As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the...As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be variable.In addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the host.Here,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(B.erythrorhynchus)in northeastern Namibia.In contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples.With this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod species.Our findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an individual.We observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal host.We noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal hosts.This study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission.展开更多
Forest habitats are critical for biodiversity,ecosystem services,human livelihoods,and well-being.Capacity to conduct theoretical and applied forest ecology research addressing direct(e.g.,deforestation)and indirect(e...Forest habitats are critical for biodiversity,ecosystem services,human livelihoods,and well-being.Capacity to conduct theoretical and applied forest ecology research addressing direct(e.g.,deforestation)and indirect(e.g.,climate change)anthropogenic pressures has benefited considerably from new field-and statistical-techniques.We used machine learning and bibliometric structural topic modelling to identify 20 latent topics comprising four principal fields from a corpus of 16,952 forest ecology/forestry articles published in eight ecology and five forestry journals between 2010 and 2022.Articles published per year increased from 820 in 2010 to 2,354 in 2021,shifting toward more applied topics.Publications from China and some countries in North America and Europe dominated,with relatively fewer articles from some countries in West and Central Africa and West Asia,despite globally important forest resources.Most study sites were in some countries in North America,Central Asia,and South America,and Australia.Articles utilizing R statistical software predominated,increasing from 29.5%in 2010 to 71.4%in 2022.The most frequently used packages included lme4,vegan,nlme,MuMIn,ggplot2,car,MASS,mgcv,multcomp and raster.R was more often used in forest ecology than applied forestry articles.R software offers advantages in script and workflow-sharing compared to other statistical packages.Our findings demonstrate that the disciplines of forest ecology/forestry are expanding both in number and scope,aided by more sophisticated statistical tools,to tackle the challenges of redressing forest habitat loss and the socio-economic impacts of deforestation.展开更多
With the rapid development of urbanization,landscape architecture has become an indispensable component of daily life.In order to achieve better landscape effects and protect the ecological environment,landscape ecolo...With the rapid development of urbanization,landscape architecture has become an indispensable component of daily life.In order to achieve better landscape effects and protect the ecological environment,landscape ecology theory can be integrated into landscape planning to carry out disciplinary crossing and integration research between landscape ecology and landscape architecture.In this study,based on the basic theories of landscape ecology,the waterfront landscape of Dapo Town was designed,with the aim to achieve ecological balance in planning,showcase biodiversity,and create a harmonious landscape ecological environment which can benefit both nature and people.This design combined artificial and natural elements while improving the natural environment,which promoted a harmonious relationship between humans and nature,thus enriching the spatial organization of the city,and playing a role in regulating the urban environment and climate.展开更多
Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems...Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems resemble the self-organizing and the healing properties of natural ecosystems. Some key ecological concepts and mechanisms are introduced into the design for the third generation grid computing architectures by inspiration of this resemblance. Also, an Ecological Network-based Computing Environment (ENCE) platform is designed in this paper. Based on the ENCE platform, a grid-computing model of three-layered grid conceptual prototype that embeds the ENCE layers is presented from the viewpoint of implementation. The implementation model should be useful to the design of the third generation grid systems.展开更多
What is it?Ecology is the science of how humans,animals and plants live together.For example,in the city you can find birds,rats,insects and plants that all live in the same space.Many of them eat things that people ...What is it?Ecology is the science of how humans,animals and plants live together.For example,in the city you can find birds,rats,insects and plants that all live in the same space.Many of them eat things that people don’t want any more.If you go to a forest,you can see different kinds of plants,insects,small animals like rabbits and birds living there;they all eat different things in the forest,and some eat each other!展开更多
At present,the major problems facing the water resource environment worldwide include water pollution,water resource shortage,and water ecosystem degradation.The discharge of industrial wastewater,agricultural non-poi...At present,the major problems facing the water resource environment worldwide include water pollution,water resource shortage,and water ecosystem degradation.The discharge of industrial wastewater,agricultural non-point source pollution,and the discharge of urban sewage lead to a serious decline in water quality,which directly affects the safety of human drinking water and the living environment of aquatic organisms.Additionally,the unbalanced distribution and excessive exploitation of water resources lead to the problem of water shortage in many areas,which then leads to social and economic contradictions and ecological crises.In terms of ecosystems,the phenomena of water ecological degradation and reduction of biodiversity are increasingly obvious,and the carrying capacity of aquatic ecosystems are gradually declining.This paper aims to analyze the natural,social,and economic factors affecting the water resource environment,and propose effective strategies to protect the water ecology.To provide a theoretical basis and practical guidance for the sustainable utilization of water resources and the long-term development of the water ecosystem.展开更多
Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructur...Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructure and composition distribution of the composite interface were investigated.The results show that semi-solid layer with a certain thickness forms near the interface due to the effect of cooling plate,which ensures successful implementation of casting the composite ingot.Two different aluminum alloys are well bonded metallurgically.The mechanical properties of composite interface were measured,the tensile and shearing strengths of composite interface are 105 and 88 MPa,respectively,which proves that the composite interface is a kind of metallurgical bonding.展开更多
Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study e...Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study ecology from genes to the biosphere. Among this trend, N:P stoichiometry is used actively in ecological interactions since nitrogen (N) and phosphorus (P) are the two most important elements in most ecosystems. This article reviews the application of N:P stoichiometry to the studies of ecological problems at different levels, including ecosystem, community and species. Meanwhile, we also provide the cellular basis of N:P stoichiometry, identify the shortages in the use of N:P stoichiometry theory, and put forward some perspectives for future research to be conducted.展开更多
Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession ...Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.展开更多
The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has ...The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by"forest-vil age-terrace-river", including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.展开更多
The leaf epidermis of Japanese honeysuckle (Lonicera japonica Thunb.) and Wild Honeysuckle (Lonicera confusa) in the genus of Flos Lonicerae were mainly observed by scanning electron microscopes (SEM) to study t...The leaf epidermis of Japanese honeysuckle (Lonicera japonica Thunb.) and Wild Honeysuckle (Lonicera confusa) in the genus of Flos Lonicerae were mainly observed by scanning electron microscopes (SEM) to study the characteristics of stomata, trichomes and dermal cell, etc.. The results showed that stoma exists only on the lower epidermis and its distribution is irregular, and leaf epidermis consist of epidermis cells, stoma complexes and bushy trichomes including glandular hair and non-glandular hair. On the upper epidermis, anticlinal wall caves in sinuous groove to countercheck the transpiration. Evidences from leaf morphological structures serve as another proof on drought-resistant mechanisms. Some strumaes distributing regularly are hypothesized as oxalic calcium on the lower epidermis under laser scanning confocal microscopy (LSCM) with Fluo-3/AM, which can increase their endurance to drought stress. Therefore, the above characteristics of Flos Lonicerae can reduce the loss of water and make Japanese honeysuckle and Wild Honeysuckle adapt to the droughty environment at Karst area in southwest China. However, there is some difference of the two species. From the SEM (Scanning Electron Microscopy) result, it is shown that on the upper epidermis, some glandular hair regularly present along the midrib of Japanese honeysuckle, but Wild Honeysuckle has no glandular hair on the upper epidermis, which can verify the relationships of Flos Lonicerae species and provide the significance for classification of Flos Lonicerae.展开更多
As an improvement on the conventional two-layer electrode (active material layerlcurrent collector), a novel sandwich-like three-layer electrode (conductive layerlactive material layertcurrent collector) for catho...As an improvement on the conventional two-layer electrode (active material layerlcurrent collector), a novel sandwich-like three-layer electrode (conductive layerlactive material layertcurrent collector) for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3+/Fe2+ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.展开更多
[Objective] The aim was to improve and restore destroyed riverine and water ecosystem and to prevent bio-diversity from deteriorating in Jari demonstration plot in Ethiopia. [Method] Biological engineering and natural...[Objective] The aim was to improve and restore destroyed riverine and water ecosystem and to prevent bio-diversity from deteriorating in Jari demonstration plot in Ethiopia. [Method] Biological engineering and naturalization were made use of to protect nature and restore wetland as per Succession Theory. [Result] Both of eco- environment and eco-functions of Mille River were restored through reconstruction of biocenosis in wetlands. [Conclusion] It is feasible to implement matched ecological projects in semiarid regions in East Africa, providing references for restoration and protection of local water resources.展开更多
As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the ...As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.展开更多
Based on the overall understanding of new cities developing based on resources,by taking Yulin City of Shaanxi Province for example and combining with relevant statistical data,main problems existing in resources deve...Based on the overall understanding of new cities developing based on resources,by taking Yulin City of Shaanxi Province for example and combining with relevant statistical data,main problems existing in resources development have been pointed out,covering simple resources industrial structure and serious wastes in resources development;insufficient intensive processing of products and low level of resources integrated utilization;and deteriorative regional eco-environment.On this basis,a new mode of landscape ecology of resource-based cities have been proposed,emphasizing constructing new green energy industrial development mode from the perspective of microscopic view;ecological industrial park of circular economy from the perspective of mesoscopic view;and the overall ecological recovery mode of the mining area from the perspective of macroscopic view.It hopes to give a vital inspiration to the sustainable development of new resources-based cities.展开更多
China is increasingly attaching importance to coordination and scientific development between humanist and economic constructions, especially for protection on rural pastoral cultural landscape. For eco-village theory...China is increasingly attaching importance to coordination and scientific development between humanist and economic constructions, especially for protection on rural pastoral cultural landscape. For eco-village theory, planning and construction of pastoral culture landscape is just a breakthrough. The research used modern landscaping technology and analyzed pastoral landscape culture, facilitating transformation of agricultural production pattern and ushering in a new trend in terms of retaining rural cultural landscapes with Chinese characteristics and inheriting and innovating rural culture.展开更多
Manuel C.Molles Jr.所著的Ecology:Concepts and Applications(《生态学:概念与应用》)在教材与网络资源的建设方面进行了有益的尝试,其主教材及辅助教学资源的设计理念值得借鉴。主教材从1999年到2008年出版了4版,主教材内容及版本更...Manuel C.Molles Jr.所著的Ecology:Concepts and Applications(《生态学:概念与应用》)在教材与网络资源的建设方面进行了有益的尝试,其主教材及辅助教学资源的设计理念值得借鉴。主教材从1999年到2008年出版了4版,主教材内容及版本更新快,力求及时反映学科前沿水平的新技术、新知识;正文内容和版式编排设计以读者为本,注重为学生服务;网上辅助教学资源围绕主教材的系列产品进行整体设计,体现利教利学的建设理念,既为教师教学提供帮助和指导,也重视给予学生自我发挥的空间,网站展示条理清晰,内容布局规范,内容介绍注重以读者为中心,满足不同客户的需求。展开更多
The Black Stork (Ciconia nigra) is a new winter resident in Beijing due to temperature changes.To understand the wintering ecology of this species better, a field survey covering the number of birds of this population...The Black Stork (Ciconia nigra) is a new winter resident in Beijing due to temperature changes.To understand the wintering ecology of this species better, a field survey covering the number of birds of this population, habitat selection, feeding activity and grouping behavior was conducted at the Shidu Nature Reserve from January 2004 to March 2009. The results show that the Black Stork selected the Juma River at this nature reserve as their new winter habitat. The number of birds in this population decreased from 28 in the 2004/2005 winter to 17 in the 2007/2008 winter with a subsequent recovery to 23 the following year. The wintering flock was formed in mid-November and dispersed in mid-March, but the date changed with seasonal temperature fluctuations. The storks exhibited feeding habitat fidelity and the main food type was fish (> 92.4%). There was no significant variation in food composition between adults and sub-adults (Mann-Whitney U test, U = 1.00, p = 0.44). Feeding activity occurred in the morning and at noon during early winter, but concentrated in the afternoon during mid winter, divided into dawn and dusk in late winter. Daily fish intake was 538 g for adults and 449 g for sub-adults if the period of foraging reached six hours in the wild, which was similar to the level under artificial feeding. Agonistic behavior among feeding birds was observed among group members in late winter. The main negative factor for wintering Black Stork was a reduced feeding habitat resulting from increased water depth due to damming of the river to benefit tourism and to wetland exploitation.展开更多
基金partially supported by the Namibia Students Financial Assistance Fund(NSFAF)Kreditanstalt für Wiederaufbau(KfW)-University of Namibia(UNAM,BMZ Ref.2015.67.015)+2 种基金funded by the project TROPIBIO NORTE-01-0145-FEDER-000046supported by Norte Portugal Regional Operational Programme(NORTE2020)developed in the framework of the“Twin Lab CIBIO/UNAM”(UNESCO Chair Life on Land)。
文摘As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be variable.In addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the host.Here,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(B.erythrorhynchus)in northeastern Namibia.In contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples.With this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod species.Our findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an individual.We observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal host.We noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal hosts.This study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission.
基金financially supported by the National Natural Science Foundation of China(31971541).
文摘Forest habitats are critical for biodiversity,ecosystem services,human livelihoods,and well-being.Capacity to conduct theoretical and applied forest ecology research addressing direct(e.g.,deforestation)and indirect(e.g.,climate change)anthropogenic pressures has benefited considerably from new field-and statistical-techniques.We used machine learning and bibliometric structural topic modelling to identify 20 latent topics comprising four principal fields from a corpus of 16,952 forest ecology/forestry articles published in eight ecology and five forestry journals between 2010 and 2022.Articles published per year increased from 820 in 2010 to 2,354 in 2021,shifting toward more applied topics.Publications from China and some countries in North America and Europe dominated,with relatively fewer articles from some countries in West and Central Africa and West Asia,despite globally important forest resources.Most study sites were in some countries in North America,Central Asia,and South America,and Australia.Articles utilizing R statistical software predominated,increasing from 29.5%in 2010 to 71.4%in 2022.The most frequently used packages included lme4,vegan,nlme,MuMIn,ggplot2,car,MASS,mgcv,multcomp and raster.R was more often used in forest ecology than applied forestry articles.R software offers advantages in script and workflow-sharing compared to other statistical packages.Our findings demonstrate that the disciplines of forest ecology/forestry are expanding both in number and scope,aided by more sophisticated statistical tools,to tackle the challenges of redressing forest habitat loss and the socio-economic impacts of deforestation.
文摘With the rapid development of urbanization,landscape architecture has become an indispensable component of daily life.In order to achieve better landscape effects and protect the ecological environment,landscape ecology theory can be integrated into landscape planning to carry out disciplinary crossing and integration research between landscape ecology and landscape architecture.In this study,based on the basic theories of landscape ecology,the waterfront landscape of Dapo Town was designed,with the aim to achieve ecological balance in planning,showcase biodiversity,and create a harmonious landscape ecological environment which can benefit both nature and people.This design combined artificial and natural elements while improving the natural environment,which promoted a harmonious relationship between humans and nature,thus enriching the spatial organization of the city,and playing a role in regulating the urban environment and climate.
基金Supported in part by the National Nature Science Foundation of China (No. 60474037 and 60004006) and Specialized Research Fund for the Doctoral Program of Higher Education from Educational Committee of China (No. 20030255009)
文摘Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems resemble the self-organizing and the healing properties of natural ecosystems. Some key ecological concepts and mechanisms are introduced into the design for the third generation grid computing architectures by inspiration of this resemblance. Also, an Ecological Network-based Computing Environment (ENCE) platform is designed in this paper. Based on the ENCE platform, a grid-computing model of three-layered grid conceptual prototype that embeds the ENCE layers is presented from the viewpoint of implementation. The implementation model should be useful to the design of the third generation grid systems.
文摘What is it?Ecology is the science of how humans,animals and plants live together.For example,in the city you can find birds,rats,insects and plants that all live in the same space.Many of them eat things that people don’t want any more.If you go to a forest,you can see different kinds of plants,insects,small animals like rabbits and birds living there;they all eat different things in the forest,and some eat each other!
基金The Knowledge Innovation Program of Wuhan-Shuguang Project(Project No.2023020201020361).
文摘At present,the major problems facing the water resource environment worldwide include water pollution,water resource shortage,and water ecosystem degradation.The discharge of industrial wastewater,agricultural non-point source pollution,and the discharge of urban sewage lead to a serious decline in water quality,which directly affects the safety of human drinking water and the living environment of aquatic organisms.Additionally,the unbalanced distribution and excessive exploitation of water resources lead to the problem of water shortage in many areas,which then leads to social and economic contradictions and ecological crises.In terms of ecosystems,the phenomena of water ecological degradation and reduction of biodiversity are increasingly obvious,and the carrying capacity of aquatic ecosystems are gradually declining.This paper aims to analyze the natural,social,and economic factors affecting the water resource environment,and propose effective strategies to protect the water ecology.To provide a theoretical basis and practical guidance for the sustainable utilization of water resources and the long-term development of the water ecosystem.
基金Project (2005CB623707) supported by the National Basic Research Program of China
文摘Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructure and composition distribution of the composite interface were investigated.The results show that semi-solid layer with a certain thickness forms near the interface due to the effect of cooling plate,which ensures successful implementation of casting the composite ingot.Two different aluminum alloys are well bonded metallurgically.The mechanical properties of composite interface were measured,the tensile and shearing strengths of composite interface are 105 and 88 MPa,respectively,which proves that the composite interface is a kind of metallurgical bonding.
文摘Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study ecology from genes to the biosphere. Among this trend, N:P stoichiometry is used actively in ecological interactions since nitrogen (N) and phosphorus (P) are the two most important elements in most ecosystems. This article reviews the application of N:P stoichiometry to the studies of ecological problems at different levels, including ecosystem, community and species. Meanwhile, we also provide the cellular basis of N:P stoichiometry, identify the shortages in the use of N:P stoichiometry theory, and put forward some perspectives for future research to be conducted.
基金TheNationalNaturalScienceFoundationofChina (No .39670 1 36) PhDFund (No .980 5580 8)ofMinistryofEducationP .R .China Center
文摘Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.
基金Supported by Project of Ministry of Human Resources and Social Security~~
文摘The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by"forest-vil age-terrace-river", including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.
基金This study was supported by the Ministry of Sciences and Technology of China (No.2005DIB3J067)the National Science Foundation of China (No.40572107, No.40231008, No.40672165 and No.30600074)+2 种基金the Chongqing Science & Technology Commission (No.2005AB7006)the Open Fund and Key Subject of Physical Geog-raphy, Southwest Normal University of China (No.250-411110)the Open Fund of Key Laboratory of Chinese Academy of Geological Sci-ences (No.KL05-20).
文摘The leaf epidermis of Japanese honeysuckle (Lonicera japonica Thunb.) and Wild Honeysuckle (Lonicera confusa) in the genus of Flos Lonicerae were mainly observed by scanning electron microscopes (SEM) to study the characteristics of stomata, trichomes and dermal cell, etc.. The results showed that stoma exists only on the lower epidermis and its distribution is irregular, and leaf epidermis consist of epidermis cells, stoma complexes and bushy trichomes including glandular hair and non-glandular hair. On the upper epidermis, anticlinal wall caves in sinuous groove to countercheck the transpiration. Evidences from leaf morphological structures serve as another proof on drought-resistant mechanisms. Some strumaes distributing regularly are hypothesized as oxalic calcium on the lower epidermis under laser scanning confocal microscopy (LSCM) with Fluo-3/AM, which can increase their endurance to drought stress. Therefore, the above characteristics of Flos Lonicerae can reduce the loss of water and make Japanese honeysuckle and Wild Honeysuckle adapt to the droughty environment at Karst area in southwest China. However, there is some difference of the two species. From the SEM (Scanning Electron Microscopy) result, it is shown that on the upper epidermis, some glandular hair regularly present along the midrib of Japanese honeysuckle, but Wild Honeysuckle has no glandular hair on the upper epidermis, which can verify the relationships of Flos Lonicerae species and provide the significance for classification of Flos Lonicerae.
基金Project(2010ZCO51)supported by Natural Science Foundation of Yunnan ProvinceProject supported by Analysis and Testing Foundation(2009-041)Starting Research Fund(14118245)from Kunming University of Science and Technology
文摘As an improvement on the conventional two-layer electrode (active material layerlcurrent collector), a novel sandwich-like three-layer electrode (conductive layerlactive material layertcurrent collector) for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3+/Fe2+ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.
基金Supported by South-South Cooperation Project of SSC/SPFS-FAO-Ethiopia-China~~
文摘[Objective] The aim was to improve and restore destroyed riverine and water ecosystem and to prevent bio-diversity from deteriorating in Jari demonstration plot in Ethiopia. [Method] Biological engineering and naturalization were made use of to protect nature and restore wetland as per Succession Theory. [Result] Both of eco- environment and eco-functions of Mille River were restored through reconstruction of biocenosis in wetlands. [Conclusion] It is feasible to implement matched ecological projects in semiarid regions in East Africa, providing references for restoration and protection of local water resources.
基金This study was supported by the National Natural Science Foundation of China (NSFC39970123 30170744)+1 种基金 Chinese Academy of Sciences (A grant KZCX2-406) and Changbai Mountain Open Research Station.
文摘As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.
文摘Based on the overall understanding of new cities developing based on resources,by taking Yulin City of Shaanxi Province for example and combining with relevant statistical data,main problems existing in resources development have been pointed out,covering simple resources industrial structure and serious wastes in resources development;insufficient intensive processing of products and low level of resources integrated utilization;and deteriorative regional eco-environment.On this basis,a new mode of landscape ecology of resource-based cities have been proposed,emphasizing constructing new green energy industrial development mode from the perspective of microscopic view;ecological industrial park of circular economy from the perspective of mesoscopic view;and the overall ecological recovery mode of the mining area from the perspective of macroscopic view.It hopes to give a vital inspiration to the sustainable development of new resources-based cities.
文摘China is increasingly attaching importance to coordination and scientific development between humanist and economic constructions, especially for protection on rural pastoral cultural landscape. For eco-village theory, planning and construction of pastoral culture landscape is just a breakthrough. The research used modern landscaping technology and analyzed pastoral landscape culture, facilitating transformation of agricultural production pattern and ushering in a new trend in terms of retaining rural cultural landscapes with Chinese characteristics and inheriting and innovating rural culture.
文摘Manuel C.Molles Jr.所著的Ecology:Concepts and Applications(《生态学:概念与应用》)在教材与网络资源的建设方面进行了有益的尝试,其主教材及辅助教学资源的设计理念值得借鉴。主教材从1999年到2008年出版了4版,主教材内容及版本更新快,力求及时反映学科前沿水平的新技术、新知识;正文内容和版式编排设计以读者为本,注重为学生服务;网上辅助教学资源围绕主教材的系列产品进行整体设计,体现利教利学的建设理念,既为教师教学提供帮助和指导,也重视给予学生自我发挥的空间,网站展示条理清晰,内容布局规范,内容介绍注重以读者为中心,满足不同客户的需求。
基金funded by the Beijing Wildlife Rescue and Rehabilitation Center
文摘The Black Stork (Ciconia nigra) is a new winter resident in Beijing due to temperature changes.To understand the wintering ecology of this species better, a field survey covering the number of birds of this population, habitat selection, feeding activity and grouping behavior was conducted at the Shidu Nature Reserve from January 2004 to March 2009. The results show that the Black Stork selected the Juma River at this nature reserve as their new winter habitat. The number of birds in this population decreased from 28 in the 2004/2005 winter to 17 in the 2007/2008 winter with a subsequent recovery to 23 the following year. The wintering flock was formed in mid-November and dispersed in mid-March, but the date changed with seasonal temperature fluctuations. The storks exhibited feeding habitat fidelity and the main food type was fish (> 92.4%). There was no significant variation in food composition between adults and sub-adults (Mann-Whitney U test, U = 1.00, p = 0.44). Feeding activity occurred in the morning and at noon during early winter, but concentrated in the afternoon during mid winter, divided into dawn and dusk in late winter. Daily fish intake was 538 g for adults and 449 g for sub-adults if the period of foraging reached six hours in the wild, which was similar to the level under artificial feeding. Agonistic behavior among feeding birds was observed among group members in late winter. The main negative factor for wintering Black Stork was a reduced feeding habitat resulting from increased water depth due to damming of the river to benefit tourism and to wetland exploitation.