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Selection of Tree and Shrub Species for Ecological Recovery in Jari Demonstration Plot in Ethiopia
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作者 汪洋 《Journal of Landscape Research》 2010年第7期11-14,共4页
Environmental degradation and deforestation in Jari Demonstration Plot needed forestation and reforestation,and the plant species selection was a key issue in the ecological recovery.Ecological information was fully c... Environmental degradation and deforestation in Jari Demonstration Plot needed forestation and reforestation,and the plant species selection was a key issue in the ecological recovery.Ecological information was fully considered regarding each species in various agro-climatic zones,altitude ranges,specific niches in different landscapes,soil preference,drought resistance and certain other important ecological factors.The species selection model represents an idea of ecological recovery and soil erosion control in the demonstration plot. 展开更多
关键词 Jari DEMONSTRATION PLOT species selection indigenous species EXOTIC species ECOLOGICAL recovery
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Selection of Indigenous Plants in Roads in Northwestern Loess Plateau Area
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作者 张铁军 王春玲 《Agricultural Science & Technology》 CAS 2012年第3期583-591,共9页
[Objective] The aim was to study on resource utilization of indigenous plants in roads in order to solve resource shortage of indigenous plant in bioengi- neering. [Method] Based on northwestern loess plateau area, we... [Objective] The aim was to study on resource utilization of indigenous plants in roads in order to solve resource shortage of indigenous plant in bioengi- neering. [Method] Based on northwestern loess plateau area, we conducted research on selection of indigenous plants and survey on the species which could live in adverse condition, mainly by surveying, with frequent tests as a supplement, to make a comprehensive observation and evaluation on plant combinations which are to be extensively applied. [Result] The research indicated that in central dividing strips, four arbors, including Platycladus orientalis (Linn.)Franco, Sabina chinensis, Sabinachinen- sis(Linn.)Ant., and Ulmus purnila L., and nine frutices, including Lycium chinense, Tamarix austromongolica, Rosa xanthina Lindl., Forsythia suspense, Atriplex canescens, Amygdalus triloba, Hippophae rharnnoides Linn., Arnorpha fruticosa L., and Syzygium aromaticum could be planted. In addition, Gleditsia sinensis Lain, Robinia pseudoacacia L, Elaeagnus angustifolia L., Rhus typhina, Salix babylonica, Salixmatsudana and Fraxinus chinensis, tall and strong, are suitable to be planted as border trees, presenting a good vision. Frutices, limited by height, are usually with more branches, which will provide a good landscape if grown with tall plants. Prunus dacidiana and Ulmus pumila L., prone to be damaged by insects, should be planted with other species to stop the infestation in space. [Conclusion] The research laid foundation for selection of indigenous plants in roads, providing references for resource shortage of indigenous plant for bioengineedng. 展开更多
关键词 Loess Plateau area ROAD indigenous plant selection Plant combination
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Environmental Correlates of Distribution of the 25 Broad-leaved Tree Species Indigenous to Guangdong Province,China 被引量:16
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作者 SuZhiyao ChenBeiguang ChangYong YangJiazhi 《Forestry Studies in China》 CAS 2004年第4期23-28,共6页
Twenty-five tree species indigenous to Guangdong Province were chosen in this study to portray their distribution patterns in relation to environmental factors. Both data of species distribution and environmental fact... Twenty-five tree species indigenous to Guangdong Province were chosen in this study to portray their distribution patterns in relation to environmental factors. Both data of species distribution and environmental factors were tabulated based on a digitized map of Guangdong Province gridded at 0.5° latitude × 0.5° longitude. Grid-based diversity was mapped using DMAP, a distribution mapping program, and horizontal patterns were assessed using Kruskal-Wallis tests. The diversity center of the indige- nous tree species under study is located north of 23° N. These tree species exhibit significant latitudinal variation (P = 0.007 4), but no significant longitudinal difference (P = 0.052 2). Non-metric Multidimensional Scaling (NMS) identified five different ecological species groups, while Canonical Correspondence Analysis (CCA) showed the distribution of tree species along each of the five envi- ronmental gradients. An understanding of the environmental correlates of distribution patterns has great implication for the introduc- tion of the indigenous tree species for afforestation. 展开更多
关键词 indigenous tree species environmental correlate distribution horizontal pattern NMS CCA Guangdong Prov- ince
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Mechanisms of species divergence through visual adaptation and sexual selection:Perspectives from a cichlid model system 被引量:3
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作者 Martine E.MAAN Ole SEEHAUSEN 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第3期285-299,共15页
The theory of ecological speciation suggests that assortative mating evolves most easily when mating preferences aredirectly linked to ecological traits that are subject to divergent selection. Sensory adaptation can ... The theory of ecological speciation suggests that assortative mating evolves most easily when mating preferences aredirectly linked to ecological traits that are subject to divergent selection. Sensory adaptation can play a major role in this process,because selective mating is often mediated by sexual signals: bright colours, complex song, pheromone blends and so on. Whendivergent sensory adaptation affects the perception of such signals, mating patterns may change as an immediate consequence.Alternatively, mating preferences can diverge as a result of indirect effects: assortative mating may be promoted by selectionagainst intermediate phenotypes that are maladapted to their (sensory) environment. For Lake Victoria cichlids, the visual environmentconstitutes an important selective force that is heterogeneous across geographical and water depth gradients. We investigatethe direct and indirect effects of this heterogeneity on the evolution of female preferences for alternative male nuptial colours(red and blue) in the genus Pundamilia. Here, we review the current evidence for divergent sensory drive in this system, extractgeneral principles, and discuss future perspectives [Current Zoology 56 (3): 285-299, 2010]. 展开更多
关键词 CICHLID Sexual selection species divergence Visual adaptation
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Effects of selection cutting on the forest structure and species diversity of evergreen broad-leaved forest in northern Fujian, southern China 被引量:2
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作者 Qiu Ren-hui Chen Han Zhuo Li-xin 《Forestry Studies in China》 CAS 2006年第1期16-20,共5页
The short-term effects of selection curing of different intensities on the forest structure and species diversity of evergreen broad-leaved forest in northern Fujian Province were investigated and analyzed. The result... The short-term effects of selection curing of different intensities on the forest structure and species diversity of evergreen broad-leaved forest in northern Fujian Province were investigated and analyzed. The results showed that selection curing of low and medium intensities caused little variation in the forest structure. After curing, the dominant species retained their leading status in the community. However, the community structure changed significantly following selection curing of high and extra-high intensities; the status of the dominant species of the community declined dramatically. Some tree species began to disappear from the sampling plots. Except for extra-high intensity curing, the diversity of tree species did not change significantly for the other three curing intensities. However, the evenness of the stands was very different among the four kinds of curing plots. For low and medium intensity selection cutting, the evenness declined slightly. For extra-high intensity selection curing, the evenness increased to some extent, which might be due to a more even distribution of tree species after curing. CuRing operations resulted in some adverse reactions to development of arborous species diversity of evergreen broad-leaved forest, particularly serious damage to the forest canopy. But the rational selection cuttings, which may benefit the restoration and maintenance of species diversity over a long period and may come about from the variations in environmental factors such as sunlight, temperature and humidity. 展开更多
关键词 selection cutting forest structure cutting intensities importance value species diversity
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Selection and evaluation of suitable tree species in dry and dusty mining areas of Northwest China 被引量:1
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作者 Xiaofang Zhu Bing Cao +4 位作者 Siming Zhao Xing Wang Hao Zhang Deping Gao Yongfeng Duan 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第6期1817-1828,共12页
To select drought-resistant and dust-tolerant native species suitable for use in the rehabilitation of major coal bases in northwest China,nine tree species were identified for growth rates,biomass,harm index,and phys... To select drought-resistant and dust-tolerant native species suitable for use in the rehabilitation of major coal bases in northwest China,nine tree species were identified for growth rates,biomass,harm index,and physiological indices under drought and high dust stress conditions.The results showed that,in the dust resistance index system,the order was Caragana korshinskii>Amorpha fruticosa>Sabina vulgaris>Hedysarum scoparium>Tamarix chinensis>Ammopiptanthus mongolicus>Ulmus pumila>C aryopteris mongholica>Elaeagnus angustifolia.In a comprehensive drought and dust resistance index system,14 indices(such as shoot length,stomatal conductance,and peroxidase)had the larger weight indices.The drought and dust resistance order of the tree species was C aragana korshinskii>Ulmus pumila>Amorpha fruticosa>Sabina vulgaris>Caryopteris mongholica>Ammopiptanthus mongolicus>H edysarum scoparium>Tamarix chinensis>Elaeagnus angustifolia.This study provides effective strategies and references for selecting suitable tree species for arid mining sites in China,and also for the revegetation of coal mining sites worldwide. 展开更多
关键词 Coal mining species selection Drought resistance Dust resistance Evaluation index system
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Selection of tree species by principal component analysis for abandoned farmland in southeastern Horqin Sandy Land,China 被引量:1
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作者 Peng Meng Jing Liu Xuefeng Bai 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第2期475-486,共12页
With changes in global climate and land use,the area of desertified farmland in southeastern Horqin Sandy Land(HSL)has increased in recent years,and farmlands are being abandoned.These abandoned farmlands(AFs)nega-tiv... With changes in global climate and land use,the area of desertified farmland in southeastern Horqin Sandy Land(HSL)has increased in recent years,and farmlands are being abandoned.These abandoned farmlands(AFs)nega-tively impact the local ecology.Therefore,the aim of the present study was to select suitable trees and shrubs for those AFs to prevent and control the desertification tendency.In this study,three AFs were fenced for 2 years,then 37 arbor and shrub species or varieties of 21 families were planted in the fenced AFs and grown for 10 years.The ecological adaptability of the species was evaluated and ranked using a principal component analysis.The results showed that the biodiversity of the AFs significantly improved after 2 years of fencing;the Shannon-Wiener index and species rich-ness of perennial grasses and forbs were 1.45 and 3.6 times higher,respectively,than for the unfenced AF.Among all species planted in fenced AFs,nine tree species had posi-tive comprehensive F(CF)values;Pinus sylvestris(Russian Shira steppe provenance),Populus alba‘Berolinensis’and Gleditsia triacanthos had CF greater than 1,and the first(PC1),second(PC2)and third(PC3)principal component values(F_(1),F_(2),F_(3))were all positive.Among the shrubs,only Lespedeza bicolor and Rosa xanthina f.normalis had CF greater than 0.All these results suggest that fencing improves biodiversity and that planting trees and shrubs that have higher CF values on the basis of fencing is an effective way to green and beautify AFs in HSL. 展开更多
关键词 Horqin Sandy Land Fenced abandoned farmland Principal component analysis Tree species selection
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Optimal Selection of Raw Material Forest Species for Edible Fungi in Guizhou Province 被引量:1
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作者 Xingui Li Lifen Peng 《Agricultural Biotechnology》 CAS 2018年第2期101-104,108,共5页
A comprehensive evaluation system,which focused on optimal selection of raw material forest species for edible fungi,was established by combination of Analytic Hierarchy Process(AHP)and Experts Grading Method(EGM).The... A comprehensive evaluation system,which focused on optimal selection of raw material forest species for edible fungi,was established by combination of Analytic Hierarchy Process(AHP)and Experts Grading Method(EGM).The evaluation system had 4 indices of grade I and 12 indices of grade II.Among the 12 indices of grade II,the weighted values of production quality of edible fungi P2(0.2874),usable time P7(0.1873),annual average increment P8(0.1873),edible fungi production suitability P1(0.0958)were larger than the values of others.Based on the comprehensive evaluation system,this study analyzed and screened 47 broadleaf species of 40 genera of 25 families.There were 16 broadleaf species having the comprehensive evaluation scores of equal to or greater than2.4000,which were available as major tree species for edible fungi development of Guizhou Province,especially species such as Liriodendron chinense,Quercus acutissima,Alnus cremastogyne,Betula luminfera,Elaeocarpus duclouxii,Elaeocarpus sylvestris,Choerospondias axillaris.The 10 broadleaf tree species with comprehensive evaluation score of 2.1000≤Y 2.4000 were recommended as candidates for edible fungi production,while the 21 broadleaf species with the comprehensive evaluation score of less than 2.1000 were not recommended. 展开更多
关键词 Edible fungi Raw material forest Excellent tree species Tree species selection Guizhou ProvinceHome
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Tree species diversity, richness, and similarity between exotic and indigenous forests in the cloud forests of Eastern Arc Mountains, Taita Hills, Kenya
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作者 Loice M.A.Omoro Petri K.E.Pellikka Paul C.Rogers 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第3期255-264,395,共11页
Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptu... Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were: Ngangao (120 ha), Chawia (86 ha), and Mbololo (185 ha). A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height (DBH) were enumerated and recorded by species. Tree regeneration (seedlings and saplings) was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey's HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land (in Ngango), or the inherent physiology (allelopathy) of some of species repelling the regeneration of others. 展开更多
关键词 BIODIVERSITY forest fragments Eastern Arc Mountains DISTURBANCE EXOTICS indigenous species
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Evaluation and Selection of Introduced Tree Species in the Beijing-Tianjin Corridor
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作者 YUAN Wenge ZHENG Jianwei +2 位作者 GU Jiancai LU Guiqiao GAO Qiuhua 《Journal of Landscape Research》 2018年第5期114-118,共5页
Based on the extensive analysis of natural and social conditions,regional development,and characteristics of tree species in the Beijing-Tianjin corridor,a comprehensive evaluation index system that consists of A,B,C,... Based on the extensive analysis of natural and social conditions,regional development,and characteristics of tree species in the Beijing-Tianjin corridor,a comprehensive evaluation index system that consists of A,B,C,D layers was established for introduced tree species.Nine local representative introduced tree species were evaluated using the analytic hierarchy process(AHP).The results showed that Platanus orientalis,Quercus mongolicus,and Zizyphusjujube performed better comprehensively and were recommended as the dominant introduced tree species in the Beijing-Tianjin corridor.Other representative introduced tree species should be appropriately developed in the region.Main factors that should be taken into account for introduced tree species including drought tolerance,wintering habit,growth rate,leanness tolerance,pollution tolerance,saline tolerance,and disease resistance. 展开更多
关键词 Evaluation selection System INTRODUCED TREE species BEIJING-TIANJIN CORRIDOR MAIN factors
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Dynamic change of arborous species diversity in natural secondary forests after selective cutting on the north slope of Changbai Mountain, Northeast China
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作者 金永焕 周莉 +3 位作者 谷会岩 代力民 申光日 刘军 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第4期299-302,共4页
The community characteristics of natural secondary forests on the north slope of Changbai Mountain after selective cutting were investigated, and the dynamics of arborous species diversity during the restoration perio... The community characteristics of natural secondary forests on the north slope of Changbai Mountain after selective cutting were investigated, and the dynamics of arborous species diversity during the restoration period of 28 years were studied. The results showed that the arborous species richness (S) had little change and kept the range of 18-22 all along, the Simpson index (D) of the secondary layer and regeneration layer and whole stand had similar trends of change, but that of the canopy layer descended slowly in initial 15 years and had little change later, and the change of diversity index was not obvious and the Shannon-Wiener index (H? fluctuated in a very small scopes (H±10%). 展开更多
关键词 Arborous species diversity Natural secondary forests selective cutting Northeast China
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Small-sized cuprous oxide species on silica boost acrolein formation via selective oxidation of propylene 被引量:2
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作者 Ling-Ling Guo Jing Yu +6 位作者 Wei-Wei Wang Jia-Xu Liu Hong-Chen Guo Chao Ma Chun-Jiang Jia Jun-Xiang Chen Rui Si 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第2期320-333,共14页
Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for the... Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for these systems remains a scientific challenge.In this work,copper oxide clusters deposited on a high-surface-area silica support were synthesized via a deposition-precipitation approach and exhibited remarkable catalytic reactivity(up to 25.5%conversion and 66.8%selectivity)in the propylene-selective oxidation of acrolein at 300℃.Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy combined with X-ray absorption fine structure measurements of the catalyst before and after the reaction confirmed the transformation of the small-sized copper oxide(CuO)clusters into cuprous oxide(Cu2O)clusters.With the aid of in situ X-ray diffraction and in situ dual beam Fourier transform infrared spectroscopy(DB-FTIR),the allyl intermediate(CH2=CHCH2*)was clearly observed,along with the as-formed Cu2O species.The intermediate can react with oxygen atoms from neighboring Cu2O species to form acrolein during the catalytic process,and the small-sized Cu2O clusters play a crucial role in the generation of acrolein via the selective oxidation of propylene. 展开更多
关键词 Propylene selective oxidation Cuprous oxide cluster Acrolein formation Active species In situ characterization
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Impact of Planted Mangrove Species on Biomass Carbon and Other Structural Attributes in Ayeyarwady Region
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作者 Aung Wunna Tun Wai Nyein Aye 《Open Journal of Forestry》 2024年第1期98-116,共19页
This study examines the impact of different mangrove species on the structure and carbon storage potential of mangrove stands in Myanmar. We focused on three species: Avicennia officinalis, Avicennia marina and Brugui... This study examines the impact of different mangrove species on the structure and carbon storage potential of mangrove stands in Myanmar. We focused on three species: Avicennia officinalis, Avicennia marina and Bruguiera sexangula. These species were selected for their fast growth, ability to protect against cyclones, and effectiveness in coastal defense during mangrove restoration. To collect data on tree structure and carbon storage, we conducted field surveys measuring parameters such as diameter at breast height (DBH), tree height and crown diameter for each tree. Non-destructive methods were used for data collection. Using ANOVA and post-hoc multiple comparison tests, we assessed differences in structure and carbon stock among the three species. Regression analysis was also performed to understand the relationship between carbon stock and structural attributes. In terms of stand densities, we observed variations among species, with pioneer stage plantations exhibiting higher densities compared to mature stands. Seedlings showed sufficient regeneration, supporting the sustainability of the forest. Biomass accumulation varied across species, with A. officinalis having the highest average biomass. Aboveground biomass showed a strong correlation with basal area. A. officinalis had the highest total biomass carbon accumulation at 55.29 ± 20.91 Mg C ha<sup>-1</sup>, with 77.43% aboveground carbon and 22.57% belowground carbon. A. marina stored 41.09 ± 11.03 Mg C ha<sup>-1</sup>, with a similar distribution of 76.05% aboveground and 23.95% belowground carbon, while B. sexangula stored 23.23 ± 3.12 Mg C ha<sup>-1</sup>, with 70.70% aboveground carbon and 29.30% belowground carbon. The amount of aboveground carbon was a significant portion of the overall carbon storage and correlated with tree density, diameter, basal area and height. Our findings highlight the importance of selecting suitable species and considering structural attributes for mangrove restoration and carbon storage efforts. These results provide valuable insights for managing mangrove plantations at regional and global levels. On average, the reported carbon sequestration was 154.40 MgCO<sub>2</sub>-eq ha<sup>-1</sup>. 展开更多
关键词 species selection BIOMASS Carbon Storage Ayeyarwady Region Myanmar
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In-situ Infrared Study on Surface Species in Selective Catalytic Reduction of NO with Hydrocarbon over Copper ZSM-5 Zeolite
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作者 ZHANG Wen xiang JIA Ming jun +4 位作者 WU Tong hao YAHIRO Hidenori IW AMOTO Masakazu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1997年第2期87-89,共3页
In┐situInfraredStudyonSurfaceSpeciesinSelectiveCatalyticReductionofNOwithHydrocarbonoverCopperZSM┐5ZeoliteZH... In┐situInfraredStudyonSurfaceSpeciesinSelectiveCatalyticReductionofNOwithHydrocarbonoverCopperZSM┐5ZeoliteZHANGWen-xiang*,JIA... 展开更多
关键词 Surface species selective catalytic reduction of NO Cu ZSM 5
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Selecting flagship species to solve a biodiversity conservation conundrum
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作者 Jie Qian Huifu Zhuang +6 位作者 Weikang Yang Yifeng Chen Shilong Chen Yanhua Qu Yuanming Zhang Yongping Yang Yuhua Wang 《Plant Diversity》 SCIE CAS CSCD 2020年第6期488-491,共4页
The difficulty of effectively monitoring and managing the environment to conserve biodiversity is as yet an unsolved conundrum.A project of the Chinese Academy of Sciences has concluded that progress can be made throu... The difficulty of effectively monitoring and managing the environment to conserve biodiversity is as yet an unsolved conundrum.A project of the Chinese Academy of Sciences has concluded that progress can be made through the use of flagship species selected using criteria drawn from conservation biology,ecosystem function,socio-economics,and cultural importance.Inclusion of the latter three criteria will help attract and maintain the commitment of the public to play full parts in carrying out any conservation measures needed.A system is proposed for scoring species to select those that are most suitable as flagships.This method can be used regardless of the size of the area chosen for attention,whether it is a region,a country,or a particular protected area. 展开更多
关键词 Flagship species selection criteria Biodiversity conservation Proposed program
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Landscape Plants Selection and Design in the Peony Garden of Xibaipo
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作者 肇丹丹 马晓晶 +2 位作者 秦强 秦安臣 贾哲 《Journal of Landscape Research》 2009年第11期54-58,共5页
Peony is a traditional famous flower in China.With the peony garden of Xibaipo as an example,the landscaping planning of functional divisions,the selection and design of landscaping plants for the peony garden are int... Peony is a traditional famous flower in China.With the peony garden of Xibaipo as an example,the landscaping planning of functional divisions,the selection and design of landscaping plants for the peony garden are introduced in this study,then the landscaping plants selection and design principles are summarized. 展开更多
关键词 LANDSCAPING PLANTS species selection and DESIGN PEONY GARDEN of Xibaipo
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Selection of Adaptive Grass and Frutex and Their Planting Benefits in the Arid-Hot Valleys of Yuanmou 被引量:13
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作者 LONG Huiying SHA Yucang +3 位作者 ZHU Hongye ZHANG Yingcui JIN Jie SHI Liangtao 《Wuhan University Journal of Natural Sciences》 CAS 2008年第3期317-323,共7页
In view of the environment character of the soil and content of the soil organic carbon, 278 species of grass and frutex were introduced from abroad and China, Some were selected by applied production and plantation b... In view of the environment character of the soil and content of the soil organic carbon, 278 species of grass and frutex were introduced from abroad and China, Some were selected by applied production and plantation benefit investigations. The results showed that: In the arid-hot valleys of Yuanmou the selected species showed the characteristics of fast growth and high yield (38 227.00 kg/hm2), high nutrition value (CP% content of legu- minous grass and frutex were 22.47%), as well as the strong ad- versity resistance to high air temperature and arid climate (soil humidity was 3.4%). The selected species not only effectively meliorated soil and increased fertility, but also improved small environment weather. 展开更多
关键词 arid-hot valleys grass and frutex species selection plantation benefit
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Assessment of natural regeneration status and diversity of tree species in the biodiversity conservation areas of Northeastern Bangladesh 被引量:2
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作者 Md. Habibur Rahman Md. Abu Sayed Arfin Khan +1 位作者 Bishwajit Roy Most. Jannatul Fardusi 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第4期551-559,共9页
A study was conducted at two-biodivcrsity conservation areas of Northeastern Bangladesh (a part of Sylhet Forest Division) to assess the species composition, diversity and density of natural regeneration of tree spe... A study was conducted at two-biodivcrsity conservation areas of Northeastern Bangladesh (a part of Sylhet Forest Division) to assess the species composition, diversity and density of natural regeneration of tree species both indigenous and exotic species. Data were collected by stratified random quadrate method during January 2010 to July 2010. Totally 200 circular plots of 2 m〉〈2 m in size had 5 different habitat types of plants namely; forest, roadside, homestead (surrounding forest dwellers house), fallow land and others (canals, streams and tea gardens side), which included a total of 55 regenerating species belonging to 28 families. Meliaceae is the dominant family and shows the highest family importance value (26.3), having six species, followed by Moraeeae (24.24). Among the five habitat types, forest (43 species) possess the highes number of species, followed by roadside (23 species). Total 15 exotic species among 9 families and 40 indigenous species with 24 families were recorded. For exotic species, Tectona grandis possess the highest relative density (11.7%) and relative frequency (10.5%); Senna siamea had highest relative abundance (7.83%). In case of indigenous species, Chickrassia tabularis possess the highest relative density (4.23%) and relative frequency (4%); Dipterocarpus turbinatus bad the highest relative abundance (3.92%). Tectona grandis (29.66) and Chickrassia tabularis (10.8) had the highest IVI for exotic and indigenous species respectively. Different diversity indic'es such as Shanon-Winner diversity index,' species diversity index, species richness index, species evenness index, Simpson index and species dominance index, etc. were applied to quantify definite diversity. The regeneration of species associated with low levelsof disturbance was in the exotic Species. Study suggests that proper protection from human disturbances and scientific management of natural regeneration of two-study forests may lead a rich biodiversity site in the country. 展开更多
关键词 BIODIVERSITY exotic species family importance value indigenous species quantitative characters
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Changes of community characteristics of a broad-leaved-conifer mixed forest after selection cutting 被引量:1
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作者 刘琪景 代力民 陈华 《Journal of Forestry Research》 SCIE CAS CSCD 1998年第3期152-159,共8页
The modification in structure, composition, and diversity, shrub, as well as herb strata ofPinus koraiensis-Tilia amurensis-Abies nephrolepis forest after 16a of selection cutting in northeastern China was studied. In... The modification in structure, composition, and diversity, shrub, as well as herb strata ofPinus koraiensis-Tilia amurensis-Abies nephrolepis forest after 16a of selection cutting in northeastern China was studied. In the selection cutting forest, individuals with small DBH classes characterized size distribution. The virgin forest, on the other hand, was mainly composed of individuals having larger DBH classes. The density of dominant species and the species diversity at tree stratum in the selection-cutting stand was significantly larger than that of in the primeval forest. The shrub layer also showed a similar result. However, the herb layer had comparatively low species diversity. Large growing space and strong light in the artificial gaps must have provided opportunities for the species of shade tolerance or shade intolerance to establish on the stand. The juveniles of non-pioneer species, which were hardly found in highly shaded virgin forest, were also released by the disturbance. Regeneration in the selection-cutting stand was prompted by the disturbance, where the density of saplings occurred nearly 3 times as much as that in the virgin stand. The growth of shrub layer was improved due to the alteration in light condition. The projection volume of the herb layer was less affected. Restoration of a semi-virgin forest to the original status after selection cutting could be possible in several decades. However, for those subjected to clear cutting, it might take several centuries. In order to promote biodiversity, it is reasonable to practice selection cutting in communities for consisting of species with various levels of shade tolerance. 展开更多
关键词 Changbai Mountain selection cutting REGENERATION species composition
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Redistributing Cu species in Cu-SSZ-13 zeolite as NH3-SCR catalyst via a simple ion-exchange 被引量:2
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作者 Ben Liu Nangui Lv +5 位作者 Chan Wang Hongwei Zhang Yuanyuan Yue Jingdong Xu Xiaotao Bi Xiaojun Bao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第1期329-341,共13页
The nature and distribution of Cu species in Cu-SSZ-13 play a vital role in selective catalytic reduction of NO by NH3(NH3-SCR),but existing methods for adjusting the Cu distribution are complex and difficult to contr... The nature and distribution of Cu species in Cu-SSZ-13 play a vital role in selective catalytic reduction of NO by NH3(NH3-SCR),but existing methods for adjusting the Cu distribution are complex and difficult to control.Herein,we report a simple and effective ion-exchange approach to regulate the Cu distribution in the one-pot synthesized Cu-SSZ-13 that possesses sufficient initial Cu species and thus provides a“natural environment”for adjusting Cu distribution precisely.By using this proposed strategy,a series of Cu-SSZ-13x zeolites with different Cu contents and distributions were obtained.It is shown that the dealumination of the as-synthesized Cu-SSZ-13 during the ion-exchange generates abundant vacant sites in the double six-membered-rings of the SSZ-13 zeolite for relocating Cu2+species and thus allows the redistribution of the Cu species.The catalytic results showed that the ion-exchanged Cu-SSZ-13 zeolites exhibit quite different catalytic performance in NH3-SCR reaction but superior to the parent counterpart.The structure–activity relationship analysis indicates that the redistribution of Cu species rather than other factors(e.g.,crystallinity,chemical composition,and porous structure)is responsible for the improved NH3-SCR performance and SO_(2) and H_(2)O resistance.Our work offers an effective method to precisely adjust the Cu distribution in preparing the industrial SCR catalysts. 展开更多
关键词 CATALYST ZEOLITE Cu-SSZ-13 Ion-exchange Redistribution of Cu species selective catalytic reduction(SCR)
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