In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We ai...In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We aimed to evaluate the patterns of biodiversity and structure of plant communities from rocky outcrops in high altitude grasslands of three areas at the Caparaó National Park, southeastern Brazil, by sampling 300 randomly distributed plots. Then, we compared the floristic composition, relative abundance, and biological and vegetation spectra among areas. We classified species as endemic and non-endemic and verified the occurrence of endangered species. Species richness was evaluated by rarefaction analysis on the sampling units. The importance value and species abundance distribution(SAD) models were assessed. We also performed an indicator species analysis. We sampled 58 species belonging to 49 genera and 32 families. The number of species decreased with increasing altitude, with significant differences being observed among areas regarding richness, abundance, and cover. Of the total number of species, 10 are endemic to the Caparaó National Park and 17 are listed on the Brazilian Red List of endangered species. The dominant families on all peaks were Asteraceae and Poaceae. The SAD models showed lognormal and geometric distributions, corroborating the fact that 10 species that were common to all three areas were also the most dominant ones in the communities and showed the highest importance values, which ranged between 35% and 60%. Indicator species analysis revealed that 28 species(48.27%) were indicators. Of these, 42.85% had maximum specificity, meaning that they occurred only in one area. Thus, the number of species per life form ratio was similar among areas, yet vegetation spectra differed, especially for hemicryptophytes. The altimetric difference among the areas showed to be a very important driver in the community assembly, influencing the evaluated variables, however, other drivers as soil depth, slope and water could also influence the community structure on a smaller and local spatial scale.展开更多
Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We eva...Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We evaluate the influence of altitude and climatic variables related to temperature and precipitation on plant community composition and species richness on Brazilian inselbergs.We assume as a premise that both climate and altitude would induce changes on plant community composition and species richness at the local level.We used plant inventory data from 370 sampling units across four inselberg sites in the Atlantic Forest of Espírito Santo State,south-eastern Brazil.We tested the univariate and multivariate effects of altitude and climate variables on community composition and species richness with multiple models.Differences in species richness between inselbergs were evaluated using sample-based data to estimate rarefaction and extrapolation curves.In addition,differences in species composition and taxonomic beta diversity were examined via novel frequency-based metrics.A contrasting climate pattern was observed between the inselberg sites,with south sites being wet compared to the dry conditions found in northern sites.Species richness by rarefaction showed a similar pattern within regional sites;however,there were marked differences between regions.Species richness and beta diversity showed significant differences among sites,with higher values in southern sites than in northern sites.In a multi-model comparison between inselberg sites,altitude significantly influenced community composition and species richness and explained more variance than climate models.This finding suggested that climate could act to some extent on these tropical inselbergs;however,altitude was a better predictor of plant community composition and species richness at the local level.展开更多
Elucidating woody community diversity and structure change along environmental gradients is still a central issue of tropical forest ecology. We have evaluated changes in alpha and beta diversity, community compositio...Elucidating woody community diversity and structure change along environmental gradients is still a central issue of tropical forest ecology. We have evaluated changes in alpha and beta diversity, community composition and structure of woody communities along an elevational gradient in Dwarf Cloud Forests, Southeast Brazil. We selected five areas along an elevational gradient(1,300-1,600 m asl), and randomly allocated 10 plots(10 m × 20 m) in each area in the Ibitipoca State Park(ISP), Serra da Mantiqueira, southeastern Brazil. All woody species(diameter at breast height ≥ 5.0 cm) were collected for taxonomic identification. Thus, we analysed the woody communities based on a phytosociological approach. Overall, 147 species and 37 families were recorded, distributed in 2,303 individuals. No differences in the species richness pattern were observed between areas using the rarefaction and extrapolation curves. Significant differences in species composition and structure between areas were observed. The high beta diversity observed, corroborated by the Jaccard coefficient, increases with decreasing altitude. Our results showed that woody communities in the studied Dwarf Cloud Forests have a higher diversity and structural variability along elevational gradient.展开更多
Evaluating the influences of fine-scale habitat heterogeneity on the composition,diversity,structure and functioning of forests is critical to understand how tropical forests will respond to climate change and devise ...Evaluating the influences of fine-scale habitat heterogeneity on the composition,diversity,structure and functioning of forests is critical to understand how tropical forests will respond to climate change and devise forest management strategies that will enhance biodiversity conservation and aboveground biomass stock.Here,we hypothesized that topographic and soil factors determine fine-scale habitat differentiation,which in turn shape community composition,species richness,structure and aboveground biomass at the local scale in tropical forests.To test this hypothesis,we selected two areas(each 100×100 m)with contrasting fine-scale topographic conditions where all trees,palms and lianas with a diameter at breast height ≥ 10 cm were tagged and identified to species.In each selected area,100 subplots of 10×10 m were established.We mainly found that higher topographic variability caused higher habitat differentiation with changes in species composition and community structure,but did not change species richness.Our habitat-scale analyses indicated that,in the less heterogeneous area,the distribution of species was more uniform along a fine-scale topographical gradient with no variation in convexity,which induced changes in structure and aboveground biomass,but not in species richness.The nonsignificant relationship between species richness and aboveground biomass may be attributable to species redundancy or functional dominance.This study suggests that environmental filtering is a fundamental process for shaping community assembly and forest functioning along a local topographical gradient in tropical forests.展开更多
Understanding how soil fertility changes due to environmental conditions and stand-age-dependent forest attributes is important for local-scale forest restoration.We evaluated the effects of stand-age-dependent forest...Understanding how soil fertility changes due to environmental conditions and stand-age-dependent forest attributes is important for local-scale forest restoration.We evaluated the effects of stand-age-dependent forest attributes(plant community composition and litter stock)on soil and technosol fertility across two second-growth Atlantic forests(SGF)after the deposition of mining tailings in Mariana,southeastern Brazil.We hypothesized that technosol fertility in the SGF tailings is positively affected by plant community composition variability,stand age,and litter stock.We used total exchangeable bases and organic matter as fertility indicators for technosol and soil,and species composition and litter stock as stand-age-dependent forest attributes.Our results showed significant differences in the stand-age-dependent forest attributes and soil chemical properties between the two forest patches(SGF tailing and SGF non-tailing)evaluated.Thus,there was a marked gradient of litter storage and fertility between soil and technosol that can be important forest recovery indicators for the affected plant communities.Furthermore,according to the tested models,we corroborated the hypothesis that technosol fertility is positively affected by stand age,plant community composition variability,and litter stock,which may contribute considerably to forest recovery on tailings.Our results demonstrate that the fertility predictors analyzed to explain the forest recovery on tailings can also be considered as ecological indicators for assessing forest restoration in areas impacted by mining tailings in Mariana.展开更多
Currently there is an urgent and special attention in actions to restore tropical forests.In this study,we evaluated the effect of different restoration methods on aboveground biomass(AGB)stock,tree community diversit...Currently there is an urgent and special attention in actions to restore tropical forests.In this study,we evaluated the effect of different restoration methods on aboveground biomass(AGB)stock,tree community diversity and structure,in areas affected by the Fundão tailings dam collapse in Mariana,Minas Gerais state,Brazil.We measured and compiled data of the AGB,community diversity and structure attributes in 36 plots distributed in six restoration treatments and six replicas:planting of native tree seedlings with fertilization and pH correction(PSf)and without fertilization and pH correction(PS);seeding of native trees with fertilization and pH correction(SDf)and without fertilization and pH correction(SD);natural regeneration with fertilization and pH correction(NRf)and without fertilization and pH correction(NR).No significant differences in substrate properties and AGB between treatments.Although biomass storage between treatments was not statistically different,there is a clear pattern showing higher values active restoration method.The Pielou index ranged from 0.520(SDf)to 0.943(NR),except for SDf all the others treatments had values higher than 0.76.This result suggests floristic heterogeneity,without ecological dominance in the plant community.Overall,active restoration had important implications for the forest restoration where natural regeneration is limited.展开更多
Ecological restoration in forest ecosystem is a priority in Mariana,Brazil.Thus,we evaluated the effects of passive and active restoration methods through different site preparation techniques by manipulating physical...Ecological restoration in forest ecosystem is a priority in Mariana,Brazil.Thus,we evaluated the effects of passive and active restoration methods through different site preparation techniques by manipulating physical-chemical properties of substrates on tree community coverage in Mariana,Brazil.A total of 48 plots(12×12 m each)were established in two areas along the flood plains with accumulation of tailings.The following treatments were established:(1)planting of native tree seedlings with fertilization(PSf)and(2)without fertilization(PS);(3)direct seeding of native trees with fertilization(SDf)and(4)without fertilization(SD);(5)natural regeneration with fertilization(NRf)and(6)without fertilization(NR).Differences in substrate properties and tree community coverage were evaluated between treatments,the substrate properties and tree community coverage relationship,and main effects of substrate fertility and texture on tree community coverage.There were marked differences in substrate and plant coverage between treatments.On average,the highest plant coverage was found in treatment with fertilization,such as NRf(59,5%)and SDf(48%).However,the treatment with seedling planting(PSf and PS)and NR did not show differences(~37%),while the lowest values were observed in SD(23%).There is a strong relationship between substrate fertility and plant community coverage,with significant positive effects.We observed that the passive and active restoration methods can be complementary in the soil and plant community coverage recovery.展开更多
Background:Predicting how natural and anthropogenic drivers shape different ecological indicators,such as plant populations along environmental gradients,can be a relevant tool for establishing management and conserva...Background:Predicting how natural and anthropogenic drivers shape different ecological indicators,such as plant populations along environmental gradients,can be a relevant tool for establishing management and conservation criteria of tropical wetlands.We aimed to assess the effects of seasonal flood disturbance,type of grasslands and topographical conditions on Croton trinitatis population distribution in a tropical wetland.Methods:The study was carried out in a seasonally flooded grassland(Central-West Brazil).We conducted samplings of soil on the dry and flood hydrophases of the Pantanal.We took the samples in eight seasonal ponds,with 1 km interval between them.Transects were marked during the flood period,observing the water level,one in the lowest zone,in the middle of the pond=low(ca.60 cm deep),one at the pond edge=mid(ca.30 cm deep)and one in the higher zone,on the external part=high(ca.1 cm deep).Results:The results showed that the topography,seasonality,and types of grassland determine differences in the abundance patterns of adult plants and seedlings,and seed bank and seed predation.The abiotic factors can shape plant population-related ecological processes and patterns,with outputs(germination and predation)and inputs(local dispersion and from neighbouring areas)of proportional seeds for the population maintenance in this environment.Conclusion:We emphasize the importance of these findings,to show that abiotic factors are not the only ones to be considered in ecological studies of distribution and structuring of populations in habitats with extreme seasonal events.展开更多
Background:Understanding how soil fertility changes due to topographical conditions and forest attributes is an essential premise for local-scale forest management practices.We evaluated the efects of topographic vari...Background:Understanding how soil fertility changes due to topographical conditions and forest attributes is an essential premise for local-scale forest management practices.We evaluated the efects of topographic variables and forest attributes on soil fertility along a local topographical gradient in a Brazilian Atlantic Forest.We hypothesised that soil fertility is positively afected by topographic variability and forest attributes(structure and diversity).We used tree species richness,composition,abundance,and aboveground biomass as forest attributes.We analysed two 1-ha for‑est patches with contrasting topographical conditions.We used diferent linear mixed efects models(LMMs)to test the main efects of diferent forest attributes and topography variables on soil fertility.Results:The results showed that higher topographic variability determines soil fertility along a fne-scale gradient.The frst two axes of the PCA explained 66.8%of the variation in soil data,with the frst axis(PCA_(1))explaining 49.6%of the variation in soil data and positively correlating with fertility-related soil properties.The second axis(PCA_(2))explained 17.2%of the variation in topographical data and positively correlated with convexity(the elevation of a plot minus the average elevation of all immediate neighbour plots)and elevation.Our best models showed that topo‑graphic variables(elevation and convexity)are the main predictors that afect fne-scale soil fertility.Conclusions:Our study demonstrates that the topographic variability,mainly elevation and convexity,determines fne-scale soil fertility in an Atlantic Forest.These results advance our understanding that context-dependent condi‑tions based on topography and soil properties have a high variability at a fne scale,which can infuence variations in forest attributes(i.e.,species distribution,diversity and structure of tree communities).In addition,the information generated in this research may be important for planning forest restoration activities(passive and active)based on the high variability of environmental variables at a fne scale.展开更多
文摘In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We aimed to evaluate the patterns of biodiversity and structure of plant communities from rocky outcrops in high altitude grasslands of three areas at the Caparaó National Park, southeastern Brazil, by sampling 300 randomly distributed plots. Then, we compared the floristic composition, relative abundance, and biological and vegetation spectra among areas. We classified species as endemic and non-endemic and verified the occurrence of endangered species. Species richness was evaluated by rarefaction analysis on the sampling units. The importance value and species abundance distribution(SAD) models were assessed. We also performed an indicator species analysis. We sampled 58 species belonging to 49 genera and 32 families. The number of species decreased with increasing altitude, with significant differences being observed among areas regarding richness, abundance, and cover. Of the total number of species, 10 are endemic to the Caparaó National Park and 17 are listed on the Brazilian Red List of endangered species. The dominant families on all peaks were Asteraceae and Poaceae. The SAD models showed lognormal and geometric distributions, corroborating the fact that 10 species that were common to all three areas were also the most dominant ones in the communities and showed the highest importance values, which ranged between 35% and 60%. Indicator species analysis revealed that 28 species(48.27%) were indicators. Of these, 42.85% had maximum specificity, meaning that they occurred only in one area. Thus, the number of species per life form ratio was similar among areas, yet vegetation spectra differed, especially for hemicryptophytes. The altimetric difference among the areas showed to be a very important driver in the community assembly, influencing the evaluated variables, however, other drivers as soil depth, slope and water could also influence the community structure on a smaller and local spatial scale.
文摘Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We evaluate the influence of altitude and climatic variables related to temperature and precipitation on plant community composition and species richness on Brazilian inselbergs.We assume as a premise that both climate and altitude would induce changes on plant community composition and species richness at the local level.We used plant inventory data from 370 sampling units across four inselberg sites in the Atlantic Forest of Espírito Santo State,south-eastern Brazil.We tested the univariate and multivariate effects of altitude and climate variables on community composition and species richness with multiple models.Differences in species richness between inselbergs were evaluated using sample-based data to estimate rarefaction and extrapolation curves.In addition,differences in species composition and taxonomic beta diversity were examined via novel frequency-based metrics.A contrasting climate pattern was observed between the inselberg sites,with south sites being wet compared to the dry conditions found in northern sites.Species richness by rarefaction showed a similar pattern within regional sites;however,there were marked differences between regions.Species richness and beta diversity showed significant differences among sites,with higher values in southern sites than in northern sites.In a multi-model comparison between inselberg sites,altitude significantly influenced community composition and species richness and explained more variance than climate models.This finding suggested that climate could act to some extent on these tropical inselbergs;however,altitude was a better predictor of plant community composition and species richness at the local level.
基金This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq(grants 454008/2014-7 and 435598/2018-0)Fundação de ApoioàPesquisa do Estado de Minas Gerais—FAPEMIG(grant APQ 2165/14)F.A.C.holds a CNPq productivity fellowship.
文摘Elucidating woody community diversity and structure change along environmental gradients is still a central issue of tropical forest ecology. We have evaluated changes in alpha and beta diversity, community composition and structure of woody communities along an elevational gradient in Dwarf Cloud Forests, Southeast Brazil. We selected five areas along an elevational gradient(1,300-1,600 m asl), and randomly allocated 10 plots(10 m × 20 m) in each area in the Ibitipoca State Park(ISP), Serra da Mantiqueira, southeastern Brazil. All woody species(diameter at breast height ≥ 5.0 cm) were collected for taxonomic identification. Thus, we analysed the woody communities based on a phytosociological approach. Overall, 147 species and 37 families were recorded, distributed in 2,303 individuals. No differences in the species richness pattern were observed between areas using the rarefaction and extrapolation curves. Significant differences in species composition and structure between areas were observed. The high beta diversity observed, corroborated by the Jaccard coefficient, increases with decreasing altitude. Our results showed that woody communities in the studied Dwarf Cloud Forests have a higher diversity and structural variability along elevational gradient.
基金financially supported by China Postdoctoral Science Foundation(Grant No.2018M643117)for ecological research at South China Normal University。
文摘Evaluating the influences of fine-scale habitat heterogeneity on the composition,diversity,structure and functioning of forests is critical to understand how tropical forests will respond to climate change and devise forest management strategies that will enhance biodiversity conservation and aboveground biomass stock.Here,we hypothesized that topographic and soil factors determine fine-scale habitat differentiation,which in turn shape community composition,species richness,structure and aboveground biomass at the local scale in tropical forests.To test this hypothesis,we selected two areas(each 100×100 m)with contrasting fine-scale topographic conditions where all trees,palms and lianas with a diameter at breast height ≥ 10 cm were tagged and identified to species.In each selected area,100 subplots of 10×10 m were established.We mainly found that higher topographic variability caused higher habitat differentiation with changes in species composition and community structure,but did not change species richness.Our habitat-scale analyses indicated that,in the less heterogeneous area,the distribution of species was more uniform along a fine-scale topographical gradient with no variation in convexity,which induced changes in structure and aboveground biomass,but not in species richness.The nonsignificant relationship between species richness and aboveground biomass may be attributable to species redundancy or functional dominance.This study suggests that environmental filtering is a fundamental process for shaping community assembly and forest functioning along a local topographical gradient in tropical forests.
文摘Understanding how soil fertility changes due to environmental conditions and stand-age-dependent forest attributes is important for local-scale forest restoration.We evaluated the effects of stand-age-dependent forest attributes(plant community composition and litter stock)on soil and technosol fertility across two second-growth Atlantic forests(SGF)after the deposition of mining tailings in Mariana,southeastern Brazil.We hypothesized that technosol fertility in the SGF tailings is positively affected by plant community composition variability,stand age,and litter stock.We used total exchangeable bases and organic matter as fertility indicators for technosol and soil,and species composition and litter stock as stand-age-dependent forest attributes.Our results showed significant differences in the stand-age-dependent forest attributes and soil chemical properties between the two forest patches(SGF tailing and SGF non-tailing)evaluated.Thus,there was a marked gradient of litter storage and fertility between soil and technosol that can be important forest recovery indicators for the affected plant communities.Furthermore,according to the tested models,we corroborated the hypothesis that technosol fertility is positively affected by stand age,plant community composition variability,and litter stock,which may contribute considerably to forest recovery on tailings.Our results demonstrate that the fertility predictors analyzed to explain the forest recovery on tailings can also be considered as ecological indicators for assessing forest restoration in areas impacted by mining tailings in Mariana.
基金To the National Council of Scientific and Technological Development of Brazil(CNPq),provided for research fellowships for S.V.Martins and to the Fundação Renova for provided infrastructure and financial support for the project.
文摘Currently there is an urgent and special attention in actions to restore tropical forests.In this study,we evaluated the effect of different restoration methods on aboveground biomass(AGB)stock,tree community diversity and structure,in areas affected by the Fundão tailings dam collapse in Mariana,Minas Gerais state,Brazil.We measured and compiled data of the AGB,community diversity and structure attributes in 36 plots distributed in six restoration treatments and six replicas:planting of native tree seedlings with fertilization and pH correction(PSf)and without fertilization and pH correction(PS);seeding of native trees with fertilization and pH correction(SDf)and without fertilization and pH correction(SD);natural regeneration with fertilization and pH correction(NRf)and without fertilization and pH correction(NR).No significant differences in substrate properties and AGB between treatments.Although biomass storage between treatments was not statistically different,there is a clear pattern showing higher values active restoration method.The Pielou index ranged from 0.520(SDf)to 0.943(NR),except for SDf all the others treatments had values higher than 0.76.This result suggests floristic heterogeneity,without ecological dominance in the plant community.Overall,active restoration had important implications for the forest restoration where natural regeneration is limited.
文摘Ecological restoration in forest ecosystem is a priority in Mariana,Brazil.Thus,we evaluated the effects of passive and active restoration methods through different site preparation techniques by manipulating physical-chemical properties of substrates on tree community coverage in Mariana,Brazil.A total of 48 plots(12×12 m each)were established in two areas along the flood plains with accumulation of tailings.The following treatments were established:(1)planting of native tree seedlings with fertilization(PSf)and(2)without fertilization(PS);(3)direct seeding of native trees with fertilization(SDf)and(4)without fertilization(SD);(5)natural regeneration with fertilization(NRf)and(6)without fertilization(NR).Differences in substrate properties and tree community coverage were evaluated between treatments,the substrate properties and tree community coverage relationship,and main effects of substrate fertility and texture on tree community coverage.There were marked differences in substrate and plant coverage between treatments.On average,the highest plant coverage was found in treatment with fertilization,such as NRf(59,5%)and SDf(48%).However,the treatment with seedling planting(PSf and PS)and NR did not show differences(~37%),while the lowest values were observed in SD(23%).There is a strong relationship between substrate fertility and plant community coverage,with significant positive effects.We observed that the passive and active restoration methods can be complementary in the soil and plant community coverage recovery.
文摘Background:Predicting how natural and anthropogenic drivers shape different ecological indicators,such as plant populations along environmental gradients,can be a relevant tool for establishing management and conservation criteria of tropical wetlands.We aimed to assess the effects of seasonal flood disturbance,type of grasslands and topographical conditions on Croton trinitatis population distribution in a tropical wetland.Methods:The study was carried out in a seasonally flooded grassland(Central-West Brazil).We conducted samplings of soil on the dry and flood hydrophases of the Pantanal.We took the samples in eight seasonal ponds,with 1 km interval between them.Transects were marked during the flood period,observing the water level,one in the lowest zone,in the middle of the pond=low(ca.60 cm deep),one at the pond edge=mid(ca.30 cm deep)and one in the higher zone,on the external part=high(ca.1 cm deep).Results:The results showed that the topography,seasonality,and types of grassland determine differences in the abundance patterns of adult plants and seedlings,and seed bank and seed predation.The abiotic factors can shape plant population-related ecological processes and patterns,with outputs(germination and predation)and inputs(local dispersion and from neighbouring areas)of proportional seeds for the population maintenance in this environment.Conclusion:We emphasize the importance of these findings,to show that abiotic factors are not the only ones to be considered in ecological studies of distribution and structuring of populations in habitats with extreme seasonal events.
基金fnanced in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brasil(CAPES)–Finance Code 001.
文摘Background:Understanding how soil fertility changes due to topographical conditions and forest attributes is an essential premise for local-scale forest management practices.We evaluated the efects of topographic variables and forest attributes on soil fertility along a local topographical gradient in a Brazilian Atlantic Forest.We hypothesised that soil fertility is positively afected by topographic variability and forest attributes(structure and diversity).We used tree species richness,composition,abundance,and aboveground biomass as forest attributes.We analysed two 1-ha for‑est patches with contrasting topographical conditions.We used diferent linear mixed efects models(LMMs)to test the main efects of diferent forest attributes and topography variables on soil fertility.Results:The results showed that higher topographic variability determines soil fertility along a fne-scale gradient.The frst two axes of the PCA explained 66.8%of the variation in soil data,with the frst axis(PCA_(1))explaining 49.6%of the variation in soil data and positively correlating with fertility-related soil properties.The second axis(PCA_(2))explained 17.2%of the variation in topographical data and positively correlated with convexity(the elevation of a plot minus the average elevation of all immediate neighbour plots)and elevation.Our best models showed that topo‑graphic variables(elevation and convexity)are the main predictors that afect fne-scale soil fertility.Conclusions:Our study demonstrates that the topographic variability,mainly elevation and convexity,determines fne-scale soil fertility in an Atlantic Forest.These results advance our understanding that context-dependent condi‑tions based on topography and soil properties have a high variability at a fne scale,which can infuence variations in forest attributes(i.e.,species distribution,diversity and structure of tree communities).In addition,the information generated in this research may be important for planning forest restoration activities(passive and active)based on the high variability of environmental variables at a fne scale.
