期刊文献+
共找到335篇文章
< 1 2 17 >
每页显示 20 50 100
Responding of zooplankton to environmental factor changes in the Changjiang River estuarine regions in spring-summer from 2016 to 2020
1
作者 Jieqing YANG Dongrong ZHANG +4 位作者 Yuange CHEN Longling OUYANG Yangyang YANG Jin ZHOU Yunrong SHI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第2期544-559,共16页
The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Ther... The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Therefore,understanding the relationships between zooplankton and environmental factors help us know the water quality.To achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory.However,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains scarce.We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy analysis.Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope.The turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in summer.The dominant species were estuarine,offshore,and eurytopic based on the adaptation to salinity.In spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore species.In addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological groups.The temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and pH.The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring,and the continuous decrease in abundance of L.euchaeta reflected the effects of local climate change.The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents.Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence. 展开更多
关键词 Changjiang River estuary(CRE) ZOOPLANKTON dominant species ecological group environmental factor CO-EXISTENCE
下载PDF
Effects of inorganic nutrients and environmental factors on the removal of n-propylbenzene and isopropylbenzene in seawater by cryptophytes Rhinomonas reticulata S6A
2
作者 Jiali CUI Shuhao DU +3 位作者 Yumei LI Haiping LI Ping ZHANG Fanping MENG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第4期1200-1215,共16页
To effectively remove n-propylbenzene(n-PBZ)and isopropylbenzene(i-PBZ)leaked into seawater using Rhinomonas reticulata S6A(a newly isolated marine microalga),the effects of three inorganic nutrients and four environm... To effectively remove n-propylbenzene(n-PBZ)and isopropylbenzene(i-PBZ)leaked into seawater using Rhinomonas reticulata S6A(a newly isolated marine microalga),the effects of three inorganic nutrients and four environmental factors on their degradation were determined after 7 d of inoculation.Results show that NaNO_(3) at 300 mg/L caused a higher removal efficiency of both n-PBZ and i-PBZ(44.79%and 39.26%),while for NaH_(2) PO_(4)·H_(2) O,greater removal rates of two PBZs(47.30%and 42.23%)were achieved at 30 and 20 mg/L,respectively.NaHCO_(3) supplementation(500-750 mg/L)resulted in a large reduction(43.67%-45.04%)in i-PBZ concentration.The change in seawater pH(from 6 to 9)did not affect the elimination of n-PBZ and i-PBZ.The most suitable salinity and temperature were 30 and 25-30℃,respectively,leading to the PBZs removal of~40%.Light intensity exhibited significant influence on elimination of PBZs,and the maximum removal efficiencies of 56.07%(n-PBZ)and 55.00%(i-PBZ)were recorded under 200 and 600μmol/(m^(2)·s),respectively.In addition,the microalga could still remove PBZs when it failed to grow well due to darkness,strong light,low temperature,or low salinity,which might mean that good growth of alga is not always a necessary condition for PBZs removal.Therefore,attention should be paid to the suitability of nutrient levels and environmental conditions(excluding pH)in seawater when using microalgae for bioremediating PBZs-contaminated seawater. 展开更多
关键词 propylbenzene(PBZ) Rhinomonas reticulata seawater inorganic nutrient environmental factor
下载PDF
Variation Characteristics of Root Traits of Different Alfalfa Cultivars under Saline-Alkaline Stress and their Relationship with Soil Environmental Factors
3
作者 Tian-Jiao Wei Guang Li +6 位作者 Yan-Ru Cui Jiao Xie Xing-Ai Gao Xing Teng Xin-Ying Zhao Fa-Chun Guan Zheng-Wei Liang 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第1期29-43,共15页
Soil salinization is the main factor that threatens the growth and development of plants and limits the increase of yield.It is of great significance to study the key soil environmental factors affecting plant root tr... Soil salinization is the main factor that threatens the growth and development of plants and limits the increase of yield.It is of great significance to study the key soil environmental factors affecting plant root traits to reveal the adaptation strategies of plants to saline-alkaline-stressed soil environments.In this study,the root biomass,root morphological parameters and root mineral nutrient content of two alfalfa cultivars with different sensitivities to alkaline stress were analyzed with black soil as the control group and the mixed saline-alkaline soil with a ratio of 7:3 between black soil and saline-alkaline soil as the saline-alkaline treatment group.At the same time,the correlation analysis of soil salinity indexes,soil nutrient indexes and the activities of key enzymes involved in soil carbon,nitrogen and phosphorus cycles was carried out.The results showed that compared with the control group,the pH,EC,and urease(URE)of the soil surrounding the roots of two alfalfa cultivars were significantly increased,while soil total nitrogen(TN),total phosphorus(TP),organic carbon(SOC),andα-glucosidase activity(AGC)were significantly decreased under saline-alkaline stress.There was no significant difference in root biomass and root morphological parameters of saline-alkaline tolerant cultivar GN under saline-alkaline stress.The number of root tips(RT),root surface area(RS)and root volume(RV)of AG were reduced by 61.16%,44.54%,and 45.31%,respectively,compared with control group.The ratios of K^(+)/Na^(+),Ca^(2+)/Na^(+)and Mg^(2+)/Na^(+)of GN were significantly higher than those of AG(p<0.05).The root fresh weight(RFW)and dry weight(RDW),root length(RL),RV and RT of alfalfa were positively regulated by soil SOC and TN,but negatively regulated by soil pH,EC,and URE(p<0.01).Root Ca^(2+)/Na+ratio was significantly positively correlated with soil TN,TP and SOC(p<0.01).The absorption of Mg and Ca ions in roots is significantly negatively regulated by soilβ-glucosidase activity(BGC)and acid phosphatase activity(APC)(p<0.05).This study improved knowledge of the relationship between root traits and soil environmental factors and offered a theoretical framework for elucidating how plant roots adapt to saline-alkaline stressed soil environments. 展开更多
关键词 Saline-alkaline stress ALFALFA root traits soil environmental factors correlation analysis
下载PDF
Geographical distribution of Batrachospermaceae genera in Asia and its environmental factors
4
作者 Mingyu QIU Fei WANG +5 位作者 Fangru NAN Jia FENG Junping LÜ Qi LIU Xudong LIU Shulian XIE 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第3期972-990,共19页
Batrachospermaceae is an important group of freshwater red algae.Available data of the latitude,longitude,and environmental factors on Batrachospermaceae distribution in Asia were analyzed to understand the geographic... Batrachospermaceae is an important group of freshwater red algae.Available data of the latitude,longitude,and environmental factors on Batrachospermaceae distribution in Asia were analyzed to understand the geographical distribution of Batrachospermaceae genera in Asia.Statistical analyses,including one-way ANOVA,correlation analysis,stepwise regression analysis,principal component analysis,and linear discriminant analysis were conducted to characterize variation in geographical distribution and growth environment.Results reveal high variation in geographical distribution and growth environment among different Batrachospermaceae genera in Asia.Specifically,correlations between latitude and all environmental factors exclusive of altitude are significant,and longitude is significantly correlated with all environmental factors except for average relative humidity.The geographical distribution and growth environment of different Batrachospermaceae genera significantly differed.Altitude,maximum temperature,average temperature,minimum temperature,average relative humidity,average wind speed,maximum wind speed,and atmospheric pressure all contributed to explaining differences in the geographical distribution of Batrachospermaceae genera.Combining the results of correlation analysis,stepwise regression analysis,and principal component analysis,all environmental factors contributed to the different geographical distribution of Batrachospermum,Paludicola,Sheathia,Sirodotia,and Remainder(the rest),all environmental factors but atmospheric pressure contributed to the different geographical distribution of Kumanoa,and all environmental factors but average wind speed and maximum wind speed contributed to the different geographical distribution of Virescentia.However,the correlation between these significantly related environmental factors and taxa is not necessarily causative,and many other environmental factors,such as temperature,pH,conductivity,shading,current velocity,dissolved oxygen,hardness,substrata types,and nutrients etc.,are likely to have an important impact on the geographical distribution of taxa,which is an important topic for future research. 展开更多
关键词 Batrachospermaceae BIOSTATISTICS environmental factor geographical distribution METROLOGY
下载PDF
Eff ects of environmental factors on the temporal and spatial variations in branch and leaf CO_(2)effl ux of Larix gmelinii var.principis-rupprechtii Mayr
5
作者 Longjie Li Xiangzhen Wang Zhongkui Jia 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期1007-1019,共13页
The CO_(2)effl ux of branches and leaves plays an important role in ecosystem carbon balance.Using a carbon fl ux system,the effl ux of Larix gmelinii var.principisrupprechtii(Dahurian larch)was investigated in 27 yea... The CO_(2)effl ux of branches and leaves plays an important role in ecosystem carbon balance.Using a carbon fl ux system,the effl ux of Larix gmelinii var.principisrupprechtii(Dahurian larch)was investigated in 27 years(immature),31 years(near-mature),and 47 years(mature)stands at diurnal,seasonal,and spatial scales(direction and height)as well as its connection with environmental factors from May to October 2020.Diurnal variation in effl ux was a single peak,and the maximum occurring between 14:00 and 16:00.Seasonal variation also exhibited a single peak,with the maximum in late July and the minimum in early October.From May to September,effl ux on the south side was the largest among the three stands,and mean values on the south side of 27 year-old,31 year-old,and 47 year-old trees were 0.50,0.97 and 1.05μmol·m^(–2)·s^(–1),respectively.The minimum occurred on the north side.Except for the maximum in July and September in the 27 year-old stand in the middle of the canopy,the maximum effl ux in the upper canopy,and the means in the 27 year-old,31 year-old,and 47 year-old stands were 0.49,0.96 and 1.04μmol·m^(-2)·s^(-1),respectively;the minimum occurred in the lower canopy.Temperatures and relative humidity infl uenced seasonal variations in effl ux.Seasonal variation in temperature sensitivity coeffi cient(Q 10)was opposite that of temperature,increasing with decreasing temperature.At the spatial scale,maximum Q 10 occurred in the mid canopy.With the effl ux and temperature data in diff erent locations,it is possible to better estimate effl ux variations in each stand. 展开更多
关键词 CO_(2)effl ux Temperature sensitivity coeffi cient(Q 10) Temporal and spatial variations environmental factors
下载PDF
Impacts of Environmental Factors on the Structure Characteristics of Avian Community in Shanghai Woodlots in Spring 被引量:31
6
作者 葛振鸣 王天厚 +2 位作者 施文彧 周立晨 薛文杰 《Zoological Research》 CAS CSCD 北大核心 2005年第1期17-24,共8页
From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which inclu... From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which included 31 resident and 24 migratory species. With statistics methodology, we analyzed the avian communities with 10 major environmental factors covering the park area, water percentage, vegetation species, canopy cover, shrub cover, grass cover, hill number, location condition, human quantity, path width, the study results indicated that: (1) the following 7 environmental factors were important to impact the structures of the avian community, they were park area, vegetation species, shrub coverage, grass coverage, hill number, location condition of the parks and path width; (2) the avian community of theses urban parks tended to deteriorate in the bird number and diversity; the man-made lake which was currently promoted in the park designing and planning process would not be good to attract the birds. 展开更多
关键词 Urban avian community Bird diversity Key environmental factor Shanghai park
下载PDF
Grey Relational Analysis between Chlorophyll a and Environmental Factors in ShaHu Lake 被引量:5
7
作者 邱小琮 赵红雪 孙晓雪 《Agricultural Science & Technology》 CAS 2010年第7期80-82,共3页
[Objective] The aim was to explore effects of environmental factors on the content of Chlorophyll a in ShaHu Lake.[Method] Based on the data in Shahu Lake from November in 2007 to September in 2008,the relationship be... [Objective] The aim was to explore effects of environmental factors on the content of Chlorophyll a in ShaHu Lake.[Method] Based on the data in Shahu Lake from November in 2007 to September in 2008,the relationship between chlorophyll a and environmental factors like water temperature,pH,secchi-depth (SD),total nitrogen,total phosphorus and potassium permanganate index was studied by grey relational analysis method.[Result] The main environmental factors affecting the content of Chlorophyll a in ShaHu Lake were in order of water temperature potassium permanganate index 〉total nitrogen 〉pH〉 total phosphorus 〉SD.[Conclusion] The research provides reference for the control of eutrophication and the reasonable development and utilization of Shahu Lake. 展开更多
关键词 Shahu Lake Chlorophyll a environmental factors Grey relational analysis
下载PDF
Relationship between Phytoplankton Distribution and Environmental Factors in the Chukchi Sea 被引量:3
8
作者 林更铭 杨清良 唐森铭 《Marine Science Bulletin》 CAS 2009年第2期55-64,共10页
Based on the samples collected from the Chukchi Sea during the FCNARE cruise from July to August in 1999 with the "Xuelong", the research vessel of SOA, China, the relationship between the distribution characterizat... Based on the samples collected from the Chukchi Sea during the FCNARE cruise from July to August in 1999 with the "Xuelong", the research vessel of SOA, China, the relationship between the distribution characterization of phytoplankton and environmental factors was analyzed with Primer 5.2 software. The result showed that the assemblages of phytoplankton in Chukchi Sea can be divided into three ecological groups: Arctic-boreal group, distributed mostly in northeastern ice-edge where the depth is more than 2 000 m and affected directly by Arctic Ocean; Boreal group, distributed in shelf-break ice in the center water where the depth is less 100 m; Eurythermal group, mainly distributed in the south which exchanged with North Pacific water through Bering Strait. The species diversity, cell density and distribution variability of phytoplankton among stations were great different. The range of phytoplankton density among stations was 1.6 × 10^3- 90 680.2 × 10^4 cells/m^3, and the ranges of diversity index and evenness index among stations were 0.07 - 0.87 and 0.33 - 3.82, respectively. Principal components analysis (PCA) showed that temperature and salinity had made important roles in the distribution of phytoplankton in the Chukchi Sea. Furthermore, the different influences of the variant water regimes, and the extremely dynamic physical nature of the drifting pack ice (e.g. packing, breaking up and melting ) introduce short-term variability into the water conditions that no doubt affect the phytoplankton distrubition. 展开更多
关键词 Chukchi Sea Phytoplankton Distribution environmental factors Multivariate analysis
下载PDF
Research on the Relationship between Three Isomers of Microcystins and Environmental Factors 被引量:3
9
作者 张洪玲 蔡金傍 李文奇 《Agricultural Science & Technology》 CAS 2011年第9期1342-1346,共5页
[Objective] The relationship between three isomers of microcystins and environmental factors were studied in the fields.[Method] Three isomers of microcystins (MC-LR,RR and YR) from water of five sampling spots in a... [Objective] The relationship between three isomers of microcystins and environmental factors were studied in the fields.[Method] Three isomers of microcystins (MC-LR,RR and YR) from water of five sampling spots in a northern reservoir were observed for one year with High Performance Liquid Chromatography analytical method in order to study the relationship between three isomers and environmental factors.[Result] The three isomers of microcystins showed positive correlation with chlorophyll a;LR and YR isomers all had significant linear positive correlations with the water temperature,but the RR isomer showed no significant correlation with the water temperature;LR and YR isomers had relatively significantly correlativities with the contents of total nitrogen,nitrate nitrogen and organic nitrogen,while the RR isomer only showed a significant negative correlation with the content of nitrate nitrogen;LR and RR isomers both showed significant positive correlations with the contents of total phosphorus and organic phosphorus,while the phosphorus hardly affected the YR isomer and showed no evident correlation.[Conclusion] The relationship between three isomers of microcystins and environmental factors such as chlorophyll a,water temperature,nitrogen,phosphorus were studied and investigated the reasons,which might offered a reference for controlling the growth of blue algae in water and toxin synthesis. 展开更多
关键词 RESERVOIR MICROCYSTINS ISOMERS environmental factors
下载PDF
Effects of Environmental Factors on NH_4^+ Release in Sediment from Chaohu Lake 被引量:3
10
作者 刘静静 汪家权 徐文炘 《Agricultural Science & Technology》 CAS 2008年第3期153-156,共4页
[Objective] The aim of the research was to reveal the influence mechanism of sediment-water exchange of nutrients in Chaohu Lake. [Method] The effects of environmental factors (overlying water, temperature, pH and dis... [Objective] The aim of the research was to reveal the influence mechanism of sediment-water exchange of nutrients in Chaohu Lake. [Method] The effects of environmental factors (overlying water, temperature, pH and dissolved oxygen concentration) on NH_4^+ release in sediment from Chaohu Lake were studied under controlled laboratory conditions. [Results] With the rising of temperature and the decrease of NH_4^+ concentration in overlying water, NH_4^+ released from sediment increased significantly. pH had a great effect on NH_4^+ release with a complicated mechanism. The largest release amount of NH_4^+ under anaerobic condition was about 6 times as much as that under aerobic condition. [Conclusion] This research would provide theoretical support for environmental management of Chaohu Lake in the project of leading water from the Yangtze River to Chaohu Lake. 展开更多
关键词 NH_4^+ release environmental factors SEDIMENT Chaohu Lake
下载PDF
Effects of Environmental Factors on Tomato Growth 被引量:3
11
作者 武利明 张喜春 肖光辉 《Agricultural Science & Technology》 CAS 2015年第2期272-277,共6页
[Objective] This study was conducted to evaluate the effects of environmental factors on the biological characteristics of tomatoes.[Method] The growth traits such as plant height,stem diameter,leaf shape index of tom... [Objective] This study was conducted to evaluate the effects of environmental factors on the biological characteristics of tomatoes.[Method] The growth traits such as plant height,stem diameter,leaf shape index of tomato plants grown under different environmental conditions(temperature,light and soil moisture content)were measured and compared.[Result] The effect of light on tomatoes was higher than that of soil moisture in high-temperature environment(30 ℃ or higher);while the speed of tomato plant growth and fruit development were improved by low light.The synthesis of chlorophyll was influenced by soil moisture and light,and greater impact of soil water content on the synthesis of chlorophyll was observed.Among the three treatments,the chlorophyll content of all the three tomato cultivars was in a descending order as follows:control〉 shading treatment〉 drought treatment.[Conclusion] This study will provide references for the control of temperature,light and soil water in tomato cultivation. 展开更多
关键词 Tomatoes environmental factors Growth and development
下载PDF
Correlation Between the Animal Community Structure and Environmental Factors in Dongbei Cave and Shuijiang Cave of Guizhou Province 被引量:9
12
作者 黎道洪 《Zoological Research》 CAS CSCD 北大核心 2006年第5期481-488,共8页
Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and... Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and forty samples from Dongbei Cave were classified into three phyla, five classes, 10 orders, 20 families and 39 species or groups of species. Four hundred and ninety-eight samples from Shuijiang Cave were classified into three phyla, six classes, 11 orders, 20 families and 25 species or groups of species. Six animal communities were identified in the light belt of the two caves according to their species types and numbers of individuals in the light belt of two cave. The communities which have the highest values of species richness community diversity, maximum diversity, evenness, dominance and community similarity are respectively: B (4. 1059), H (2.4716), B (3.3322), E (0.9042), C (0.3442) and A - C (0. 5251). The community diversity and correlation of environmental factors were also studied. The temperature, humidity, content of CO2 and N2, content of organic matter and some inorganic salts in soil were analyzed by Pearson correlation. The results showed that the content of organic matter in soil is positively related to species number, species richness and maximum community diversity, with correlations of 0. 885, 0.909, 0. 868 respectively (two-tailed significance test, P ≤ 0. 05), and significantly positively related to diversity, with the coefficient of 0.611, (two-tailed significance test, P ≤ 0. 1). This suggests that the content of organic matter in soil is one of the important elements influencing the community variation of cave animals. Outside the cave, temperature and humidity are important factors impacting on community diver- sity. As the temperature in all seasons in the cave is stable and the humidity is always high (above 90% ), the temperature and humidity have weak correlation to community diversity in caves. 展开更多
关键词 Animal community structure environmental factor Dongbei Cave Shuijiang Cave Guizhou province
下载PDF
Plankton community composition in the Three Gorges Reservoir Region revealed by PCR-DGGE and its relationships with environmental factors 被引量:27
13
作者 YAN Qingyun YU Yuhe +2 位作者 FENG Weisong YU Zhigang CHEN Hongtao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第6期732-738,共7页
To explore the relationships between community composition and the environment in a reservoir ecosystem, plankton communities from the Three Gorges Reservoir Region were studied by PCR-denaturing gradient gel electrop... To explore the relationships between community composition and the environment in a reservoir ecosystem, plankton communities from the Three Gorges Reservoir Region were studied by PCR-denaturing gradient gel electrophoresis fingerprinting. Bacterial and eukaryotic operational taxonomic units (OTUs), generated by DGGE analysis of the PCR-amplified 16S and 18S rRNA genes, were used as surrogates for the dominant "biodiversity units". OTU composition among the sites was heterogeneous; 46.7% of the total bacterial OTUs (45) and 64.1% of the eukaryotic OTUs (39) were identified in less than half of the sampling sites. Unweighted pair group method with arithmetic averages (UPGMA) clustering of the OTUs suggested that the plankton communities in the Xiangxi Rive sites were not always significantly different from those from the Yangtze River sites, despite clear differences in their environmental characterizations. Canonical correspondence analysis (CCA) was applied to further investigate the relationships between OTU composition and the environmental factors. The first two CCA ordination axes suggested that the bacterial community composition was primarily correlated with the variables of NO3^--N, dissolved oxygen (DO), and SiO3^2--Si, whereas, the eukaryotic community was mainly correlated with the concentrations of DO, PO4^3--P, and SiO3^2--Si. 展开更多
关键词 plankton community environmental factors denaturing gradient gel electrophoresis (DGGE) spatial pattern Three Gorges Reservoir Region
下载PDF
Distribution of meiofaunal abundance in relation to environmental factors in Beibu Gulf,South China Sea 被引量:17
14
作者 CAI Lizhe FU Sujing +1 位作者 YANG Jie ZHOU Xiping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第6期92-103,共12页
This study aims to explore the distribution of meiofaunal abundance in relation to environmental factors in the Beibu Gulf, a natural semi-enclosed part of the South China Sea, surrounded by China and Vietnam. Meiofau... This study aims to explore the distribution of meiofaunal abundance in relation to environmental factors in the Beibu Gulf, a natural semi-enclosed part of the South China Sea, surrounded by China and Vietnam. Meiofauna and ten benthic environmental factors were determined at 27 sampling stations in the Beibu Gulf in four surveys during 2006 2007. The results show a clear geographical trend in meiofaunal abundance, water depth, salinity and clay content. The meiofaunal abundance and the clay content decreased, whereas the water depth and the salinity increased from the north to the south of the Gulf. The percentage of meiofaunal abundance in the 0 2 cm layer increased, whereas in the 2-5 cm and 5 10 cm layers it decreased from the north to the south of the Gulf. Correlation analysis show significant negative correlations between meiofaunal abundance and water depth, benthic temperature, salinity and pH, but significant positive correlations between meiofaunal abundance and dissolved oxygen, chlorophyll a and clay content. 展开更多
关键词 MEIOFAUNA ABUNDANCE DISTRIBUTION environmental factors South China Sea BeibuGulf
下载PDF
Effects of Environmental Factors on Tree Seedling Regeneration in a Pine-oak Mixed Forest in the Qinling Mountains, China 被引量:14
15
作者 YU Fei WANG De-xiang +3 位作者 SHI Xiao-xiao YI Xian-feng HUANG Qing-ping HU You-ning 《Journal of Mountain Science》 SCIE CSCD 2013年第5期845-853,共9页
Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided ... Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided into five subplots) respectively based on the altitudinal gradient, stand density, slope location, and slope aspect to investigate the effects of environmental factors on tree seedling regeneration in a pine-oak mixed forest. The results indicated that the seedling density was significantly higher at altitudes of 1,283 m to 1,665 m, whereas the sapling density did not differ with altitudes. The seedling and sapling density decreased significantly at 1,835 m. The seedling densities on the upper slopes were much higher than those on the middle and lower slopes, whereas the sapling density had no difference. The sapling density decreased southwest (20°-75°) whereas gradually from the it increased on the shady slopes to the northeast (40°). The seedling density increased from southwest (20°) to northeast (40°The seedling and sapling densities increased with the stand density (850 trees ha-1 to 1,525 trees ha-1) whereas the sapling density was significantly lower in stands (1,9oo trees ha-O. Principal components analysis showed that the slope aspect and stand density had more important roles in tree regeneration in this study region compared with the other two factors. Therefore, our findings suggest that it will be beneficial to keep stands at a moderate density on shady slopes. Appropriate thinning of higher density stands is also expected to promote the natural regeneration of pine-oak mixed forest. 展开更多
关键词 environmental factors Pine-oak mixedforest Qinling Mountains REGENERATION
下载PDF
Independent and combined effects of environmental factors and miR-126, miR-143, and miR-145 on the risk of coronary heart disease 被引量:10
16
作者 Da-Cen LIN Jia-Bing LIN +6 位作者 Zhou CHEN Rong CHEN Chun-Yu WAN Shao-Wei LIN Qi-Shuang RUAN Huang-Yuan LI Si-Ying WU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2017年第11期688-695,共8页
Objective To evaluate the effects of environmental factors and microRNAs (miRNAs) (miR-126, miR-143, and miR-145) on the risk of coronary heart disease (CHD). Methods A frequency-matched case-control study (450... Objective To evaluate the effects of environmental factors and microRNAs (miRNAs) (miR-126, miR-143, and miR-145) on the risk of coronary heart disease (CHD). Methods A frequency-matched case-control study (450 patients, 450 controls) was conducted from April 2014 to December 2016 in Fuzhou City, China. Environmental factors were investigated using a self-administered questionnaire, and the expression levels of miR-126, rniR-143, and miR-145 were determined by quantitative real-time Polymerase Chain Reaction (PCR) in pe- ripheral blood mononuclear cells. Unconditional logistic regression models were used for statistical evaluation. Results Alcohol consumption, high-salt diets, high-intensity work, and lack of physical activity were significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. MiR-126, miR-143, and miR-145 were highly expressed in the CHD group compared with the control group. After adjustment for other environmental factors, unconditional logistic regression results revealed that miR-126, miR-143, and depression were the independent risk factors of CHD, and light diet was the independent protective factor of CHD. Conclusions Our data suggest that a family history of CHD, anxiety, and alcohol consumption was significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. Furthermore, miR-126 and miR-143 in combination with several risk factors, could play a joint role in the development of CHD. Therefore, it is necessary to manage patients with CHD in all directions and multiple level. 展开更多
关键词 Case-control study Coronary heart disease environmental factors Gene-environment interaction MiR- 126 MiR- 143 MiR- 145
下载PDF
Seasonal succession of phytoplankton in response to the variation of environmental factors in the Gaolan River, Three Gorges Reservoir, China 被引量:8
17
作者 彭成荣 张浪 +1 位作者 郑杨忠 李敦海 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第4期737-749,共13页
To understand the responses of a freshwater ecosystem to the impoundment of the Three Gorges Reservoir (TGR), phytoplankton was monitored in the tributaries of the TGR area. From August 2010 to July 2011, algal spec... To understand the responses of a freshwater ecosystem to the impoundment of the Three Gorges Reservoir (TGR), phytoplankton was monitored in the tributaries of the TGR area. From August 2010 to July 2011, algal species composition, abundance, chlorophyll a and other environmental parameters were investigated in the Gaolan River, which is a tributary of Xiangxi River. Thirty-one algal genera from seven phyla were identified. Results show that the lowest concentrations of total phosphorus (TP) and total nitrogen (TN) were 0.06 mg/L and 1.08 rag/L, respectively. The values of TP and TN exceeded the threshold concentration of the eutrophic state suggested for freshwater bodies. In the Gaolan River, the succession of phytoplankton showed clear seasonal characteristics. Different dominant species were observed among seasons under the control of environment factors. In spring and summer, the dominant species were Nitzschia sp. and Aphanizomenon flos-aquae (L.) Ralfs, the limiting nutrient was NO3^--N, and the key environmental factor for phytoplankton population succession was water temperature (WT). In autumn and winter, the dominant species were A.flos-aquae and Chlorella sp., the limiting nutrient was pO3--P, and the key environmental factors were transparency and WT. This study illustrates the influence of physical and chemical factors on phytoplankton seasonal succession in a tributary of TGR since the downstream regions of Xiangxi River and Gaolan River became reservoirs after impoundment of the Three Gorges Dam. We suggest that this activity has significantly affected water quality in the dam area. 展开更多
关键词 environmental factors PHYTOPLANKTON SUCCESSION Three Gorges Reservoir (TGR)
下载PDF
Effects of forest cover types and environmental factors on soil respiration dynamics in a coastal sand dune of subtropical China 被引量:6
18
作者 Wei Gao Zhiqun Huang +2 位作者 Gongfu Ye Xinjian Yue Zhiyong Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第6期1645-1655,共11页
Trees on sand dunes are more sensitive to environmental changes because sandy soils have extremely low water holding capacity and nutrient availability. We investigated the dynamics of soil respiration(Rs) for seconda... Trees on sand dunes are more sensitive to environmental changes because sandy soils have extremely low water holding capacity and nutrient availability. We investigated the dynamics of soil respiration(Rs) for secondary natural Litsea forest and plantations of casuarina,pine, acacia and eucalyptus. Results show that significant diurnal variations of Rsoccurred in autumn for the eucalyptus species and in summer for the pine species, with higher mean soil respiration at night. However, significant seasonal variations of Rswere found in all five forest stands. Rschanged exponentially with soil temperatures at the 10-cm depth; the models explain 43.3–77.0% of Rs variations. Positive relationships between seasonal Rsand soil moisture varied with stands. The correlations were significant only in the secondary forest, and the eucalyptus and pine plantations. The temperature sensitivity parameter(Q10 value) of Rsranged from 1.64 in casuarina plantation to 2.32 the in secondary forest; annual Rswas highest in the secondary forest and lowest in the pine plantation. The results indicate that soil temperatures and moisture are the primary environmental controls of soil respiration and mainly act through a direct influence on roots and microbial activity. Differences in root biomass, quality of litter,and soil properties(pH, total N, available P, and exchangeable Mg) were also significant factors. 展开更多
关键词 Coastal sand dunes Soil respiration Secondary forest PINE CASUARINA ACACIA Eucalyptus plantations environmental factor Q_(10)
下载PDF
Effects of Abiotic Environmental Factors on Soybean Cyst Nematode 被引量:13
19
作者 DUAN Yu-xi ZHENG Ya-nan +3 位作者 CHEN Li-jie ZHOU Xiao-min WANG Yuan-yuan SUN Jing-shuang 《Agricultural Sciences in China》 CSCD 2009年第3期317-325,共9页
As a pest, in order to complete its life history and reproduces effectively, soybean cyst nematode (SCN) (Heterodera glycines Ichinche 1952) must adapt to various environments and conditions for long periods of ev... As a pest, in order to complete its life history and reproduces effectively, soybean cyst nematode (SCN) (Heterodera glycines Ichinche 1952) must adapt to various environments and conditions for long periods of evolution. The nematode is widely dispersed year after year. Controlling this pest requires understanding characters and adaptability of SCN. Effects of abiotic factors, such as temperature, soil humidity, agrotype, pH value, ions, plant exudates, agricultural chemical and cultivation systems on SCN, are reviewed in this paper. The results show that SCN is able to endure various environmental stresses, especially low temperature. Because of its special life history, cyst stage help SCN over winter, resistance of SCN to environmental stress is strong. A few studies have reported the mechanism of SCN environmental adaptability. We emphasized the importance of studying environmental adaptability of SCN, which would benefit the control of SCN by ecological means. 展开更多
关键词 soybean cyst nematodes (SCN) ABIOTIC environmental factors ECOLOGICAL
下载PDF
Effects of interactions between environmental factors and KIF1B genetic variants on the risk of hepatocellular carcinoma in a Chinese cohort 被引量:6
20
作者 Jun-Hu Chen Yan-Yan Wang +7 位作者 Wei-Biao Lv Yu Gan Wei Chang Na-Na Tian Xiao-Hui Huang Li Liu Xin-Fa Yu Si-Dong Chen 《World Journal of Gastroenterology》 SCIE CAS 2016年第16期4183-4190,共8页
AIM: To examine the effect of the potential interaction between KIF1 B variants(rs17401966 and rs3748578) and environmental factors on the risk of hepatocellular carcinoma(HCC) in a high-risk region in China.METHODS: ... AIM: To examine the effect of the potential interaction between KIF1 B variants(rs17401966 and rs3748578) and environmental factors on the risk of hepatocellular carcinoma(HCC) in a high-risk region in China.METHODS: Three hundred and six patients with HCC and 306 hospital-based control participants residing in the Shunde region of Guangdong Province, China were enrolled. Clinical characteristics were collected by reviewing the complete medical histories from the patient archives, and epidemiological data were collected using a questionnaire and clinical examination. Two single nucleotide polymorphisms(SNPs) of KIF1B(rs17401966 and rs3748578) were chosen for the current study. All subjects were genotypedusing a Taq Man real-time polymerase chain reaction. Multiplicative and additive logistic regression models were used to evaluate various gene-environment interactions.RESULTS: Smoking, frequent consumption of raw freshwater fish, hepatitis B virus(HBV) infection, and a family history of HCC were important risk factors for HCC in this population. Chronic infection with HBV was the most important environmental risk factor for HCC [odds ratio(OR) = 12.02; 95% confidence interval(95%CI): 6.02-24.00]. No significant association was found between the KIF1 B variants alone and the risk of HCC. Nevertheless, a significant additive effect modification was observed between rs17401966 and alcohol consumption(P for additive interaction = 0.0382). Compared with non-drinkers carrying either the AG or GG genotype of rs17401966, individuals classified as alcohol consumers with the AA genotype of rs17401966 had a significantly increased risk of HCC(OR = 2.36; 95%CI: 1.49-3.74).CONCLUSION: The gene-environment interaction between the KIF1 B rs17401966 variant and alcohol consumption may contribute to the development of HCC in Chinese individuals. 展开更多
关键词 Hepatocellular carcinoma Kinesin family member 1B environmental factors Alcohol drinking Gene-environment interaction
下载PDF
上一页 1 2 17 下一页 到第
使用帮助 返回顶部