Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies ha...Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping SGDCs.Here,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical forest.For this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural Reserve.We also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest plots.We found that speciesα-diversity was negatively correlated with geneticα-diversity.Canopy structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-diversity.These contrasting effects contributed to the formation of a negativeα-SGDC.Further,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target species.Speciesβ-diversity,in contrast,was positively correlated with geneticβ-diversity.Differences in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-SGDC.Our study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs.展开更多
To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the dow...To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.展开更多
Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection...Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.展开更多
Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully...Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully exploited.To extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast China.Spectral and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant species.The results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source independently.Similarly,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was accurate.Including terrain factors and removing spatial correlation from NFRI sample points further improved the recognition accuracy.The optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,respectively.The high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant species.Visualizing the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.展开更多
In floristic research,the grid mapping method is a crucial and highly effective tool for investigating the flora of specific regions.This methodology aids in the collection of comprehensive data,thereby promoting a th...In floristic research,the grid mapping method is a crucial and highly effective tool for investigating the flora of specific regions.This methodology aids in the collection of comprehensive data,thereby promoting a thorough understanding of regional plant diversity.This paper presents findings from a grid mapping study conducted in the Surkhan-Sherabad botanical-geographic region(SShBGR),acknowledged as one of the major floristic areas in southwestern Uzbekistan.Using an expansive dataset of 14,317 records comprised of herbarium specimens and field diary entries collected from 1897 to 2023,we evaluated the stages and seasonal dynamics of data accumulation,species richness(SR),and collection density(CD)within 5 km×5 km grid cells.We further examined the taxonomic and life form composition of the region's flora.Our analysis revealed that the grid mapping phase(2021–2023)produced a significantly greater volume of specimens and taxonomic diversity compared with other periods(1897–1940,1941–1993,and 1994–2020).Field research spanned 206 grid cells during 2021–2023,resulting in 11,883 samples,including 6469 herbarium specimens and 5414 field records.Overall,fieldwork covered 251 of the 253 grid cells within the SShBGR.Notably,the highest species diversity was documented in the B198 grid cell,recording 160 species.In terms of collection density,the E198 grid cell produced 475 samples.Overall,we identified 1053 species distributed across 439 genera and 78 families in the SShBGR.The flora of this region aligned significantly with the dominant families commonly found in the Holarctic,highlighting vital ecological connections.Among our findings,the Asteraceae family was the most polymorphic,with 147 species,followed by the continually stable and diverse Poaceae,Fabaceae,Brassicaceae,and Amaranthaceae.Besides,our analysis revealed a predominance of therophyte life forms,which constituted 52%(552 species)of the total flora.The findings underscore the necessity for continual data collection efforts to further enhance our understanding of the biodiversity in the SShBGR.The results of this study demonstrated that the application of grid-based mapping in floristic studies proves to be an effective tool for assessing biodiversity and identifying key taxonomic groups.展开更多
In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainti...In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainties in the response mechanism of stability of plant community biomass in alpine meadows of the Qinghai-Xizang Plateau,China to these two major climate factors.Given this,based on field control experiments,this study systematically evaluated the effects of different levels of climate warming(W0(no warming),W1(air temperature increased by 0.47℃ or soil temperature increased by 0.61℃),W2(air temperature increased by 0.92℃ or soil temperature increased by 1.09℃),W3(air temperature increased by 1.44℃ or soil temperature increased by 1.95℃)),nitrogen deposition(N0(0 kg N/(hm^(2)·a)),N16(16 kg N/(hm^(2)·a)),and N32(32 kg N/(hm^(2)·a))),and their interactions on plant community biomass and its temporal stability,and explored its potential regulatory mechanisms.The results showed that the biomass of total community,Gramineae,and dominant species increased significantly with increasing temperature,but the biomass of common and rare species decreased significantly.Nitrogen deposition also significantly promoted the biomass accumulation of community and gramineous plants.Under the treatment of W3N32,the biomass of plant community,Gramineae,and dominant species reached the highest values,indicating that there was a synergistic effect under this treatment.Structural equation model showed that increasing temperature significantly decreased the stability of plant community biomass by reducing the stability of grass and dominant species biomass and weakening species asynchronism.Interaction of increased nitrogen deposition and temperature increased the biomass fluctuation of grass functional group,thus amplifying its negative influence on community stability.More attention should be paid to the response and regulatory mechanisms of dominant species and functional groups under global climate change.This study provides a theoretical basis for revealing the stability maintenance mechanism of alpine grassland and also provides scientific support for the development of future grassland ecosystem management and assessment.展开更多
Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient i...Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients.Along a rainfall gradient on the northern Tibetan Plateau,we conducted an 8-year nitrogen(N)addition experiment in four alpine grasslands:alpine desert steppe(ADS),alpine steppe(AS),alpine meadow steppe(AMS),alpine meadow(AM),and we used twoway ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands.We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients,while there was no change in AS and a gradual increase in ADS.The temporal stability showed different patterns of gradual decreases in ADS and AM,and a unimodal trend in AMS with increasing N gradients.However,N addition had no effect on the temporal stability of AS.Dominant species stability was the controlling factor for alpine grasslands along the transect,while the effect of asynchrony gradually increased with decreasing precipitation.These findings highlight that community composition,especially the dominant species,along the environmental gradient can mediate the effects of N inputs on community temporal stability.Thus,the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.展开更多
[Objective] The aim was to study the species,quantity and community traits of dominant plant in karst mountain grassland plant community so as to provide support for the vegetation restoration in karst mountain grassl...[Objective] The aim was to study the species,quantity and community traits of dominant plant in karst mountain grassland plant community so as to provide support for the vegetation restoration in karst mountain grassland.[Method] Standard plot sites investigation method was used study the quantity traits of different plant communities of different altitudes and slopes.[Result] The IV SDR4 were the highest in the all plot sites of plant community on the kasrt mountain grassland,but the IV SDR4 were showed a trend of decreasing with the increasing of the altitude.The dominant quantity was increasing with the altitude upward,so the altitude was the mostly factor for plant community construction.[Conclusion] Altitude was the main factor to influence the community structure of plant.展开更多
Based on the data of four seasonal marine surveys in the East China Sea （23°30′-33°N, 118°30′-128°E）during 1997-2000, the author studied the ecological characters of dominant Pteropoda species ...Based on the data of four seasonal marine surveys in the East China Sea （23°30′-33°N, 118°30′-128°E）during 1997-2000, the author studied the ecological characters of dominant Pteropoda species in the area. Results showed that there were five dominant Pteropoda species, more in summer, less in autumn and even in other seasons. These species, though belonging warm water species, can be categorized into two different groups in habitability. The first group was acicula, Desmopterus papilio and Creseis virgule, while adapted in summer and autumn, including Creseis the second group in winter and spring, represented by Limacina trochiformis and Agadina syimpsoni. The first group was more abundant than the second one. Besides, the first group contributed more to the Pteropoda abundance having higher occurrence frequency and aggregation intensity than the second. In horizontal distribution, the first group species reside in nearshore, and they could migrate to shallow place near estuary and aggregated in high density, while the second one was different： lower abundance, less occurred and aggregated because they were halophilic warm water species, and they were usually abundant in offshore area.展开更多
Dominant species of zooplankton community vary with latitude. Though China possesses a vast coastal area in northwestern Pacific, studies on the latitudinal dominant species gradient are rare. We collected zooplankton...Dominant species of zooplankton community vary with latitude. Though China possesses a vast coastal area in northwestern Pacific, studies on the latitudinal dominant species gradient are rare. We collected zooplankton samples from Haizhou Bay(34.56?–35.19?N, 119.51?–120.30?E), Yueqing Bay(28.14?–28.38?N, 121.10?–121.21?E) and Dongshan Bay(23.65?–23.90?N, 117.45?–117.60?E) in May 2012 and May 2013 to preliminarily characterize the latitudinal dominant species distribution. All the samples were collected vertically using a 0.505 mm mesh plankton net with 0.8 m in mouth diameter from bottom to surface. Calanus sinicus, Aidanosagitta crassa, Labidocera euchaeta, Zonosagitta nagae, Acartia pacifica and Paracalanus parvus were found to be dominant. C. sinicus was the most dominant species and the unique one occurred in all three bays. With latitude decreasing, both the abundance and proportion of C. sinicus declined sharply. Cluster analysis showed that the 6 dominant species could be divided into 3 groups, based on their occurrences in the three bays. Our results suggested that the distribution of dominant species along the coast of China has a significant latitudinal gradient. C. sinicus which widely distributes in the coastal water of the northwestern Pacific can well adapt to the temperature at different latitudes. The high abundance in Haizhou Bay indicated that C. sinicus was an exemplary warm-temperate species, and more commonly occurs in the north of China seas. The ecological characteristics of dominant species change from warm-temperate type in high-latitudinal bays to warm water type in low-latitudinal bays.展开更多
Since 2015,green tides with Ulva prolifera as the dominant species in the Qinhuangdao coastal waters have continued to occur.In this study,the relationship between green tides in Qinhuangdao and the Yellow Sea(setting...Since 2015,green tides with Ulva prolifera as the dominant species in the Qinhuangdao coastal waters have continued to occur.In this study,the relationship between green tides in Qinhuangdao and the Yellow Sea(setting sites in Rudong and Qingdao)was evaluated by genetic analyses of U.prolifera.Single nucleotide polymorphism(SNP)markers were used to analyze genetic diversity and genetic relationships among groups.Genetic differentiation was lower among floating U.prolifera populations in Rudong and Qingdao than in Qinhuangdao.The floating U.prolifera population had higher genetic diversity and polymorphism levels in Qingdao and Rudong than in Qinhuangdao.Physiological experiments showed that the growth rate and net buoyancy of floating U.prolifera were highest in Qinhuangdao and Qingdao,respectively,under the same environmental conditions(temperature and light).Overall,these findings showed that U.prolifera populations in the Qinhuangdao and Yellow Sea green tides(Rudong and Qingdao)differ significantly at the molecular and physiological levels.Therefore,the Qinhuangdao green tide is not correlated with the Yellow Sea green tide and has a different origin and development mode.This study provides insight into the mechanism underlying green tide blooms in coastal waters of China.展开更多
Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence ...Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.展开更多
The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field d...The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 ktg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level （including the nutrient supply from the terrestrial runoffs） was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that dia- toms were the main phytoplankton in this area, and Skeletonerna costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends： 1） Skeletonema （mainly S. costatum） was dominant throughout the year; and 2） seasonal succession trends were Coscinodiscus （spring） →Chaetoceros （summer and autumn） → Coscinodiscus （winter）. The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas： average annual phytoplankton biomass and dinoflagellate proportion both presented increased trends during the 1950s - 2000s.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
Since 2015,green tides have been blooming in offshore waters of Qinhuangdao,with serious impacts on the local ecological environment and tourism.Ulva australis,Bryopsis plumosa,and U.prolifera are the dominant species...Since 2015,green tides have been blooming in offshore waters of Qinhuangdao,with serious impacts on the local ecological environment and tourism.Ulva australis,Bryopsis plumosa,and U.prolifera are the dominant species of Qinhuangdao green tides,following a sequential succession pattern.Ulva prolifera is the dominant species,with the highest biomass and the greatest influence on the local ecological environment.To study the reason of green tide dominant species succession and U.profilera became the dominant species with the largest biomass,we compared and analyzed the growth and nutrient uptake capacity of the three algae.The results showed that temperature significantly affects the growth of the three species.Within the temperature range of the experimental setup,the optimum temperature for the growth of U.australis,B.plumosa and U.profilera is10℃,15℃,and 20–25℃,respectively.Combined with the temperature variation trend during green tide bloom development,we believe that temperature is the key environmental factor for the succession of the dominant species.Ulva prolifera has a higher growth rate than U.australis and B.plumosa under the same nitrate,ammonium,and phosphate levels.Significant differences in the maximum absorption rate(R_(max))and R_(max)/Ks(the relationship between uptake rate and substrate concentration)values indicated that U.prolifera had an apparent competitive advantage over U.australis and B.plumosa regarding nutrient uptake.Therefore,the strong growth and nutrient uptake capacities of U.prolifera might be the main reason for becoming the dominant species with the largest biomass in Qinhuangdao green tides.展开更多
Background： Knowledge of the different kinds of tree communities that currently exist can provide a baseline for assessing the ecological attributes of forests and monitoring future changes. Forest inventory data can...Background： Knowledge of the different kinds of tree communities that currently exist can provide a baseline for assessing the ecological attributes of forests and monitoring future changes. Forest inventory data can facilitate the development of this baseline knowledge across broad extents, but they first must be classified into forest community types. Here, we compared three alternative classifications across the United States using data from over 117,000 U.S. Department of Agriculture Forest Service Forest Inventory and Analysis （FIA） plots. Methods： Each plot had three forest community type labels： （1） ＂FIA＂ types were assigned by the FIA program using a supervised method; （2） ＂USNVC＂ types were assigned via a key based on the U.S. National Vegetation Classification; （3） ＂empirical＂ types resulted from unsupervised clustering of tree species information. We assessed the degree to which analog classes occurred among classifications, compared indicator species values, and used random forest models to determine how well the classifications could be predicted using environmental variables. Results： The classifications generated groups of classes that had broadly similar distributions, but often there was no one-to-one analog across the classifications. The Iongleaf pine forest community type stood out as the exception： it was the only class with strong analogs across all classifications. Analogs were most lacking for forest community types with species that occurred across a range of geographic and environmental conditions, such as Ioblolly pine types, indicator species metrics were generally high for the USNVC, suggesting that LJSNVC classes are floristically well-defined. The empirical classification was best predicted by environmental variables. The most important predictors differed slightly but were broadly similar across all classifications, and included slope, amount of forest in the surrounding landscape, average minimum temperature, and other climate variables. Conclusions： The classifications have similarities and differences that reflect their differing approaches and Dbjectives. They are most consistent for forest community types that occur in a relatively narrow range of Invironmental conditions, and differ most for types with wide-ranging tree species. Environmental variables at variety of scales were important for predicting all classifications, though strongest for the empirical and FIA, guggesting that each is useful for studying how forest communities respond to of multi-scale environmental processes, including global change drivers.展开更多
Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individ...Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individuals were identified and 92.31% of total species appeared in natural forests, and 75.38% of total species appeared in plantations. The orders of Lepidoptera, Coleoptera, Diptera and Hymenoptera covered most of the collected arthropods. In different forest types, diversity indices is natural mixed forests （Betula platyphylla x Larix gmelinii）〉 natural pure B. platyphylla forests〉natural pure L. gmelinii forests〉plantations with pesticide treatment〉plantations without pesticide treatment. In natural forests, more than 70% of the arthropod families, species and individuals were distributed in shrub and herb layer, while in plantations 75% of the arthropod families, 78% of species and 80% of individuals were also distributed in shrub and herb layer. Lepidoptera, including Loxostege sticticalis （Linnaeus）, Chilo suppressalis （Walker） and Lymantria dispar （Linnaeus）, had the highest dominant degree.展开更多
The distributional trends and their controlling factors of dominant species and nannofossil abundance in sur face sediments of marginal and coastal seas in low to middle latitudes and high latitudes are discussed on t...The distributional trends and their controlling factors of dominant species and nannofossil abundance in sur face sediments of marginal and coastal seas in low to middle latitudes and high latitudes are discussed on the basis of theanalysis of 146 samples from the nothern and central parts of the South China Sea and of comparison between the resultsof current work and data from other seas.Despite significant variations in taxonomic composition between seas or between areas within one sea, there are somegeneral trends in nannofossil distribution of marginal and coastal seas. All those nannofossil assemblages in middle and lowlatitudes are dominated by two species: Gephyrocapsa oceanica and Emiliania huxleyi. Although the relative abundanceof these species may vary greatly from area to area, Gephyrocapsa oceanica in general prevails in nearshore or semiclosedenvironments, increasing in number towards the shoreline, while Emiliania huxleyi increases in relative abundance to wards continental slope and open ocean environments, decreasing in abundance again only in very deep-water, i. e., nearthe CCD. Similarly, the abundance of calcareous nannofossils, as a whole, is lower nearshore, increasing with water depthtowards the continental slope, and then decreasing again towards and near the CCD. In high latitudes, the dominantspecies are Emiliania huxleyi and Coccolithus pelagicus.There are two groups of factors controlling the nannofossil distribution in surface sediments: ecological factors, in cluding particularly water temperature, supply of nutrients; and sedimentological factors, including influx of terrigenousmaterials and deep-water carbonate dissolution.展开更多
Lowland tropical forest in Peninsular Malaysia consist a valuable dipterocarp timber species. In fact, dipterocarp tree species growth well when the ecology is maintained and their growth are dependent on the micro cl...Lowland tropical forest in Peninsular Malaysia consist a valuable dipterocarp timber species. In fact, dipterocarp tree species growth well when the ecology is maintained and their growth are dependent on the micro climate and also affected by lithology types. This study was carried out to identify and map tree species dominancy by lithology types at Hulu Sedili Forest Reserve （HSFR） using Geographic Information System （GIS） technique. Different lithology type maps were derived namely Igneous, Sedimentary and Limestone. Through GIS operations tree species data collected from pre-felling inventory and ground survey were overlaid with lithology features. Results showed that at Sedimentary and Igneous types, the presence of dipterocarpaceae family is only 3.09%, and non-dipterocarpaceae family was 96.91%. Syzygium spp. （19.83%） was the most abundance in Igneous and Sedimentary. Meanwhile, Elateriospermum tapos （9.92%） and Lauraceae＇s family （7.22%） were found to be the most dominant species in Sedimentary types, Macaranga spp. （11.21%） and Elateriospermum tapos （11.02%） in igneous types. However, a Limestone type was discarded from analysis due to unavailable pre-felling data. Thus, this study indicated that there was variation in species dominancy of different lithology types. On the other hand, GIS demonstrated its capability as a useful tool in identifying and maps the location of trees species based on lithology types.展开更多
The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Ther...The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Therefore,understanding the relationships between zooplankton and environmental factors help us know the water quality.To achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory.However,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains scarce.We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy analysis.Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope.The turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in summer.The dominant species were estuarine,offshore,and eurytopic based on the adaptation to salinity.In spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore species.In addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological groups.The temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and pH.The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring,and the continuous decrease in abundance of L.euchaeta reflected the effects of local climate change.The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents.Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence.展开更多
基金funded by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB31000000)the Joint Fund of the National Natural Science Foundation of China-Yunnan Province (U1902203)+1 种基金Major Program for Basic Research Project of Yunnan Province (202101BC070002)Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (151C53KYSB20200019)
文摘Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping SGDCs.Here,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical forest.For this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural Reserve.We also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest plots.We found that speciesα-diversity was negatively correlated with geneticα-diversity.Canopy structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-diversity.These contrasting effects contributed to the formation of a negativeα-SGDC.Further,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target species.Speciesβ-diversity,in contrast,was positively correlated with geneticβ-diversity.Differences in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-SGDC.Our study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs.
基金Supported by the National Key Scientific Research Project(No.2018YFC1508200)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX 23_0714)+1 种基金the China Scholarship Council(No.202206710066)the Construction Project of Wenzhou Hydrology High quality Development Pilot Zone(No.WZSW-GZLFZXXQ-202105)。
文摘To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.
基金the Natural Science Foundation of Inner Mongolia,China(2023JQ01)the National Key R&D Program of China(2019YFA0607103)+2 种基金the Central Government Guides Local Science and Technology Development Fund Projects(2022ZY0224)the Open Project Program of Ministry of Education Key Laboratory of Ecology and Resources Use of the Mongolian Plateau,Hohhot,Inner Mongolia,China(KF2023003)Major Science and Technology Project of Inner Mongolia Autonomous Region:Monitoring,Assessment and Early Warning Technology Research of Biodiversity in Inner Mongolia(2021ZD0011)for financial support.
文摘Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.
基金supported by the National Technology Extension Fund of Forestry,Forest Vegetation Carbon Storage Monitoring Technology Based on Watershed Algorithm ([2019]06)Fundamental Research Funds for the Central Universities (No.PTYX202107).
文摘Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully exploited.To extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast China.Spectral and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant species.The results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source independently.Similarly,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was accurate.Including terrain factors and removing spatial correlation from NFRI sample points further improved the recognition accuracy.The optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,respectively.The high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant species.Visualizing the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.
基金supported by the grant from the State Programs"Grid Mapping of the Flora of Uzbekistan'during 2020–2024"the grant from the State Programs"Creation of the Digital Platform of the Plant World of Central Uzbekistan"during 2025–2029the State Research Project"Taxonomic Revision of Polymorphic Plant Families of the Flora of Uzbekistan"from the Institute of Botany,Academy of Sciences of the Republic of Uzbekistan (A-FA-2021-427)
文摘In floristic research,the grid mapping method is a crucial and highly effective tool for investigating the flora of specific regions.This methodology aids in the collection of comprehensive data,thereby promoting a thorough understanding of regional plant diversity.This paper presents findings from a grid mapping study conducted in the Surkhan-Sherabad botanical-geographic region(SShBGR),acknowledged as one of the major floristic areas in southwestern Uzbekistan.Using an expansive dataset of 14,317 records comprised of herbarium specimens and field diary entries collected from 1897 to 2023,we evaluated the stages and seasonal dynamics of data accumulation,species richness(SR),and collection density(CD)within 5 km×5 km grid cells.We further examined the taxonomic and life form composition of the region's flora.Our analysis revealed that the grid mapping phase(2021–2023)produced a significantly greater volume of specimens and taxonomic diversity compared with other periods(1897–1940,1941–1993,and 1994–2020).Field research spanned 206 grid cells during 2021–2023,resulting in 11,883 samples,including 6469 herbarium specimens and 5414 field records.Overall,fieldwork covered 251 of the 253 grid cells within the SShBGR.Notably,the highest species diversity was documented in the B198 grid cell,recording 160 species.In terms of collection density,the E198 grid cell produced 475 samples.Overall,we identified 1053 species distributed across 439 genera and 78 families in the SShBGR.The flora of this region aligned significantly with the dominant families commonly found in the Holarctic,highlighting vital ecological connections.Among our findings,the Asteraceae family was the most polymorphic,with 147 species,followed by the continually stable and diverse Poaceae,Fabaceae,Brassicaceae,and Amaranthaceae.Besides,our analysis revealed a predominance of therophyte life forms,which constituted 52%(552 species)of the total flora.The findings underscore the necessity for continual data collection efforts to further enhance our understanding of the biodiversity in the SShBGR.The results of this study demonstrated that the application of grid-based mapping in floristic studies proves to be an effective tool for assessing biodiversity and identifying key taxonomic groups.
基金supported by the Key Research and Development and Transformation Plan of Qinghai Provincial Science and Technology Department(2024-NK-137)the Qinghai Province Science and Technology Commissioner Special Project(2024-NK-P28).
文摘In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainties in the response mechanism of stability of plant community biomass in alpine meadows of the Qinghai-Xizang Plateau,China to these two major climate factors.Given this,based on field control experiments,this study systematically evaluated the effects of different levels of climate warming(W0(no warming),W1(air temperature increased by 0.47℃ or soil temperature increased by 0.61℃),W2(air temperature increased by 0.92℃ or soil temperature increased by 1.09℃),W3(air temperature increased by 1.44℃ or soil temperature increased by 1.95℃)),nitrogen deposition(N0(0 kg N/(hm^(2)·a)),N16(16 kg N/(hm^(2)·a)),and N32(32 kg N/(hm^(2)·a))),and their interactions on plant community biomass and its temporal stability,and explored its potential regulatory mechanisms.The results showed that the biomass of total community,Gramineae,and dominant species increased significantly with increasing temperature,but the biomass of common and rare species decreased significantly.Nitrogen deposition also significantly promoted the biomass accumulation of community and gramineous plants.Under the treatment of W3N32,the biomass of plant community,Gramineae,and dominant species reached the highest values,indicating that there was a synergistic effect under this treatment.Structural equation model showed that increasing temperature significantly decreased the stability of plant community biomass by reducing the stability of grass and dominant species biomass and weakening species asynchronism.Interaction of increased nitrogen deposition and temperature increased the biomass fluctuation of grass functional group,thus amplifying its negative influence on community stability.More attention should be paid to the response and regulatory mechanisms of dominant species and functional groups under global climate change.This study provides a theoretical basis for revealing the stability maintenance mechanism of alpine grassland and also provides scientific support for the development of future grassland ecosystem management and assessment.
基金financially supported by the National Natural Science Foundation of China(42071066)the West Light Foundation of the Chinese Academy of Sciences(2021)+1 种基金the National Key Research and Development Program of China(2023YFF1304304)the Natural Science Foundation of XizangAutonomous Region,China(XZ202201ZR0026G)。
文摘Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients.Along a rainfall gradient on the northern Tibetan Plateau,we conducted an 8-year nitrogen(N)addition experiment in four alpine grasslands:alpine desert steppe(ADS),alpine steppe(AS),alpine meadow steppe(AMS),alpine meadow(AM),and we used twoway ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands.We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients,while there was no change in AS and a gradual increase in ADS.The temporal stability showed different patterns of gradual decreases in ADS and AM,and a unimodal trend in AMS with increasing N gradients.However,N addition had no effect on the temporal stability of AS.Dominant species stability was the controlling factor for alpine grasslands along the transect,while the effect of asynchrony gradually increased with decreasing precipitation.These findings highlight that community composition,especially the dominant species,along the environmental gradient can mediate the effects of N inputs on community temporal stability.Thus,the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.
基金Supported by Innovative Capacity Building Projects of Guizhou Insti-tutions (Qianke [ 2009 ] 4013 )Graduate Innovation Fund ofGuizhou Academy of Agricultural Sciences (Guizhou Academy ofAgricultural Sciences 2010010)~~
文摘[Objective] The aim was to study the species,quantity and community traits of dominant plant in karst mountain grassland plant community so as to provide support for the vegetation restoration in karst mountain grassland.[Method] Standard plot sites investigation method was used study the quantity traits of different plant communities of different altitudes and slopes.[Result] The IV SDR4 were the highest in the all plot sites of plant community on the kasrt mountain grassland,but the IV SDR4 were showed a trend of decreasing with the increasing of the altitude.The dominant quantity was increasing with the altitude upward,so the altitude was the mostly factor for plant community construction.[Conclusion] Altitude was the main factor to influence the community structure of plant.
基金This study was funded by Major Research Plan of the NSFC (No. 90511005), Major State Basic Research Development Program of China (973 Program, No. 2001CB409700-07).
文摘Based on the data of four seasonal marine surveys in the East China Sea （23°30′-33°N, 118°30′-128°E）during 1997-2000, the author studied the ecological characters of dominant Pteropoda species in the area. Results showed that there were five dominant Pteropoda species, more in summer, less in autumn and even in other seasons. These species, though belonging warm water species, can be categorized into two different groups in habitability. The first group was acicula, Desmopterus papilio and Creseis virgule, while adapted in summer and autumn, including Creseis the second group in winter and spring, represented by Limacina trochiformis and Agadina syimpsoni. The first group was more abundant than the second one. Besides, the first group contributed more to the Pteropoda abundance having higher occurrence frequency and aggregation intensity than the second. In horizontal distribution, the first group species reside in nearshore, and they could migrate to shallow place near estuary and aggregated in high density, while the second one was different： lower abundance, less occurred and aggregated because they were halophilic warm water species, and they were usually abundant in offshore area.
基金funded by the National Natural Science Foundation of China (No. 41176131)the National Special Research Fund for Non-Profit Marine Sector (No. 201305027-8)
文摘Dominant species of zooplankton community vary with latitude. Though China possesses a vast coastal area in northwestern Pacific, studies on the latitudinal dominant species gradient are rare. We collected zooplankton samples from Haizhou Bay(34.56?–35.19?N, 119.51?–120.30?E), Yueqing Bay(28.14?–28.38?N, 121.10?–121.21?E) and Dongshan Bay(23.65?–23.90?N, 117.45?–117.60?E) in May 2012 and May 2013 to preliminarily characterize the latitudinal dominant species distribution. All the samples were collected vertically using a 0.505 mm mesh plankton net with 0.8 m in mouth diameter from bottom to surface. Calanus sinicus, Aidanosagitta crassa, Labidocera euchaeta, Zonosagitta nagae, Acartia pacifica and Paracalanus parvus were found to be dominant. C. sinicus was the most dominant species and the unique one occurred in all three bays. With latitude decreasing, both the abundance and proportion of C. sinicus declined sharply. Cluster analysis showed that the 6 dominant species could be divided into 3 groups, based on their occurrences in the three bays. Our results suggested that the distribution of dominant species along the coast of China has a significant latitudinal gradient. C. sinicus which widely distributes in the coastal water of the northwestern Pacific can well adapt to the temperature at different latitudes. The high abundance in Haizhou Bay indicated that C. sinicus was an exemplary warm-temperate species, and more commonly occurs in the north of China seas. The ecological characteristics of dominant species change from warm-temperate type in high-latitudinal bays to warm water type in low-latitudinal bays.
基金The Fund of Key Laboratory of Ecological PrewarningProtection and Restoration of Bohai Sea,Ministry of Natural Resources under contract No.2022107+1 种基金the National Key Research and Development Program of China under contract No.2019YFC1407902the Qingdao Postdoctoral Applied Research Project of China under contract No.QDBSH202001。
文摘Since 2015,green tides with Ulva prolifera as the dominant species in the Qinhuangdao coastal waters have continued to occur.In this study,the relationship between green tides in Qinhuangdao and the Yellow Sea(setting sites in Rudong and Qingdao)was evaluated by genetic analyses of U.prolifera.Single nucleotide polymorphism(SNP)markers were used to analyze genetic diversity and genetic relationships among groups.Genetic differentiation was lower among floating U.prolifera populations in Rudong and Qingdao than in Qinhuangdao.The floating U.prolifera population had higher genetic diversity and polymorphism levels in Qingdao and Rudong than in Qinhuangdao.Physiological experiments showed that the growth rate and net buoyancy of floating U.prolifera were highest in Qinhuangdao and Qingdao,respectively,under the same environmental conditions(temperature and light).Overall,these findings showed that U.prolifera populations in the Qinhuangdao and Yellow Sea green tides(Rudong and Qingdao)differ significantly at the molecular and physiological levels.Therefore,the Qinhuangdao green tide is not correlated with the Yellow Sea green tide and has a different origin and development mode.This study provides insight into the mechanism underlying green tide blooms in coastal waters of China.
基金funded by the National Remote Sensing Centre,Hyderabad,India under NRSC-DOS-DBTGovt.of India project entitled‘‘Biodiversity Characterization in Southern parts of Karnataka’’(Project Number:UAS(B)/DR/GOI/245/2011-12)
文摘Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.
基金the National Basic Research Program of China (Nos. 2001 CB409703 and 2010CB428701)the National Natural Science Foundation of China (Nos. 41140037 and 41276 069)
文摘The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 ktg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level （including the nutrient supply from the terrestrial runoffs） was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that dia- toms were the main phytoplankton in this area, and Skeletonerna costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends： 1） Skeletonema （mainly S. costatum） was dominant throughout the year; and 2） seasonal succession trends were Coscinodiscus （spring） →Chaetoceros （summer and autumn） → Coscinodiscus （winter）. The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas： average annual phytoplankton biomass and dinoflagellate proportion both presented increased trends during the 1950s - 2000s.
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The Fund of Key Laboratory of Ecological Prewarning,Protection and Restoration of Bohai Sea,Ministry of Natural Resources under contract No.2022107the Qingdao Postdoctoral Applied Research Project under contract No.QDBSH202001。
文摘Since 2015,green tides have been blooming in offshore waters of Qinhuangdao,with serious impacts on the local ecological environment and tourism.Ulva australis,Bryopsis plumosa,and U.prolifera are the dominant species of Qinhuangdao green tides,following a sequential succession pattern.Ulva prolifera is the dominant species,with the highest biomass and the greatest influence on the local ecological environment.To study the reason of green tide dominant species succession and U.profilera became the dominant species with the largest biomass,we compared and analyzed the growth and nutrient uptake capacity of the three algae.The results showed that temperature significantly affects the growth of the three species.Within the temperature range of the experimental setup,the optimum temperature for the growth of U.australis,B.plumosa and U.profilera is10℃,15℃,and 20–25℃,respectively.Combined with the temperature variation trend during green tide bloom development,we believe that temperature is the key environmental factor for the succession of the dominant species.Ulva prolifera has a higher growth rate than U.australis and B.plumosa under the same nitrate,ammonium,and phosphate levels.Significant differences in the maximum absorption rate(R_(max))and R_(max)/Ks(the relationship between uptake rate and substrate concentration)values indicated that U.prolifera had an apparent competitive advantage over U.australis and B.plumosa regarding nutrient uptake.Therefore,the strong growth and nutrient uptake capacities of U.prolifera might be the main reason for becoming the dominant species with the largest biomass in Qinhuangdao green tides.
基金Funding for this work came from the USDA Forest Service Resources Planning Act Assessment,via an agreement with North Carolina State University
文摘Background： Knowledge of the different kinds of tree communities that currently exist can provide a baseline for assessing the ecological attributes of forests and monitoring future changes. Forest inventory data can facilitate the development of this baseline knowledge across broad extents, but they first must be classified into forest community types. Here, we compared three alternative classifications across the United States using data from over 117,000 U.S. Department of Agriculture Forest Service Forest Inventory and Analysis （FIA） plots. Methods： Each plot had three forest community type labels： （1） ＂FIA＂ types were assigned by the FIA program using a supervised method; （2） ＂USNVC＂ types were assigned via a key based on the U.S. National Vegetation Classification; （3） ＂empirical＂ types resulted from unsupervised clustering of tree species information. We assessed the degree to which analog classes occurred among classifications, compared indicator species values, and used random forest models to determine how well the classifications could be predicted using environmental variables. Results： The classifications generated groups of classes that had broadly similar distributions, but often there was no one-to-one analog across the classifications. The Iongleaf pine forest community type stood out as the exception： it was the only class with strong analogs across all classifications. Analogs were most lacking for forest community types with species that occurred across a range of geographic and environmental conditions, such as Ioblolly pine types, indicator species metrics were generally high for the USNVC, suggesting that LJSNVC classes are floristically well-defined. The empirical classification was best predicted by environmental variables. The most important predictors differed slightly but were broadly similar across all classifications, and included slope, amount of forest in the surrounding landscape, average minimum temperature, and other climate variables. Conclusions： The classifications have similarities and differences that reflect their differing approaches and Dbjectives. They are most consistent for forest community types that occur in a relatively narrow range of Invironmental conditions, and differ most for types with wide-ranging tree species. Environmental variables at variety of scales were important for predicting all classifications, though strongest for the empirical and FIA, guggesting that each is useful for studying how forest communities respond to of multi-scale environmental processes, including global change drivers.
基金supported by Biodiversity and Forest Pest Problems in Northeast China (BIOPROC)a cooperative project between Beijing Forestry University and Helsinki Universitythe Program for Changjiang Scholars and Innovative Research Team in Universities (PCSIRT0607)
文摘Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individuals were identified and 92.31% of total species appeared in natural forests, and 75.38% of total species appeared in plantations. The orders of Lepidoptera, Coleoptera, Diptera and Hymenoptera covered most of the collected arthropods. In different forest types, diversity indices is natural mixed forests （Betula platyphylla x Larix gmelinii）〉 natural pure B. platyphylla forests〉natural pure L. gmelinii forests〉plantations with pesticide treatment〉plantations without pesticide treatment. In natural forests, more than 70% of the arthropod families, species and individuals were distributed in shrub and herb layer, while in plantations 75% of the arthropod families, 78% of species and 80% of individuals were also distributed in shrub and herb layer. Lepidoptera, including Loxostege sticticalis （Linnaeus）, Chilo suppressalis （Walker） and Lymantria dispar （Linnaeus）, had the highest dominant degree.
文摘The distributional trends and their controlling factors of dominant species and nannofossil abundance in sur face sediments of marginal and coastal seas in low to middle latitudes and high latitudes are discussed on the basis of theanalysis of 146 samples from the nothern and central parts of the South China Sea and of comparison between the resultsof current work and data from other seas.Despite significant variations in taxonomic composition between seas or between areas within one sea, there are somegeneral trends in nannofossil distribution of marginal and coastal seas. All those nannofossil assemblages in middle and lowlatitudes are dominated by two species: Gephyrocapsa oceanica and Emiliania huxleyi. Although the relative abundanceof these species may vary greatly from area to area, Gephyrocapsa oceanica in general prevails in nearshore or semiclosedenvironments, increasing in number towards the shoreline, while Emiliania huxleyi increases in relative abundance to wards continental slope and open ocean environments, decreasing in abundance again only in very deep-water, i. e., nearthe CCD. Similarly, the abundance of calcareous nannofossils, as a whole, is lower nearshore, increasing with water depthtowards the continental slope, and then decreasing again towards and near the CCD. In high latitudes, the dominantspecies are Emiliania huxleyi and Coccolithus pelagicus.There are two groups of factors controlling the nannofossil distribution in surface sediments: ecological factors, in cluding particularly water temperature, supply of nutrients; and sedimentological factors, including influx of terrigenousmaterials and deep-water carbonate dissolution.
文摘Lowland tropical forest in Peninsular Malaysia consist a valuable dipterocarp timber species. In fact, dipterocarp tree species growth well when the ecology is maintained and their growth are dependent on the micro climate and also affected by lithology types. This study was carried out to identify and map tree species dominancy by lithology types at Hulu Sedili Forest Reserve （HSFR） using Geographic Information System （GIS） technique. Different lithology type maps were derived namely Igneous, Sedimentary and Limestone. Through GIS operations tree species data collected from pre-felling inventory and ground survey were overlaid with lithology features. Results showed that at Sedimentary and Igneous types, the presence of dipterocarpaceae family is only 3.09%, and non-dipterocarpaceae family was 96.91%. Syzygium spp. （19.83%） was the most abundance in Igneous and Sedimentary. Meanwhile, Elateriospermum tapos （9.92%） and Lauraceae＇s family （7.22%） were found to be the most dominant species in Sedimentary types, Macaranga spp. （11.21%） and Elateriospermum tapos （11.02%） in igneous types. However, a Limestone type was discarded from analysis due to unavailable pre-felling data. Thus, this study indicated that there was variation in species dominancy of different lithology types. On the other hand, GIS demonstrated its capability as a useful tool in identifying and maps the location of trees species based on lithology types.
基金Supported by the Innovation Team Project of Ecological Environment Monitoring and Restoration of Fishery Waters in the East China Sea of the Chinese Academy of Fishery Sciences(No.2020TD14)the National Basic Research Program of China(973 Program)(No.2010CB429005)。
文摘The estuarine areas are under frequent influence from freshwater intrusion and ocean currents,in which zooplankton species are diversified and variable as they are sensitive to physio-chemical variations in water.Therefore,understanding the relationships between zooplankton and environmental factors help us know the water quality.To achieve co-existence with species in similar ecological group or habit,they could inevitably alter themselves to fit the ecology and adjust the function according to the competitive exclusion in ecological theory.However,information of the co-existence of dominant species in the Changjiang(Yangtze)River estuary(CRE)and adjacent waters remains scarce.We explored the relationships between dominant zooplankton and environmental factors in the study region in spring-summer from 2016 to 2020,involving particularly the composition of dominant species,ecological groups,their relationships with environmental factors,and co-existence of important species,using the non-multidimensional scale analysis(nMDS)method and redundancy analysis.Results show that Labidocera euchaeta and Tortanus vermiculus were dominant species in the study scope.The turnover rate of dominant zooplankton was greater(>50%)in spring while the species number was higher in summer.The dominant species were estuarine,offshore,and eurytopic based on the adaptation to salinity.In spring,the ecological groups were dominated by estuarine species,while in summer by estuarine and offshore species.In addition,the nMDS showed that the dominant species in the same ecological group were more dispersed and not prominently clustered;the dominant species were staggered among different ecological groups.The temperature,salinity,pH,dissolved oxygen,and chlorophyll a were the main environmental factors on the distribution of the dominant species in spring,while in summer were dissolved oxygen,temperature,salinity,and pH.The domination of medusae of Nemopsis bachei and Pleurobrachia globosa in zooplankton community in spring,and the continuous decrease in abundance of L.euchaeta reflected the effects of local climate change.The temperature and salinity changes in different years and the subsequent response of zooplankton reflected the influence of freshwater intrusion and/or ocean currents.Zooplankton in similar ecological habits exhibited the competitive exclusion in terms of co-existence.
