期刊文献+
共找到233篇文章
< 1 2 12 >
每页显示 20 50 100
Fungi Diversity of Ginseng Rhizosphere Soil in Northeastern China 被引量:8
1
作者 陈曦 孙晓东 +1 位作者 毕思远 吕国忠 《Agricultural Science & Technology》 CAS 2010年第2期132-136,共5页
[Objective] The aim was to know the pathogenic fungi types and distribution law in ginseng rhizosphere soil.[Method] During May to Oct.in 2008 and 2009,more than 200 soil samples were collected from ginseng rhizospher... [Objective] The aim was to know the pathogenic fungi types and distribution law in ginseng rhizosphere soil.[Method] During May to Oct.in 2008 and 2009,more than 200 soil samples were collected from ginseng rhizosphere soil in Ji an City,Fusong County of Jilin Province and Huanren County of Liaoning Province.Soil dilution plate method and soil particle method were adopted to isolate and culture soil fungi,then classification and identification were carried out.[Result] 33 species of 22 fungal genera were id... 展开更多
关键词 MICROORGANISM ECOLOGY SPECIES Quantity
下载PDF
改进型MST-人工湿地组合工艺处理分散生活污水的研究 被引量:1
2
作者 张志芳 陈立爱 +2 位作者 侯红勋 张静 杨引浩 《安徽建筑大学学报》 2016年第2期65-69,74,共6页
在温室型MST装置中加入人工浮岛构成生态/生物一体化装置,出水经过人工湿地深度处理,将此组合工艺用于分散生活污水处理中,研究其可行性。研究发现当COD、NH4+-N、TN进水浓度分别为323.46mg/L、25.98mg/L、34.57mg/L时,出水浓度分别为28... 在温室型MST装置中加入人工浮岛构成生态/生物一体化装置,出水经过人工湿地深度处理,将此组合工艺用于分散生活污水处理中,研究其可行性。研究发现当COD、NH4+-N、TN进水浓度分别为323.46mg/L、25.98mg/L、34.57mg/L时,出水浓度分别为28.79mg/L、0.93mg/L、9.65mg/L,平均去除率分别为89%、96%、72%,达到了《城镇污水出水处理厂污染物排放标准》一级A标的标准,证明了该工艺的可行性。 展开更多
关键词 MST 生物接触氧化 人工浮岛 人工湿地 生物/生态
下载PDF
Bioturbation Effects of Benthic Fish on Soil Microorganism of Paddy Field 被引量:5
3
作者 胡勇军 孙刚 +1 位作者 房岩 韩国军 《Agricultural Science & Technology》 CAS 2010年第4期172-175,共4页
[Objective]The research aimed to explore the bioturbation effects of benthic fish Misgurnus anguillicaudatus on soil microorganism(microflora,biomass,and special physiological groups) of paddy field.[Method]The expe... [Objective]The research aimed to explore the bioturbation effects of benthic fish Misgurnus anguillicaudatus on soil microorganism(microflora,biomass,and special physiological groups) of paddy field.[Method]The experiments were conducted locally and quantitatively in field,using plate count and MPN methods.[Result]In the microflora of paddy soil tested,the quantity of bacteria is the largest,followed by actinomycetes and fungus.Compared with the control paddy fields,in rice-fish paddy fields the quantities of bacteria,actinomycetes and fungus were higher,at significance level P 〈0.05,P 〈0.01,and P 〈0.01 respectively.The microbial biomass C and N in rice-fish paddy fields is remarkably higher than those in control paddy fields,both at significance level P 〈0.01;the microbial biomass P in rice-fish paddy fields is higher than that in control paddy fields,but at significance level P 〈0.05.Benthic fish promotes the growth of soil azotobacter,cellulolytic bacteria,nitrobacteria,sulfur bacteria,and ammonifying bacteria,restricts the reproduction of nitrate reducing bacteria and sulfate reducing bacteria.[Conclusion]The benthic fish had important effects on microflora,microbial biomass,and special microorganism physiological groups of paddy soil,improves the living conditions of soil microorganisms,promotes the soil fertility and bio-chemical activity,which is beneficial for improving the supply ability of soil nutrients such as N,P,S,as well as the efficiency of nutrient utilization. 展开更多
关键词 Benthic fish Soil microorganism Paddy field Integrated ecosystem BIOTURBATION
下载PDF
Vertical variation and storage of nitrogen in an aquic brown soil under different land uses 被引量:9
4
作者 张玉革 姜勇 +2 位作者 梁文举 闻大中 张玉龙 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期192-196,共5页
The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenya... The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenyang Experimental Station of Ecology, Chinese Academy of Sciences in November of 2003. The results showed that different land uses had different profile distributions of soil total nitrogen (STN), alkali N, ammonium (NH4+-N) and nitrate (NO3--N). The sequence of STN storage was woodland >maize field > fallow field > paddy field, while that of NO3--N content was maize field > paddy field > woodland > fallow field, suggesting the different root biomass and biological N cycling under various land uses. The STN storage in the depth of 0-100 cm of woodland averaged to 11.41 thm-1, being 1.65 and 1.25 times as much as that in paddy and maize fields, respec-tively, while there was no significant difference between maize and fallow fields. The comparatively higher amount of NO3--N in maize and paddy fields may be due to nitrogen fertilization and anthropogenic disturbance. Soil alkali N was significantly related with STN, and the correlation could be expressed by a linear regression model under each land use (R20.929, p<0.001). Such a correlation was slightly closer in nature (woodland and fallow field) than in agro ecosystems (paddy and maize fields). Heavy N fertilization induced an excess of crop need, and led to a comparatively higher amount of soil NO3--N in cultivated fields than in fallow field and woodland. It is suggested that agroforestry practices have the potential to make a significant contribution to both crop production and environment protection. 展开更多
关键词 Aquic brown soil Land use Soil nitrogen storage Vertical variation
下载PDF
Status of urban vegetation in Guangzhou City 被引量:12
5
作者 管东生 陈玉娟 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第3期249-252,共4页
According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey f... According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment. 展开更多
关键词 Urban vegetation STATUS Human impact
下载PDF
Advances in Research on the Structure and Diversity Variation of Insect Communities in Wetland 被引量:1
6
作者 刘佳妮 张瑜愉 +5 位作者 徐松萍 赵晓红 尹利方 华金珠 姚丽媛 郭丽红 《Agricultural Science & Technology》 CAS 2017年第5期914-917,956,共5页
The species diversity, structure and dynamic rules of insect communities in wetland can provide data of the insects for the protection, utilization and monitor- ing of wetland, which is an essential link to maintain t... The species diversity, structure and dynamic rules of insect communities in wetland can provide data of the insects for the protection, utilization and monitor- ing of wetland, which is an essential link to maintain the healthy ecological system of the wetland and protect the biodiversity in the wetland. A systematic study on the composition and succession of insect communities in the wetland, as well as the indication of insect groups can provide a theoretical basis for wetland protection and management, and thus promote the development of regional economy and en- vironmental protection. 展开更多
关键词 WETLAND Insect community BIODIVERSITY ECOSYSTEM
下载PDF
A New Model on Origin and Evolution of Biology 被引量:1
7
作者 王奕蛟 冯綮一 柴立和 《Agricultural Science & Technology》 CAS 2009年第4期4-7,共4页
Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on th... Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research. 展开更多
关键词 Biological origin and evolution COMPLEXITY Generalized entropy
下载PDF
Study of the Short-time Eco-physiological Response of Plant Leaves to Dust 被引量:20
8
作者 陈雄文 《Acta Botanica Sinica》 CSCD 2001年第10期1058-1064,共7页
The short-time eco-physiological response to dust was measured for the leaves of 22 local popular plant species including roadside trees, fruit trees, forest trees and crop species in Beijing. The dust did affect the ... The short-time eco-physiological response to dust was measured for the leaves of 22 local popular plant species including roadside trees, fruit trees, forest trees and crop species in Beijing. The dust did affect the eco-physiology of leaves of these species. After being covered by dust the instant net photosynthetic rates of most plant species changed insignificantly, but it decreased by more than 35% for 5 species, and it increased by-more than 57% for Ginkgo biloba L. The respiration rates of 12 plant species increased significantly, but it decreased significantly for Malus pumila Mill. (M. communis D C.) and Cotinus coggygria (L.) Scop., and it changed insignificantly for the other 8 species. The transpiration rates of 5 plant species increased significantly, however, they decreased for 9 species, and changed insignificantly for the other 8 species. Platanus occidentalis L. had highest dust carrying capacity. After 2 h the physiological indices did not change significantly for Diospyros kaki L. f., G. biloba and Populus tomentosa Carr. The implications of the research are that Ulmus laevis Pall., M. pumila (M. communis), D. kaki and G. biloba are suitable for amelioration of dust storm damage and increase in local economical development near the sources of dust storms in western China. And in the cities, such as Beijing and other dust areas, the plants have high dust-carrying capacity can be planted for air cleaning. 展开更多
关键词 LEAVES eco-physiological response DUST
下载PDF
Mechanism of Nutrient Silicon and Water Temperature Influences on Phytoplankton Growth 被引量:3
9
作者 杨东方 高振会 +2 位作者 孙培艳 李梅 曲延峰 《Marine Science Bulletin》 CAS 2006年第2期49-59,共11页
This paper analyzed how nutrient silicon and water temperature influenced the variation of phytoplankton growth and the change of its assemblage structure, and probed the different characteristics of the variation of ... This paper analyzed how nutrient silicon and water temperature influenced the variation of phytoplankton growth and the change of its assemblage structure, and probed the different characteristics of the variation of phytoplankton growth and the different profiles of the change of its assemblage structure influenced by nutrient silicon and water temperature. Taking Jiaozhou Bay for example, this paper showed the process of both the variation of phytoplankton growth and the change of its assemblage structure, unveiled the mechanism of nutrient silicon and water temperature influencing the variation of phytoplankton growth and the change of its assemblage structure, and determined that nutrient silicon and water temperature were the motive power for the healthy running of the marine ecosystem. 展开更多
关键词 SILICON water temperature phytoplankton growth assemblage structure mechanism
下载PDF
Study on Bio-Ecology of the Spider Clubiona corrugate
10
作者 李秦晋 王娟 +2 位作者 严真真 赵丽 王智 《Agricultural Science & Technology》 CAS 2015年第6期1243-1246,共4页
Objective] Field and laboratory observation was conducted to investigate Clubiona corrugate. [Method] The trials investigated the bio-ecology and behavior of the spider C. corrugate. [Result] The spider overwintered w... Objective] Field and laboratory observation was conducted to investigate Clubiona corrugate. [Method] The trials investigated the bio-ecology and behavior of the spider C. corrugate. [Result] The spider overwintered with spiderlings, adults and instars turn into adults after 6-8 molts. It had 2-3 generations each year in Hunan, and it owned the character of overlapping of generation in paddies. The average duration of generations of C. corrugate was 158.2 days, and the survival days av-eraged 223.2 days. The female and male mated several times without cannibalistic behavior, average number of eggs female laid throughout its adult life was 371.5, and hatchability can get 85.4%. The sex ratio was 1∶1. Its capability of resistance to starvation and drought was strong. Through indoor observation, the spider can sur-vive 25-61 days under the condition of no water and food. [Conclusion] The behav-ior of C. corrugate was also recorded in detail, and female usual y has a strong a-bility to protect their egg-sacs and spiderlings. At present, the bio-ecology and be-havior of the spider C. corrugate had not been reported. 展开更多
关键词 Clubiona corrugate BIOLOGY ECOLOGY SPIDER
下载PDF
RELATIONSHIP BETWEEN GROWTH AND MORPHOLOGY OF METARRHIZIUM ANISOPLIAE IN BIOTRANSFORMATION OF STEROID 被引量:2
11
作者 阳葵 李晓静 +2 位作者 王积分 段世铎 张鎏 《Transactions of Tianjin University》 EI CAS 2001年第1期1-6,共6页
The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled t... The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled to growth phases:the fractal dimension,a feature calculated from the morphological images,increases during the late lag phase and the early exponential phase,and culminates at a value near 2.4 at half of the exponential phase.This can be attributed to the marked change of rough and smooth pellet proportions during growth and the change can be well expressed by the fractal analysis of mycelial morphology.The mycelial morphology is also strongly related to the biotransformation activity:a mycelial sample was withdrawn from the culture to use for fractal analysis before the steroid substrate (16α,17α epoxy 4 pregnene 3,20 dione) was added;the higher fractal dimension corresponds to the higher conversion rate of steroid biotransformation.And the maximum of fractal dimension appeared prior to the maximum of biomass concentration.It is therefore possible to utilize the fractal dimension curve to supervise the fermentation process more timely and availably than to use the conventional biomass curve to do. 展开更多
关键词 metarrhizium anisopliae MORPHOLOGY GROWTH fractal dimension BIOTRANSFORMATION STEROID
下载PDF
First report of an endophyte (Diaporthe phaseolorum var. sojae) from Kandelia candel
12
作者 程中山 唐文成 +5 位作者 徐树兰 孙士锋 黄伯友 晏希 陈其津 林永成 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期277-282,共6页
Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from ... Mangrove endophytic fungus 1893 was isolated from Kandelia candel from an estuarine mangrove on the South China Sea Coast Two new lactones 1893A and 1893B, together with other known compounds, have been isolated from its fermentation broth. To classify the endophyte correctly for further industrial application, a combination of morphological and molecular techniques was used to approach its identity. The endophyte was compared with similar species having trichogynes or trichogyne-like hyphae which apparently fused with an- theridium-like hyphae, and perithecia initials developing from an ascogonial coil surrounded by enveloping hyphae in early developmental stages on pure culture. Further morphological characteristics on host and non-host were used for comparison with similar species when the endophyte was cultivated on leaves ofKandelia candel and Mangifera indica, respectively, which resulted in classifying the endophyte as a Phomopsis specics. The ITS sequence of rDNA was used to infer its phylogenetic relationships with Phomopsis species that resembled the strain in morphology or ecology. Finally, the endophyte was identified as Diaporthe phaseolorum var. sojae based on morphological and molecular evidence. Our study is a first report ofDiaporthephaseolorum var. sojae isolated from mangrove Kandelia candel. 展开更多
关键词 PHOMOPSIS mangrove endophyte morphology PHYLOGENY
下载PDF
Characteristics and the Issue of Eco-safety for the Plant Biodiversity in Longtan Nature Reserve
13
作者 贾桂康 欧钟慧 《Agricultural Science & Technology》 CAS 2013年第7期1049-1052,共4页
The characteristic and status quo of plant biodiversity in Longtan Nature Reserve was evaluated from the three aspects of species diversity, genetic diversity and ecosystem dioversity. And the primary eco-safety influ... The characteristic and status quo of plant biodiversity in Longtan Nature Reserve was evaluated from the three aspects of species diversity, genetic diversity and ecosystem dioversity. And the primary eco-safety influencing factors for plant biodiversity in Longtan nature reserve were put forward. The results show that the plant species in Longtan Nature Reserve was abundant, including 2 821 species of vascular bundle plants belonging to 1029 genera, 205 families. The main problems influencing eco-safety included the destruction of endangered wild plants and exotic species invasion. 展开更多
关键词 Plant biodiversity Eco-safety Longtan Nature Reserve
下载PDF
Construction and application of an assessment index system for evalu ating the eco-community’s sustainability 被引量:1
14
作者 韩英 代力民 +2 位作者 赵小汎 于大炮 吴胜男 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第2期154-158,共5页
An assessment index system including environment, socio-culture, economy and technology was established for evaluating environmental construction level of community (objective construction), and questionnaire was de... An assessment index system including environment, socio-culture, economy and technology was established for evaluating environmental construction level of community (objective construction), and questionnaire was designed according to paper review for evaluating residential satisfaction (subjective satisfaction). The index system was divided into four layers: system (A), subsystems (B), categories (C), and indicators (D), and in total of 38 indicators was established. The Xihe community, affiliated to Nanfen district, Benxi City, Liaoning Province, China was selected as a case study. Results indicated that the community sustainability index related to objective environmental construction was 0.4355 and was classified as class Ⅲ (moderate); the community sustainability index related to the residential satisfaction was 0.4255, belonging to class Ⅲ. In conclusion, the sustainability of Xihe community was moderate and needed to be improved. Residential satisfaction was lower than objective environmental construction. The assessment index system established in this study is able to reflect the comprehensive sustainability of community and can be used to evaluate other similar communities' sustainability. 展开更多
关键词 community sustainability assessment index system objective environmental construction residential satisfaction Xihe community
下载PDF
A Technological Overview of Biogas Production from Biowaste 被引量:9
15
作者 Spyridon Achinas Vasileios Achinas Gerrit Jan Willem Euverink 《Engineering》 SCIE EI 2017年第3期299-307,共9页
The current irrational use of fossil fuels and the impact of greenhouse gases on the environment are driving research into renewable energy production from organic resources and waste. The global energy demand is high... The current irrational use of fossil fuels and the impact of greenhouse gases on the environment are driving research into renewable energy production from organic resources and waste. The global energy demand is high, and most of this energy is produced from fossil resources. Recent studies report that anaerobic di- gestion (AD) is an efficient alternative technology that combines biofuel production with sustainable waste management, and various technological trends exist in the biogas industry that enhance the production and quality of biogas. Further investments in AD are expected to meet with increasing success due to the low cost of available feedstocks and the wide range of uses for biogas (i.e., for heating, electricity, and fuel). Bio- gas production is growing in the European energy market and offers an economical alternative for bioenergy production. The objective of this work is to provide an overview of biogas production from lignocellulosic waste, thus providing information toward crucial issues in the biogas economy. 展开更多
关键词 Anaerobic digestion BIOGAS Sustainable energy Lignocellulosic waste Microbial ecology
下载PDF
ECOLOGICAL SERIES OF SOIL ANIMALS IN DARLIDAI MOUNTAIN 被引量:4
16
作者 HOUWei-ling FANHong 《Chinese Geographical Science》 SCIE CSCD 2002年第4期378-382,共5页
The ecological series of soil animals under the broad-leaved and pine mix ed forest in Darlidai Mountain was studied.Seven sample plots were selected according to different altitude gradients,which belong to dif feren... The ecological series of soil animals under the broad-leaved and pine mix ed forest in Darlidai Mountain was studied.Seven sample plots were selected according to different altitude gradients,which belong to dif ferent vegeta-tion types.By investigating and analyzing soil animals in every sample p lot it is found that there are 45group s and 1956individuals,which are involved in 3phylums,7classes,16orders,respectively.The altitude is a key factor which af-fects ecological series of soil anim als.Both the groups and individuals of soil animals increase with altitu de increasing under certain conditions,which con trastes with ordinary cases,resulting from special micro-climate in studied area.The groups and individuls of soil animals are the most under the broad-leaved and pine forest on the top of the mount ain,and the least under Picea-Abies forest in the foot of the mountain. 展开更多
关键词 darlidai mountain soil animals ecological series
下载PDF
Physical and chemical processes promoting dominance of the toxic cyanobacterium Cylindrospermopsis raciborskii 被引量:4
17
作者 Michele A. BURFORD Timothy W. DAVIS 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第4期883-891,共9页
The freshwater cyanobacterium, Cylindrospermopsis raciborskii (Woloszyflska) Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cytoand hepatotoxi... The freshwater cyanobacterium, Cylindrospermopsis raciborskii (Woloszyflska) Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cytoand hepatotoxins (cylindrospermopsins, saxitoxins), making blooms of this species a serious health concern for humans. In the last 10 15 years, there has been a considerable body of research conducted on the ecology, physiology and toxin production of this species and this paper reviews these studies with a focus on the cylindrospermopsin (CYN)-producing strains. C. raciborskii has low light requirements, close to neutral buoyancy, and a wide temperature tolerance, giving it the capacity to grow in many lentic waterbodies. It also has a flexible strategy with respect to nitrogen (N) utilisation; being able to switch between utilising fixed and atmospheric N as sources of N fluctuate. Additionally this species has a high phosphate (DIP) affinity and storage capacity. Like many cyanobacteria, it also has the capacity to use dissolved organic phosphorus (DOP). Changes in nutrient concentrations, light levels and temperature have also been found to affect production of the toxin CYN by this species. However, optimal toxin production does not necessarily occur when growth rates are optimal. Additionally, different strains of C. raciborskii vary in their cell quota of CYN, making it difficult to predict toxin concentrations, based on C. raciborskii cell densities. In summary, the ecological flexibility of this organism means that controlling blooms of C. raciborskii is a difficult undertaking. However, improved understanding of factors promoting the species and toxin production by genetically capable strains will lead to improved predictive models of blooms. 展开更多
关键词 CYANOBACTERIA FRESHWATER algal toxins NUTRIENTS light temperature
下载PDF
Preliminary Study on Biological Characteristics of Degraded Soil Ecosystems in Dry Hot Valley of the Jinsha River 被引量:21
18
作者 HEYURONG YANGWANQIN +1 位作者 WANGKAIYUN SONGGUANGYU 《Pedosphere》 SCIE CAS CSCD 2002年第4期365-372,共8页
Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jins... Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jinsha River, China. Results showed that Hymenoptera, Araneae and Collembola were the dominant groups of soil animals in the plots studied. The numbers of groups and individuals and density of soil animals in the dry red soil series were higher than those in the Vertisol series, and the numbers of individuals and density of soil animals decreased with the degree of soil degradation. Bacteria dominated microbiocoenosis not only in the dry red soils but also in the Vertisols. Microbial numbers of the dry red soil series were higher than those of Vertisol series, and decreased with the degree of soil degradation. The activities of catalase, invertase, urease and alkaline phosphatase declined with the degradation degree and showed a significant decline with depth in the profiles of both the dry red soils and the Vertisols, but activities of polyphenol oxidase and acid and neutral phosphatase showed the same tendencies only in the Vertisols. It was concluded that the characteristics of soil animals, microorganisms and enzymatic activity could be used as the bio-indicators to show the degradation degree of the dry red soils and Vertisols. Correlation among these soil bio-indicators was highly significant. 展开更多
关键词 degraded soil ecosystem soil enzyme soil fauna soil microbes
下载PDF
ANALYSIS OF HABITAT PATTERN CHANGE OF RED-CROWNED CRANES IN THE LIAO HE DELTA USING SPATIAL DIVERSITY INDEX 被引量:3
19
作者 WANGLing LIXiu-zhen +1 位作者 HUYuan-man GUODu-fa 《Chinese Geographical Science》 SCIE CSCD 2003年第2期164-170,共7页
Habitat pattern change of red-crowned cranes (Grus japonensis) in t he Liaohe Delta between 1988 and 1998 was analyzed with the help of Spatial Dive rsity Index based on remote sensing data and field investigation. Th... Habitat pattern change of red-crowned cranes (Grus japonensis) in t he Liaohe Delta between 1988 and 1998 was analyzed with the help of Spatial Dive rsity Index based on remote sensing data and field investigation. The result sho wed that the influence from human activities on the wetland habitat of red-crow ned cranes was prominent with the development of oil and agricultural exploitati on, and the habitat pattern of red-crowned cranes had been obviously changed by the human disturbance during the ten years. The areas with high Spatial Diversi ty values (SD≥0.65) and that with mid-high values (0.5≤SD< 0.65), which const ituted the main part of suitable habitat of red-crowned cranes,had reduced to 9142ha and 5576ha respectively, with the shrinking of natural land cover, such a s reed and Suaeda community. The habitat pattern became more fragmented, which w as caused by roads and wells during oil exploration. It was indicated that the s uitability and quality of habitat for red-crowned cranes in the Liaohe Delta we re degraded in the last decade. The results also showed that diversity index cou ld reflect the habitat suitability of red-crowned cranes quantitatively and des cribe the spatial pattern of the habitat explicitly. This study will provide a s cientific basis for habitat protection of red-crowned cranes and other rare spe cies in wetlands. 展开更多
关键词 spatial diversity Index red-crowned crane ( GrUS japonensis) habitatpattern the liaohe delta
下载PDF
Comparative study of responses in the brown algae Sargassum thunbergii to zinc and cadmium stress 被引量:3
20
作者 LU Fang DIND Gang +3 位作者 LIU Wei ZHAN Dongmei WU Haiyi GUO We 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第3期933-941,共9页
Heavy metal pollution in aquatic system is becoming a serious problem worldwide. In this study, responses of Sargassum thunbergii to dif ferent concentrations(0, 0.1, 0.5, 1.0 and 5.0 mg/L) of zinc(Zn) and cadmium(Cd)... Heavy metal pollution in aquatic system is becoming a serious problem worldwide. In this study, responses of Sargassum thunbergii to dif ferent concentrations(0, 0.1, 0.5, 1.0 and 5.0 mg/L) of zinc(Zn) and cadmium(Cd) exposure separately were studied for 15 days in laboratory-controlled conditions. The results show that the specifi c growth rates increased slightly under the lower Zn concentration treatment(0.1 mg/L) at the first 5 d and then decreased gradually, which were significantly reduced with the exposure time in higher Zn concentrations and all Cd treatments compared to respective control, especially for 1.0 and 5.0 mg/L Cd. Chlorophyll a contents showed significant increase in 0.1 mg/L Zn treatment, whereas the gradually reduction were observed in the other three Zn treatments and all Cd treatments. The oxygen evolution rate and respiration rate presented distinct behavior in the Zn-treated samples, but both declined steadily with the exposure time in Cd treatments. The P/R value analyses showed similar variation patterns as chlorophyll a contents. Real-time PCR showed that lower Zn concentration(0.1 mg/L) increased mRNA expression of rbcL gene, whereas higher Zn concentrations and Cd reduced the rbcL expression. Taken together, these findings strongly indicate that Zn and Cd had different effects on S. thunbergii both at the physiological and gene transcription levels, the transcript level of photosynthesis-related gene rbcL can be used as an useful molecular marker of algal growth and environment impacts. 展开更多
关键词 Sargassum thunbergii heavy metal stress chlorophyll photosynthesis rate respiration rate rbcL GENE
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部