transmission also coincides with indoor activity and is increased among school children.展开更多
The major factors which contro1 the climate of China are three in number:(l)distribution of land and water,(2)mountain barriers and altitudes,and(3)cyclonic storms.Since China is located on the eastern side of thecont...The major factors which contro1 the climate of China are three in number:(l)distribution of land and water,(2)mountain barriers and altitudes,and(3)cyclonic storms.Since China is located on the eastern side of thecontinent of Eurasia,it has a continental climate,i.e.,quite warm in summer and quite cold in winter as compared with other places on the same latitude.展开更多
Pinus densiflora is a pine species native to the Korean peninsula,and seed orchards have supplied mate-rial needed for afforestation in South Korea.Climate vari-ables affecting seed production have not been identified...Pinus densiflora is a pine species native to the Korean peninsula,and seed orchards have supplied mate-rial needed for afforestation in South Korea.Climate vari-ables affecting seed production have not been identified.The purpose of this study was to determine climate variables that influence annual seed production of two seed orchards using multiple linear regression(MLR),elastic net regres-sion(ENR)and partial least square regression(PLSR)mod-els.The PLSR model included 12 climatic variables from 2003 to 2020 and explained 74.3%of the total variation in seed production.It showed better predictive performance(R2=0.662)than the EN(0.516)and the MLR(0.366)mod-els.Among the 12 climatic variables,July temperature two years prior to seed production and July precipitation after one year had the strongest influence on seed production.The time periods indicated by the two variables corresponded to pollen cone initiation and female gametophyte development.The results will be helpful for developing seed collection plans,selecting new orchard sites with favorable climatic conditions,and investigating the relationships between seed production and climatic factors in related pine species.展开更多
The study investigated the relationship between climatic variables and food security in households in the districts of Huancayo(Chongos Alto,Viques,Pucará,and Huancayo)during the COVID-19 pandemic.A cross-section...The study investigated the relationship between climatic variables and food security in households in the districts of Huancayo(Chongos Alto,Viques,Pucará,and Huancayo)during the COVID-19 pandemic.A cross-sectional observational study was conducted with a sample of 272 households out of 36,453.Food security data were collected through ques-tionnaires,and climatic variables(temperature,humidity,and precipitation)were obtained from CEPREANDES weather stations between September 2020 and February 2021.The results showed that 44.49% of households experienced mild food insecurity,while 55.5%experienced moderate food insecurity.Recorded climatic conditions included maximum temperatures of 28℃ in Pucaráand 27℃ in Huancayo,and a minimum of-8℃ in Chongos Alto.Relative humidity reached 89%in Pucaráand 87%in Chongos Alto and Huancayo,while maximum rainfall was 28 mm in Chongos Alto and 23 mm in Huancayo.Multivariate analysis revealed that relative humidity had a significant association with moderate food insecurity(B=16.406;95% CI:-64735 to 64768),increasing the risk 16 times under high humidity conditions.No significant relationships were found with temperature(B=-7.107;95% CI:-77320 to 77306)or precipitation(B=-7.831;95% CI:-25690 to 25674).It was concluded that relative humidity is a key factor in food security,particularly during the pandemic,while other climatic variables showed no significant impacts.These findings highlight the need for urgent adaptations to climatic challenges in vulnerable contexts.展开更多
The relationship between eco-hydrographic benefit of forest vegetation and climatic environmental factors is one of the focuses in the research on environmental protection and ecosystem countermeasures in Wetland. Th...The relationship between eco-hydrographic benefit of forest vegetation and climatic environmental factors is one of the focuses in the research on environmental protection and ecosystem countermeasures in Wetland. The runoff, sediment and soil moisture rate dynamics in Robinia pseudoacacia plantation and its clearcut area were investigated in the natural runoff experiment plots in Yellow River Delta Wet- land, Shandong Province, China. The correlation of height increment ofR. pseudoacacia with nine climate factors such as light, water, heat, etc. was analyzed by stepwise regression analysis. The results showed that the amounts of runoff and sediment in clearcut area of R. pseudoacacia were 53.9%-150.8% and 172.8%-387.1% higher than that in Robinia pseudoacacia plantation, respectively. The runoff peak value in R. pseudoacacia stand was obviously lower than that in clerarcut area, meantime, the occurrence of runoffpeak in R. pseudoacacia stand was 25 min later than in its clerarcut area. The soil moisture rates in R. pseudoacacia stand and its clearcut varied periodically with annual rainfall precipitation in both dry season and humid season. The annual mean soil moisture rate in R. pseudoacacia stand was 23.3%-25.6% higher than that in its clearcut area. Meanwhile, a regression model reflecting the correlation between the height increment of R. pseudoacacia and climatic factors was developed by stepwise regression procedure method. It showed that the light was the most important factor for the height increment ofR. pseudoacacia, followed by water and heat factors.展开更多
Aims This study aimed to develop radial growth models and to predict the potential spatial distribution of Pinus densiflora(Japanese red pine)and Quercus spp.(Oaks)in South Korea,considering topographic and climatic f...Aims This study aimed to develop radial growth models and to predict the potential spatial distribution of Pinus densiflora(Japanese red pine)and Quercus spp.(Oaks)in South Korea,considering topographic and climatic factors.Methods We used a dataset of diameter at breast height and radial growth estimates of individual trees,topographic and climatic factors in systematic sample plots distributed over the whole of South Korea.On the basis that radial growth is attributed primarily to tree age,we developed a radial growth model employing tree age as an explanatory variable.We estimated standard growth(SG),defined as radial growth of the tree at age 30,to eliminate the influence of tree age on radial growth.In addition,SG estimates including the Topographic Wetness Index,temperature and precipitation were calculated by the Generalized Additive Model.Important Findings As a result of variogram analysis of SG,we found spatial autocorrelation between SG,topographic and climatic factors.Incremental temperature had negative impacts on radial growth of P.densiflora and positive impacts on that of Quercus spp.Precipitation was associated with positive effects on both tree species.Based on the model,we found that radial growth of P.densiflora would be more vulnerable than that of Quercus spp.to climatic factors.Through simulation with the radial growth model,it was predicted that P.densiflora stands would be gradually replaced with Quercus spp.stands in eastern coastal and southern regions of South Korea in the future.The models developed in this study will be helpful for understanding the impact of climatic factors on tree growth and for predicting changes in distribution of P.densiflora and Quercus spp.due to climate change in South Korea.展开更多
Objective:This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage...Objective:This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage, wind velocity, which are closely associated with global climate change, and to provide a reference for plague prevention and control. Methods: We conducted a regression analysis to find the possible climate factors associated with the density of Himalaya marmot, and analyzed the response characters of Himalayan marmot to climate change.Results: Dailyprecipitation days(>=0.1 mm) and sunshine percentage were significantly associated with thedensityofHimalayan marmot(p<0.01). Conclusion: Climate change was associated with the risk of plague. This phenomenon is valuable for Himalayan marmot and plague prevention. More studies are needed to understand the impact of climate change on Himalayan marmot and plague.展开更多
基金Supported by Modern Agricultural Industry Technology System(nycytx-19-E16)Natural Science Foundation of Hunan Province(10JJ3063)~~
文摘[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were set up to investigate the yield of Zhongzhu No.2,based on which we assessed the adaptability of Zhongzhu No.2 to various eco-regions and further analyzed the climatic factors causing the difference in eco-adaptability.[Result] Ramie yield varied largely among various experimental sites and the yield difference appeared to be well repeatable,with a differential value between the maximum and the minimum reaching 2.3 kg/20 m2.Analysis of the yield data,together with climatic factors in various ecological regions showed that yield of Zhongzhu No.2 was significantly correlated with rainfall,sunshine hours,relative humidity during its growing period.Of the climatic factors,sunshine hours and rainfall can positively promote yield increase,while relative humidity negatively regulate ramie yield.[Conclusion] The climatic indices,including rainfall,sunshine duration and relative humidity are a key factor causing yield difference in ramie among different regions of Yangtze Valley.
基金Supported by Scientific Research Fund Project from Nanjing University of Information Science & Technology (20070005)
文摘According to the distribution of arid and humid regions in China,the typical arid region (Erjina),the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) and the typical humid region (Poyang Lake basin) were selected as the study areas.Based on NDVI data from 1982 to 2000 and meteorological observing data of three study areas from 1981 to 2000,the interactions between vegetation NDVI and climatic factors (temperature and precipitation) in typical arid and humid regions were discussed in this study.The results showed that in the responses of vegetation to climatic factors,vegetation in the typical arid region (Erjina) was more sensitive to precipitation,while vegetation in the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) was more sensitive to both temperature and precipitation,and vegetation in the typical humid region (Poyang Lake basin) was more sensitive to temperature.As for effects of vegetation on climatic factors,there was a remarkable negative correlation between vegetation NDVI in the past winter and temperature in the present summer,and also a significant positive correlation between vegetation NDVI in the past winter and precipitation in the present summer.However,in the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau),there was a significant positive correlation between vegetation NDVI in the present spring and temperature in the present summer.
基金supported by the Special Climate Change Research Program of China Meteorological Ad-ministration (No.062700s010c01)the Special Scientific Research Fund of Meteorological Public Welfare Profession of China (No.201206024)
文摘This study focuses on examining the characteristics of climate factors and extreme climate events in Northeast China during 1961- 2010 by using daily data from 104 stations, including surface air temperature, precipitation, wind speed, sunshine duration, and snow depth. Results show that annual mean temperature increased at a significant rate of 0.35℃ per decade, most notably in the Lesser Khingan Mountains and in winter. Annual rainfall had no obvious linear trend, while rainy days had a significant decreasing trend. So, the rain intensity increased. High-temperature days had a weak increasing trend, and low-temperature days and cold wave showed significant decreasing trends with rates of 3.9 d per decade and -0.64 times per decade, respectively. Frequency and spatial scope of low-temperature hazard reduced significantly. Warm days and warm nights significantly increased at 1.0 and 2.4 d per decade, while cold days and cold nights decreased significantly at -1.8 and -4.1 d per decade, respectively. The nighttime warming rate was much higher than that for daytime, indicating that nighttime warming had a greater contribution to the overall warming trend than daytime warming. The annual mean wind speed, gale days, and sunshine duration had significant decreasing trends at rates of-0.21 m s-1 per decade, -4.0 d per decade and -43.3 h per decade, respectively. The snow cover onset dates postponed at a rate of 1.2 d per decade, and the snow cover end date advanced at 1.5 d per decade, which leads to shorter snow cover duration by -2.7 d per decade. Meanwhile, the maximum snow depth decreased at -0.52 cm per decade. In addition, the snow cover duration shows a higher correlation with precipitation than with temperature, which suggests that precipitation plays a more important role in maintaining snow cover duration than temperature.
基金supported by the Science and Technology Innovation Platforms Initiative of Northeast Normal University under the project "Ecological Security and Data Assemblage of the Changbai Mountains International Georegion(Project No.106111065202)"the National Grand Fundamental Research 973 Program of China (Project No.2009CB426305)
文摘This study examined the temporal variation of the Normalized Difference Vegetation Index （NDVI） and its relationship with climatic factors in the Changbai Mountain Natural Reserve （CMNR） during 2000 - 2009. The results showed as follows. The average NDVI values increased at a rate of 0.0024 year-1. The increase rate differed with vegetation types, such as 0.0034 year-1 for forest and 0.0017 year-1 for tundra. Trend analyses revealed a consistent NDVI increase at the start and end of the growing season but little variation or decrease observed in July during the study period. The NDVI in CMNR showed a stronger correlation with temperature than with precipitation, especially in spring and autumn. A stronger correlation was observed between NDVI and temperature in the tundra zone （2,000-2,600m） than in the coniferous forest （1,100-1,700m） and Korean pine-broadleaved mixed forest （7oo-1,1oom） zones. The results indicate that vegetation at higher elevations is more sensitive to temperature change. NDVI variation had a strong correlation with temperature change （r=0.7311, p〈0.01） but less significant correlation with precipitation change. The result indicates that temperature can serve as a main indicator of vegetation sensitivity in the CMNR.
基金supported by the National Natural Science Foundation of China (No. 31471988 and 31200287)
文摘Global climate change is a threat to animals in nearly all biomes and ecosystems, especially for ectotherm whose life activities highly depend on environmental thermal regime. Population genetic diversity which is essential for adaptation to environmental change is a useful index for long-term species survival. In this paper, genetic diversity of eight Phrynocephalus forsythii population which distributed in Tarim Basin, China, were evaluated based on three mtDNA gene and its correlation with environment factors were investigated using RDA. Our result revealed that, the level of genetic diversity of P. forsythii populations was related to its location but there was no significant correlation between genetic distances and geographic distances in P. forsythii. However, we find that mtDNA of P. forsythii was subjected to selection pressure during evolution and population genetic diversity was significantly positively related to variation coefficient of rainfall(VCR) and altitude(AL), while significantly negatively related to longitude(N) and annual average temperature(AAT). Our result supported the previous prediction that excessive ambient heat is a threat to P. forsythii.
文摘Panax wangianus （Syn. Panax pseudoginseng） S. C. Sun （Araliaceae） is a critically endangered, medicinal plant of North-East India. The objective of this study was to determine how plant size affects flowering phenology and to evaluate the effect of climatic factors on flowering, fruiting and seed production. Data on vegetative and repro- ductive characters were monitored from 2016 individuals of Panax wangianus population in Law Lyngdoh, Smit sacred grove in Nongkrem, Shillong, India. Leaflet area was measured by a planimeter. Size variables of both vegetative and reproductive traits in different age classes were measured. Climatic factors were recorded from 2007 to 2009. Age was recorded by counting the number of bud scale scars on the rhizome. Light intensity and relative humidity were measured using a photometer, LiCor Model LI-189 and thermohygrometer respectively. Different climatic variables are correlated with vegetative and reproductive phenological events. Statistical analysis revealed that a strong positive correlation was observed between the age versus vegetative and reproductive characters, except 1%–2% plants showed neoteny. Morphological variations were observed in natural conditions on the basis of the number of prong and carpellate conditions. Phenological status revealed that most of the individuals of the age class 35–50 years and above 50 years contributed the most to flowering, fruiting and seed production. Age class was significant to predict the size of the plant and its reproductive capacity. Climatic factors such as temperature, precipitation and relative humidity show synergistic effect on both the vegetative and reproductive phases in Panax wangianus in the undisturbed Nongkrem sacred grove. The color of flowers of P. wangianus also varied depending upon the sunlight intensity. Therefore, in the view of conservationand management, the age class of 35–50 years and above 50 years is the most important for population sustainability.
基金Supported by China Meteorological Administration Key Technology Integration and Application Project(CMAJG2013M47)Yunnan Provincial Science and Technology Plan(2010CA017)~~
文摘[Objective] The aim was to analyze the suitability of climatic factors for broad bean in Kunming. [Method] The suitability model of broad bean growth and development was established, involving temperature, rainfal , and sunshine, with consideration of bioecology characters of broad beans, in order to make further analysis of suitability of meteorological factors. [Result] Under average climate condition, temperature and sunshine suitability kept higher in the whole growth stage, but rainfal suitability was lower. Hence, lower temperature and insufficient rainfal are limiting factors of broad bean yield. Based on analysis of meteorological factors in 2013, it suggested that temperature and sunshine suitability kept higher in 2013, but rainfal suitability only reached over 0.6 in seedling stage, with rest below. [Conclusion] In the whole growth stage of broad bean in 2013, comprehensive meteorological factors kept middle or higher level and the suitability model reflects suitability of meteorological factors to crops in an objective way, which provides references for improving meteorological services.
基金the National Key Research and Development Program of China(2016YFD0300106)the National Natural Science Foundation of China(31601247).
文摘Water scarcity has become a limiting factor for increasing crop production.Finding ways to improve water use efficiency(WUE)has become an urgent task for Chinese agriculture.To understand the response of different maize populations to changes in precipitation and the effects of changes in maize populations on WUE,this study conducted maize population experiments using maize hybrids with different plant types(compact and semi compact)and different planting densities at 25 locations across China.It was found that,as precipitation increased across different locations,maize grain yield first increased and then decreased,while WUE decreased significantly.Analyzing the relationship between WUE and the main climatic factors,this study found that WUE was significantly and negatively correlated with precipitation(R(daily mean precipitation)and R(accumulated precipitation))and was positively correlated with temperature(TM(daily mean maximum temperature),T_(M-m)(T_(m),daily mean minimum temperature)and GDD(growing degree days))and solar radiation(Ra(daily mean solar radiation)and Ra(accumulated solar radiation))over different growth periods.Significant differences in maize grain yield,WUE and precipitation were found at different planting densities.The population densities were ranked as follows according to maize grain yield and WUE based on the multi-site experiment data:60000 plants ha^(-1)(P_(2))>90000 plants ha^(-1)(P_(3))>30000 plants ha^(-1)(P_(1)).Further analysis showed that,as maize population increased,water consumption increased significantly while soil evaporation decreased significantly.Significant differences were found between the WUE of ZD958(compact type)and that of LD981(semi-compact type),as well as among the WUE values at different planting densities.In addition,choosing the optimum hybrid and planting density increased WUE by 21.70 and 14.92%,respectively,which showed that the hybrid played a more significant role than the planting density in improving WUE.Therefore,choosing drought-resistant hybrids could be more effective than increasing the planting density to increase maize grain yield and WUE in northern China.Comprehensive consideration of climatic impacts,drought-resistant hybrids(e.g.,ZD958)and planting density(e.g.,60000 plants ha^(-1))is an effective way to increase maize grain yield and WUE across different regions of China.
基金supported by the National Research and Development Program of China(Nos.2020YFA0608203 and 2016YFC1402003)the FengYun Application Pioneering Project of China Meteorological Administration(No.FYAPP2021)+1 种基金the National Natural Science Foundation of China(No.42001362)the NUIST-Reading Research Institute Pump-Priming Application.
文摘Sea ice has important effect on the marine ecosystem and people living in the surrounding regions in winter.However,the understanding on changes of sea ice in the Bohai and northern Huanghai Sea(BNHS),China is still limited.Based on the images from Visible and InfraRed Radiometer(VIRR)onboard Chinese second generation polar-orbit meteorological series satellites FY-3A/B/C,the sea ice areas in the BNHS were extracted from December 2008 to March 2019,the spatio-temporal distribution charac-teristics of sea ice and the relationship between sea ice area and climatic factors were analyzed,then a preliminary sea ice forecast model based on the climatic factors was developed.The results showed that sea ice area in the BNHS in each December was relatively small and rather high sea ice occurrence probability appeared in the offshore areas in Liaodong Bay and northern Huanghai Sea.The sea ice area in January or February each year was the largest,and sea ice occurred in most of areas in Liaodong Bay and northern Huanghai Sea with rather high probability and in some areas in Bohai Bay and Laizhou Bay with relatively high probability.How-ever,the sea ice area in each March was the smallest,and sea ice was even melted completely occasionally,hence with relatively low occurrence probability in Liaodong Bay.As for the inter-annual variability of sea ice in the BNHS during the research period,the sea ice area was largest in winter 2010/11 and smallest in winter 2014/15,and annual sea ice area presented a decreasing trend.The at-mospheric temperature,western Pacific subtropical high(WPSH),Asia polar vortex(APV),Asian monsoon circulation(AMC)and Eurasian monsoon circulation(EMC)were very important climatic factors for sea ice formation and they had significant correlations with sea ice area.Therefore,a preliminary sea ice forecast model was constructed by using eight climatic factors including western Pacific subtropical high area index(WPSHAI),western Pacific subtropical high intensity index(WPSHII),western Pacific subtro-pical high northern boundary position index(WPSHNBPI),Asia polar vortex area index(APVAI),Asian zonal circulation index(AZCI),Asian meridional circulation index(AMCI),Eurasian zonal circulation index(EZCI)and mean minimum atmospheric tem-perature(MMAT).The model was confirmed to have a robust forecast effect by using F-test and validated sample data.The results are useful for monitoring sea ice with remote sensed data and forecasting sea ice conditions by climatic indices.
文摘Climatic factor＇s effect was studied on the radial growth of teak （Tectona grandis L.F.） by using the stem analysis of 36 trees distributed in 6 plantations in Parakou and Tchaourou districts in northern Benin. The results showed that the plantations of Parakou were in general more productive than those of Tchaourou. The annual average growth was estimated in the first five years at 0.86 cm/year for Parakou and 0.76 cm/year at Tchaourou. The analysis of the radial growth showed that a significant percentage of the variance was allotted to the growth model. It follows that a big part of the ring width was predetermined before the intervention of the other factors, in particular the climatic conditions. The percentage of the variance related to the climatic conditions was thus more reduced for the plantations of Tchaourou than those of Parakou. The radial growth was influenced by the conditions of humidity （evapotranspiration, humidity and rain） of February to May on the one hand and those from August to October on the other hand.
基金The Strategic Priority Research Program from the Chinese Academy of Sciences No.XDA05080201 National Natural Science Foundation of China, No.41071061
文摘There are differing views regarding the climatic factors that limit radial growth of Qilian juniper （Juniperus przewalskii Kom.） at the upper treelines on the northeastern Tibetan Plateau. In this study, trees from an upper tree northeastern Tibetan Plateau were selected to limits the radial growth of Qilian juniper. Using ine site in the Anyemaqen Mountains of the present new evidence that low temperature a signal-free regional curve standardization （SF-RCS） method, a ring-width chronology for Qilian juniper was developed extending from AD 1082 to 2010. The results of correlation analysis between tree-ring index and instrumental climatic variables showed that both winter （December in the previous year and January in the current year） and summer （July and August in the current year） temperatures were signifi- cantly and positively correlated with the tree-ring index. Precipitation in June was also significantly and positively correlated with the tree-ring index, but was not as important as low temperature in controlling tree growth. To test the key limiting climatic factor for tree radial growth at different altitudes, an indicator termed the ＂relative distance to upper treeline＂ （RDUT） was developed to quantify the representativeness of collected samples for the forest＇s upper treeline. The RDUT showed that the upper 20% of the forest belt may be an important boundary in terms of capturing the temperature signal from tree-ring width at the upper treelines on the northeastern Tibetan Plateau. Our findings enhance the existing understanding that temperature is the limiting factor at upper treelines on the northeastern Tibetan Plateau, and will be useful in the reconstruction of past temperature in future studies.
基金Supported by National Natural Science Fund Item,China(41361020,40961031)
文摘Taking Lancang County as a study area with a large area of eucalyptus introduction in Yunnan, spatiotemporal change characteristics of vegetation cover, as well as the relationships between Enhanced Vegetation Index（EVl） and climatic factors （temperature and precipitation） were analyzed by using the data of MODIS-EVI from 2005 to 2010. The results indicated that： （1） The vegetation cover was overall good, and the annual average values of EVl were greater than 0.395 and showed a slow increasing trend from 2005 to 2010 in study area; the monthly average values of EVl ranged from 0.296 to 0.538, and seasonal variability was obvious. Monthly average values of EVl usually fell to the lowest level in February and March, and reached the peak in July and August. From the perspective of space, average EVl over the years significantly varied in different towns of Lancang County. During 2005 -2010, in 92.534% area of total, vegetation coverage change were not obvious; in 7.25% area of total, vegeta- tion becoming better; only in 0.02% area of total, vegetation cover were getting worse. （2） Monthly average values of EVl were significantly correlated with monthly average rainfall in Lancang County. The maxima of monthly average EVI and rainfall appeared in August on summer, while the minima of monthly average EVl and rainfall appeared in February and January on winter respectively. （3） Monthly average EVl was somewhat relative with monthly average temperature. The maxima of monthly average EVl and temperature appeared in June and August respectively, while the minima appeared in January and February respectively.
文摘The use of Geographic Information System (GIS) has significantly helped managers provide optimal models of sustainable agricultural development, identify local features related to agricultural production and their proper zoning, identify agricultural needs and constraints and finally provide the appropriate structure of land use. The main purpose of this study was to determine areas capable of cultivating Pistachio according to the parameters affecting the Pistachio cultivation in Roshtkhar town. Statistics of meteorological stations of the town were taken from Meteorology Organization of Khorasan Razavi for the period of 1989-2010 in order to determine climatic parameters required to cultivate Pistachio. For mapping surface elevation, slope, aspect, and TIN of the geographic organization of armed forces with a scale of 1:250,000 topographic maps were used. For mapping vegetation and land use in the area under study, land capability map of the area on a scale of 1:250,000 from the institute of soil and water was used. Also information on cultivation and annual production of agricultural statistics, published by Agriculture was used. Finally, it was concluded that the northeast and southwest of Roshtkhar town are the most prone areas to cultivate Pistachio.
文摘Dear Editor,Varicella,also known as chickenpox,is caused by the varicella-zoster virus(VZV),which has a genome comprising 125 kb of linear double-stranded DNA encoding approximately 71 proteins,is highly contagious,and spreads from person to person through direct contact with the rash or through contact with aerosolized droplets.Unsurprisingly,groups of people,social interaction,and urbanization have been positively correlated with an increased incidence of varicella.Viral transmission also coincides with indoor activity and is increased among school children.
文摘The major factors which contro1 the climate of China are three in number:(l)distribution of land and water,(2)mountain barriers and altitudes,and(3)cyclonic storms.Since China is located on the eastern side of thecontinent of Eurasia,it has a continental climate,i.e.,quite warm in summer and quite cold in winter as compared with other places on the same latitude.
基金supported by the National Institute of Forest Sciencethe R&D Program for Forest Science Technology (No.2022458B10-2224-0201) of the Korea Forest Service
文摘Pinus densiflora is a pine species native to the Korean peninsula,and seed orchards have supplied mate-rial needed for afforestation in South Korea.Climate vari-ables affecting seed production have not been identified.The purpose of this study was to determine climate variables that influence annual seed production of two seed orchards using multiple linear regression(MLR),elastic net regres-sion(ENR)and partial least square regression(PLSR)mod-els.The PLSR model included 12 climatic variables from 2003 to 2020 and explained 74.3%of the total variation in seed production.It showed better predictive performance(R2=0.662)than the EN(0.516)and the MLR(0.366)mod-els.Among the 12 climatic variables,July temperature two years prior to seed production and July precipitation after one year had the strongest influence on seed production.The time periods indicated by the two variables corresponded to pollen cone initiation and female gametophyte development.The results will be helpful for developing seed collection plans,selecting new orchard sites with favorable climatic conditions,and investigating the relationships between seed production and climatic factors in related pine species.
文摘The study investigated the relationship between climatic variables and food security in households in the districts of Huancayo(Chongos Alto,Viques,Pucará,and Huancayo)during the COVID-19 pandemic.A cross-sectional observational study was conducted with a sample of 272 households out of 36,453.Food security data were collected through ques-tionnaires,and climatic variables(temperature,humidity,and precipitation)were obtained from CEPREANDES weather stations between September 2020 and February 2021.The results showed that 44.49% of households experienced mild food insecurity,while 55.5%experienced moderate food insecurity.Recorded climatic conditions included maximum temperatures of 28℃ in Pucaráand 27℃ in Huancayo,and a minimum of-8℃ in Chongos Alto.Relative humidity reached 89%in Pucaráand 87%in Chongos Alto and Huancayo,while maximum rainfall was 28 mm in Chongos Alto and 23 mm in Huancayo.Multivariate analysis revealed that relative humidity had a significant association with moderate food insecurity(B=16.406;95% CI:-64735 to 64768),increasing the risk 16 times under high humidity conditions.No significant relationships were found with temperature(B=-7.107;95% CI:-77320 to 77306)or precipitation(B=-7.831;95% CI:-25690 to 25674).It was concluded that relative humidity is a key factor in food security,particularly during the pandemic,while other climatic variables showed no significant impacts.These findings highlight the need for urgent adaptations to climatic challenges in vulnerable contexts.
基金the National "11th Five Year" Plan of Science and technology (2006BAD26B06,2006BAD03A1205) Ecological Restore Project of Water Resources Ministry of China (2006-2008)
文摘The relationship between eco-hydrographic benefit of forest vegetation and climatic environmental factors is one of the focuses in the research on environmental protection and ecosystem countermeasures in Wetland. The runoff, sediment and soil moisture rate dynamics in Robinia pseudoacacia plantation and its clearcut area were investigated in the natural runoff experiment plots in Yellow River Delta Wet- land, Shandong Province, China. The correlation of height increment ofR. pseudoacacia with nine climate factors such as light, water, heat, etc. was analyzed by stepwise regression analysis. The results showed that the amounts of runoff and sediment in clearcut area of R. pseudoacacia were 53.9%-150.8% and 172.8%-387.1% higher than that in Robinia pseudoacacia plantation, respectively. The runoff peak value in R. pseudoacacia stand was obviously lower than that in clerarcut area, meantime, the occurrence of runoffpeak in R. pseudoacacia stand was 25 min later than in its clerarcut area. The soil moisture rates in R. pseudoacacia stand and its clearcut varied periodically with annual rainfall precipitation in both dry season and humid season. The annual mean soil moisture rate in R. pseudoacacia stand was 23.3%-25.6% higher than that in its clearcut area. Meanwhile, a regression model reflecting the correlation between the height increment of R. pseudoacacia and climatic factors was developed by stepwise regression procedure method. It showed that the light was the most important factor for the height increment ofR. pseudoacacia, followed by water and heat factors.
基金Korea Forest Service research project‘Growth response model for major tree species using tree-ring information of national forest inventory(Project No:S120911L030130)’‘A3 Foresight Program(A307-K005)’provided by National Research Foundation of Korea.
文摘Aims This study aimed to develop radial growth models and to predict the potential spatial distribution of Pinus densiflora(Japanese red pine)and Quercus spp.(Oaks)in South Korea,considering topographic and climatic factors.Methods We used a dataset of diameter at breast height and radial growth estimates of individual trees,topographic and climatic factors in systematic sample plots distributed over the whole of South Korea.On the basis that radial growth is attributed primarily to tree age,we developed a radial growth model employing tree age as an explanatory variable.We estimated standard growth(SG),defined as radial growth of the tree at age 30,to eliminate the influence of tree age on radial growth.In addition,SG estimates including the Topographic Wetness Index,temperature and precipitation were calculated by the Generalized Additive Model.Important Findings As a result of variogram analysis of SG,we found spatial autocorrelation between SG,topographic and climatic factors.Incremental temperature had negative impacts on radial growth of P.densiflora and positive impacts on that of Quercus spp.Precipitation was associated with positive effects on both tree species.Based on the model,we found that radial growth of P.densiflora would be more vulnerable than that of Quercus spp.to climatic factors.Through simulation with the radial growth model,it was predicted that P.densiflora stands would be gradually replaced with Quercus spp.stands in eastern coastal and southern regions of South Korea in the future.The models developed in this study will be helpful for understanding the impact of climatic factors on tree growth and for predicting changes in distribution of P.densiflora and Quercus spp.due to climate change in South Korea.
基金The Basic Application Project of Qinghai Provincegrant number:2013-Z-747
文摘Objective:This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage, wind velocity, which are closely associated with global climate change, and to provide a reference for plague prevention and control. Methods: We conducted a regression analysis to find the possible climate factors associated with the density of Himalaya marmot, and analyzed the response characters of Himalayan marmot to climate change.Results: Dailyprecipitation days(>=0.1 mm) and sunshine percentage were significantly associated with thedensityofHimalayan marmot(p<0.01). Conclusion: Climate change was associated with the risk of plague. This phenomenon is valuable for Himalayan marmot and plague prevention. More studies are needed to understand the impact of climate change on Himalayan marmot and plague.
