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Research on Uncertainties in Evaluation Indicator System for Ecological Residential Community
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作者 JIAO Sheng GUAN Chen-yin +2 位作者 ZENG Guang-ming LIU Jian-ong Zhou Jian-fei 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2009年第S1期177-181,共5页
In the process of evaluating,the weights of indicators are firstly determined by AHP and Delphi methods;and the values of indicators are normalized by grey correlative coefficient method.A suit of means were put forwa... In the process of evaluating,the weights of indicators are firstly determined by AHP and Delphi methods;and the values of indicators are normalized by grey correlative coefficient method.A suit of means were put forward,by which a qualitative and quantitative evaluation indicator system suitable for the situation of China and uncertainties can be established.Both idiographic and operable methods and process were presented.Following the principle of elasticity,hiberarchy and maneuverability,a three-layer evaluation indicator system was established by AHP in Jiuyi ecological residential community,which includes 5 subsystems and 24 indicatiors.The weights of indicators are measured by AHP and expert estimate and their best indicators values up to par were determined by fuzzy mathematics and optimization.The whole evaluation indicator system not only has an active and practical effect on estimating ecological residential community,but also guides ecological residential community planning. 展开更多
关键词 ecological residential community evaluation indicator system ecological risk evaluation UNCERTAINTY fuzzy mathematics grey correlative coefficient
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Construction of Xi'an ecological old-age care community in the new urbanization
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作者 JIAN Ai 《Ecological Economy》 2018年第2期123-128,共6页
The new urbanization is an important carrier of ecological civilization construction, and ecological old-age care is the concrete manifestation of the perfect combination of the two, the proper meaning of the new urba... The new urbanization is an important carrier of ecological civilization construction, and ecological old-age care is the concrete manifestation of the perfect combination of the two, the proper meaning of the new urbanization connotation and an inevitable trend of its development. Based on the analysis of the connotation and relationship between the new urbanization and ecological old-age care, together with the current situation and existing problems of the current nursing institutions and ecological old-age care in Xi'an area, this paper discusses the major issues that should be noticed when constructing the ecological old-age care community in Xi'an and three main construction modes. 展开更多
关键词 new urbanization Xi’an ecological old-age care community
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Drivers and patterns of community completeness suggest that Tuscan Fagus sylvatica forests can naturally have a low plant diversity
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作者 Emanuele Fanfarillo Leopoldo de Simone +9 位作者 Tiberio Fiaschi Bruno Foggi Antonio Gabellini Matilde Gennai Simona Maccherini Emilia Pafumi Enrico Tordoni Daniele Viciani Giulio Zangari Claudia Angiolini 《Forest Ecosystems》 2025年第2期190-200,共11页
European beech(Fagus sylvatica L.)forests can have a high variability in plant species richness and abundance,from monospecific stands to highly species-rich communities.To understand what causes the low plant diversi... European beech(Fagus sylvatica L.)forests can have a high variability in plant species richness and abundance,from monospecific stands to highly species-rich communities.To understand what causes the low plant diversity observed in some beech forests,we analyzed the drivers of plant community completeness in 155 vegetation plots.Data were collected in mature,closed-canopy beech forests in Tuscany,central Italy.Site-specific species pools were estimated based on species co-occurrences.We used Generalized Least Squares linear modeling to assess the effects of anthropogenic and environmental drivers on the community completeness of whole communities and on the set of specialist species of beech forests.We also tested the response of the total cover of the herb layer to the selected predictors and related both the predictive and response variables to species composition in a Non-metric Multidimensional Scaling ordination.The community completeness of whole communities and that of beech forest specialists were negatively affected by total beech cover and positively influenced by slope.Moreover,the community completeness of whole communities was negatively impacted by elevation and positively influenced by disturbance frequency.The cover of the herb layer decreased with increasing beech cover,elevation,and precipitation.High community completeness and high cover of the herb layer were associated with the presence of thermophilic species of mixed deciduous woods in low-elevation beech forests.Our results suggest that a low plant community completeness and a low cover of the herb layer are mainly due to the competition by beech itself when it forms pure forests in its ecological optimum.Such competition is better exerted at upper elevations and in sites with low slopes,where beech litter accumulation is a limiting factor for understory species.Such evidence suggests that species absence in mature beech forests is mainly due to natural drivers and should therefore not be considered an indicator of ecological degradation of the forest. 展开更多
关键词 BIODIVERSITY community ecology Dark diversity Forest structure Species absence Species pool
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Ecological characteristics of artificial vegetation communities on excavated slopes at the Xiangjiaba hydroelectric power station 被引量:3
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作者 夏振尧 许文年 《Journal of Chongqing University》 CAS 2009年第2期75-81,共7页
This paper reports the investigation of artificial vegetation communities on excavated slopes in a construction perturbed area of the Xiangjiaba hydroelectric power station in the Jinsha River Basin, P. R. China. Belt... This paper reports the investigation of artificial vegetation communities on excavated slopes in a construction perturbed area of the Xiangjiaba hydroelectric power station in the Jinsha River Basin, P. R. China. Belt transect and random quadrats were used in sampling and recording the vegetation of the four selected plots on the slopes. The community of each plot was characterized based on the coverage, relative importance value, richness, diversity, evenness of species derived from the survey data. Problems of these communities were identified and corresponding regulation measures were proposed to accelerate the positive succession process of the ecosystem. It is demonstrated that the artificial vegetation restoration on the excavated slope has improved the ecological environment. 展开更多
关键词 VEGETATION ecological community artificial vegetation community ecological characteristics regulation analysis
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Research Overview on Urban Plant Community
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作者 廉丽华 申曙光 《Journal of Landscape Research》 2010年第2期43-46,共4页
The concept of plant community and community classification were expatiated, the study history and actuality were summarized, and the developmental trends of phytocoenology were prospected.
关键词 Plant community community classfication community structure community ecology
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Plant community composition and interspecific relationships among dominant species on a post-seismic landslide in Hongchun Gully, China 被引量:7
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作者 HUANG You-you HAN Han +1 位作者 TANG Chuan LIU Shou-jiang 《Journal of Mountain Science》 SCIE CSCD 2017年第10期1985-1994,共10页
The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics... The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area. 展开更多
关键词 ecological rehabilitation Plant communities Vegetation recovery Geological hazard Hongchun Gully
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Community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary during water and sediment discharge regulation 被引量:2
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作者 REN Zhonghua LI Fan +4 位作者 WEI Jiali LI Shaowen LV Zhenbo GAO Yanjie CONG Xuri 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第8期74-81,共8页
The community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes(1-month) in macroben... The community characteristics of macrobenthos in the Huanghe(Yellow River) Estuary is influenced by a combination of natural and anthropogenic factors. Here, we investigated short-term changes(1-month) in macrobenthic community structure in response to water and sediment discharge regulation(WSDR) in 2011.Specifically, we sampled the macrobenthos at 18 sampling stations situated at four distances(5, 10, 20, and 40 km)from the mouth of the Huanghe Estuary before(mid-June), during(early-July), and after(mid-July) WSDR. The results showed that a total of 73, 72, and 85 species were collected before, during, and after WSDR, respectively.Then, 13, 1, and 16 dominant species were detected at this three periods. Four phyla were primarily detected at all three periods(Annelida, Mollusca, Arthropoda, and Echinodermata). However, while Mollusca and Annelida were the most important phyla in our study, Echinodermata and Annelida were the most important phyla in 1982,demonstrating major changes to community structure over a 3-decadal period. All stations were of high quality BOPA index before WSDR, whereas two and three stations were of reduced quality BOPA index during and after WSDR, respectively. The results of ABC curves showed that had incurred disturbed conditions after human activities WSDR. Most important of all, multivariate analyses and RDA analysis indicated that the structure of the macrobenthic community was closely linked to environment factors, including that organic content factor caused the distribution of macrobenthic community mostly during WSDR, while water depth after WSDR affected the macro benthos community structure seriously, and during WSDR, the environment factor influencing it was not single, including organic content, sulfide content, Hg and As. These differences may have been due to changes in water transparency negatively impacting the growth and development of macrobenthos, due to specific lifehistory requirements. Our results demonstrate that anthropogenic activity is having both long-term(3 decadal)and short term(1-month) impacts on the structure of the macrobenthic community of the Huanghe Estuary. In conclusion, human activities WSDR influence the habitat environment of macro benthos, including the water temperature, nutrients, bioturbation, and so on. Therefore, we suggest the necessity to strengthen regulations of land-derived organic pollutant input to maintain the ecological balance of the Huanghe Estuary. 展开更多
关键词 macrobenthos Huanghe(Yellow River) Estuary ecology community structure environment factors
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Plant community on a volcano mountaintop reveals unique high-altitude vegetation in southeastern Brazil
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作者 Igor Musauer KESSOUS Ruy JoséValka ALVES +1 位作者 Nílber Gonçalves da SILVA Amilcar Walter SAPORETTI JUNIOR 《Journal of Mountain Science》 SCIE CSCD 2024年第9期3018-3030,共13页
Mountains exhibit a high degree of endemism and diversity,however,quantifying their biodiversity can be challenging.Similar to islands,species isolation in mountainous regions results in comparable patterns of evoluti... Mountains exhibit a high degree of endemism and diversity,however,quantifying their biodiversity can be challenging.Similar to islands,species isolation in mountainous regions results in comparable patterns of evolution and extinction,rendering their biodiversity unique and highly susceptible to anthropogenic threats.The topographic relief in mountains plays a crucial role in creating habitat complexity,which in turn contribute to high plant diversity.Here,we investigated plant diversity in the volcano mountaintop vegetation on the Poços de Caldas Plateau,a region situated in the ecotone between the Atlantic Forest and Cerrado,characterized by natural radiation and significant anthropogenic intervention.We employed an automated approach through the filtering of georeferenced and non-georeferenced data to obtain a list of plant species in the region.Additionally,we statistically investigated the similarity among different high-altitude vegetations belonging to the campos de altitude from the Atlantic Forest and campos rupestres from the Cerrado.The plateau exhibits high plant diversity,including 1,659 specific and infraspecific taxa,especially belonging to Asteraceae and Poaceae.Our analyses suggest that geographical distance is a strong predictor of dissimilarity and that the Poços de Caldas Plateau is more floristically related to the campos rupestres,despite being associated with campos de altitude.The region possesses a unique set of biodiversity,indicating that it may be a distinct formation.Additionally,we hypothesize that Pleistocene events likely influenced the conformation of the current floristic composition in the region through species interchange between the Cerrado and Atlantic Forest.Our study also highlights the few taxa assessed for conservation status and anthropogenic threats that this habitat is facing. 展开更多
关键词 Atlantic Forest BIOGEOGRAPHY CERRADO community ecology GRASSLAND
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Omnivore or Insectivore?Diet Composition in the Starred or Roughtail Rock Agama,Laudakia vulgaris(Squamata:Agamidae)
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作者 Mohammad A.ABU BAKER Sajeda J.JABER +2 位作者 Ahmad A.KATBEH-BADER Ahmad M.DISI Zuhair S.AMR 《Asian Herpetological Research》 2025年第3期314-317,共4页
Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of s... Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of species diversity and occurs in a variety of habitats(Uetz et al.,2024). 展开更多
关键词 trophic interactions diet composition Laudakia vulgaris rock agama community ecology INSECTIVORE OMNIVORE dietary preferences
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Diversity of Sucking Lice on Small Mammals in the Surrounding Areas of Erhai Lake in Yunnan,China 被引量:3
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作者 董文鸽 郭宪国 +2 位作者 门兴元 钱体军 吴滇 《Entomotaxonomia》 CSCD 北大核心 2009年第1期68-80,共13页
An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were c... An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders (Rodentia, Insectivora, Scandentia and Carnivora), while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts. 展开更多
关键词 ANOPLURA small mammal species diversity community ecology co-evolution.
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Integrity of Local Ecosystems and Storm Water Management in Residential Areas
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作者 WANG Lin WANG Weida GONG Zhaoguo 《Journal of Ocean University of China》 SCIE CAS 2006年第4期363-367,共5页
The authors designed an ecological storm water system in a residential area to replace the conventional underground channels for the collection of storm water so as to reduce the nutrients and sediments discharged. Th... The authors designed an ecological storm water system in a residential area to replace the conventional underground channels for the collection of storm water so as to reduce the nutrients and sediments discharged. This system contains natural sub-creeks as drainage channels discharging overflow to nearby creeks, an open green trench, a storage pond, and natural sub-creeks. The sub -creeks were designed to be integrated into community landscape, which not only increases the efficiency of water usage, but also improves the aesthetic qualities of the community residence area as required by Agenda 21. This research proved the feasibility of an open storm water collection and utilization system for the design of a community water system. 展开更多
关键词 storm water management ecological community water management open trench GREENWAY pond system
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Structural and functional variations of phytoplankton communities in the face of multiple disturbances 被引量:4
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作者 Jun R.Yang Xiaoqing Yu +2 位作者 Huihuang Chen Yi-Ming Kuo Jun Yang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2021年第2期287-297,共11页
The global decline of freshwater biodiversity caused by climate change and human activities are supposed to disrupt ecosystem services related to water quality and alter the structure and function of aquatic communiti... The global decline of freshwater biodiversity caused by climate change and human activities are supposed to disrupt ecosystem services related to water quality and alter the structure and function of aquatic communities across space and time,yet the effects of the combination of these factors on plankton community ecosystem has received relatively little attention.This study aimed to explore the impacts of disturbances(e.g.human activity,temperature,precipitation,and water level)on phytoplankton community structure(i.e.community evenness and community composition)and function(i.e.resource use efficiency)in four subtropical reservoirs over 7 years from 2010 to 2016.Our results showed that community turnover(measured as community dissimilarity)was positively related to disturbance frequency,but no significant correlation was found between phytoplankton biodiversity(i.e.evenness)and disturbance frequency.Phytoplankton resource use efficiency(RUE=phytoplankton biomass/total phosphorus)was increased with a higher frequency of disturbance with an exception of cyanobacteria.The RUE of Cyanobacteria and diatoms showed significantly negative correlations with their community evenness,while the RUE of Chlorophyta exhibited a positive correlation with their community turnover.We suggest that multiple environmental disturbances may play crucial roles in shaping the structure and functioning of plankton communities in subtropical reservoirs,and mechanism of this process can provide key information for freshwater uses,management and conservation. 展开更多
关键词 ALGAE BIODIVERSITY community ecology PLANKTON Resource use efficiency Subtropical reservoir
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Alpine Ecosystems of Northwest Yunnan,China:an Initial Assessment for Conservation 被引量:4
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作者 Ruth Sherman Renee Mullen +2 位作者 LI Haomin FANG Zhendong WANG Yi 《Journal of Mountain Science》 SCIE CSCD 2007年第3期181-192,共12页
Implementing conservation actions on-the-ground is not a straightforward process,especially when faced with high scientific uncertainty due to limited available information. This is especially acute in regions of the ... Implementing conservation actions on-the-ground is not a straightforward process,especially when faced with high scientific uncertainty due to limited available information. This is especially acute in regions of the world that harbor many unique species that have not been well studied,such as the alpine zone of the Hengduan Mountains of Northwest Yunnan (NWY),a global biodiversity hotspot and site of The Nature Conservancy’s Yunnan Great Rivers Project. We conducted a quantitative,but rapid regional-level assessment of the alpine flora across NWY to provide a broad-based understanding of local and regional patterns of the alpine flora,the first large-scale analysis of alpine biodiversity patterns in this region. Multivariate analyses were used to classify the major plant community types and link community patterns to habitat variables. Our analysis indicated that most species had small distributions and/or small population sizes. Strong patterns emerged with higher diversity in the more northern mountains,but beta diversity was high,averaging only 10% among sites. The ordinations indicated that elevation and geographic location were the dominant environ-mental gradients underlying the differences in the species composition among communities. The high beta diversity across the alpine of these mountains implies that conservation strategies ultimately will require the protection of large numbers of species over a large geographical area. However,prioritiza-tion should be given to areas where potential payoffs are greatest. Sites with high species richness also have a greater number of endemic species,and,by focusing efforts on these sites,conservation investments would be maximized by protecting the greatest number of unique species. 展开更多
关键词 Biodiversity hotspot cluster analysis plant community ecology conservation action GRAZING Hengduan Mountains non-metric multidimensional scaling plant species richness World Heritage Site Yunnan Great Rivers Project(YGRP) alpine ecosystems China
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Studies on island intertidal benthic ecology in Fujian 被引量:2
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作者 Zhou Shiqiang, Guo Feng, Tian Yue, Wu Lisheng, Li Rongguan 1 Institute of Subtropical Oceanology, Xiamen University, Xiamen 361005, China 2 Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2001年第3期417-425,共9页
A total of 862 benthic species were identified in the island intertidal zone in Fujian, of which 734 species are animals and 128 species algae. Determination of Jaccard's similarity index of species was made on th... A total of 862 benthic species were identified in the island intertidal zone in Fujian, of which 734 species are animals and 128 species algae. Determination of Jaccard's similarity index of species was made on the intertidal communities around 11 major islands. Based on hierarchical clustering (WPGMA) and polar ordination, the benthic communities may be classified into three types; the estu-arine type, the bay and harbour type and open sea type. The distribution of the benthic community is related to the location of the island and its habitats of which, salinity and hydrodynamics are the major factors controlling the distribution of the communities. 展开更多
关键词 Intertidal zone benthic community ecology Fujian coast islands
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Cretaceous-Paleocene Foraminiferal Communities from the Western Tarim Basin and Their Environmental Significance 被引量:1
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作者 Hao Yichun Guo XianpuDepartment of geology , China University of Geosciences , Beijing 100083 《Journal of Earth Science》 SCIE CAS CSCD 1990年第1期38-46,共9页
Foraminifera is one of the most important fossil faunas of the marine Cretaceous and Paleocene in the Western Tarim Basin, which can be divided into 9 communities. This paper deals mainly with the changes of environme... Foraminifera is one of the most important fossil faunas of the marine Cretaceous and Paleocene in the Western Tarim Basin, which can be divided into 9 communities. This paper deals mainly with the changes of environments in which the foraminiferal communities existed,especially with the changes of temperature and salinity revealed by analyses of test composition and trace elements in the tests , and by statistic studies of species density, richness , diversity ,equitability and dominance . 展开更多
关键词 foraminiferal community ecological environment Cretaceous Paleocene Western Tarim Basin Xinjiang .
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Evolutionary fingerprint, phylogenetic and forest structure of tropical montane Atlantic cloud forests along an elevation gradient
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作者 Ravi Fernandes MARIANO Vanessa Leite REZENDE +7 位作者 Cléber Rodrigo de SOUZA Patrícia Vieira POMPEU Rubens Manoel dos SANTOS Carolina Njaime MENDES Aloysio Souza de MOURA Felipe Santana MACHADO Warley Augusto Caldas CARVALHO Marco Aurélio Leite FONTES 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1259-1271,共13页
Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influ... Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest,a historically neglected ecoregion.We evaluated the phylogenetic structure,forest structure(tree basal area and tree density)and species richness along an elevation gradient,as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities.To do so,we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l.without large elevation gaps.The relationships between elevation and phylogenetic structure,forest structure and species richness were investigated through Linear Models.The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny.Our results showed decreased species richness at higher elevations and independence between forest structure,phylogenetic structure and elevation.We also verified that there is a phylogenetic signal associated with elevation-success by lineages.We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range.On the other hand,elevation is not associated with forest structure or phylogenetic structure.Furthermore,closely related taxa tend to have their higher ecological success in similar elevations.Finally,we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes(i.e.global warming)due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions(i.e.minimum temperature)associated with each elevation range. 展开更多
关键词 Atlantic Forest Cloud forest CONSERVATION community ecology Montane forests Phylogenetic diversity Phylogenetic signal
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Explaining patterns of species dominance in the shrub steppe systems of the Junggar Basin(China) and Great Basin(USA)
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作者 Wendy TROWBRIDGE Thomas ALBRIGHT +3 位作者 Scot FERGUSON Jun LI Barry PERRYMAN Robert S NOWAK 《Journal of Arid Land》 SCIE CSCD 2013年第4期415-427,共13页
Natural scientists have long recognized that regions with similar climate tend to have similar vegetation.Preliminary observations suggest that shrub steppe communities of the western US and western China may be two s... Natural scientists have long recognized that regions with similar climate tend to have similar vegetation.Preliminary observations suggest that shrub steppe communities of the western US and western China may be two such regions with similar annual precipitation,temperature,land use,and vegetation.These cold dry shrub steppes have traditionally been grazed.Despite these similarities,patterns of species dominance are different.Annual species that are rare in China become dominant when introduced to the United States.The objective of this study was to investigate how climate,land use and community structure may explain these patterns of species dominance.Community structure and grazing intensity were measured at 5 sites in each region.This information was combined with a broader review of the literature describing the history of grazing in both basins.Climate was analyzed based on a spatially-gridded,interpolated weather time series (monthly records) and climatological summary (1961-1990 mean conditions) data set from the Climate Research Unit.We found that differences in summer precipitation and winter minimum temperature,land use intensity,and shrub size may all contribute to the dominance of annual species in the Great Basin,particularly Bromus tectorum.In particular,previous work indicates that summer precipitation and winter temperature drive the distribution of Bromus tectorum in the Great Basin.As a result,sites with wet summers and cold springs,similar to the Chinese sites,would not be expected to be dominated by Bromus tectorum.A history of more intense grazing of the Chinese sites,as described in the literature,also is likely to decrease fire frequency,and decreases litter and shrub dominance,all of which have been demonstrated to be important in Bromus tectorum establishment and ultimate dominance.Further research is necessary to determine if other annuals that follow the same pattern of scarcity in the Junggar Basin and dominance in the Great Basin are responding to the same influences. 展开更多
关键词 CLIMATE community ecology convergent evolution Bromus tectorum shrub steppe Junggar Basin Great Basin
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Intraguild niche partitioning in granivorous birds from the late past
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作者 Ana B.Navarro Juliano A.Bogoni +1 位作者 Marcelo Z.Moreira Luís F.Silveira 《Avian Research》 SCIE CSCD 2023年第1期70-77,共8页
Niche partitioning is a widespread ecological strategy within trophic guilds,ensuring the coexistence of sympatric species by reducing interspecific competition.Stable isotope analysis of carbon and nitrogen and isoto... Niche partitioning is a widespread ecological strategy within trophic guilds,ensuring the coexistence of sympatric species by reducing interspecific competition.Stable isotope analysis of carbon and nitrogen and isotopic niche metrics(width and overlap)are used as a proxy to investigate niche partitioning among species of a guild.In our study,we investigated if niche partitioning was an ecological mechanism contributing to the coexistence of granivorous birds from the same geographic region along time,employing an isotopic approach.We sampled and isotopically analyzed(δ^(13)C andδ^(15)N values)wing feathers from 58 specimens of granivorous birds collected between 1900 and 1966 in southeastern Brazil.We grouped birds according to the main habitat type used by them(forest:Cyanoloxia brissonii,Leptotila and Leptotila verreauxi;and grassland:Columbina squammata and Sicalis flaveola).We used the Isotopic Richness(IRic)metric to measure the isotopic niche width and the Isotopic Similarity(ISim)and Isotopic Nestedness(INes)metrics to measure the niche overlap between groups and species.The results of low isotopic niche overlap suggest that common granivorous birds had a clear niche partitioning in southeastern Brazil in the late past,especially through foraging in distinct habitat types(forest and grassland;ISim=0.1,INes=0.2).Niche overlaps in almost all species-by-species comparisons were low(ISim≤0.3,INes≤0.4),except between C.brissonii and L.verreauxi(ISim=0.6,INes=1.0).These results suggest that these birds,belonging to the same trophic guild,coexisted through niche and resource partitioning.Despite being considered a plastic trophic guild,the isotopic niche partitioning among granivorous birds indicates that each of these species uses a set of specific resources and habitats.This raises an ecological concern about the homogenization of landscapes across the Neotropics,oversimplifying food resources and habitats to granivorous birds. 展开更多
关键词 Atlantic forest Avian ecology CERRADO community ecology DIET Foraging ecology Habitat use Trophic relations
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