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Effect of human disturbance on the structure and regeneration of forests in the Nevado de Toluca National Park, Mexico 被引量:5
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作者 Angel Rolando Endara Agramont Sergio Franco Maass +2 位作者 Gabino Nava Bernal Juan Ignacio Valdez Hernández Todd S.Fredericksen 《Journal of Forestry Research》 CAS CSCD 2012年第1期39-44,共6页
Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those domi- nated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The... Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those domi- nated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The vertical structure was defined by three strata in the coniferous forests and two strata in the broadleaved forests. Timber harvesting in Abies religiosa and Quercus laurina forests and fires generated by humans in Pinus hartwegii forests impeded the recruitment of saplings. Mature trees were also heavily impacted by logging in Pinus hartwegii forests. On the contrary, Alnusjorullensis forests were increas- ing due to the disturbance of Pinus and Quercus forests, as well aban- doned crop lands within the park. A combination of logging, uncon- trolled fire, and grazing appears to be compromising the recruitment of important tree species in this national park. These factors, together with human settlements, have also increased the proportion of early succes- sional species. Changes in forest structure from human disturbance indicate a need to control these activities if conservation goals are not to be compromised. 展开更多
关键词 forest structure human disturbance mountain forests
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Human Disturbance Reduces Plant Species Diversity and Stability of Phyllostachys pubescens Forests 被引量:1
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作者 Ji Lei Rong Chen +1 位作者 Renyi Gui Jianshuang Gao 《Research in Ecology》 2020年第1期1-11,共11页
Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems.Human activity can completely alter plant species diversity and cause serious degradation of ecosystems bu... Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems.Human activity can completely alter plant species diversity and cause serious degradation of ecosystems but its impact on bamboo forest still lacks of systematic evaluation.In this study,we performed a field investigation to reveal the influences of human disturbances on the plant diversity and stability of Moso bamboo forests at Southern China.The selected bamboo fields contained different intensities of human activities that could be classified as slight,moderate and severe disturbance level.Species richness index S,Shannon-Wienner index H,Simpson index D,Pielou index Jsw,community similarity index IS and community stability index were employed to quantitatively evaluate the plant species diversity and stability.The survey revealed that there were 203 species belonging to 83 families and 108 genera in Moso bamboo forests.The number of plant species in the Moso bamboo forests decreased with the increasing of disturbance intensity.The species diversity indexes generally followed the order of slight>moderate>severe disturbance,as well as the richness index S,Shannon-Wienner index H and Pielou index Jsw.The similarity and species stability of the bamboo forest communities also decreased with the increase of the disturbance intensity.Under the severe disturbance,plant species replacement occurred strongly.The obtained results provide some a guideline for the sustainable management of bamboo forest. 展开更多
关键词 human disturbance Bamboo forest Species diversity STABILITY
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Resource selection of moose(Alces alces cameloides) and their response to human disturbances in the northwestern slope of Lesser Khingan Mountains, northeastern China
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作者 HU Suxian JIANG Guangshun +2 位作者 MA Jianzhang ZHANG Minghai LIU Hui 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第4期727-734,共8页
Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the ... Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the southern most edge of its distribution in Asia. To study resource selection characteristics of moose and their response to human distur- bances and forest resource variables, the field work was conducted in Heilongiiang Provincial Shengshan Forestry Farm, which is located in the northwestern slope of Lesser Khingan Mountains, northeastern China, from January to March in both 2006 and 2007. A total of 428 plots were examined within the study area. Signs of moose use were found in 19 plots. Based on the analysis of resource selection function, we found that moose selected areas with higher densities of mixed deciduous broadleaf patch and mixed coniferous and broad leaf patch, and a higher NDVI value. Moose avoided settlement 6 km away and remained low probability of occurrence within 3 km from roads, 展开更多
关键词 Alces alces cameloides human disturbances resource selec-tion function Kappa statistic
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Effect of Human Disturbance on Species Diversity of Staphylidae
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作者 Li Yujie Zhang Jindong 《Plant Diseases and Pests》 CAS 2015年第6期30-34,共5页
From July to September in 2005, the resources of Staphylinidae in four types of human disturbance regions ( human gathering area, grain for green re- gion, grazing region and rare disturbance region) in Erlang Mount... From July to September in 2005, the resources of Staphylinidae in four types of human disturbance regions ( human gathering area, grain for green re- gion, grazing region and rare disturbance region) in Erlang Mountain, Sichuan were investigated, and the individual number, species composition and diversity characteristics were analyzed. The result showed that the individual number, species diversity index (H') and the evenness index (J) decreased with the decrea- sing intensity of human disturbance. The species diversity index and the evenness index in human gathering area were the highest of 4.1301 6 and O. 850 2, respec- tively. Simpson predominant index (A) enhanced with the decreasing intensity of human disturbance, which reached the peak of 0. 199 6 in rare disturbance re- gion. The community similarity index/3 of Staphylinidae at different human disturbance regions ranged from 0 -0.25, indicating that the species compositions were extremely different among this four types of regions. Based on these results, it was found that human activities were closely related to individuals number and species dive^ity of Staphylinidae in Erlang Mountain, and human disturbance may add habitat heterogeneity and facilitate to the species diversity of Staphylinidae communi- ties. 展开更多
关键词 STAPHYLINIDAE human disturbance Species diversity Erlang Mountain
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Impact of Human Disturbance on Fiddler Crab (<i>Uca tangeri</i>) Burrow Morphology, Distribution and Chemistry at Eagle Island, Niger Delta, Nigeria
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作者 Aroloye O. Numbere 《Open Journal of Marine Science》 2020年第4期191-202,共12页
<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The... <span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 55) followed by medium (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 30) and highly (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.</span> 展开更多
关键词 BURROW human disturbance Heavy Metals MANGROVES Fiddler Crab Sand Fill
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Effects of human disturbance on liana community diversity and structure in a tropical rainforest, Malaysia: implication for conservation 被引量:6
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作者 Patrick Addo-Fordjour Zakaria B.Rahmad A.M.S.Shahrul 《Journal of Plant Ecology》 SCIE 2012年第4期391-399,共9页
Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the respon... Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the response of liana communities to disturbance,calling for more research in the area.The present study was carried out to investigate the response of liana diversity and structure to human disturbance within two major forests in the Penang National Park,Malaysia.The study also looked at the implication of the findings for conservation.Methods A total of 15 40×40-m^(2)(or 40-m×40-m)plots each were randomly located across a range of habitats in a primary forest and disturbed secondary forest.Trees with diameter at breast height≥10 cm were examined for lianas with diameter≥2 cm.Both lianas and trees were enumerated and compared between the two forests.Diversity and structural variables of lianas were compared between the two forests using the t-test analysis.Tree abundance was also compared between the two forests with t-test,while linear regression analysis was run to determine the effects of tree abundance on liana abundance.Important Findings A total of 46 liana species belonging to 27 genera and 15 families were identified in the study.Human disturbance significantly reduced liana species richness and species diversity in the secondary forest.Liana abundance remained the same in both forests whereas liana basal area was;7 times higher in the primary forest.Twiners and hook climbers were significantly more abundant in the primary and secondary forest,respectively.Large diameter lianas were more abundant in the primary forest compared with the secondary forest.The diameter distribution of most families in the primary forest followed the inverted J-shaped curve whereas only a few of the families in the secondary forest did so.Tree abundance was significantly higher in the primary forest.The abundance of lianas significantly depended on tree abundance in all the forests.The study has provided evidence of negative effects of human disturbance on liana diversity and structure that does not auger well for biodiversity in the forest.In view of the critical role of lianas in maintaining biodiversity in the forest ecosystem,lianas in the national park should be protected from further exploitation. 展开更多
关键词 climbing mechanism CONSERVATION liana diversity and structure human disturbance
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Fluctuations and patterns of desert rodent communities under human disturbance:fluctuating tendency and sensitive response of their population
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作者 Xiaodong WU Heping FU 《Frontiers in Biology》 CSCD 2008年第1期89-100,共12页
The four kinds of sites under different kinds of human disturbances,i.e.a farmland area,a rotational-grazing area,an over-grazing area and a prohibited-grazing area,were selected in the typical region of the Alashan D... The four kinds of sites under different kinds of human disturbances,i.e.a farmland area,a rotational-grazing area,an over-grazing area and a prohibited-grazing area,were selected in the typical region of the Alashan Desert of Inner Mongolia from April to October in 2002,2003 and 2004 respectively.The fluctuating tendency of rodent communities and the sensitive response of their populations were studied using mark-recapture and trap-day methods.The four kinds of mark-recapture samples and line samples were taken in different human disturbance areas.The area of the mark-recapturing sample was 0.95 hm2 and that of the line sample was 10 km2.The samples were collected every month in the mark-recapturing sites for four consecutive days and in line sites in April,July and October every year.The variable matrix was composed of the numbers of captured rodents of the rodent communities.The sensitive response of the populations in the communities was analyzed with principal component analysis(PCA).Results showed that there were different types of rodent communities under different kinds of human disturbance on two scales in three years.In each scale,there were large differences in both the number of species and the number of main population in the rodent communities under different kinds of human disturbance on the farmland area and over-grazing area especially.The results of PCA showed that the sensitive response of the populations of the communities was significantly different under different kinds of human disturbance on the two scales in the three years.Cricetulus barabensis was the most sensitive on the farmland area,there were no differences in sensitive response of the various rodents on the rotational-grazing area,and Dipus sagitta and Phodopus roborovskii were the most sensitive in the over-grazing area. 展开更多
关键词 RODENT community human disturbance POPULATION SENSITIVE DESERT
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Cause and consequence of landscape fragmentation and changing disturbance by socio-economic development in mountain landscape system of South Korea 被引量:1
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作者 Sun Kee Hong Center for Education Research, Seoul National University, Seoul 151 742, Korea 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1999年第2期54-60,共7页
Through the statistics and the analysis of landscape map, changes of lands use regime and landscape structure during 20 years were investigated in the agriculture forestry complexed mountain landscape system of Yangd... Through the statistics and the analysis of landscape map, changes of lands use regime and landscape structure during 20 years were investigated in the agriculture forestry complexed mountain landscape system of Yangdong Myon, Yangpyung Gun in the central Korea. Landscape changes of this region was inter related to the recent socio economic development of rural life. Utilization of biomass and other traditional forest management were drastically abandoned in recent 10 years. Landscape analysis of maps showed that the area of secondary vegetation that had been sustained by human nature disturbance was decreased by using of plantation during this time. Those decreased areas were replaced to plantation for wood production and other purpose. Past area of woody species dominated in plantation also substituted to other species. Traditional human activity on secondary vegetation was disappeared. Consequently, the advanced management regimes such as new plantation and cultivation extending areas were increased in abandoned land. 展开更多
关键词 human disturbance Korea mountain landscape landscape fragmentation urbanization.
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Genetic effects of historical anthropogenic disturbance on a long-lived endangered tropical tree Vatica mangachapoi
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作者 Zhicong Dai Chuncan Si +6 位作者 Deli Zhai Ping Huang Shanshan Qi Ying Lin Ruiping Wang Qiongxin Zhong Daolin Du 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第2期291-299,共9页
The endangered Vatica mangachapoi,a longlived,tropical tree with economic and ecological importance found in Hainan,China,was used to assess the hypothesis that historical human activities in Hainan’s tropical rain f... The endangered Vatica mangachapoi,a longlived,tropical tree with economic and ecological importance found in Hainan,China,was used to assess the hypothesis that historical human activities in Hainan’s tropical rain forest could have negative effects on the genetic diversity of V.mangachapoi.Three hundred and twenty individuals from 11 natural populations—which were classified into three groups according to levels of disturbance—were sampled and analyzed with ISSRmarkers.Although genetic diversity of V.mangachapoi is high at the species level,it is relatively low within populations.A significant genetic differentiation occurs among different disturbance levels.Significant isolation-by-distance indicated relevant historical anthropogenic changes.Our findings showed that historical human disturbances significantly increase the genetic differentiation and slightly decrease the genetic diversity of long-lived tree V.mangachapoi.Relevant targeting conservation actions were recommended. 展开更多
关键词 Endangered plant Genetic variability human disturbance Tropical forest Vatica mangachapoi
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Impacts of environmental conditions on woody plant diversity,structure and regeneration in forest patches of Guna Mountain:Este District,South Gondar Zone,Ethiopia
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作者 DILNESSA Gashaye ZERIHUN Woldu +1 位作者 SILESHI Nemomissa ENYEW Adgo 《Journal of Mountain Science》 SCIE CSCD 2023年第7期1940-1953,共14页
Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,str... Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,structure and regeneration in forest patches of Guna Mountain:the case of Este District,South Gondar Zone,north-west Ethiopia.A total of 71 square sample plots(400 m~2 each) were established at 10 transects laid in five forest patches of the study area to collect vegetation data including the abundance of species,height and diameter at breast height(DBH).Environmental data including available potassium,available phosphorus,cation exchange capacity,soil texture,electrical conductivity,soil acidity,total nitrogen,organic matter,organic carbon,sodium adsorption ratio,exchangeable sodium percentage,bulk density,aspect,elevation,slope,latitude and longitude data were collected in the same plots.A correlation analysis between vegetation and environmental data was performed using rcorr(x) function in package Hmisc in R Programming Language.The most pronounced impacts were observed in altitude,grazing and pH,positively and silt,sand,electrical conductivity and cation exchange capacity,negatively.In addition,strong and significant impacts on plant structure were also observed due to the variation in soil texture and p H.The difference in aspect,sand and slope also impacted plant regeneration.The study showed that environmental parameters influence the diversity,structure and regeneration of woody plants.These parameters can be considered in the rehabilitation of the vegetation cover and conservation efforts of the rare woody species.Conservation measures that can minimalize the negative influences of environmental conditions can be applied through collaboration with communities around the forest patches. 展开更多
关键词 ALTITUDE human disturbance Environmental condition Plant diversity Plant structure VEGETATION
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Exploring the effects of anthropogenic disturbance on predator inspection activity in Trinidadian guppies
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作者 Alix J.P Brusseau Laurence E.A.Feyten +1 位作者 Adam L.Crane Grant E.Brown 《Current Zoology》 SCIE CAS CSCD 2024年第1期109-111,共3页
Prey animals are often faced with uncertainty due to having imperfect information regarding current local conditions,including predation risks and the availability of reliable foraging opportunities(Dall 2010).As this... Prey animals are often faced with uncertainty due to having imperfect information regarding current local conditions,including predation risks and the availability of reliable foraging opportunities(Dall 2010).As this uncertainty increases,the probability of making costly behavioral errors also increases,leading to more risk averse behavioral tactics(Feyten et al.2019).For example,Trinidadian guppies Poecilia reticulata are far more risk averse when faced with multiple unknown sources of risk assessment information than when faced with a mix of known and unknown cues(Feyten et al.2019).Prey can reduce uncertainty by gathering and integrating private and social information regarding current risk levels within microhabitats(Dall 2010;Munoz and Blumstein 2012). 展开更多
关键词 human disturbance information availability information reliability predator-prey interactions risk assessment UNCERTAINTY
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Estimating and mapping forest biomass in northeast China using joint forest resources inventory and remote sensing data 被引量:5
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作者 Xinchuang Wang Shidong Wang Limin Dai 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期789-803,共15页
Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study,... Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study, forest plot sample data, forest resources inventory(FRI) data, and SPOT Vegetation(SPOT-VGT) normalized difference vegetation index(NDVI) data were used to estimate total forest biomass and spatial distribution of forest biomass in northeast China(with 1 km resolution). Total forest biomass at both county and provincial scales was estimated using FRI data of 11 different forest types obtained by sampling 1156 forest plots, and newly-created volume to biomass conversion models. The biomass density at the county scale and SPOT-VGT NDVI data were used to estimate the spatial distribution of forest biomass. The results suggest that the total forest biomass was 2.4 Pg(1 Pg = 10g), with an average of 77.2 Mg ha, during the study period. Forests having greater biomass density were located in the middle mountain ranges in the study area. Human activities affected forest biomass at different elevations, slopes and aspects. The results suggest that the volume to biomass conversion models that could be developed using more plot samples and more detailed forest type classifications would be better suited for the study area and would provide more accurate biomass estimates. Use of both FRI and remote sensing data allowed the down-scaling of regional forest biomass statistics to forest cover pixels to produce a relatively fineresolution biomass map. 展开更多
关键词 Forest biomass Biomass density Spatial distribution human disturbance Remote sensing
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Landscape ecological characteristics in temporal changes of riverside open space in urbanized area 被引量:3
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作者 Shigeru TANIMOTO Nobukazu NAKAGOSHI 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1999年第2期28-32,共5页
1IntroductionRecentlyinJapan,theriverspaceinurbanareasischangingintoriverparks,riveropenspaceandnatureorient... 1IntroductionRecentlyinJapan,theriverspaceinurbanareasischangingintoriverparks,riveropenspaceandnatureorientedbank.Consequen... 展开更多
关键词 human disturbance landscape index park planning riparian vegetation urbanization park planning riparian vegetation urbanization.
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Functional trait and community phylogenetic analyses reveal environmental filtering as the major determinant of assembly of tropical forest tree communities in the Western Ghats biodiversity hotspot in India 被引量:2
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作者 K.Nagaraju Shivaprakash B.R.Ramesh +1 位作者 Ramanan Umashaanker Selvadurai Dayanandan 《Forest Ecosystems》 SCIE CSCD 2018年第4期345-360,共16页
Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is t... Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is thought to be the first order determinant of abundance and distribution patterns of tree species with contrasting traits such as evergreen and deciduous leaf phenology. However, the relative role of neutral, and niche-based processes in the evolution of these patterns remain poorly understood.Methods: Here, we perform an integrated analysis of the data on tree species abundance, functional traits and community phylogeny from a network of 96 forest plots, each 1 ha in size, distributed along a broad environmental gradient in the central Western Ghats, India. Then, we determine the relative importance of various process in assembly and structuring of tropical forest communities with evergreen and deciduous leaf phenology.Results: The deciduous leaf phenological trait has repeatedly evolved among multiple distantly related lineages. Tree communities in dry deciduous forests were phylogenetically clustered and showed a low range and variance of functional traits related to light harvesting, reproduction, and growth suggesting niche-based processes such as environmental filtering play a vital role in the assembly of tree communities in these forests. The external factors such as human-mediated disturbance also significantly, but to a lesser extent, influences the species and phylogenetic turnover.Conclusions: These findings revealed that the environmental filtering plays a significant role in assembly of tree communities in the biologically diverse tropical forests in the Western Ghats biodiversity hotspot. 展开更多
关键词 Functional traits Phylogenetic turnover DECIDUOUS EVERGREEN Niche-based processes human disturbance
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Heavy collecting induces smaller and deeper Fritillariae Cirrhosae Bulbus in the wild 被引量:1
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作者 Xinhui Li Lin Liu +1 位作者 Xu Gu Jianying Xiang 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第4期208-213,共6页
Fritillariae Cirrhosae Bulbus is a well-known traditional Chine medicinal herb. However, the demand for this herb is leading to over-collection and its decline in the wild. This study aims to investigate the ecologica... Fritillariae Cirrhosae Bulbus is a well-known traditional Chine medicinal herb. However, the demand for this herb is leading to over-collection and its decline in the wild. This study aims to investigate the ecological conditions of Fritillaria cirrhosa under the influence of human disturbance, biotic species interactions and climatic conditions. We established a total of 78 plots at 14 sites of F. cirrhosa in its distribution center, the Hengduan Mountains area. At each site, we estimated the abundance of F. cirrhosa at different distances from roads. The diameter and height of F. cirrhosa fruit and bulbs were measured and compared to underground bulb depth. We then analyzed the effects of environmental conditions and human disturbance on the abundance of F. cirrhosa using variance partitioning. We found that(1)abundance of F. cirrhosa and their underground bulb depth showed a significant linear increase with the distance from the main road;(2) the diameter/height of fruits and the diameter/height of fruits/bulbs showed significantly different responses to the human disturbance;(3) the community associates,climate and spatial conditions can explain 58%, 22% and 27%, respectively, of the variance in the F. cirrhosa abundance. These results highlight the fact that human disturbance and biotic factors have a great influence on the survival of F. cirrhosa, even more than climate conditions. 展开更多
关键词 Fritillaria cirrhosa human disturbance Plant abundance Biotic interactions
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Reproduction and genetic diversity of Juniperus squamata along an elevational gradient in the Hengduan Mountains 被引量:1
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作者 Tsam Ju Zhi-Tong Han +5 位作者 Markus Ruhsam Jia-Liang Li Wen-Jing Tao Sonam Tso Georg Miehe Kang-Shan Mao 《Plant Diversity》 SCIE CAS CSCD 2022年第4期369-376,共8页
Elevation plays a crucial factor in the distribution of plants,as environmental conditions become increasingly harsh at higher elevations.Previous studies have mainly focused on the effects of large-scale elevational ... Elevation plays a crucial factor in the distribution of plants,as environmental conditions become increasingly harsh at higher elevations.Previous studies have mainly focused on the effects of large-scale elevational gradients on plants,with little attention on the impact of smaller-scale gradients.In this study we used 14 microsatellite loci to survey the genetic structure of 332 Juniperus squamata plants along elevation gradient from two sites in the Hengduan Mountains.We found that the genetic structure(single,clonal,mosaic)of J.squamata shrubs is affected by differences in elevational gradients of only 150 m.Shrubs in the mid-elevation plots rarely have a clonal or mosaic structure compared to shrubs in lower-or higher-elevation plots.Human activity can significantly affect genetic structure,as well as reproductive strategy and genetic diversity.Sub-populations at mid-elevations had the highest yield of seed cones,lower levels of asexual reproduction and higher levels of genetic diversity.This may be due to the trade-off between elevational stress and anthropogenic disturbance at mid-elevation since there is greater elevational stress at higher-elevations and greater intensity of anthropogenic disturbance at lower-elevations.Our findings provide new insights into the finer scale genetic structure of alpine shrubs,which may improve the conservation and management of shrublands,a major vegetation type on the Hengduan Mountains and the Qinghai-Tibet Plateau. 展开更多
关键词 Fine-scale structure Juniperus squamata High elevation human disturbance
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Does bird photography affect nest predation and feeding frequency? 被引量:1
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作者 Xiaocai Tan Shilong Liu +1 位作者 Eben Goodale Aiwu Jiang 《Avian Research》 SCIE CSCD 2022年第2期159-164,共6页
Bird photography is a popular and growing form of ecotourism that contributes to the economic growth of local communities,but its disturbance to bird reproduction remains understudied.We worked in a tropical forest of... Bird photography is a popular and growing form of ecotourism that contributes to the economic growth of local communities,but its disturbance to bird reproduction remains understudied.We worked in a tropical forest of southern China,which has experienced a sharp increase in the number of photographers in recent years.We compared nests that were photographed and those that were not,in their nest predation and parental feeding rates.Including nests of 42 species,the results demonstrate that the predation rate of nests that were not photographed(incubation stage:43.3%of 194 nests;nestling stage:34.5%of 110 nests)was significantly higher than that of photographed ones(incubation:2.4%of 83 nests;nestling:11.1%of 81 nests).Among different nest types,open cup nests in shrub and trees were most affected by photography,in both incubation and nestling stages.Of five factors investigated,including three natural factors(nest stage,structure and position),and two anthropogenic factors(photography and distance to forest edge),only photographic disturbance and nest structure had significant effects(open nests had higher predation).The feeding frequency at nests when photographers were present was not strongly different from when they were not present.Human activity therefore had no negative effects on the birds,but showed a positive effect on their nesting success,in terms of reducing nest predation rates.However,there needs to be further assessment of other aspects of nesting(e.g.,clutch size,duration of nestlings in nests),and other kinds of stress responses(e.g.,hormonal changes),before the total effect of bird photography can be understood. 展开更多
关键词 Bird photography Bird reproduction ECOTOURISM human disturbance Nest predation
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Harvesting of forest products and implications for Afrotemperate bird communities in a montane forest of the Eastern Cape, South Africa
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作者 Jessica Leaver Johann C.Carstens Michael I.Cherry 《Forest Ecosystems》 SCIE CSCD 2019年第4期352-366,共15页
Background: Harvesting of forest products is a widespread driver of disturbance in developing nations, where policies are increasingly aimed at managing natural forests for sustainable use. There is thus need for rese... Background: Harvesting of forest products is a widespread driver of disturbance in developing nations, where policies are increasingly aimed at managing natural forests for sustainable use. There is thus need for research aimed at understanding the impact of resource use on forest habitats and concomitant effects on biodiversity.Afromontane forests in the Eastern Cape, South Africa are harvested informally for poles and medicinal bark and occur along elevational gradients of 800–1600 m above sea level. Patterns of spatial diversity and human disturbance are expected to be affected by elevation. Furthermore, species’ responses to disturbance are expected to vary depending on their level of habitat specialisation. Understanding harvest impacts on forest biodiversity thus requires disentangling the separate effects of elevation and disturbance, and considering forest-specialist and forest-generalist species separately. This study comprises two components. First, harvest activities, resultant harvestmediated habitat heterogeneity, and avifaunal species richness, composition and beta-diversity were compared across two elevational zones in a harvested forest. Second, the role of harvest-mediated habitat heterogeneity in driving patterns of avifaunal diversity were assessed, while controlling for elevation, and considering forest-specialist and forest-generalist species separately.Results: Harvest rates were higher, and activities more varied in the lower elevation zone, with significant impacts of harvesting on habitat features resulting in higher harvest-mediated habitat heterogeneity at lower elevations.Harvest-mediated increases in habitat heterogeneity positively affected forest-generalist species richness, while forest-specialist richness was negatively affected. While species composition of both groups differed across elevational zones, variation in harvest-mediated habitat heterogeneity did not fully account for this, suggesting that factors other than disturbance shape avifaunal communities along the elevation gradient. However, variation in harvest-mediated habitat heterogeneity accounted for the amount of beta-diversity attributed to species turnover in the forest-specialist assemblage, indicating that harvest disturbances affect the mechanisms driving beta-diversity of this group.Conclusion: Spatial patterns of avifaunal diversity are affected by elevation over a 300-m gradient. Harvesting results in increased habitat heterogeneity, which variably affects avifaunal communities at the forest-scale, with positive effects for forest generalists and negative effects for forest-specialists. 展开更多
关键词 human disturbance Habitat heterogeneity Habitat modification BETA-DIVERSITY ELEVATION Generalist species Forest-specialist species
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Microhabitat characteristics related to seasonal roost switching:implications from a threatened and introduced cockatoo species in an urban landscape
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作者 Sifeng Wang L.M.Chu 《Avian Research》 CSCD 2021年第3期317-326,共10页
Background:Communal roosting is a common avian social behaviour,which potentially provides foraging benefits,predation avoidance or thermoregulation in birds.To identify the crucial environmental factors associated wi... Background:Communal roosting is a common avian social behaviour,which potentially provides foraging benefits,predation avoidance or thermoregulation in birds.To identify the crucial environmental factors associated with roost site selection,most studies have focused on the comparison of physical characteristics between roosts and non-roosts.However,the differences among roosts have usually been neglected and the causes of roost switching have seldom been investigated.Methods:To explore the variations among roost sites and assess the most influential environmental factors related to seasonal roost switching,we conducted a 105-day observation on an introduced population of critically endan-gered Yellow-crested Cockatoo(Cacatua sulphurea)in an urban environment in Hong Kong from 2014 to 2016.We identified seven roost sites that were occupied in different seasons and then measured their microhabitat character-istics in terms of land use types,human disturbance and microclimate temperature.To quantify these differences,we used Pearson’s chi-squared test,partial least squares determinant analysis(PLS-DA)and one-way repeated measures ANOVA,respectively.Results:Our results distinguished roost sites occupied in three seasons,i.e.spring,summer and winter roosts,using several microhabitat characteristics.The land use types were significantly associated with roosts,where spring roosts were usually located in tree-dominated areas,which are the major feeding grounds.The discriminant analysis on human disturbance variables indicated that summer roosts were positively associated with night illumination.The microhabitat temperatures of winter roosts were significantly higher than those of most other roosts on cold nights.Conclusions:The results highlighted significant variations among roosts,and seasonal roost switching was likely driven by specific microhabitat characteristics of each roost site,such as microclimate.It also helps us understand the behavioural adaptation of birds to urban environments. 展开更多
关键词 Communal roosting human disturbance Land use MICROCLIMATE Seasonal variation
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Does disturbance regime change community assembly of angiosperm plant communities in the boreal forest? 被引量:6
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作者 Jian Zhang Stephen J.Mayor Fangliang He 《Journal of Plant Ecology》 SCIE 2014年第2期188-201,共14页
Aims To examine if and how species and phylogenetic diversity change in relation to disturbance,we conducted a review of ecological literature by testing the consistency of the relationship between phylogenetic divers... Aims To examine if and how species and phylogenetic diversity change in relation to disturbance,we conducted a review of ecological literature by testing the consistency of the relationship between phylogenetic diversity and disturbance and compared taxonomic groups,type of disturbance and ecosystem/habitat context.We provide a case study of the phylogenetic diversity–disturbance relationship in angiosperm plant communities of a boreal forest region,compared with types of natural and anthropogenic disturbances and plant growth forms.Methods Using a large-scale sampling plot network along a complete(0–100%)anthropogenic disturbance gradient in the boreal biome,we compared the changes of angiosperm plant community structure and composition across plots.We estimated natural disturbance with historical records of major fires.We then calculated phylogenetic diversity indexes and determined species richness in order to compare linear and polynomial trends along disturbance gradients.We also compared the changes of community structure for different types of anthropogenic disturbances and examined how the relationships between species and phylogenetic diversity and disturbance regimes vary among three different life forms(i.e.forbs,graminoids and woody plants).Important Findings Phylogenetic diversity was inconsistently related to disturbance in previous studies,regardless of taxon,disturbance type or ecosystem context.In the understudied boreal ecosystem,angiosperm plant communities varied greatly in species richness and phylogenetic diversity along anthropogenic disturbance gradients and among different disturbance types.In general,a quadratic curve described the relationship between species richness and anthropogenic disturbance,with the highest richness at intermediate anthropogenic disturbance levels.However,phylogenetic diversity was not related to disturbance in any consistent manner and species richness was not correlated with phylogenetic diversity.Phylogenetic relatedness was also inconsistent across plant growth forms and different anthropogenic disturbance types.Unlike the inconsistent patterns observed for anthropogenic disturbance,community assembly among localities varying in time since natural disturbance exhibited a distinct signature of phylogenetic relatedness,although those trends varied among plant growth forms. 展开更多
关键词 community assembly community phylogenetics community structure BIODIVERSITY human disturbance PHYLOGENY TAIGA
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