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Patch occupancy by the Chinese Grouse(Tetrastes sewerzowi)in a fragmented landscape 被引量:2
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作者 Siegfried KLAUS Winfried VOIGT +2 位作者 方昀 Peter SELSAM 孙悦华 《Chinese Birds》 CSCD 2013年第3期232-239,共8页
The Chinese Grouse (Tetrastes sewerzowi) is a rare, endemic bird in China, inhabiting conifer-dominated mountain forests. Both the natural fragmentation and heavy cutting of mature forests have resulted in patchy grou... The Chinese Grouse (Tetrastes sewerzowi) is a rare, endemic bird in China, inhabiting conifer-dominated mountain forests. Both the natural fragmentation and heavy cutting of mature forests have resulted in patchy grouse habitats. We used SPOT (XS-sensor) satellite imagery to discriminate between open land and conifer or broadleaf forests. The area analyzed is about 120000 ha in size and includes the Lianhuashan Nature Reserve and the Yeliguan Forestry Park. We identiifed 4111 ha of mature coniferous forests in 229 patches (maximum 332 ha, mean 18 ha) as the habitat used by Chinese Grouse throughout the year. We examined 31 forest islands of different sizes and degrees of isolation for the presence of Chinese Grouse. We used generalized linear models (GLM) with binomial error structure and logit link function to estimate the probability of Chinese Grouse occupancy in a forest fragment. Habitat patch size (hs) and distance to the next occupied fragment (doc) were used as predictor variables, important for occupancy. Small habitat islands were disproportionately less likely to be occupied than large, nearby habitats. There was a clear speciifc habitat size of about 40 ha, above which habitat fragments were occupied more often. Suitable habitat fragments isolated by more than 2 km appeared to be inaccessible to Chinese Grouse. The results have been used in reforestation projects to establish linking corridors in the study area. 展开更多
关键词 Tetrastes sewerzowi habitat fragmentation patch size ISOLATION Lianhuashan reserve China
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β-diversity Patterns of Plant Community in Fragmented Habitat in a Degenerated Meadow in Songnen Plain,China 被引量:11
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作者 HAN Dayong LI Haiyan YANG Yunfei 《Chinese Geographical Science》 SCIE CSCD 2009年第4期375-381,共7页
A number of isolated islands of Leymus chinensis + herbosa community were investigated in fragmented habitat islands, by Braun-Blanquet field survey approach, in a degenerated meadow in the Songnen Plain, China in 20... A number of isolated islands of Leymus chinensis + herbosa community were investigated in fragmented habitat islands, by Braun-Blanquet field survey approach, in a degenerated meadow in the Songnen Plain, China in 2007. These islands were classified as large, medium, and small scales on the basis of the island area (100-1000m2, large island; 50-100m2, middle island; 10-50m2, small island). Each scale of the investigation involved eight islands. The responses ofβ-diversity patterns of plant taxon to the habitat fragmentation at local community and metacommunity levels were analyzed on different scales of 24 isolated islands. The results indicated that at the local community level, there were 57 species belonging to 20 families and 49 genera in large islands, 49 species belonging to 16 families and 40 genera in middle islands, and 27 species belonging to eight families and 23 genera in small islands, β-diversity indexes for species, genus and family in large, middle, and small islands varied greatly, and the highest value of the indexes was not noted in the largest island. However, the average of the data obtained at the three scales showed that across large islands, Whittaker indexes were low and Bray-Curtis similarity indexes were high, while across small islands, Whittaker indexes were high and Bray-Curtis similarity indexes were low. At the metacommunity level, Whittaker indexes for species and genus showed a great significantly negative double logarithmic correlation (p〈0.01) with the island area, whereas the Bray-Curtis indexes for species, genus and family showed a great significantly positive double logarithmic correlation (p〈0.01) with the island area. At both local community and metacommunity levels, tumovers of species and genus could respond more sensitively to spatial changes of plant diversity patterns than that of family. Hence, the species and the genus could be used for the analysis offl-diversity patterns of plant community. 展开更多
关键词 habitat fragmentation local community METACOMMUNITY plant taxon β-diversity
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Plant assemblage and diversity variation with human disturbances in coastal habitats of the western Arabian Gulf
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作者 Raafat H ABD EL-WAHAB 《Journal of Arid Land》 SCIE CSCD 2016年第5期787-798,共12页
Knowledge about plant diversity along disturbance gradients is essential for conservation and management of fragmented coastal habitats.This study examined the effects of human disturbance intensity in coastal habitat... Knowledge about plant diversity along disturbance gradients is essential for conservation and management of fragmented coastal habitats.This study examined the effects of human disturbance intensity in coastal habitats of Kuwait on diversity,composition,identity and assemblage of vascular plant species.Plant survey data from 113 plots (5m×5m each) were randomly selected in 51 sites at coastal fragmented habitats at three levels of disturbance intensities (high,moderate and low) and were statistically analyzed.The results revealed that about 76% of the recorded species are considered threatened species in Kuwait,most of which are being lost in high disturbed habitats.Disturbance led to the dominance of Zygophyllum qatarense,Cornulaca aucheri and Salsola imbricata,which are species of disturbance indicators.Richness,total plant cover and species diversity were higher in moderate and low disturbed habitats than in high disturbed habitats.Beta diversity between high and low disturbed habitats was higher than either between high and moderate,or between moderate and low disturbed habitats.Cluster analyses showed statistically significant differences in composition of plant assemblages,which indicate high beta diversity between the habitat types.Intensive urbanization and industrialization are among the most serious threats that contribute to declines in biological diversity and rapid fragmentation of coastal habitats in Kuwait.Establishing protective enclosures in the disturbed habitats,planting endangered and vulnerable species,and establishing a natural reserve at Nuwaiseeb are recommended conservation actions to avoid loss of the fragmented coastal habitats and to facilitate restoration of native plants. 展开更多
关键词 plant diversity disturbance gradient threatened species habitat fragmentation coastal habitat salt marsh restoration
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Habitat Loss,Uneven Distribution of Resources and Fragmented Landscapes—A Resource Based Model of the Patch Size Effect
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作者 Pawel Adamski Adam Marcin Cmiel 《Applied Mathematics》 2014年第19期3206-3216,共11页
The problem of habitat fragmentation is recently an important issue in ecological research as well as in the practical approach of nature conservation. According to the most popular approaches, habitats are considered... The problem of habitat fragmentation is recently an important issue in ecological research as well as in the practical approach of nature conservation. According to the most popular approaches, habitats are considered as the homogenous parts of the landscape. Also the metapopulation concept problem of the inert habitat heterogenity is considered quite seldom. These approaches have some weak points resulting from the assumption that the border between habitat patches and the metapopulation matrix is fairly sharp. This paper presents a resource-based concept of habitats, based on mathematical theory of point processes, which can be easily applied to analysing the problem of uneven distribution of resources. The basic assumption is that the random distribution of resources may be mathematically described as the realisation of a certain point process. According to our method, it is possible to calculate the expected quantities of available resources as well as the minimum area of habitat that includes the expected abundance of the resource. This approach may be very useful to understand some crucial phenomena in landscape ecology, such as the patch size effect and its connection to habitat loss and fragmentation. 展开更多
关键词 Patch Size Effect Allee Effect Habitat Loss Habitat Fragmentation Poisson Process Process Intensity Critical Patch Size
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Achievements and challenges of primate conservation in China 被引量:1
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作者 Bao-Guo Li He Zhang +21 位作者 Ming Li Xue-Long Jiang Peng-Fei Fan Jiang Zhou Song-Tao Guo Xiao-Guang Qi Jin-Hua Li Ji-Qi Lu Dong-Po Xia Liang-Wei Cui Zuo-Fu Xiang Qi-Hai Zhou Zhi-Pang Huang Cheng-Ming Huang Wen Xiao Hui-Jian Hu Zhi-Xin Zhou Ming-Yong Chen Da-Yong Li Peng-Lai Fan Yin Yang Ru-Liang Pan 《Zoological Research(Diversity and Conservation)》 2024年第1期66-74,共9页
The dual impact of climate change and human activities has precipitated a sharp decline in primate biodiversity globally.China is home to the most diverse primate species in the Northern hemisphere,which face severe e... The dual impact of climate change and human activities has precipitated a sharp decline in primate biodiversity globally.China is home to the most diverse primate species in the Northern hemisphere,which face severe ecological threats due to the expansion of modern agriculture,extensive exploitation and consumption of natural resources,and excessive land development during its transition from an agricultural to a modern society.In response,China has implemented various ecological conservation measures,including habitat restoration and protection.These efforts have made substantial strides in biodiversity conservation,with certain regions witnessing an increase in primate populations.In the current study,we conducted a systematic review of historical documents and field research data related to Chinese primates,evaluating the endangered status of primate species in China.Despite improvements in the habitats of most primate species and some population growth,many species still face severe threats,including declining and small populations.Species such as the Myanmar snub-nosed monkey(Rhinopithecus strykeri),eastern black crested gibbon(Nomascus nasutus),and Hainan gibbon(N.hainanus)remain particularly vulnerable due to their limited distribution ranges and extremely small populations.Insufficient scientific data,fragmented information,and not enough studies in conservation biology further compound the challenges.Moreover,there is a notable lack of detailed population monitoring data for species such as the Bengal slow loris(Nycticebus bengalensis),pygmy slow loris(N.pygmaeus),Indochinese gray langur(Trachypithecus crepusculus),Shortridge’s langur(T.shortridgei),and capped langur(T.pileatus),which hinders the development of practical and targeted conservation management strategies.Therefore,for national biodiversity conservation,there is an urgent need for specialized primate surveys,enhancing habitat protection and restoration,and increasing focus on cross-border conservation strategies and regional cooperation.There is also a need to establish a comprehensive and systematic research database platform,conduct continuous and in-depth research in primate biology,and actively engage in the scientific assessment of ecotourism.Additionally,strengthening public awareness and education on wildlife conservation remains essential.Such integrated and systematic efforts will provide scientific support for the current and future conservation and management of primate species in China. 展开更多
关键词 PRIMATES BIODIVERSITY Habitat fragmentation Habitat restoration Conservation strategies
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Environmental determinants of social wasp diversity and assemblage structure in an Amazonian archipelagic landscape
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作者 Jose Victor Alves Ferreira Alexandre Somavilla +3 位作者 Maíra Benchimol Ana Filipa Palmeirim Carlos A.Peres Danielle Storck-Tonon 《Zoological Research(Diversity and Conservation)》 2024年第2期121-129,共9页
Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversit... Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversity,invertebrate taxa,that may be critical to ecosystem functioning,have been overlooked.We assessed the assemblage-level responses of social wasps to forest insularization induced by the Balbina Hydroelectric Dam in Central Brazilian Amazonia.Employing Malaise trapping,we captured wasps on 27 forest islands and three continuous forests.We constructed Generalized Linear Models and employed a model selection approach to examine the impact of local variables(fire severity(FIRE)and basal area of pioneer tree species(PIONEER))and landscape-scale variables(amount of habitat(COVER))on patterns of species richness,composition,and body size of wasps.A total of 374 individuals(29 species)were collected across all sampling sites.COVER was the main predictor of species richness,while PIONEER was the only variable that explained variation in community composition,with a negative effect on body size.Our results add evidence to the pervasive impacts of large hydroelectric dams on tropical forest biodiversity,and suggest that social wasps,among other invertebrates,can be used as bioindicators in infrastructure development projects. 展开更多
关键词 Habitat amount hypothesis Habitat fragmentation Habitat loss Hydroelectric dams Invertebrates
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Nestedness of bird assemblages in the karst forest fragments of southwestern Guangxi, China 被引量:3
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作者 李肇天 陆舟 +3 位作者 舒晓莲 蒋光伟 许亮 周放 《Chinese Birds》 CSCD 2013年第2期170-183,共14页
The limestone region in southwestern Guangxi contains the most typical karst landforms in the world. Due to their destruction, the original forests mainly survive in nature reserves in the form of fragmented areas. Fr... The limestone region in southwestern Guangxi contains the most typical karst landforms in the world. Due to their destruction, the original forests mainly survive in nature reserves in the form of fragmented areas. From June 2009 to September 2010 we conducted an investigation of 13 relatively isolated habitats or sites, selected from each of the 13 nature reserves in southwestern Guangxi, with the least amount of anthropological activity and the largest presence of the original vegetation, in order to study the distribution of birds on forest fragments. The distribution patterns of the birds and the factors which affect them were analyzed by using the 'BINMATNEST' software and the Spearman’s rank correlation analysis, to determine: 1) whether nested patterns of birds in the karst area of southwestern Guangxi exist or not and 2) which factors are correlated with the nested patterns and the effect of these factors on forming nested patterns. The results show that the birds had statistically significant nested patterns in the karst area and the specificity of the habitat of the birds had a significant effect on the nested patterns. We suggest possible reasons for these results, based on the characteristics of the seasonal tropical rain forests in the study area and on neutral theory. We also urgently recommend that close attention be paid to the protection of the diversity of the environment for birds in all fragmented habitats. 展开更多
关键词 BIRDS NESTEDNESS habitat fragmentation karst area neutral theory
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Breeding biology and novel reproductive behaviour in the Hainan Partridge(Arborophila ardens) 被引量:3
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作者 Xiaodong Rao Canchao Yang Wei Liang 《Avian Research》 CSCD 2017年第4期232-237,共6页
Background: The Hainan Partridge(Arborophila ardens) is endemic to Hainan Island,China,and is listed as vulnerable(VU) because its population size is steadily decreasing due to illegal hunting and habitat loss.Its bre... Background: The Hainan Partridge(Arborophila ardens) is endemic to Hainan Island,China,and is listed as vulnerable(VU) because its population size is steadily decreasing due to illegal hunting and habitat loss.Its breeding biology is poorly known.Methods: This study was conducted in three sites in the major tropical primary rainforest in Hainan.Nests of the Hainan Partridge were found by monitoring radio-tracked individuals.Video recorders were set up to monitor reproductive behaviour of Hainan Partridge when nests were found.Results: Here for the first time we report the breeding biology of Hainan Partridge by providing information on its nest site,nest,eggs,and reproductive behaviour.We found that Hainan Partridges laid immaculate white eggs in ground nests which were totally covered by dry leaves and small branches forming arches that provided optimal concealment.A novel and regular behaviour was found in Hainan Partridges since they grasped leaves and small branches and then threw them on or around their nests to provide cover during incubation and after hatching of chicks.Conclusions: Recruitment behaviour in Hainan Partridges benefit from supplementation of nest arch material to nests,cover the nest entrance and thus maintain or increase nest concealment.However,it may also contribute to concealment of the track which could expose their activities and clues for predators.Our finding implies that the Hainan Partridge has evolved such a novel reproductive behaviour under the strong selection of predation pressure.Due to habitat fragmentation and habitat loss,we suggest setting up arch structures and provide small branches and leaves in degraded or fragmented habitats to improve their suitability for partridge reproduction.This method may contribute to increasing the reproductive success of Hainan Partridge and thus compensate for its continuous population decrease. 展开更多
关键词 Habitat fragmentation Habitat loss Nest arch Nest concealment Recruitment behavior
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Habitat suitability change of red-crowned crane in Yellow River Delta Nature Reserve 被引量:2
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作者 CAO Ming-chang LIU Gao-huan 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第2期141-147,共7页
Habitat loss and fragmentation are mainly associated with population decrease of endangered species and biodiversity loss. The habitat suitability maps of red-crowned crane (Grusjaponensis) in 1992, 1999 and 2006 we... Habitat loss and fragmentation are mainly associated with population decrease of endangered species and biodiversity loss. The habitat suitability maps of red-crowned crane (Grusjaponensis) in 1992, 1999 and 2006 were produced by using Ecological Niche Suitability Model (ENSM) in Yellow River Delta Nature Reserve (118°33′-119°20′E longitude, 37°35′-38°12′N latitude), Shandong Province, China. Based on the habitat suitability maps, the causation and change law of habitat loss and fragmentation of red-crowned crane were analyzed by selecting a series of landscape pattern indices. Results showed that due to scarcities of fresh water sources, habitat suitability of red-crowned crane in 1999 was inferior to that in 1992 and 2006 no matter whether human disturbances existed or not. Besides, human disturbance activities, especially road disturbances, increased rapidly during the period of 1992-2006. This worsened the habitat loss and frag- mentation of red-crowned crane, and led to degrading habitat suitability of red-crowned crane in 2006, compared with that in 1992. In conclusion, fresh water sources and human disturbance activities are the two main factors that drive the habitat suitability change of red-crowned crane. 展开更多
关键词 red-crowned crane Yellow River Delta Nature Reserve habitat suitability habitat loss habitat fragmentation
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High levels of genetic diversity and an absence of genetic structure among breeding populations of the endangered Rufous-backed Bunting in Inner Mongolia,China:implications for conservation 被引量:1
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作者 Shi Li Dan Li +3 位作者 Lishi Zhang Weiping Shang Bo Qin Yunlei Jiang 《Avian Research》 CSCD 2021年第1期52-62,共11页
Background:The Rufous-backed Bunting,Emberiza jankowskii,is an endangered species that is primarily distributed in Inner Mongolia,China.The main threats to the continued persistence of this species are habitat loss an... Background:The Rufous-backed Bunting,Emberiza jankowskii,is an endangered species that is primarily distributed in Inner Mongolia,China.The main threats to the continued persistence of this species are habitat loss and degradation.However,the impact of population loss on genetic diversity remains unclear.To support future conservation and management efforts,we assessed the genetic diversity and population structure of E.jankowskii using mitochondrial DNA and microsatellites.Methods:Blood samples were collected from 7-8-day-old nestlings in Inner Mongolia,China between May and August of 2012 and 2013.Mitochondrial DNA sequences and microsatellite markers were used to assess the genetic diversity,genetic structure and inbreeding of E.jankowskii.The results of genetic diversity and inbreeding were compared to other avian species.Results:We found an unexpectedly high level of genetic diversity in terms of mitochondrial DNA and microsatellite compared to other avian species.However,there were high levels of gene flow and minimal genetic structuring,among the fragmented breeding populations of E.jankowskii in Inner Mongolia.These findings suggest that E.jankowskii in Inner Mongolia is a metapopulation.Despite the high genetic diversity of E.jankowskii,local populations in each small patch remain at risk of extinction due to habitat loss.In addition,the E.jankowskii population has a high risk of inbreeding.Conclusions:To minimize further loss of genetic diversity of this endangered species,we suggest that the E.jankowskii in Inner Mongolia should be considered as a protected species for management purposes.Conservation efforts should concentrate on E.jankowskii habitat management.This may be most effectively achieved by protecting the current breeding habitats and prohibiting over-grazing. 展开更多
关键词 CONSERVATION Emberiza jankowskii Genetic diversity Genetic structure Habitat fragmentation
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Effects of Habitat Fragmentation on Species Diversity of Animals and Plants
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作者 GU Huijie 《Journal of Landscape Research》 2021年第3期87-89,94,共4页
Habitat fragmentation has been a research hotspot of biodiversity,and an important "bottleneck" restricting biodiversity.Habitat fragmentation can cause species loss and affect the process of immigration and... Habitat fragmentation has been a research hotspot of biodiversity,and an important "bottleneck" restricting biodiversity.Habitat fragmentation can cause species loss and affect the process of immigration and colonization by decreasing habitat size and increasing isolation degree among populations,thereby affecting species diversity of animals and plants.This paper elaborated the concept and main theory of habitat fragmentation and the influence of habitat fragmentation on species diversity of animals and plants,and suggested that studies on the effects of habitat fragmentation on species diversity at multi-trophic levels and larger scales should be strengthened. 展开更多
关键词 Habitat fragmentation BIODIVERSITY Habitat area Isolation degree
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Arthropods on plants in a fragmented Neotropical dry forest: A functional analysis of area loss and edge effects 被引量:3
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作者 Ezequiel Gonzalez Adriana Salvo Graciela Valladares 《Insect Science》 SCIE CAS CSCD 2015年第1期129-138,共10页
Loss and fragmentation of natural ecosystems are widely recognized as the most important threats to biodiversity conservation, with Neotropical dry forests among the most endangered ecosystems. Area and edge effects a... Loss and fragmentation of natural ecosystems are widely recognized as the most important threats to biodiversity conservation, with Neotropical dry forests among the most endangered ecosystems. Area and edge effects are major factors in fragmented landscapes. Here, we examine area and edge effects and their interaction, on ensembles of arthropods associated to native vegetation in a fragmented Chaco Serrano forest. We analyzed family richness and community composition of herbivores, predators, and parasitoids on three native plant species in 12 fragments of varying size and at edge/interior positions. We also looked for indicator families by using Indicator Species Analysis. Loss of family richness with the reduction of forest fragment area was observed for the three functional groups, with sirnilar magnitude. Herbivores were richer at the edges without interaction between edge and area effects, whereas predators were not affected by edge/interior position and parasitoid richness showed an interaction between area and position, with a steeper area slope at the edges. Family composition of herbivore, predator, and parasitoid assemblages was also affected by forest area and/or edge/interior situation. We found three indicator families for large remnants and five for edges. Our results support the key role of forest area for conservation of arthropods taxonomic and functional diversity in a highly threatened region, and emphasize the need to understand the interactions between area and edge effects on such diversity. 展开更多
关键词 area loss Chaco Serrano edge effect forest arthropods functional groups habitat fragmentation
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Risk factors connected to gastrointestinal parasites in mantled Alouatta palliata mexicana and black howler monkeys Alouatta pigra living in continuous and in fragmented rainforests in Mexico 被引量:1
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作者 Genoveva TREJO-MACIAS Alejandro ESTRADA 《Current Zoology》 SCIE CAS CSCD 2012年第3期375-383,共9页
In this study we document the prevalence of gastrointestinal parasites (helminths and protozoans) found in fecal samples of populations of Alouatta palliata mexicana and ofA. pigra in Los Tuxtlas and in Palenque, so... In this study we document the prevalence of gastrointestinal parasites (helminths and protozoans) found in fecal samples of populations of Alouatta palliata mexicana and ofA. pigra in Los Tuxtlas and in Palenque, southeast Mexico, and its re- lation to habitat condition, sex/age and season. Nineteen parasite morphotypes were detected in the fecal samples from populations of the two howler monkeys, of which 58% were shared by both species. When considering all parasite species, populations of the two howler species were more likely to be parasitized in fragmented habitat compared to continuous habitat. Individuals of both howler monkey species that lived in fragmented habitat had a higher prevalence of Controrchis biliophilus. A. p. mexicana individuals had a higher prevalence of Trypanoxyuris minutus than A. pigra, probably the result of the larger group sizes found in the former species, and T. minutus was more likely to be found in A. palliata individuals that lived in fragmented habitat. Adult A. p. mexicana males had a higher risk of being parasitized compared to adult females, but these differences were not detected in A. pigra, Parasite species such as Entamoeba sp., Nematoda sp. 28, Nematoda sp. B and Parabronema sp. where only found during the wet season in both howler monkey species. Populations of both howler monkey species had a higher prevalence of Nematoda sp. A in the wet season and Ascaridae eggs were only detected during the wet season in A. pigra. Other parasites detected displayed no clear seasonal pattern [Current Zoology 58 (3): 375-383, 2012]. 展开更多
关键词 Gastrointestinal parasites Habitat fragmentation SEASONALITY Alouatta palliata mexicana Alouatta pigra Mexico
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Corridor connecting giant panda habitats from north to south in the Min Mountains, Sichuan, China 被引量:1
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作者 Kaipu YIN Yan XIE Ning WU 《Integrative Zoology》 SCIE CSCD 2006年第4期170-178,共9页
The giant panda faces severe threats from habitat fragmentation and isolation.Currently,giant panda populations have been fragmented into 30 habitat patches.The disappearance of isolated small populations and studies ... The giant panda faces severe threats from habitat fragmentation and isolation.Currently,giant panda populations have been fragmented into 30 habitat patches.The disappearance of isolated small populations and studies on the genetic diversity of various populations have shown that small isolated panda populations are at a high risk of dying out completely.Habitat fragmentation has seriously impaired the ability of the giant panda to resist climate changes and other natural disasters,such as large-scale,synchronous bamboo blooming.The Min Mountains have the largest population of pandas in China,numbering 581 individuals and accounting for 52%of the total(1114)in China.Geographic isolation means that giant pandas in the Min Mountains are divided into two populations(population A in the north and population B in the south).Population B,which had only 42 individuals in 1989,is severely threatened by high-density human populations and the loss of genetic diversity.However,we have identified an important corridor connecting the two populations.This paper explains the importance and the feasibility of reestablishing this corridor.Due to the special geographic locations of these two populations(two rivers block the migration of giant pandas between south and north),the corridor is the only passage for giant pandas in the region.Recent studies have also shown an increase of giant panda activity in the area of the corridor.However,vegetation in the corridor has been severely degraded.Bamboo forest must be restored in this area to provide food for the pandas during migration.The effects of human activities must be reduced in order to maintain panda habitat.We believe that a restored corridor will be of great benefit to the survival of giant pandas in the Min Mountains,especially for population B.Successful re-establishment of a corridor will be a valuable model for corridor construction in the future. 展开更多
关键词 CORRIDOR giant panda habitat fragmentation Min Mountains SICHUAN
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Plant growth in a fragmented forest is a consequence of top-down and bottom-up processes, but not their interaction
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作者 Brad J.Farmilo John W.Morgan Dale G.Nimmo 《Journal of Plant Ecology》 SCIE CSCD 2017年第4期601-609,共9页
Aims Habitat loss and fragmentation are the leading causes of global biodiversity decline.How fragmentation(leading to edge effects,increased isolation and declining habitat size)interacts with top-down processes like... Aims Habitat loss and fragmentation are the leading causes of global biodiversity decline.How fragmentation(leading to edge effects,increased isolation and declining habitat size)interacts with top-down processes like vertebrate herbivory,an important driver of vegetation structure and composition in many ecosystems,is poorly quantified.Interactions between fragmentation and changes in her-bivory may exacerbate their individual influences on plant growth,with implications for management of native plant communities within fragmented landscapes.We examined the effects of habitat fragmentation on herbivore activity,and also how both fragmen-tation and mammalian herbivory influence growth of understorey plant species.Methods This study was conducted at the Wog Wog habitat fragmentation experiment,located in south-eastern New South Wales,Australia.We use herbivore exclusion plots across an experimentally frag-mented landscape to assess the interactive effects of fragmenta-tion and herbivory on the growth of four plant species that vary in growth form and rarity in the landscape.Important Findings We observed species-specific responses to both herbivory and fragmentation,but no additive or interactive effects between these drivers.We show that a reduction in herbivore activity within frag-ments does not correspond with an increase in plant growth,even for the most palatable species.Rather,top-down processes continue to operate across the fragmented landscape.Although changes in habitat conditions within fragments appear to negatively influence both plant growth and mammalian herbivore activity,it is likely that alterations to bottom-up effects(i.e.fragmentation)may be more important than top-down effects(i.e.herbivores)for the spe-cies under investigation.The species-specific response of plants to herbivory or fragmentation may have implications for temporal and spatial population persistence in fragmented landscapes and ulti-mately fragment vegetation structure. 展开更多
关键词 Wog Wog habitat fragmentation experiment Pinus radiata HERBIVORY understorey plants PLANTATION EUCALYPT
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Plant-pollinator metanetworks in fragmented landscapes:a simulation study
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作者 Ehsan Rahimi Chuleui Jung 《Ecological Processes》 SCIE EI CSCD 2023年第1期415-424,共10页
Background The topology of the plant-pollinator network can be explained by the species’abundance and their random interactions.Plant-pollinator networks can be studied in the context of a landscape,because each patc... Background The topology of the plant-pollinator network can be explained by the species’abundance and their random interactions.Plant-pollinator networks can be studied in the context of a landscape,because each patch can accommodate a certain local network.Local populations of pollinators in the landscape can be connected through migration and then constitute a metanetwork that is known as a combination of spatial and ecological networks.In this regard,habitat fragmentation can affect the topology of plant-pollinator metanetworks through changes in the species abundance and limiting their interactions.However,it is not clear what pattern(fragmented or aggregated)of the landscape structure can accommodate networks with a higher degree of specialization.Methods we created simulated landscapes with different forest proportions scenarios(from 5%to 50%of the total landscape)and degrees of fragmentation.Then,for each landscape,we limited the proportion of pollinators to the forest patch.We assumed that plants and pollinators are randomly distributed around the landscape and interact randomly.We used landscape metrics to measure different aspects of landscape structure and bipartite metrics for calculating the degree of specialization in plant-pollinator networks.Results The statistical relationship between bipartite and landscape metrics showed that the relationship between the topology of plant-pollinator networks and the landscape structure is affected by the forest amount in the landscape and the degree of forest fragmentation.We also found that according to the nestedness and H2(a measure of specialization)metrics,fragmented landscapes contain more general plant-pollinator networks.Conclusions Our findings suggest that fragmented landscapes,characterized by scattered forest patches,can promote higher levels of interaction between limited pollinators and diverse flowers,leading to more general plant-pollinator networks. 展开更多
关键词 Plant–pollinator metanetwork Habitat fragmentation Simulated landscape Landscape metrics Bipartite metrics
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Nestedness of snake assemblages on islands of an inundated lake 被引量:7
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作者 Yanping WANG Xi WANG Ping DING 《Current Zoology》 SCIE CAS CSCD 2012年第6期828-836,共9页
Abstract Nestedness is a pattern frequently reported for faunal assemblages in fragmented systems. Although nestedness has been documented for a wide range of taxa, it is rarely tested in snake assemblages. To arrive ... Abstract Nestedness is a pattern frequently reported for faunal assemblages in fragmented systems. Although nestedness has been documented for a wide range of taxa, it is rarely tested in snake assemblages. To arrive at robust generalizations about processes and mechanisms structuring island biotas, it is important to examine under-represented taxa such as snakes for the insights they may offer. We tested for the existence of nestedness and underlying causal mechanisms using snake data collected on islands in the Thousand Island Lake, China. We used the line-transect method to survey snake occupancy and abundance on 20 islands during two breeding seasons in 2009 and 2010. We used the recently developed metric WNODF to estimate nestedness. We used Spearman rank correlations to examine the associations of nestedness and habitat variables (area, isolation, and habitat diversity) as well as life-history traits (body size, clutch size, geographical range size and area requirement) related to species extinction and immigration tendencies. Snake assemblages were significantly nested and were shaped by extinction processes mediated through area effects and habitat nestedness. The nestedness of snake assemblages was not due to passive sampling or selective colonization. From a conservation viewpoint, our results indicate that we should protect both the largest island with the most species-rich community and habitat-rich islands to maximize the number of species preserved . 展开更多
关键词 Habitat fragmentation Habitat nestedness NESTEDNESS Selective extinction SNAKE Thousand Island Lake
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Impact of deforestation on habitat connectivity thresholds for large carnivores in tropical forests 被引量:2
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作者 Miriam A.Zemanova Humberto L.Perotto-Baldivieso +3 位作者 Emily L.Dickins Andrew B.Gill John P.Leonard David B.Wester 《Ecological Processes》 SCIE EI 2017年第1期214-224,共11页
Introduction:Deforestation significantly impacts large carnivores that depend on large tracts of interconnected forest habitat and that are sensitive to human activities.Understanding the relationship between habitat ... Introduction:Deforestation significantly impacts large carnivores that depend on large tracts of interconnected forest habitat and that are sensitive to human activities.Understanding the relationship between habitat use and spatial distribution of such species across human modified landscapes is critical when planning effective conservation strategies.This study assessed the presence of potential landscape connectivity thresholds resulting from habitat fragmentation associated with different deforestation patterns using a scale-based approach that links species-specific home ranges with the extent of anthropogenic activities.The objectives were(1)to quantify the spatial and temporal distribution of natural vegetation for five common deforestation patterns and(2)to evaluate the connectivity associated with these patterns and the existence of potential thresholds affecting jaguar dispersal.The Bolivian lowlands,located within jaguar conservation units,were analysed with landscape metrics to capture the spatial and temporal changes within deforested areas and to determine potential impact on jaguar connectivity and connectivity thresholds for dispersal.Results:Over the period of 1976–2005,the amount of natural vegetation has decreased by more than 40%in all locations with the biggest changes occurring between 1991 and 2000.Landscape spatial structure around jaguar locations showed that jaguars used areas with mean proportion of natural areas=83.14%(SE=3.72%),mean patch density=1.16 patches/100 ha(SE=0.28 patches/100 ha),mean patch area=616.95 ha(SE=172.89 ha)and mean edge density=705.27 m/ha(SE=182.19 m/ha).We observed strong fragmentation processes in all study locations,which has resulted in the connectivity of jaguar habitat decreasing to<20%by 2005.A connectivity threshold zone was observed when the proportion of natural vegetation was less than 58.4%(SE=1.3).Conclusions:Assessing fragmentation and connectivity for carnivores within the extent of human-modified landscapes proved to be an effective way to understand the changes caused by deforestation and their potential effects on large carnivore habitats.Our study highlights the importance of scale-based approaches for assessing current conservation challenges to protect large carnivores. 展开更多
关键词 Bolivian lowlands Habitat fragmentation Landscape metrics Panthera onca THRESHOLD
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Persistent pollutants and the patchiness of urban green areas as drivers of genetic richness in the epiphytic moss Leptodon smithii
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作者 Valeria Spagnuolo Flavia De Nicola +5 位作者 Stefano Terracciano Roberto Bargagli Daniela Baldantoni Fabrizio Monaci Anna Alfani Simonetta Giordano 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第12期2493-2499,共7页
We determined genetic variation and metal and polycyclic aromatic hydrocarbon concentrations in Leptodon smithii moss collected in holm oak stands at cities, outskirts and remote areas of Campania and Tuscany(Italy)... We determined genetic variation and metal and polycyclic aromatic hydrocarbon concentrations in Leptodon smithii moss collected in holm oak stands at cities, outskirts and remote areas of Campania and Tuscany(Italy) to investigate if anthropogenic pressure(pollutant emissions and land use change) affects moss genetic richness. In both regions, metal and polycyclic aromatic hydrocarbon concentrations reflected the trend urban 〉 outskirts 〉 remote areas, excepting Tuscany remote site. In both regions,the moss gene diversity increased from urban to remote areas. The findings suggest the extent and the fragmentation of urban green areas, as drivers of moss genetic richness. 展开更多
关键词 Gene diversity Metals Polycyclic aromatic hydrocarbons Habitat fragmentation Environmental disturbance
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The integration of climate change,spatial dynamics,and habitat fragmentation:A conceptual overview
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作者 Marcel HOLYOAK Sacha K.HEATH 《Integrative Zoology》 SCIE CSCD 2016年第1期40-59,共20页
A growing number of studies have looked at how climate change alters the effects of habitat fragmentation and degradation on both single and multiple species;some raise concern that biodiversity loss and its effects w... A growing number of studies have looked at how climate change alters the effects of habitat fragmentation and degradation on both single and multiple species;some raise concern that biodiversity loss and its effects will be exacerbated.The published literature on spatial dynamics(such as dispersal and metapopulation dynamics),habitat fragmentation and climate change requires synthesis and a conceptual framework to simplify thinking.We propose a framework that integrates how climate change affects spatial population dynamics and the effects of habitat fragmentation in terms of:(i)habitat quality,quantity and distribution;(ii)habitat connectivity;and(iii)the dynamics of habitat itself.We use the framework to categorize existing autecological studies and investigate how each is affected by anthropogenic climate change.It is clear that a changing climate produces changes in the geographic distribution of climatic conditions,and the amount and quality of habitat.The most thorough published studies show how such changes impact metapopulation persistence,source-sink dynamics,changes in species’geographic range and community composition.Climate-related changes in movement behavior and quantity,quality and distribution of habitat have also produced empirical changes in habitat connectivity for some species.An underexplored area is how habitat dynamics that are driven by climatic processes will affect species that live in dynamic habitats.We end our discussion by suggesting ways to improve current attempts to integrate climate change,spatial population dynamics and habitat fragmentation effects,and suggest distinct areas of study that might provide opportunities for more fully integrative work. 展开更多
关键词 global change global climate change habitat fragmentation METAPOPULATION spatial dynamics.
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