Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 120 )

2018 ( 1096 )

2017 ( 1120 )

2016 ( 1087 )

Custom range...

Search Results: 1 - 10 of 81730 matches for " SANG Wei-Guo "
All listed articles are free for downloading (OA Articles)
Page 1 /81730
Display every page Item
Modelling changes of a deciduous broad-leaved forest in warm temperate zone of China

SANG Wei-Guo,

生态学报 , 2004,
Abstract: A warm temperate deciduous forest in Dongling Mountain of Beijing was simulated with forest gap dynamics model, FORET1, in order to predict its future changes. The model parameters were derived from both historical and currently measured data; and the model was tested against observed data. Results showed that the model simulation of forest species composition, biomass and production matched well with observed data. Model simulation of the dynamics of this warm temperate deciduous forest indicate that the changes in net primary production was clearly unregulated and extremely unstable, with a peak around 30 years and repeated patterns of dynamics in biomass production every 110 years. The patterns of temporal dynamics of this forest are comparable to other forest ecosystems worldwide.

LIU Wei,ZHU Li,SANG Wei-Guo,

植物生态学报 , 2007,
Abstract: Aims Amaranthus retroflexus is the most harmful,widely distributed invasive species in its genus.Our objective was to determine its potential worldwide distribution and compare that with its present distribution.Methods We selected 28 environmental factors including climatic,topographic and soil factors as GIS layers and determined their quantitative relationship with the actual global distribution of the species,based on 4 207 herbarium records. Principal component analysis(PCA) was used to select the environmental factors influencing the distribution of the species.Based on these results,we estimated the central and maximum potential distribution of A.retroflexus and compared them to its actual geographical distribution.Important findings Fourteen environmental factors importantly affected the distribution of A.retroflexus.The central potential distribution range was southern New Zealand,southeastern Australia,some areas in northern South America,northwestern and southeastern North America,most of Europe and southeastern China.The maximum potential distribution range was southcentral South America,most of North America,some areas in northern Africa,most of Europe,some areas in southern and northern Australia and most of Asia including most of China except Tibet,Qinghai Province,Xinjiang and western Sichuan Province.The potential central distribution of the species matched its actual distribution,whereas the potential maximum distribution was much larger.
Effects of simulated warming and precipitation change on seedling emergence and growth of Quercus mongolica in Dongling Mountain, Beijing, China

DONG Li-Jia,SANG Wei-Guo,

植物生态学报 , 2012,
Abstract: Aims Temperature and water supply are crucial drivers for plant seedling regeneration. Dongling Mountain is one of the temperate areas most sensitive to climate change in China, and Quercus mongolica is the dominant species. Our objective was to investigate how climate change (warming and precipitation change) affects the physiological and ecological processes of seeds and seedlings of Q. mongolica to determine the regeneration mechanisms and change in patterns of this key species. Methods We used a controlled, growth-chamber experiment for rising temperature and changing water supply. There were three levels for both temperature and water supply: monthly mean temperature (control) over past the 18 years and increased by 2 ℃ and 6 ℃ and monthly mean precipitation (control) and +30% and-30%. Seeds of Q. mongolica were collected in fall of 2010, planted in May 2011, and grown in pots under the treatments. We periodically measured traits of seedling emergence and growth during the first growing season. Important findings Seedling emergence percentage was affected by precipitation and its interaction with temperature, while seedling growth and biomass were affected by temperature and precipitation alone, rather than by their interaction. Increased temperature by 2 ℃ and water addition shortened the seedling emergence time; increased temperature by 6 ℃ combined with reduction of water increased seed mortality and reduced seedling emergence percentage, yet with water addition promoted seedling dynamics. Increased temperature by 2 ℃ had no significant effects on seedling growth, while increased by 6 ℃ significantly increased the specific leaf area, restricted the seedling growth and biomass, and reduced the ratio of root and shoot. In addition, water reduction reduced only root biomass but not shoot, total biomass and root:shoot. Water addition significantly promoted growth of length,increased leaf numbers and increased aboveground biomass,especially leaf biomass.Therefore,proper temperature elevation or water addition may benefit the potential regeneration ability of Q.mongolica,but highly elevated temperature with reduced precipitation may be deleterious under future climate change.

CHEN Sha,SANG Wei-Guo,

植物生态学报 , 2007,
Abstract: 以辽东栎(Quercus liaotungensis)为主的落叶阔叶林、华北落叶松(Larix principis-rupprechtii)林和油松(Pinus tabulaeformis)林是暖温带林区具有代表性的森林群落类型。该研究应用国内外流行的半球图方法,通过对这3种森林群落叶面积指数和林冠开阔度的测定和综合比较,分析了叶面积指数和林冠开阔度的季节动态,揭示了暖温带地区不同类型森林群落叶面积指数和林冠开阔度的特征。研究结果表明,落叶阔叶林(优势种为辽东栎、棘皮桦(Betula dahurica)和五角枫(Acer mono))和华北落叶松林两种落叶森林群落的叶面积指数值均随生长季的到来而呈现增长的趋势,最大值出现在8月;林冠开阔度值随着生长季的到来而下降,最大值出现在11月。落叶阔叶林的叶面积指数和林冠开阔度的季节动态较之华北落叶松林明显。油松是常绿树种,其群落叶面积指数和林冠开阔度的变化程度均不明显,但林冠开阔度的变化趋势也是与叶面积指数的变化趋势相反。通过计算得出叶面积指数和林冠开阔度相关显著,并且呈现指数回归的关系。此研究结果为以遥感途径获取暖温带地区叶面积指数提供了地面校正依据,为研究该地区植被林冠的异质性及其造成的影响,以及进一步对该地区林分、景观和区域尺度上碳、水分和通量等方面的模拟提供了基础数据。
Different responses of radial growth to climate warming in Pinus koraiensis and Picea jezoensis var.komarovii at their upper elevational limits in Changbai Mountain,China

LI Guang-Qi,BAI Fan,SANG Wei-Guo,

植物生态学报 , 2011,
Abstract: Aims Temperature is generally considered the limiting factor for tree growth at species’ upper elevational limits. Our objectives were to determine the upper elevational limit response of radial growth in Pinus koraiensis and Picea jezoensis var. komarovii to climate warming in Changbai Mountain Nature Reserve of China and to elucidate temperature sensitivity of radial growth. Methods We selected typical trees at each species’ upper limit for increment coring and established ring-width chronologies for both species. We compared the general trend of the chronologies with temperatures during 1958–2006. To determine species’ response to rising temperature, we analyzed the relationship between chronology and important meteorological factors (temperature, precipitation, growing season length, effective accumulative temperature, etc.) using correlation, response function, moving correlation and pointing year analyses. Important findings As temperature rose, ring widths in Pinus koraiensis exhibited the same increasing trend as temperature, while ring widths in Picea jezoensis var. komarovii exhibited decreasing sensitivity to temperature. The increase of temperature and precipitation in the growing season mutually enhance Pinus koraiensis growth. Prolongation of the growing season and rising temperature during the growing season also can accelerate the growth of Pinus koraiensis. For Picea jezoensis var. komarovii, water stress caused by increasing temperature is the main reason for its relationship between ring width and temperature. Correlations between Picea jezoensis var. komarovii ring width and almost all temperature indices are significantly negative. As temperature rose, correlations between ring width and precipitation, especially spring precipitation, changed from negative to positive. High temperature in each month and inadequate precipitation in the middle and late growing season are the important meteorology conditions for narrow rings. Also, the insignificant extension of the growing season may relate to reduced temperature sensitivity in tree ring growth.
Effects of Dietary L-carnitine and Betaine on Serum Biochemical Indices of Large Yellow Croaker (Pseudosciaena crocea) Cultured in Floating Net Cages
Wei-guo Sang,Shi-qiu Deng,Ji-kang Shentu,Lei Wang
Advance Journal of Food Science and Technology , 2012,
Abstract: The objective of this study was to investigate the biochemical changes of large yellow croaker as affected by dietary supplements. Large yellow croaker (Pseudosciaena crocea) is a marine species that is widely cultured in China due to its high commercial value. However, the cage-cultured large yellow croakers were found to be less tasty compared with wild large yellow croakers due to high lipid in their body, which significantly impacts the commercial markets. Triglycerides, cholesterol and free fatty acids are main lipid ingredients in the animal body. The fish were fed with basal diet or basal diet supplemented with L-carnitine (0.08% of dry weight diet) or betaine (0.8% of dry weight diet) for 12 weeks in seawater floating net cages (3×2×1.5 m) each holding 60 fishes. Three net cages were assigned to each dietary treatment, as replications. The seawater temperature ranged from 18 to 31°C and salinity from 25 to 28 g/kg. Fish were hand-fed one of the experimental diets to apparent satiety twice daily (05:00 and 17:30) throughout the 12 week experimental period. The results indicate that L-carnitine or betaine in diets significantly reduced Serum Triglyceride (STG) and Serum Cholesterol (SCH) levels while increased Serum Free Fatty Acids (SFFA) content (p<0.05). The diets of L-carnitine or betaine supplements on serum biochemical indices of that fish species have positive effects. These results suggested that the supplementation with L-carnitine or betaine is one of the effective ways to improve the meat quality of large yellow croakers cultured in floating net cages.
Management mechanism of biotechnology safety in China and abroad

SANG Wei-Guo,MA Ke-Ping,WEI Wei,

生物多样性 , 2000,
Abstract: 综述了国内外生物安全管理机制,特别是生物技术安全管理机构和运行方式,分别就国际组织、美洲、欧洲和亚洲国家以及中国的有关制定、颁布和实施生物安全管理的作法和机构进行讨论,重点介绍了我国现有的生物技术安全管理办法、法则及其运行机制,最后提出了我国未来生物技术安全管理办法发展的重点。
Activity of antioxidant enzymes in the invasive plant Eupatorium odoratum under various environm environmental stresses

LU Ping,SANG Wei-Guo,MA Ke-Ping,

生态学报 , 2006,
Abstract: 飞机草(Eupatorium odoratum)原产于中南美洲,在我国最早发现于1934年,目前已经分布到云南、海南、台湾、广东等省区,是一种典型的外来入侵种。研究其在逆境条件下的生理适应机制对于有效治理该入侵种具有十分重要的意义。研究了其在不同环境胁迫条件(高温、低温和干旱)下抗氧化酶系统的变化。结果表明:超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)和脱氢抗血酸还原酶(DHAR)在3种环境胁迫下酶活性都升高;过氧化氢酶(CAT)在高温胁迫下升高,而在低温和干旱胁迫下酶活性降低;过氧化物酶(POD)和单脱氢抗坏血酸还原酶(MDAR)在高温和干旱胁迫下酶活性升高,而在低温胁迫下酶活性降低;谷胱甘肽还原酶(GR)在高温和干旱胁迫下酶活性升高,而在低温胁迫下保持不变。这些研究结果可能有助于寻找到一条控制飞机草的新途径。

SANG Wei-Guo,CHEN Ling-Zhi,WANG Xi-Wu,

植物生态学报 , 2000,
Abstract: The "Gap model" method was applied in a study of the long-term dynamics of Quercus liaotungensis forest in a warm temperate area of North China. Parameters were derived from a combination of the known history of forest management and observed data. The model was then tested on a set of observed data. It was found to reasonably simulate forest composition and biomass. Modeling the dynamics of Q. liaotungensis forests showed the following: 1) The pattern of biomass dynamics was cyclical, with a period of 110 years; 2) Variation in leaf area index (LAI) in the modeled forest was closely related to its competitive status; 3) Variation in net production was unregulated and extremely unstable, with a peak at 30 years. These are closely comparable to results from similar studies in other regions of the world.

LU Ping,SANG Wei-Guo,MA Ke-Ping,

植物生态学报 , 2005,
Abstract: 紫茎泽兰(Eupatorium adenophorum)是20世纪40年代经中缅边境传入我国的一种外来入侵种,原产于中美洲的墨西哥和哥斯达黎加,现已在我国南方和西南地区广泛分布,并且其蔓延速度极快,引起了社会各界的广泛关注。近年来,随着研究的不断深入和拓展,新的研究成果不断涌现,使紫茎泽兰成功入侵的机理性问题不断被揭示出来。该文简要介绍了目前我国关于紫茎泽兰研究的几个热点问题,这些问题主要围绕着紫茎泽兰的分布和预测、入侵扩散机制以及防除方法3 个方面展开。其中以紫茎泽兰作为典型外来入侵种来研究其入侵扩散机制的工作最多。该文就目前的研究进展做一综述,并提出今后的研究建议。
Page 1 /81730
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.