Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest chang...Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.展开更多
Five years＇ （2000-2004） continuous study has been carried out on small mammals such as rodents in seven different sample plots, at three different altitudes and in six different ecological environment types in the ...Five years＇ （2000-2004） continuous study has been carried out on small mammals such as rodents in seven different sample plots, at three different altitudes and in six different ecological environment types in the eastern part of the Wuling Mountains, south bank of the Three Gorges of Yangtze River in Hubei. A total of 29 297 rat clamps/times were placed and 2271 small mammals such as rodents were captured, and 26 small mammals were captured by other means. All the small mammals captured belonged to 8 families 19 genera and 24 species, of which rodentia accounted for 70.83% and insectivora 29.17%. Through analysis of the data, the results showed that： 1 ） although the species richness had a trend of increasing along different sample plots as altitude increased from south to north, quite a few species showed a wide habitat range in a vertical distribution （ 15 species were dispersed over three zones and two species over two zones） , indicating a strong adaptability of small mammals such as rOdents at lower altitudes in most areas and comparatively less vertical span of entire mountains; 2） whether in seven different sample plots or six different ecological types, Apodemus agrarius and Rattus norvegicus were dominant species below 1200m, and Anourosorex squamipes, Niviventer confucianus and Apodemus draco were dominant above altitudes of 1300m, however, in quantity they were short of identical regularity, meaning they did not increase as the altitude did, or decrease as the ecological areas changed; 3）the density in winter was obviously greater than that in spring, and the distribution showed an increasing trend along with altitude, but the density in different sample plots was short of identical regularity, showing changes in different seasons and altitude grades had an important impact on small mammals such as rodents; 4） in species diversity and evenness index, there were obvious changes between the seven different sample plots, probably caused by frequent human interference in this area. Comparatively speaking, there was less human interference at high altitudes where vegetation was rich and had a high diversity and evenness index, and the boundary effect and community stability were obvious. Most ecological types have been seriously interfered with due to excessive assart at low altitudes with singular vegetation and low diversity and evenness index and poor community stability, showing an ecosystem with poor anti-reversion. If human interference can be reduced in those communities at high altitudes with low diversity and evenness index, the biological diversity in the communities will gradually recover to similar levels of other ecological areas.展开更多
As a typical inland wetland, Yangguan nature reserve wetland in Dunhuang is one of the important stops of migratory route for birds, which is vulnerable and particular. Study on the community characteristics and speci...As a typical inland wetland, Yangguan nature reserve wetland in Dunhuang is one of the important stops of migratory route for birds, which is vulnerable and particular. Study on the community characteristics and species diversity of wetland has great signifi cance for biodiversity protection. Based on the fi eld investigation, the fl oristic composition, geographical elements and species diversity of wetland plants were studied in Yangguan reserve of Dunhuang. The results showed that 26 families, 56 genera and 74 species were recorded in the study area. The largest families were the Gramineae and Chenopodiaceae, accounting for 29.73% of the total. Herbs were the most abundant life-form, accounting for 77.03% of the total. The fl oral geographical elements of the plants were mainly composed of temperate zone distribution type. By using two way indicator species analysis(TWINSPAN), the vegetation in 36 sampling plots could be classifi ed into 8 communities. The species diversity indexes of communities were relatively low, but had large differences among each other. According to the importance value, the Margalef richness index(Rm) ranged from 0 to 4.200. Simpson diversity index(D) was between 0 and 0.512; Shannon diversity index(H) ranged from 0 to 1.400, and Pielou evenness index(J) was within the range of 0.538 to 1.000. The results indicated that the plant species were relatively rare and simple in general, the species diversity of communities was low, and the ecological environment was fragile in Yangguan nature reserve of Dunhuang.展开更多
[Objective] This study aimed at researching the species diversity of Populus shanxiensis community in Heichashan Mountain. [Method] Based on sampling methods, investigation in sampling spots was carried out according ...[Objective] This study aimed at researching the species diversity of Populus shanxiensis community in Heichashan Mountain. [Method] Based on sampling methods, investigation in sampling spots was carried out according to the important indicator, the abundance index （N0）, Simpson index （λ）, Shannon-Weiner index （H＇） and homogeneity index （E1 and E5） were used for analysis. [Results] Species diversity index of Populus shanxiensis community was not only depended on the species compositions of communities, but also closely related to the important value of species. The order of abundance index and diversity index in each layer of Populus shanxiensis community was herb layershrub layertree layer, and the abundance index was positively related to the diversity index; while the variation trend of community homogeneity index was different from that of abundance index and diversity index, and the homogeneity had shown negative correlation with the dominance. [Conclusion] In this study, the growth status and conditions of Populus shanxiensis were further understood and researched, which had laid theoretical foundation for protecting the endangered species and provided basic information for the future studies of endangered species and related disciplines.展开更多
Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging ...Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging to 46 family, 103 genera and 144 species were counted at ≥30 cm DBH （diameter at breast height） using 28 permanent belt transects with a size of 1 ha （10 m × 1000 m）. Four different tree communities were identified. The primary forests was dominated by Shorea robusta （mean density 464.77 trees.ha^-1, 105 species） and Schima wallichii （336.25 trees.ha^-1, 82 species）, while the secondary forests was dominated by Tectona grandis （333.88 trees.ha^-1, 105 species） and Hevea brasiliensis （299.67 trees.ha^-1, 82 species）. Overall mean basal area in this study was 18.01m2.ha^-1; the maximum value was recorded in primary Shorea forest （26.21 m2.ha^-1）. Mean density and diversity indices were differed significantly within four different communities. No significant differences were observed in number of species, genera, family and tree basal cover area. Significant relationships were found between the species richness and different tree population groups across the communities. Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumu- lation of native oligarchic small tree species. Seventeen species were recorded with 〈2 individuals of which Saraca asoka （Roxb.） de Wilde and Entada phaseoloides （L.） Men＇. etc. extensively used in local ethnomedicinal formulations. The present S. robusta Gaertn dominated forest was recorded richer （105 species） than other reported studies. Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests. Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur. The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T. grandis L. dominated community.展开更多
[ Objective] To reveal structure and function of alpine meadow ecosystem and thus to provide a scientific basis for development, utilization and scientific management of alpine meadow pasture as well as sustainable de...[ Objective] To reveal structure and function of alpine meadow ecosystem and thus to provide a scientific basis for development, utilization and scientific management of alpine meadow pasture as well as sustainable development of grassland agriculture. [ Method] Charactedstics of Kobresia humilis communities with primary vegetation （community I） and degraded vegetation （community II） were analyzed. [Result] Species richness, biodiversity index and biomass of the community I were respectively 42, 3. 531 and 3 553.1 g/m^2, which were respectively higher than those of the community II （37, 2.270 and 3 391.1 g/m^2）. Correlation analysis shows that community biomass was correlated positively with the dchness index （ P 〈 0.01 ）, and biodiversity index was correlated positively with the aboveground biomass and dchness index （ P 〈 0.01 ）. [ Conclusion] The Kobresia humilis community I has reasonable structure and large coverage of ground vegetation, which play an important role in maintenance of biodiversity and ecosystem function.展开更多
By using quadrat sampling method, the community structure and diversity of ground cover plants in the flight area in Tianjin Binhai International Airport were investigated from spring to autumn in 2015. The results sh...By using quadrat sampling method, the community structure and diversity of ground cover plants in the flight area in Tianjin Binhai International Airport were investigated from spring to autumn in 2015. The results showed that 58 plant species were recorded at the airport, belonging to 18 families and 48 genera. Dominant plant species showed seasonal characteristics. Specifically, lxeri chinensis （ Thunb. ） Nakai and Lagopsis supina （ Steph. ） Ik. -Gal. ex Knorr. were the dominant species in spring; Lagopsis supina, Cirsium setosum （Willd.） MB, Plantago asiatica L. , Cynanchum chinense R. Br. and Humulus scandens （I_our.） Merr. were the dominant species in summer; Chloris virgata Sw. and Eleusine indica （L.） Gaertn. were the dominant species in autumn. Quantitative characteris- tics of the dominant species, including the density, frequency, coverage and height, varied in different seasons. In different seasons, changes in the diversity of plant communities in three sampling points were analyzed. The results indicated that plant communities in summer exhibited the highest diversity and the most uni- form distribution. This study provided a theoretical basis for avoidance of bird strike in Tianjin Binhai International Airport.展开更多
Tree communities contribute to maintenance of species diversity in tropical forests. Coexistence of many tree species is not without competition. Therefore, coexistence of tree species and size diversities occur seque...Tree communities contribute to maintenance of species diversity in tropical forests. Coexistence of many tree species is not without competition. Therefore, coexistence of tree species and size diversities occur sequentially or simultaneously in tropical natural forests. Understanding coexistence and competition mechanisms of tree species requires knowledge of interactions within and between species. However, many conservation efforts and strategies failed due to inability to identify and maintain functional coexistence mechanisms among tree species in the forest. Also, most trees died because of pressure on their habitats and not because of limiting growth resources. Hence, species identity, minimum distance and size of the neighbouring trees which are responsible for coexistence of competing trees in most tropical forests have not been explicitly reviewed. Therefore, this review evaluated some of the density dependent mechanisms for coexistence of tree species alpha diversity in tropical forests. Many interactive mechanisms are responsible for coexistence tree species in tropical forests. Inter- and intra-specific competitions are the most significant and both facilitate positive and negative density dependence. Therefore, switching from negative to positive density dependence may occur in some situations. Positive and negative density effects regulate species abundance and coexistence through conspecific and heterospecific structures. Aggregates of conspecific and heterospecific neighbours constitute forest spatial structure. Negative density interactions are mutually exclusive and basically ranged from effect of species identity of neighbours, distance to neighbours and tree size of the neighbours to reference trees in the community structures. Some mechanisms shorten distances for heterospecific than conspecific interactions. Conspecific structures improved survival and growth of rare tree species. Interactive mechanisms in tree community and population structures facilitate species diversity and size inequality, respectively.展开更多
Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park （SBGE）, Chi...Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park （SBGE）, Chittagong, Bangladesh to analyze the natural regeneration and tree species diversity in disturbed and less disturbed zones. Stratified and systematic random sampling was used to select 50 sample plots from each of the two zones. A total number of 109 plant species from 43 families were recorded in the study; of which 93 species were of natural origin while the rest were planted. From the species with natural origin 66 were tree species, 9 were shrub species and 28 were climbers. Species richness, density of regeneration and disturbance index in the height classes （0- 0.5 m） and {dbh 〉 6 cm） indicated significant differences between the zones. The study analyzed how disturbances affect species diversity in the area. It was found that species richness and basal area are negatively related with disturbances. Moreover, density （N/ha） of trees was more likely to decrease with increasing tree height that reflects the huge demand of local people to harvest large trees as part of their income generating activities. The study findings have implications for future managementdecisions of the SGBE. To restore these ecosystems, management should focus on both biodiversity eonservation and providing benefits to local people without hampering forest ecosystems.展开更多
Research has indicated that simple forest eco-system composition,structure and diversity have uncompli-cated community relationships and insufficient pest control capabilities.To investigate changing characteristics o...Research has indicated that simple forest eco-system composition,structure and diversity have uncompli-cated community relationships and insufficient pest control capabilities.To investigate changing characteristics of plant and insect communities in under pest outbreaks in Larix principis-rupprechtii plantations,the research areas were defined as mature(48–50 years)and young(24–29 years)infested stands along with healthy stands.The results show a reduction in the complexity and diversity of plant communi-ties and herbaceous plant guilds(polycultures of beneficial plants)and the complexity and dominance of insect com-munities,especially natural insect enemies.The results also show the relative simplicity of the main factors of commu-nity change and development that represent the characteris-tics of pest outbreaks in L.principis-rupprechtii plantations.The complexity and diversity of plant communities,particu-larly herbaceous plant guilds play a fundamental role in the regulation and development in forest ecosystems.展开更多
The synthesis of evolutionary biology and community ecology aims to understand how genetic variation within one species can shape community properties and how the ecological properties of a community can drive the evo...The synthesis of evolutionary biology and community ecology aims to understand how genetic variation within one species can shape community properties and how the ecological properties of a community can drive the evolution of a species.A rarely explored aspect is whether the interaction of genetic variation and community properties depends on the species'ecological role.Here we investigated the interactions among environmental factors,species diversity,and the within-species genetic diversity of species with different ecological roles.Using high-throughput DNA sequencing,we genotyped a canopydominant tree species,Parashorea chinensis,and an understory-abundant species,Pittosporopsis kerrii,from fifteen plots in Xishuangbanna tropical seasonal rainforest and estimated their adaptive,neutral and total genetic diversity;we also surveyed species diversity and assayed key soil nutrients.Structural equation modelling revealed that soil nitrogen availability created an opposing effect in species diversity and adaptive genetic diversity of the canopy-dominant Pa.chinensis.The increased adaptive genetic diversity of Pa.chinensis led to greater species diversity by promoting co-existence.Increased species diversity reduced the adaptive genetic diversity of the dominant understory species,Pi.kerrii,which was promoted by the adaptive genetic diversity of the canopy-dominant Pa.chinensis.However,such relationships were absent when neutral genetic diversity or total genetic diversity were used in the model.Our results demonstrated the important ecological interaction between adaptive genetic diversity and species diversity,but the pattern of the interaction depends on the identity of the species.Our results highlight the significant ecological role of dominant species in competitive interactions and regulation of community structure.展开更多
Xiangshan bay is a narrow semi-closed bay and situated on the northwestern coast of the East China Sea. Over past decades, it has become to a major bay with intensive human activities, dense urbanized area, and poor w...Xiangshan bay is a narrow semi-closed bay and situated on the northwestern coast of the East China Sea. Over past decades, it has become to a major bay with intensive human activities, dense urbanized area, and poor water quality. The aim of this paper was to reveal the ecological status through the elucidation of the species composition, abundance, biomass and diversity of macrobenthos in this bay. Six intertidal sections were surveyed from January 2007 to November 2008 quarterly. Sections TG, HD and XH are located in the three inner bays, sections QJ and WS are located near the thermal power plants, and section XX is located at the outer part of Xiangshan Bay. Great variations in macrobenthos community were indentified, and the species composition of the community in the present study showed the dominance in the order of molluscs （bivalves and gastropods）, crustaceans and others, and only few Polychaeta were recorded. Only three dominant species, Littorina brevicula, llyplax tansuiensis, and Cerithidea cingu- lata were collected in all the sections, and a total of 19 dominant species were recorded only in one section. Two-way ANOVA analyses of abundance indicated that there were significant differences among sections or seasons. Shannon-Wiener diversity index （H＇） had its maximum （2.45） in section QJ, and minimum （1.76） in section TG Multiple irregular k-dominance plots clearly showed that the study area was polluted and the macrobenthos community was under stress. We conclude that the macrobenthos of Xiang- shan Bay have been disturbed by human activities, especially at the interior bay.展开更多
Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we cl...Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.展开更多
Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study,...Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study, we analyzed species and phylogenetic diversity and community structures for woody and herbaceous plants along two elevational transects on Mt. Baekhwa, South Korea. The species richness and phylogenetic diversity of woody plants showed monotonic declining patterns with increasing elevation along all transects, whereas herbaceous plants showed different patterns, such as no relationship and a reversed unimodal pattern, between the study transects. The main drivers of these patterns were climate and habitat variables for woody and herbaceous plants, respectively. In addition, the phylogenetic community structure primarily showed phylogenetic clustering regulated by deterministic processes, especially environmental filtering, such as climate or habitat factors, along the two transects, although herbaceous plants along a transect depicted phylogenetic randomness as a result of a neutral process. Our findings suggest that deterministic and neutral processes may simultaneously control the community structures along small-scale elevational gradients such as local transects, although the deterministic process may be the predominant type.展开更多
Rodents form a vital component of Free State ecosystems and monitoring them may be a relatively quick andinexpensive method of indicating healthy or unhealthy ecosystem functioning. Using removal trapping, we havestud...Rodents form a vital component of Free State ecosystems and monitoring them may be a relatively quick andinexpensive method of indicating healthy or unhealthy ecosystem functioning. Using removal trapping, we havestudied rodent seasonal abundance, species richness, Shannon diversity, and evenness of rodents in four habitats inthe Tussen-die-Riviere Nature Reserve, inspected the most successful sampling method for these habitats, andreport on their community structure and how it is related to an Ecological Index (≈ EI value of grassland). Bothspecies richness and Shannon diversity increased significantly with EI value. The indicator species Mastomyscoucha occurred at all plots, but contributed the largest proportion of the total captures (ca. 80%) at the plot withlowest EI value. Other results important for small mammal monitoring and collecting are that trap success andspecies richness was highest in autumn. This study also confirms that four days and nights continuous trapping isessential for the effective sampling of rodent communities in Free State grasslands. Our results partially supportexpectations that the number of specialist species increases with succession, M. coucha dominance acts as anindicator of habitat disturbance, rodent species richness conforms to Tilman’s hump-shaped curve model, and addsto a baseline of diversity indices in a variety of grassland habitats.展开更多
[Objectives]This study was conducted to analyze species composition, community appearance, plant life-type spectrum, flora distribution, plant community structure and plant diversity indexes of Mingyue Park in Jingzho...[Objectives]This study was conducted to analyze species composition, community appearance, plant life-type spectrum, flora distribution, plant community structure and plant diversity indexes of Mingyue Park in Jingzhou City, as well as the ecological functions of plants in cooling, humidification, shading, and noise reduction. [Methods] A quadart method was used to investigate plant communitues of Mingyue Park in Jingzhou City. [Results] There were 141 species in the park, including 44 tree speceies, 35 shrub speceies, and 62 herb speceies. The arber-shrub-grass structure was the dominant plant community structure. The Simpson index(D), Shannon-Wiener index(H) and Pielou index(J) of the herb layer were higher than those of the tree layer and the shrub layer, and the shrub layer was the lowest. The results of ecological function research showed that the plant communities had a significant shading effect and a certain ability to reduce noise. The comprehensive conclusion showed that the ecological function indexes of the arbor-shrub-grass structure in Mingyue Park were significantly higher than those of the arbor-shrub structure and the single-tree structure. In order to improve the ecological benefits of plant communities in Mingyue Park, the plant diversity can be increased in the later construction to enrich community structures. [Conclusions] This study evaluated the ecological benefits of plant communities in Mingyue Park, and provides a scientific basis for the plant configuration of parks in Jingzhou and other regions.展开更多
From Jan</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2013 to Nov</span><span style="font-family:Verdana;">.<...From Jan</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2013 to Nov</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2018, we carried out the investigation on vegetation studies in the ecological monitoring programs, Shenzhen</span><span style="font-family:Verdana;"> and</span><span style="font-family:""><span style="font-family:Verdana;"> totally researched 170 plant communities of mountain areas etc., </span><span style="font-family:Verdana;">few areas of street regions and parks etc., for communities’ structural characteristics and plant diversity. We comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level and the main affected factors. We also researched and analyzed these communities’ structural characteristics and pant diversity, </span><span style="font-family:Verdana;">comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level, the main affected factors;researched and analyzed the relationship between plant community structure characteristics with the absorbing ability to PM</span><sub><span style="font-family:Verdana;">2.5</span></sub><span style="font-family:Verdana;"> pollutants. The result showed that the structure and plant diversity of natural </span><span style="font-family:Verdana;">forest </span></span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">obviously better than</span><span style="font-family:Verdana;"> artificial disturbed forest or artificial forest, the semi-natural forest w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> the middle level of the forests, In the indices of height, DBH, coverage and crow width etc. of tree layer, natural forests and semi-natural forests were obvious higher than that of artificial disturbed forest or artificial forest;in some forests of artificial disturbed forest or artificial forest, though their richness indices of family and genus were a slightly higher, but this contribution was majorly due to herb layer plants, and some shrub layer plants. Analyz</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> three kinds of communities, the number of tree layer species of natural forest was</span><span style="font-family:Verdana;"> the </span><span style="font-family:""><span style="font-family:Verdana;">largest, and their every </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity index value was </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">highest;these characteristics values of semi-natural forest were second, artificial disturbed forests or artificial forests were </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">lowest;in shrub layer, and herb layer, few </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity indices of artificial disturbed forest or artificial forest were </span><span style="font-family:Verdana;">a slightly higher than that of some natural forests, but the integral values of the diversity indices of natural forest and semi-natural forest were obvious</span></span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> higher than the former. The research showed that in the artificial disturbed forest or artificial forest, because there have some little scale clearing area</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;">, so some pioneer plant species could enter the community and formed a temporarily </span><span style="font-family:Verdana;">increase of species diversity, however</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> these species major </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> some shrub and herb plants;but tree layer possessed obvious</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> more, even surpass</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> several ten times biomass than shrub and herb layers</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> Therefore</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the respect</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of maintain ecosystem stability and other</span><span style="font-family:Verdana;"> ecological efficient have </span><span style="font-family:Verdana;">major and dominated position and so on;and then this community can </span></span><span style="font-family:Verdana;">be </span><span style="font-family:Verdana;">natural recovery and succession, those forementioned new entire plants shall withdraw from the community and are replaced by the original plants of the community;but this process has already caused the ecological efficient loss and ecosystem unstable. Above research results are better evidence and theory reference to the argument problems on that </span><span style="font-family:Verdana;">are</span><span style="font-family:""><span style="font-family:Verdana;"> natural forest and natural restoration forest biodiversity higher? or is artificial forest biodiversity higher? and or is more artificial disturbed forest higher?</span><span style="font-family:Verdana;"> Our researches showed that used random investigation method set quadrats, and combined typical investigation method, the structural indices in the all layer of community and all diversity indices of tree, shrub and herb layers and the integral values </span></span><span style="font-family:Verdana;">were</span><span style="font-family:""><span style="font-family:Verdana;"> similar, same or usually these indices in the community which set 600 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 800 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total quatrat area were higher (</span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity) than that of more than 3000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 4000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 7000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, even more than 17,000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;">rat area of communities. These lot</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of researches further proved that according to minimum area method for vegetation survey, in subtropical region, using random investigation method combined with typical investigation set 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> - 500 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:""><span展开更多
Botanically, the Mayoko district is known only through anecdotal descriptions made in the colonial era. The present study was undertaken as part of the prerequisite for a mining feasibility study where a benchmark of ...Botanically, the Mayoko district is known only through anecdotal descriptions made in the colonial era. The present study was undertaken as part of the prerequisite for a mining feasibility study where a benchmark of the floristic composition, diversity and structure of the vegetation was needed to evaluate potential biodiversity offset areas and to guide species selection for post-mining re-vegetation. The study area comprised approximately 160,000 ha and 235 sample sites were surveyed using the Braun-Blanquet method of phytosociology. Diversity of each plant association was expressed in terms of various diversity parameters. Twelve associations were described and mapped. The associations ranged from highly disturbed and degraded to fairly intact forest associations. A wet to dry gradient and permanently inundated to temporary inundated gradient could also be distinguished. The approach followed here proved remarkably robust in illustrating the complexity in a topographically complex region of the Chaillu Massif. The data provided a high level of insight into the possible dynamics of the rainforest and indications as to possible successional pathways. This information provides a better level of understanding of forest structure and evolution potential than studies limited to trees, remote sensing carbon assessments, or time change series.展开更多
The diversity,community structure and seasonal variation in demersal nekton off the Changjiang(Yangtze)River estuary was evaluated using monthly trawl survey data,collected between December 2008 and November 2009.A to...The diversity,community structure and seasonal variation in demersal nekton off the Changjiang(Yangtze)River estuary was evaluated using monthly trawl survey data,collected between December 2008 and November 2009.A total of 95 species(56 teleosts,11 cephalopods,and 28 decapod crustaceans)from 69 genera,49 families and 15 orders were collected.These species could be classifi ed into six groups on the basis of temporal distribution patterns.The resident crab Ovalipes punctatus dominated the community,both in number and biomass.A clear seasonal succession was observed in the species composition.Cluster analysis revealed three primary seasonal groups corresponding to the samples collected in winter-spring,late spring-summer and late summer-autumn.The highest biomass and lowest diversity were observed in summer,while the lowest biomass and highest diversity in winter.The abundance-biomass comparison curves and community composition suggested that the investigated community was moderately disturbed.The results suggest that reduction in fi shing pressure and in the degree of seasonal hypoxia are essential for sustainable resource management off the Changjiang River estuary.展开更多
基金funded by the Guangxi Natural Science Foundation Program (2022GXNSFAA035583 and 2020GXNSFAA159108)National Natural Science Foundation of China (32060305)+2 种基金Foundation of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University)Ministry of Education, China (ERESEP 2021Z06)Chinese Forest Biodiversity Monitoring Network
文摘Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.
基金National Natural Science Foundation of China(30070679)the Natural Science Foundation of Hubei Province(2004ABA138)+1 种基金the Key Technology R&D Programme Foundation of Hubei Province(2002AA301C43)the Hubei Health Bureau Research Programme Foundation(NX200427)
文摘Five years＇ （2000-2004） continuous study has been carried out on small mammals such as rodents in seven different sample plots, at three different altitudes and in six different ecological environment types in the eastern part of the Wuling Mountains, south bank of the Three Gorges of Yangtze River in Hubei. A total of 29 297 rat clamps/times were placed and 2271 small mammals such as rodents were captured, and 26 small mammals were captured by other means. All the small mammals captured belonged to 8 families 19 genera and 24 species, of which rodentia accounted for 70.83% and insectivora 29.17%. Through analysis of the data, the results showed that： 1 ） although the species richness had a trend of increasing along different sample plots as altitude increased from south to north, quite a few species showed a wide habitat range in a vertical distribution （ 15 species were dispersed over three zones and two species over two zones） , indicating a strong adaptability of small mammals such as rOdents at lower altitudes in most areas and comparatively less vertical span of entire mountains; 2） whether in seven different sample plots or six different ecological types, Apodemus agrarius and Rattus norvegicus were dominant species below 1200m, and Anourosorex squamipes, Niviventer confucianus and Apodemus draco were dominant above altitudes of 1300m, however, in quantity they were short of identical regularity, meaning they did not increase as the altitude did, or decrease as the ecological areas changed; 3）the density in winter was obviously greater than that in spring, and the distribution showed an increasing trend along with altitude, but the density in different sample plots was short of identical regularity, showing changes in different seasons and altitude grades had an important impact on small mammals such as rodents; 4） in species diversity and evenness index, there were obvious changes between the seven different sample plots, probably caused by frequent human interference in this area. Comparatively speaking, there was less human interference at high altitudes where vegetation was rich and had a high diversity and evenness index, and the boundary effect and community stability were obvious. Most ecological types have been seriously interfered with due to excessive assart at low altitudes with singular vegetation and low diversity and evenness index and poor community stability, showing an ecosystem with poor anti-reversion. If human interference can be reduced in those communities at high altitudes with low diversity and evenness index, the biological diversity in the communities will gradually recover to similar levels of other ecological areas.
基金Sponsored by Global Change Special Funded Project of National Key Scientifi c Research Program(2013CB956000)
文摘As a typical inland wetland, Yangguan nature reserve wetland in Dunhuang is one of the important stops of migratory route for birds, which is vulnerable and particular. Study on the community characteristics and species diversity of wetland has great signifi cance for biodiversity protection. Based on the fi eld investigation, the fl oristic composition, geographical elements and species diversity of wetland plants were studied in Yangguan reserve of Dunhuang. The results showed that 26 families, 56 genera and 74 species were recorded in the study area. The largest families were the Gramineae and Chenopodiaceae, accounting for 29.73% of the total. Herbs were the most abundant life-form, accounting for 77.03% of the total. The fl oral geographical elements of the plants were mainly composed of temperate zone distribution type. By using two way indicator species analysis(TWINSPAN), the vegetation in 36 sampling plots could be classifi ed into 8 communities. The species diversity indexes of communities were relatively low, but had large differences among each other. According to the importance value, the Margalef richness index(Rm) ranged from 0 to 4.200. Simpson diversity index(D) was between 0 and 0.512; Shannon diversity index(H) ranged from 0 to 1.400, and Pielou evenness index(J) was within the range of 0.538 to 1.000. The results indicated that the plant species were relatively rare and simple in general, the species diversity of communities was low, and the ecological environment was fragile in Yangguan nature reserve of Dunhuang.
基金Supported by the Fund of Investigation and Evaluation of Biological Diversity in Shanxi Province of Ministry of Environmental Protection~~
文摘[Objective] This study aimed at researching the species diversity of Populus shanxiensis community in Heichashan Mountain. [Method] Based on sampling methods, investigation in sampling spots was carried out according to the important indicator, the abundance index （N0）, Simpson index （λ）, Shannon-Weiner index （H＇） and homogeneity index （E1 and E5） were used for analysis. [Results] Species diversity index of Populus shanxiensis community was not only depended on the species compositions of communities, but also closely related to the important value of species. The order of abundance index and diversity index in each layer of Populus shanxiensis community was herb layershrub layertree layer, and the abundance index was positively related to the diversity index; while the variation trend of community homogeneity index was different from that of abundance index and diversity index, and the homogeneity had shown negative correlation with the dominance. [Conclusion] In this study, the growth status and conditions of Populus shanxiensis were further understood and researched, which had laid theoretical foundation for protecting the endangered species and provided basic information for the future studies of endangered species and related disciplines.
基金supported by DBT Network Project (BT/PR7928/NDB/52/9/2006)Department of Biotechnology(DBT),Govt. of India
文摘Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging to 46 family, 103 genera and 144 species were counted at ≥30 cm DBH （diameter at breast height） using 28 permanent belt transects with a size of 1 ha （10 m × 1000 m）. Four different tree communities were identified. The primary forests was dominated by Shorea robusta （mean density 464.77 trees.ha^-1, 105 species） and Schima wallichii （336.25 trees.ha^-1, 82 species）, while the secondary forests was dominated by Tectona grandis （333.88 trees.ha^-1, 105 species） and Hevea brasiliensis （299.67 trees.ha^-1, 82 species）. Overall mean basal area in this study was 18.01m2.ha^-1; the maximum value was recorded in primary Shorea forest （26.21 m2.ha^-1）. Mean density and diversity indices were differed significantly within four different communities. No significant differences were observed in number of species, genera, family and tree basal cover area. Significant relationships were found between the species richness and different tree population groups across the communities. Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumu- lation of native oligarchic small tree species. Seventeen species were recorded with 〈2 individuals of which Saraca asoka （Roxb.） de Wilde and Entada phaseoloides （L.） Men＇. etc. extensively used in local ethnomedicinal formulations. The present S. robusta Gaertn dominated forest was recorded richer （105 species） than other reported studies. Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests. Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur. The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T. grandis L. dominated community.
基金supported by the grants of the Research Fund for the Young and Middle-Aged of Qinghai University (2009-QN-16)the National of the People's Republic of China 11th Five-Year Technology Based Plan Topic (2008BAC39B04)
文摘[ Objective] To reveal structure and function of alpine meadow ecosystem and thus to provide a scientific basis for development, utilization and scientific management of alpine meadow pasture as well as sustainable development of grassland agriculture. [ Method] Charactedstics of Kobresia humilis communities with primary vegetation （community I） and degraded vegetation （community II） were analyzed. [Result] Species richness, biodiversity index and biomass of the community I were respectively 42, 3. 531 and 3 553.1 g/m^2, which were respectively higher than those of the community II （37, 2.270 and 3 391.1 g/m^2）. Correlation analysis shows that community biomass was correlated positively with the dchness index （ P 〈 0.01 ）, and biodiversity index was correlated positively with the aboveground biomass and dchness index （ P 〈 0.01 ）. [ Conclusion] The Kobresia humilis community I has reasonable structure and large coverage of ground vegetation, which play an important role in maintenance of biodiversity and ecosystem function.
基金Supported by Civil Aviation ProjectEntrusted Project of Tianjin Binhai International Airport
文摘By using quadrat sampling method, the community structure and diversity of ground cover plants in the flight area in Tianjin Binhai International Airport were investigated from spring to autumn in 2015. The results showed that 58 plant species were recorded at the airport, belonging to 18 families and 48 genera. Dominant plant species showed seasonal characteristics. Specifically, lxeri chinensis （ Thunb. ） Nakai and Lagopsis supina （ Steph. ） Ik. -Gal. ex Knorr. were the dominant species in spring; Lagopsis supina, Cirsium setosum （Willd.） MB, Plantago asiatica L. , Cynanchum chinense R. Br. and Humulus scandens （I_our.） Merr. were the dominant species in summer; Chloris virgata Sw. and Eleusine indica （L.） Gaertn. were the dominant species in autumn. Quantitative characteris- tics of the dominant species, including the density, frequency, coverage and height, varied in different seasons. In different seasons, changes in the diversity of plant communities in three sampling points were analyzed. The results indicated that plant communities in summer exhibited the highest diversity and the most uni- form distribution. This study provided a theoretical basis for avoidance of bird strike in Tianjin Binhai International Airport.
文摘Tree communities contribute to maintenance of species diversity in tropical forests. Coexistence of many tree species is not without competition. Therefore, coexistence of tree species and size diversities occur sequentially or simultaneously in tropical natural forests. Understanding coexistence and competition mechanisms of tree species requires knowledge of interactions within and between species. However, many conservation efforts and strategies failed due to inability to identify and maintain functional coexistence mechanisms among tree species in the forest. Also, most trees died because of pressure on their habitats and not because of limiting growth resources. Hence, species identity, minimum distance and size of the neighbouring trees which are responsible for coexistence of competing trees in most tropical forests have not been explicitly reviewed. Therefore, this review evaluated some of the density dependent mechanisms for coexistence of tree species alpha diversity in tropical forests. Many interactive mechanisms are responsible for coexistence tree species in tropical forests. Inter- and intra-specific competitions are the most significant and both facilitate positive and negative density dependence. Therefore, switching from negative to positive density dependence may occur in some situations. Positive and negative density effects regulate species abundance and coexistence through conspecific and heterospecific structures. Aggregates of conspecific and heterospecific neighbours constitute forest spatial structure. Negative density interactions are mutually exclusive and basically ranged from effect of species identity of neighbours, distance to neighbours and tree size of the neighbours to reference trees in the community structures. Some mechanisms shorten distances for heterospecific than conspecific interactions. Conspecific structures improved survival and growth of rare tree species. Interactive mechanisms in tree community and population structures facilitate species diversity and size inequality, respectively.
基金supported by the OG (sterreichische Orient-Gesellschaft Hammer Purgstall) Vienna, Austria
文摘Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park （SBGE）, Chittagong, Bangladesh to analyze the natural regeneration and tree species diversity in disturbed and less disturbed zones. Stratified and systematic random sampling was used to select 50 sample plots from each of the two zones. A total number of 109 plant species from 43 families were recorded in the study; of which 93 species were of natural origin while the rest were planted. From the species with natural origin 66 were tree species, 9 were shrub species and 28 were climbers. Species richness, density of regeneration and disturbance index in the height classes （0- 0.5 m） and {dbh 〉 6 cm） indicated significant differences between the zones. The study analyzed how disturbances affect species diversity in the area. It was found that species richness and basal area are negatively related with disturbances. Moreover, density （N/ha） of trees was more likely to decrease with increasing tree height that reflects the huge demand of local people to harvest large trees as part of their income generating activities. The study findings have implications for future managementdecisions of the SGBE. To restore these ecosystems, management should focus on both biodiversity eonservation and providing benefits to local people without hampering forest ecosystems.
基金supported by National Natural Science Foundation of China (grant no.32371882)
文摘Research has indicated that simple forest eco-system composition,structure and diversity have uncompli-cated community relationships and insufficient pest control capabilities.To investigate changing characteristics of plant and insect communities in under pest outbreaks in Larix principis-rupprechtii plantations,the research areas were defined as mature(48–50 years)and young(24–29 years)infested stands along with healthy stands.The results show a reduction in the complexity and diversity of plant communi-ties and herbaceous plant guilds(polycultures of beneficial plants)and the complexity and dominance of insect com-munities,especially natural insect enemies.The results also show the relative simplicity of the main factors of commu-nity change and development that represent the characteris-tics of pest outbreaks in L.principis-rupprechtii plantations.The complexity and diversity of plant communities,particu-larly herbaceous plant guilds play a fundamental role in the regulation and development in forest ecosystems.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences,Grant No.XDB31000000the National Natural Science Foundation of China(No.31370267).
文摘The synthesis of evolutionary biology and community ecology aims to understand how genetic variation within one species can shape community properties and how the ecological properties of a community can drive the evolution of a species.A rarely explored aspect is whether the interaction of genetic variation and community properties depends on the species'ecological role.Here we investigated the interactions among environmental factors,species diversity,and the within-species genetic diversity of species with different ecological roles.Using high-throughput DNA sequencing,we genotyped a canopydominant tree species,Parashorea chinensis,and an understory-abundant species,Pittosporopsis kerrii,from fifteen plots in Xishuangbanna tropical seasonal rainforest and estimated their adaptive,neutral and total genetic diversity;we also surveyed species diversity and assayed key soil nutrients.Structural equation modelling revealed that soil nitrogen availability created an opposing effect in species diversity and adaptive genetic diversity of the canopy-dominant Pa.chinensis.The increased adaptive genetic diversity of Pa.chinensis led to greater species diversity by promoting co-existence.Increased species diversity reduced the adaptive genetic diversity of the dominant understory species,Pi.kerrii,which was promoted by the adaptive genetic diversity of the canopy-dominant Pa.chinensis.However,such relationships were absent when neutral genetic diversity or total genetic diversity were used in the model.Our results demonstrated the important ecological interaction between adaptive genetic diversity and species diversity,but the pattern of the interaction depends on the identity of the species.Our results highlight the significant ecological role of dominant species in competitive interactions and regulation of community structure.
基金financial support from the Ningbo Science and Technology Bureau and the Ningbo Oceanology and Fishery Bureau for Technology and Research of Marine Ecological Environmental Protection and Restoration of Xiangshan Bay (No. 2006C 10030)
文摘Xiangshan bay is a narrow semi-closed bay and situated on the northwestern coast of the East China Sea. Over past decades, it has become to a major bay with intensive human activities, dense urbanized area, and poor water quality. The aim of this paper was to reveal the ecological status through the elucidation of the species composition, abundance, biomass and diversity of macrobenthos in this bay. Six intertidal sections were surveyed from January 2007 to November 2008 quarterly. Sections TG, HD and XH are located in the three inner bays, sections QJ and WS are located near the thermal power plants, and section XX is located at the outer part of Xiangshan Bay. Great variations in macrobenthos community were indentified, and the species composition of the community in the present study showed the dominance in the order of molluscs （bivalves and gastropods）, crustaceans and others, and only few Polychaeta were recorded. Only three dominant species, Littorina brevicula, llyplax tansuiensis, and Cerithidea cingu- lata were collected in all the sections, and a total of 19 dominant species were recorded only in one section. Two-way ANOVA analyses of abundance indicated that there were significant differences among sections or seasons. Shannon-Wiener diversity index （H＇） had its maximum （2.45） in section QJ, and minimum （1.76） in section TG Multiple irregular k-dominance plots clearly showed that the study area was polluted and the macrobenthos community was under stress. We conclude that the macrobenthos of Xiang- shan Bay have been disturbed by human activities, especially at the interior bay.
基金This study received financial support from the Science and Technology Department of Yunnan University,China(2019YNU002)Major Program for Basic Research Project of Yunnan Province,China(202101BC070002)the Special Foundation for National Science and Technology Basic Resources Investigation of China(2019FY202300).
文摘Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.
基金funded by the Korea Green Promotion Agency, Korea Forest Service
文摘Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study, we analyzed species and phylogenetic diversity and community structures for woody and herbaceous plants along two elevational transects on Mt. Baekhwa, South Korea. The species richness and phylogenetic diversity of woody plants showed monotonic declining patterns with increasing elevation along all transects, whereas herbaceous plants showed different patterns, such as no relationship and a reversed unimodal pattern, between the study transects. The main drivers of these patterns were climate and habitat variables for woody and herbaceous plants, respectively. In addition, the phylogenetic community structure primarily showed phylogenetic clustering regulated by deterministic processes, especially environmental filtering, such as climate or habitat factors, along the two transects, although herbaceous plants along a transect depicted phylogenetic randomness as a result of a neutral process. Our findings suggest that deterministic and neutral processes may simultaneously control the community structures along small-scale elevational gradients such as local transects, although the deterministic process may be the predominant type.
文摘Rodents form a vital component of Free State ecosystems and monitoring them may be a relatively quick andinexpensive method of indicating healthy or unhealthy ecosystem functioning. Using removal trapping, we havestudied rodent seasonal abundance, species richness, Shannon diversity, and evenness of rodents in four habitats inthe Tussen-die-Riviere Nature Reserve, inspected the most successful sampling method for these habitats, andreport on their community structure and how it is related to an Ecological Index (≈ EI value of grassland). Bothspecies richness and Shannon diversity increased significantly with EI value. The indicator species Mastomyscoucha occurred at all plots, but contributed the largest proportion of the total captures (ca. 80%) at the plot withlowest EI value. Other results important for small mammal monitoring and collecting are that trap success andspecies richness was highest in autumn. This study also confirms that four days and nights continuous trapping isessential for the effective sampling of rodent communities in Free State grasslands. Our results partially supportexpectations that the number of specialist species increases with succession, M. coucha dominance acts as anindicator of habitat disturbance, rodent species richness conforms to Tilman’s hump-shaped curve model, and addsto a baseline of diversity indices in a variety of grassland habitats.
基金Supported by National Natural Science Foundation of China (31270740)Natural Science Foundation of Hubei Province (2017CFB390)。
文摘[Objectives]This study was conducted to analyze species composition, community appearance, plant life-type spectrum, flora distribution, plant community structure and plant diversity indexes of Mingyue Park in Jingzhou City, as well as the ecological functions of plants in cooling, humidification, shading, and noise reduction. [Methods] A quadart method was used to investigate plant communitues of Mingyue Park in Jingzhou City. [Results] There were 141 species in the park, including 44 tree speceies, 35 shrub speceies, and 62 herb speceies. The arber-shrub-grass structure was the dominant plant community structure. The Simpson index(D), Shannon-Wiener index(H) and Pielou index(J) of the herb layer were higher than those of the tree layer and the shrub layer, and the shrub layer was the lowest. The results of ecological function research showed that the plant communities had a significant shading effect and a certain ability to reduce noise. The comprehensive conclusion showed that the ecological function indexes of the arbor-shrub-grass structure in Mingyue Park were significantly higher than those of the arbor-shrub structure and the single-tree structure. In order to improve the ecological benefits of plant communities in Mingyue Park, the plant diversity can be increased in the later construction to enrich community structures. [Conclusions] This study evaluated the ecological benefits of plant communities in Mingyue Park, and provides a scientific basis for the plant configuration of parks in Jingzhou and other regions.
文摘From Jan</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2013 to Nov</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2018, we carried out the investigation on vegetation studies in the ecological monitoring programs, Shenzhen</span><span style="font-family:Verdana;"> and</span><span style="font-family:""><span style="font-family:Verdana;"> totally researched 170 plant communities of mountain areas etc., </span><span style="font-family:Verdana;">few areas of street regions and parks etc., for communities’ structural characteristics and plant diversity. We comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level and the main affected factors. We also researched and analyzed these communities’ structural characteristics and pant diversity, </span><span style="font-family:Verdana;">comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level, the main affected factors;researched and analyzed the relationship between plant community structure characteristics with the absorbing ability to PM</span><sub><span style="font-family:Verdana;">2.5</span></sub><span style="font-family:Verdana;"> pollutants. The result showed that the structure and plant diversity of natural </span><span style="font-family:Verdana;">forest </span></span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">obviously better than</span><span style="font-family:Verdana;"> artificial disturbed forest or artificial forest, the semi-natural forest w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> the middle level of the forests, In the indices of height, DBH, coverage and crow width etc. of tree layer, natural forests and semi-natural forests were obvious higher than that of artificial disturbed forest or artificial forest;in some forests of artificial disturbed forest or artificial forest, though their richness indices of family and genus were a slightly higher, but this contribution was majorly due to herb layer plants, and some shrub layer plants. Analyz</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> three kinds of communities, the number of tree layer species of natural forest was</span><span style="font-family:Verdana;"> the </span><span style="font-family:""><span style="font-family:Verdana;">largest, and their every </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity index value was </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">highest;these characteristics values of semi-natural forest were second, artificial disturbed forests or artificial forests were </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">lowest;in shrub layer, and herb layer, few </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity indices of artificial disturbed forest or artificial forest were </span><span style="font-family:Verdana;">a slightly higher than that of some natural forests, but the integral values of the diversity indices of natural forest and semi-natural forest were obvious</span></span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> higher than the former. The research showed that in the artificial disturbed forest or artificial forest, because there have some little scale clearing area</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;">, so some pioneer plant species could enter the community and formed a temporarily </span><span style="font-family:Verdana;">increase of species diversity, however</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> these species major </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> some shrub and herb plants;but tree layer possessed obvious</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> more, even surpass</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> several ten times biomass than shrub and herb layers</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> Therefore</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the respect</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of maintain ecosystem stability and other</span><span style="font-family:Verdana;"> ecological efficient have </span><span style="font-family:Verdana;">major and dominated position and so on;and then this community can </span></span><span style="font-family:Verdana;">be </span><span style="font-family:Verdana;">natural recovery and succession, those forementioned new entire plants shall withdraw from the community and are replaced by the original plants of the community;but this process has already caused the ecological efficient loss and ecosystem unstable. Above research results are better evidence and theory reference to the argument problems on that </span><span style="font-family:Verdana;">are</span><span style="font-family:""><span style="font-family:Verdana;"> natural forest and natural restoration forest biodiversity higher? or is artificial forest biodiversity higher? and or is more artificial disturbed forest higher?</span><span style="font-family:Verdana;"> Our researches showed that used random investigation method set quadrats, and combined typical investigation method, the structural indices in the all layer of community and all diversity indices of tree, shrub and herb layers and the integral values </span></span><span style="font-family:Verdana;">were</span><span style="font-family:""><span style="font-family:Verdana;"> similar, same or usually these indices in the community which set 600 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 800 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total quatrat area were higher (</span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity) than that of more than 3000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 4000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 7000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, even more than 17,000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;">rat area of communities. These lot</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of researches further proved that according to minimum area method for vegetation survey, in subtropical region, using random investigation method combined with typical investigation set 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> - 500 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:""><span
文摘Botanically, the Mayoko district is known only through anecdotal descriptions made in the colonial era. The present study was undertaken as part of the prerequisite for a mining feasibility study where a benchmark of the floristic composition, diversity and structure of the vegetation was needed to evaluate potential biodiversity offset areas and to guide species selection for post-mining re-vegetation. The study area comprised approximately 160,000 ha and 235 sample sites were surveyed using the Braun-Blanquet method of phytosociology. Diversity of each plant association was expressed in terms of various diversity parameters. Twelve associations were described and mapped. The associations ranged from highly disturbed and degraded to fairly intact forest associations. A wet to dry gradient and permanently inundated to temporary inundated gradient could also be distinguished. The approach followed here proved remarkably robust in illustrating the complexity in a topographically complex region of the Chaillu Massif. The data provided a high level of insight into the possible dynamics of the rainforest and indications as to possible successional pathways. This information provides a better level of understanding of forest structure and evolution potential than studies limited to trees, remote sensing carbon assessments, or time change series.
基金Supported by the National Key Technology R&D Program of China(No.2007BAD43B01)the National Special Research Fund for Non-Profit Sector(Agriculture)(No.201303047)the Special Fund of Chinese Central Government for Basic Scientific Research Operations in Commonweal Research Institutes(No.2008T04)
文摘The diversity,community structure and seasonal variation in demersal nekton off the Changjiang(Yangtze)River estuary was evaluated using monthly trawl survey data,collected between December 2008 and November 2009.A total of 95 species(56 teleosts,11 cephalopods,and 28 decapod crustaceans)from 69 genera,49 families and 15 orders were collected.These species could be classifi ed into six groups on the basis of temporal distribution patterns.The resident crab Ovalipes punctatus dominated the community,both in number and biomass.A clear seasonal succession was observed in the species composition.Cluster analysis revealed three primary seasonal groups corresponding to the samples collected in winter-spring,late spring-summer and late summer-autumn.The highest biomass and lowest diversity were observed in summer,while the lowest biomass and highest diversity in winter.The abundance-biomass comparison curves and community composition suggested that the investigated community was moderately disturbed.The results suggest that reduction in fi shing pressure and in the degree of seasonal hypoxia are essential for sustainable resource management off the Changjiang River estuary.
