Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influ...Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest,a historically neglected ecoregion.We evaluated the phylogenetic structure,forest structure(tree basal area and tree density)and species richness along an elevation gradient,as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities.To do so,we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l.without large elevation gaps.The relationships between elevation and phylogenetic structure,forest structure and species richness were investigated through Linear Models.The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny.Our results showed decreased species richness at higher elevations and independence between forest structure,phylogenetic structure and elevation.We also verified that there is a phylogenetic signal associated with elevation-success by lineages.We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range.On the other hand,elevation is not associated with forest structure or phylogenetic structure.Furthermore,closely related taxa tend to have their higher ecological success in similar elevations.Finally,we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes(i.e.global warming)due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions(i.e.minimum temperature)associated with each elevation range.展开更多
Beech (Fagus orientalis Lipsky) forest covers about 565,000 ha of land in Guilan province, north of Iran and forms a major carbon pool. It is an important economic, soil protection and recreation resource. We studied ...Beech (Fagus orientalis Lipsky) forest covers about 565,000 ha of land in Guilan province, north of Iran and forms a major carbon pool. It is an important economic, soil protection and recreation resource. We studied long-term effects of fire on the structure and composition 37 years after fire occurrence in these forests. To do this research, we selected 85 ha burned and 85 ha unburned beech forests). The results indicated that the fire had not changed the overall uneven-aged structure, but it changed forest composition from pure stands to mixed stands that now include species such as Carpinus betulus, Acer cappadocicum and Alnus subcordata. The density of trees and regeneration was significantly increased, while the density of shrubs significantly decreased. The main reasons for increased tree regeneration were attributed to (1) reduction of litter depth, and (2) increase in available light from opening of the canopy and reduction in shrub competition. It is apparent that the forest is on a path to return to its natural state before the fire after 37 years.展开更多
This article describes the application of GPS, image processing analysis and statistical tools for determination of forest structure and biodiversity. The idea is based on determination of forest area using GPS tools,...This article describes the application of GPS, image processing analysis and statistical tools for determination of forest structure and biodiversity. The idea is based on determination of forest area using GPS tools, then taking representative plots “samples” about 5% - 10% of the forest and counting the tree species in each plot (sample). This process enables the estimation of species population in each plot. The sum of all species population enables the calculation of relative density of each species. Multiplying species population with plot number of the forest enables the calculations of total species population in the forest. Calculating the relative density enables the determination of dominant, co-dominant, suppressed and flour structure of the forest. To determine the age of the forest, we apply our method on determining the diameter of trees and grouping them to four groups, this enables the estimation of dominant age within single species. From these data, we can estimate the age of the forest. This field protocol is easy and applicable and provides good results in estimating structure, age and biodiversity in the forest.展开更多
A critical first step in establishing biosphere reserves—under the Man and Biosphere Programme of UNESCO—is to generate baseline information for future courses of action. The present study aims to assess the structu...A critical first step in establishing biosphere reserves—under the Man and Biosphere Programme of UNESCO—is to generate baseline information for future courses of action. The present study aims to assess the structure and composition of forests—along with anthropogenic pressures mounting on these forests in the buffer zone of one such biosphere reserves—the Pachmarhi biosphere reserve of India. The quadrat method was employed for sampling vegetation, and information on anthropogenic pressures was collected by conducting interviews with local people and forest officials and collecting it from secondary sources. A total of 39 tree species were sampled in 82 quadrats; of these 26 tree species were in standing stage, 25 in sapling, and 35 in seedling. Chloroxylon swietenia emerged as the most dominant tree species having highest importance value index, followed by Tectona grandis, Terminalia tomentosa, and Hardwickia binata.Nine tree species and their saplings, including Sterculia urens and Terminalia arjuna, were exploited so badly that they were only found in the seedlings stage. The unavailability of standing trees of 12 important tree species including Aegle marmelos and Phyllanthus emblica indicates the intensity and gravity of anthropogenic pressures on these important tree species. If the present anthropogenic pressure continues, which has inhibited the regeneration of several tree species, then substantial negative ecological and societal consequences can be expected.展开更多
Vietnam is one of the countries with high biological diversity in the world but also greatly influenced by climate change.Therefore,it is necessary to have a solution for sustainable forest management through field su...Vietnam is one of the countries with high biological diversity in the world but also greatly influenced by climate change.Therefore,it is necessary to have a solution for sustainable forest management through field surveys in permanent plots to study forest ecology,combining advanced GIS(Geographic Information System)technologies such as Google Earth,Global Mapper,etc.to monitor changes in forest structure and dynamics.The paper is based on the inheritance of the first measurement data in 2012 and directly measures in the second time after 5 years in 2017 at a 10-ha plot with ten 1-ha subplots.The results show that the number of trees is the highest at the diameter class of 10-20 cm(<20 cm),accounting for about 60%of the total number of trees of each 1-ha sub-plot and the study site and at the height of<20 m,respectively 8,402 out of 10,261 in 2012 and 8,189 out of 10,013 in 2017 were measured.In addition,the result of this paper indicates that Google Earth software is one of the most effective GIS tools in planning biodiversity conservation strategies and natural resource management.展开更多
Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of gre...Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity (DIV), forest structure ((stem density (DEN), mean basal area (MBA) and mean height class (MHC)) and disturbance (DIS) were explored along 2,400 m altitudinal gradient in Hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest (LoF) to mid- altitude forest (MiF) and montane forest (MoF) in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method (PCQM) with 96 sampling points and 83 vegetation samples by plot method (PM) were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters: DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend using both forest biodiversity and mensuration data in management process of forest ecosystems.展开更多
Forests in Kenya are managed under different management regimes, including traditional community based forest management, command and control, participatory forest management, leasehold, concessions, and private. Asse...Forests in Kenya are managed under different management regimes, including traditional community based forest management, command and control, participatory forest management, leasehold, concessions, and private. Assessment of these regimes’ impact (positively or negatively) on forest conservation has not been done. The study was done to determine the impact on forest conservation of three management regimes traditional community based forest management, command and control, and participatory forest management. The survey was done through secondary data, focus group discussion, key informant interview, household survey, ecological survey, and land cover and land use analysis through GIS. The results indicate that the forest site under participatory forest management witnessed better forest management. In this site, the forest zone witnessing best management was the one near the forest station where the rangers are located and adjacent to the community that has been involved in forest management and benefited most from project intervention, an incentive for their participation in forest management. The forests under traditional community based forest management faced a high forest degradation rate. Forest under command and control regime witnessed the best forest condition improvement attributed to the management regime not allowing consumptive forest resource utilization. Each regime was best under its’ legislative framework and would facilitate better forest management and contribute to improved livelihoods without compromising forest quality. Participatory forest management was the most preferred management regime contributing to better forest management, improved community livelihoods, and formally involved communities and other stakeholders. Each regime’s appropriateness would be enhanced through stakeholder capacity building, institutional reform, adequate financial facilitation, and appropriate implementation. Therefore, adopting participatory forest management attributes to the other two management regimes would enhance their appropriateness, while appreciating that the management objective determines the regime being implemented in each forest.展开更多
The ecotone, the spatial transition zone between two vegetation communities, is claimed to have more species than the adjoining communities.However, empirical studies do not always confirm higher richness at the ecoto...The ecotone, the spatial transition zone between two vegetation communities, is claimed to have more species than the adjoining communities.However, empirical studies do not always confirm higher richness at the ecotone. The ecotone position and structure are dynamic over time and space and it is driven by the changes in climate, land use or their interaction. In this context, we assessed the forestgrassland ecotone of temperate mountains in central Nepal by i) comparing species composition and richness across the ecotone, ii) analyzing if the forestgrassland ecotone is shifting towards the grassland center by colonizing them with trees, and iii)discussing the consequence of changed disturbance regime in the dynamics of this ecotone and the surrounding grasslands. We analyzed vegetation data sampled from belt transects laid across the forestgrassland ecotone in semi-natural grassland patches.Vegetation data consisting of species richness and composition, and size structure and regeneration of the two most dominant tree species, namely Rhododendron arboreum and Abies spectabilis, from the transects, were used to analyze the trend of the forest-grassland ecotone. Forest and grasslands were different in terms of floristic composition and diversity. Vascular plant species richness linearly increased while moving from forest interior to grassland center. Spatial pattern of tree size structure and regeneration infers that forest boundary is advancing towards the grasslands at the expense of the grassland area, and tree establishment in the grasslands is part of a successional process. Temporally, tree establishment in grasslands started following the gradual decline in disturbance. We argue that local processes in terms of changed land use may best explain the phenomenon of ecotone shift and consequent forest expansion in these grasslands. We underpin the need for further research on the mechanism, rate and spatial extent of ecotone shift by using advanced tools to understand the process indepth.展开更多
The Araliaceae family consists of numerous species of medical plants of significant value as non-wood forest products.To conserve and culture these plants in natural forest stands is an important undertaking which sho...The Araliaceae family consists of numerous species of medical plants of significant value as non-wood forest products.To conserve and culture these plants in natural forest stands is an important undertaking which should be implemented according to the relationship between forest structure and understory population.In this study,thirtyfive plots were established in natural A ralia elata stands.Taller individual and denser populations were found in the northern and in the eastern regions,respectively.Both population densities and individual leaf weight increased along longitude.In contrast,their relationship with elevation and DBH were negative.Along with the altitude gradient,both height and root-collar diameter increased but population density declined.Root-collar diameter and population density decreased with latitude and DBH,respectively.Overall,dominant trees unlikely enforced strong disturbance to the development of understory A.elata populations unless concerning some specific topographic factors.展开更多
In Europe, very small forest areas can be considered to be old-growth, and they are mainly located in Eastern Europe. The typical structures of old growth forests infrequently occur in Mediterranean mountainous enviro...In Europe, very small forest areas can be considered to be old-growth, and they are mainly located in Eastern Europe. The typical structures of old growth forests infrequently occur in Mediterranean mountainous environments, since they have been affected by human activities for centuries. This study focused on a remote and almost pure Italian maple stand located in southern Italy, which has not been managed for long time due to its inaccessibility. The effects of natural evolution on the forest stand were evaluated through the analysis of the spatial and chronological structure and the regeneration patterns, then estimating the amounts and quality of deadwood occurrence. Across the whole stand, all the trees with DBH(diameter at breast height) larger than 50 cm(LLT, large living trees) were measured(DBH and height) and age was also determined through a dendrochronological approach. The diameters observed ranged between 50 and 145 cm with ages of 120 to 250 years. The Latham index calculated for trees within the sample plot highlighted a multilayered canopy with a dominant layer of largeliving trees(age > 120 years). The size-class distribution of stems had a reverse-J shape, and basal area was 52 m^2 ha^(-1). Deadwood was exclusively constituted by standing dead trees and CWD and its volume was on average 31 m^3 ha^(-1). Pure Italian maple forests are generally rare in Europe, and it was unexpected to find a forest stand characterized by a so complex structure with old growth attributes. The study of complex forest stand, even if small, could give precious information on the forest evolution, clarifying also diverse auto-ecological traits of tree species that usually are not common in our forests.展开更多
Tropical forests play a critical role in mitigating climate change because they account for large amount o terrestrial carbon storage and productivity.However,there are many uncertainties associated with the estimatio...Tropical forests play a critical role in mitigating climate change because they account for large amount o terrestrial carbon storage and productivity.However,there are many uncertainties associated with the estimation o carbon dynamics.We estimated forest structure and carbon dynamics along a slope(17.3°–42.8°)and to assess the relations between forest structures,carbon dynamics,and slopes in an intact lowland mixed dipterocarp forest,in Kuala Belalong,Brunei Darussalam.Living biomass,basa area,stand density,crown properties,and tree family composition were measured for forest structure.Growth rate,litter production,and litter decomposition rates were also measured for carbon dynamics.The crown form index and the crown position index were used to assess crown properties,which we categorized into five stages,from very poor to perfect.The living biomass,basal area and stand density were 261.5–940.7 Mg ha^(-1),43.6–63.6 m^2ha^(-1)and 6,675–8400 tree ha^(-1),respectively.The average crown form and position index were 4,which means that the crown are mostly symmetrical and sufficiently exposed for photosynthesis.The mean biomass growth rate,litter production,litter decomposition rate were estimated as11.9,11.6 Mg ha^(-1)a^(-1),and 7.2 g a^(-1),respectively.Biomass growth rate was significantly correlated with living biomass,basal area,and crown form.Crown form appeared to strongly influence living biomass,basal area and biomass growth rate in terms of light acquisition.However,basal area,stand density,crown properties,and biomass growth rate did not vary by slope or tree family composition.The results indicate that carbon accumulation by tree growth in an intact lowland mixed dipterocarp forest depends on crown properties.Absence of any effect of tree family composition on carbon accumulation suggests that the main driver of biomass accumulation in old-growth forests of Borneo is not species-specific characteristics of tree species.展开更多
Understanding the interaction between canopy structure and the parameters of interception loss is essential in predicting the variations in partitioning rainfall and water resources as affected by changes in canopy st...Understanding the interaction between canopy structure and the parameters of interception loss is essential in predicting the variations in partitioning rainfall and water resources as affected by changes in canopy structure and in implementing water-based management in semiarid forest plantations.In this study,seasonal variations in rainfall interception loss and canopy storage capacity as driven by canopy structure were predicted and the linkages were tested using seasonal filed measurements.The study was conducted in nine 50 m×50 m Robinia pseudoacacia plots in the semiarid region of China’s Loess Plateau.Gross rain-fall,throughfall and stemflow were measured in seasons with and without leaves in 2015 and 2016.Results show that measured average interception loss for the nine plots were 17.9% and 9.4% of gross rainfall during periods with leaves (the growing season) and without leaves, respectively. Average canopy storage capacity estimated using an indirect method was 1.3 mm in the growing season and 0.2 mm in the leafless season. Correlations of relative interception loss and canopy storage capacity to canopy variables were highest for leaf/wood area index (LAI/WAI) and canopy cover, fol-lowed by bark area, basal area, tree height and stand density. Combined canopy cover, leaf/wood area index and bark area multiple regression models of interception loss and canopy storage capacity were established for the growing season and in the leafless season in 2015. It explained 97% and 96% of the variations in relative interception loss during seasons with and without leaves, respectively. It also explained 98% and 99% of the variations in canopy storage capacity during seasons with and without leaves, respectively. The empiri-cal regression models were validated using field data col-lected in 2016. The models satisfactorily predicted relative interception loss and canopy storage capacity during seasons with and without leaves. This study provides greater under-standing about the effects of changes in tree canopy structure (e.g., dieback or mortality) on hydrological processes.展开更多
The bottleneck analysis of the minimum coat problem for the generalized netwok(MCPGN) is discussed.The analysis is based on the network simplex algorithm,which gains negative cost graphs by constructing augmented fore...The bottleneck analysis of the minimum coat problem for the generalized netwok(MCPGN) is discussed.The analysis is based on the network simplex algorithm,which gains negative cost graphs by constructing augmented forest structure,then augments flows on the negative cost graphs until the optimal revolution is gained Bottleneck structure is presented after analyzing the augmented forest structure.The negative cost augmented graphs are constructed with the bottleneck structure.The arcs that block the negative cost augmented graph are the elements of the bottleneck.The bottleneck analysis for the generalized circulation problem,the minimum circulation problem and the circulation problem are discussed respectively as the basal problems,then that for MCPGN is achieved.An example is presented at the end.展开更多
The present study was carried out at two different gradients of unburnt and burnt Anogeissus latifolia forest sites in the Garhwal region, India. At each gradient, the unburnt and burnt forest sites were further categ...The present study was carried out at two different gradients of unburnt and burnt Anogeissus latifolia forest sites in the Garhwal region, India. At each gradient, the unburnt and burnt forest sites were further categorized into three different elevations, i.e., lower (700 m), middle (850 m) and upper (1000 m). At each elevation, the density of trees, saplings and seedlings was higher at the unburnt sites except for trees at the upper elevation which was higher at the burnt sites. The total basal area of each layer of forest was also higher at the unburnt sites. The study revealed that the lower number of saplings and seedlings at the burnt forest sites might be due to the effect of fire. Most trees in the lower dbh classes were affected by forest fire at the burnt sites which reduced the total density and total basal area of the trees compared to the unburnt sites. The diversity of trees increased with increasing elevation. However, the diversity of saplings and seedlings reduced with increasing elevation.展开更多
As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic spaces.Previous studies note that vegetation structure is...As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic spaces.Previous studies note that vegetation structure is a key factor influencing bird sounds in urban forests;hence,adjusting the frequency composition may be a strategy for birds to avoid anthropogenic noise to mask their songs.However,it is unknown whether the response mechanisms of bird vocalizations to vegetation structure remain consistent despite being impacted by anthropogenic noise.It was hypothesized that anthropogenic noise in urban forests occupies the low-frequency space of bird songs,leading to a possible reshaping of the acoustic niches of forests,and the vegetation structure of urban forests is the critical factor that shapes the acoustic space for bird vocalization.Passive acoustic monitoring in various urban forests was used to monitor natural and anthropogenic noises,and sounds were classified into three acoustic scenes(bird sounds,human sounds,and bird-human sounds)to determine interconnections between bird sounds,anthropogenic noise,and vegetation structure.Anthropogenic noise altered the acoustic niche of urban forests by intruding into the low-frequency space used by birds,and vegetation structures related to volume(trunk volume and branch volume)and density(number of branches and leaf area index)significantly impact the diversity of bird sounds.Our findings indicate that the response to low and high frequency signals to vegetation structure is distinct.By clarifying this relationship,our results contribute to understanding of how vegetation structure influences bird sounds in urban forests impacted by anthropogenic noise.展开更多
Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest chang...Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.展开更多
Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The s...Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The succession patterns of methanotrophic communities and functions in Wudalianchi volcano forest soils could provide a basis for the study of evolutionary mechanisms between soil microorganisms,the environment,and carbon cycling of temperate forest ecosystems under climate change.In this study,the characteristics and drivers of methanotrophic community structure and function of two volcanic soils at different stages of development are analyzed,including an old volcano and a new volcano,which most recently erupted 300 years and 17-19×10^(5)years ago,respectively,and a non-volcano hills as control,based on space for time substitution and Miseq sequencing and bioinformation technology.The results showed that CH_(4) fluxes were significantly higher in old-stage volcano forest soils than new-stage forest soils and non-volcano forest soils.There were significant differences in the community composition and diversity of soil methanotrophs from different volcano forest soils.Methylococcus was the dominant genus in all soil samples.Additionally,the relative abundance of Methylococcus,along with Clonothrix,Methyloglobulus,Methylomagum,Methylomonas and Methylosarcina,were the important genera responsible for the differences in methanotrophic community structure in different volcano forest soils.The relative abundance of methanotroph belonging toγ-proteobacteria was significantly higher than that belonging toα-proteobacteria(P<0.05).Chao1,Shannon and Simpson indices of soil methanotrophic community were significantly lower in new-stage volcanos and were significantly affected by bulk density,total porosity,p H,nitrate,dissolved organic carbon and dissolved organic nitrogen.There were significant differences in community structure between new-stage and old-stage volcanoes.Bulk density and p H are important soil properties contributing to the divergence of methanotrophs community structure,and changes in soil properties due to soil development time are important factors driving differences in methanotrophs communities in Wudalianchi volcanic soils.展开更多
基金supported this work by granting the doctoral scholarship to Ravi Fernandes Mariano,Carolina Njaime Mendes and Cléber Rodrigo de Souza,and through the master’s scholarship to Aloysio Souza de Mourathe postdoctoral scholarship to Vanessa Leite Rezende+2 种基金The authors also thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPQ)by project funding(Edital Universal 2014,Process 459739/2014-0)the Instituto Alto-Montana da Serra Fina,the Fundação de AmparoàPesquisa do Estado de Minas Gerais(FAPEMIG)the Fundação Grupo Boticário de ProteçãoàNatureza,and finally the Fundo de Recuperação,Proteção e Desenvolvimento Sustentável das Bacias Hidrográficas do Estado de Minas Gerais(Fhidro).
文摘Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest,a historically neglected ecoregion.We evaluated the phylogenetic structure,forest structure(tree basal area and tree density)and species richness along an elevation gradient,as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities.To do so,we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l.without large elevation gaps.The relationships between elevation and phylogenetic structure,forest structure and species richness were investigated through Linear Models.The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny.Our results showed decreased species richness at higher elevations and independence between forest structure,phylogenetic structure and elevation.We also verified that there is a phylogenetic signal associated with elevation-success by lineages.We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range.On the other hand,elevation is not associated with forest structure or phylogenetic structure.Furthermore,closely related taxa tend to have their higher ecological success in similar elevations.Finally,we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes(i.e.global warming)due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions(i.e.minimum temperature)associated with each elevation range.
文摘Beech (Fagus orientalis Lipsky) forest covers about 565,000 ha of land in Guilan province, north of Iran and forms a major carbon pool. It is an important economic, soil protection and recreation resource. We studied long-term effects of fire on the structure and composition 37 years after fire occurrence in these forests. To do this research, we selected 85 ha burned and 85 ha unburned beech forests). The results indicated that the fire had not changed the overall uneven-aged structure, but it changed forest composition from pure stands to mixed stands that now include species such as Carpinus betulus, Acer cappadocicum and Alnus subcordata. The density of trees and regeneration was significantly increased, while the density of shrubs significantly decreased. The main reasons for increased tree regeneration were attributed to (1) reduction of litter depth, and (2) increase in available light from opening of the canopy and reduction in shrub competition. It is apparent that the forest is on a path to return to its natural state before the fire after 37 years.
文摘This article describes the application of GPS, image processing analysis and statistical tools for determination of forest structure and biodiversity. The idea is based on determination of forest area using GPS tools, then taking representative plots “samples” about 5% - 10% of the forest and counting the tree species in each plot (sample). This process enables the estimation of species population in each plot. The sum of all species population enables the calculation of relative density of each species. Multiplying species population with plot number of the forest enables the calculations of total species population in the forest. Calculating the relative density enables the determination of dominant, co-dominant, suppressed and flour structure of the forest. To determine the age of the forest, we apply our method on determining the diameter of trees and grouping them to four groups, this enables the estimation of dominant age within single species. From these data, we can estimate the age of the forest. This field protocol is easy and applicable and provides good results in estimating structure, age and biodiversity in the forest.
基金funded under the grant IIFM/RP-Int./CPK/2009-11/04
文摘A critical first step in establishing biosphere reserves—under the Man and Biosphere Programme of UNESCO—is to generate baseline information for future courses of action. The present study aims to assess the structure and composition of forests—along with anthropogenic pressures mounting on these forests in the buffer zone of one such biosphere reserves—the Pachmarhi biosphere reserve of India. The quadrat method was employed for sampling vegetation, and information on anthropogenic pressures was collected by conducting interviews with local people and forest officials and collecting it from secondary sources. A total of 39 tree species were sampled in 82 quadrats; of these 26 tree species were in standing stage, 25 in sapling, and 35 in seedling. Chloroxylon swietenia emerged as the most dominant tree species having highest importance value index, followed by Tectona grandis, Terminalia tomentosa, and Hardwickia binata.Nine tree species and their saplings, including Sterculia urens and Terminalia arjuna, were exploited so badly that they were only found in the seedlings stage. The unavailability of standing trees of 12 important tree species including Aegle marmelos and Phyllanthus emblica indicates the intensity and gravity of anthropogenic pressures on these important tree species. If the present anthropogenic pressure continues, which has inhibited the regeneration of several tree species, then substantial negative ecological and societal consequences can be expected.
文摘Vietnam is one of the countries with high biological diversity in the world but also greatly influenced by climate change.Therefore,it is necessary to have a solution for sustainable forest management through field surveys in permanent plots to study forest ecology,combining advanced GIS(Geographic Information System)technologies such as Google Earth,Global Mapper,etc.to monitor changes in forest structure and dynamics.The paper is based on the inheritance of the first measurement data in 2012 and directly measures in the second time after 5 years in 2017 at a 10-ha plot with ten 1-ha subplots.The results show that the number of trees is the highest at the diameter class of 10-20 cm(<20 cm),accounting for about 60%of the total number of trees of each 1-ha sub-plot and the study site and at the height of<20 m,respectively 8,402 out of 10,261 in 2012 and 8,189 out of 10,013 in 2017 were measured.In addition,the result of this paper indicates that Google Earth software is one of the most effective GIS tools in planning biodiversity conservation strategies and natural resource management.
文摘Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity (DIV), forest structure ((stem density (DEN), mean basal area (MBA) and mean height class (MHC)) and disturbance (DIS) were explored along 2,400 m altitudinal gradient in Hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest (LoF) to mid- altitude forest (MiF) and montane forest (MoF) in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method (PCQM) with 96 sampling points and 83 vegetation samples by plot method (PM) were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters: DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend using both forest biodiversity and mensuration data in management process of forest ecosystems.
文摘Forests in Kenya are managed under different management regimes, including traditional community based forest management, command and control, participatory forest management, leasehold, concessions, and private. Assessment of these regimes’ impact (positively or negatively) on forest conservation has not been done. The study was done to determine the impact on forest conservation of three management regimes traditional community based forest management, command and control, and participatory forest management. The survey was done through secondary data, focus group discussion, key informant interview, household survey, ecological survey, and land cover and land use analysis through GIS. The results indicate that the forest site under participatory forest management witnessed better forest management. In this site, the forest zone witnessing best management was the one near the forest station where the rangers are located and adjacent to the community that has been involved in forest management and benefited most from project intervention, an incentive for their participation in forest management. The forests under traditional community based forest management faced a high forest degradation rate. Forest under command and control regime witnessed the best forest condition improvement attributed to the management regime not allowing consumptive forest resource utilization. Each regime was best under its’ legislative framework and would facilitate better forest management and contribute to improved livelihoods without compromising forest quality. Participatory forest management was the most preferred management regime contributing to better forest management, improved community livelihoods, and formally involved communities and other stakeholders. Each regime’s appropriateness would be enhanced through stakeholder capacity building, institutional reform, adequate financial facilitation, and appropriate implementation. Therefore, adopting participatory forest management attributes to the other two management regimes would enhance their appropriateness, while appreciating that the management objective determines the regime being implemented in each forest.
基金financial support from the NOrad's Program for MAsters Studies (NOMA) at Central Department of Botany, Tribhuvan University, Kathmandu, Nepalfunded by the Norwegian Research Council (190153/V10)Grolle Olsens Legat
文摘The ecotone, the spatial transition zone between two vegetation communities, is claimed to have more species than the adjoining communities.However, empirical studies do not always confirm higher richness at the ecotone. The ecotone position and structure are dynamic over time and space and it is driven by the changes in climate, land use or their interaction. In this context, we assessed the forestgrassland ecotone of temperate mountains in central Nepal by i) comparing species composition and richness across the ecotone, ii) analyzing if the forestgrassland ecotone is shifting towards the grassland center by colonizing them with trees, and iii)discussing the consequence of changed disturbance regime in the dynamics of this ecotone and the surrounding grasslands. We analyzed vegetation data sampled from belt transects laid across the forestgrassland ecotone in semi-natural grassland patches.Vegetation data consisting of species richness and composition, and size structure and regeneration of the two most dominant tree species, namely Rhododendron arboreum and Abies spectabilis, from the transects, were used to analyze the trend of the forest-grassland ecotone. Forest and grasslands were different in terms of floristic composition and diversity. Vascular plant species richness linearly increased while moving from forest interior to grassland center. Spatial pattern of tree size structure and regeneration infers that forest boundary is advancing towards the grasslands at the expense of the grassland area, and tree establishment in the grasslands is part of a successional process. Temporally, tree establishment in grasslands started following the gradual decline in disturbance. We argue that local processes in terms of changed land use may best explain the phenomenon of ecotone shift and consequent forest expansion in these grasslands. We underpin the need for further research on the mechanism, rate and spatial extent of ecotone shift by using advanced tools to understand the process indepth.
基金funded by the National Key Research and Development Program of China(Grant Number 2016YFC0500300)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Number XDA23070503)+5 种基金the National Natural Science Foundation of China(Grant Numbers 419711224186101731600496)the Regional Key Project in S&T Services Network Program of the Chinese Academy of Sciences(Grant Numbers KFJ-STSQYZD-044KFJ-STS-ZDTP-048)the Funding for Jilin Environmental Science(Grant Number 2017-16)。
文摘The Araliaceae family consists of numerous species of medical plants of significant value as non-wood forest products.To conserve and culture these plants in natural forest stands is an important undertaking which should be implemented according to the relationship between forest structure and understory population.In this study,thirtyfive plots were established in natural A ralia elata stands.Taller individual and denser populations were found in the northern and in the eastern regions,respectively.Both population densities and individual leaf weight increased along longitude.In contrast,their relationship with elevation and DBH were negative.Along with the altitude gradient,both height and root-collar diameter increased but population density declined.Root-collar diameter and population density decreased with latitude and DBH,respectively.Overall,dominant trees unlikely enforced strong disturbance to the development of understory A.elata populations unless concerning some specific topographic factors.
基金partially developed within the scope of research project LIFE+2013 "PAN LIFE Project-Natura 2000 Action Programme.Life+Nature-2013-LIFE13 NAT/IT/001075
文摘In Europe, very small forest areas can be considered to be old-growth, and they are mainly located in Eastern Europe. The typical structures of old growth forests infrequently occur in Mediterranean mountainous environments, since they have been affected by human activities for centuries. This study focused on a remote and almost pure Italian maple stand located in southern Italy, which has not been managed for long time due to its inaccessibility. The effects of natural evolution on the forest stand were evaluated through the analysis of the spatial and chronological structure and the regeneration patterns, then estimating the amounts and quality of deadwood occurrence. Across the whole stand, all the trees with DBH(diameter at breast height) larger than 50 cm(LLT, large living trees) were measured(DBH and height) and age was also determined through a dendrochronological approach. The diameters observed ranged between 50 and 145 cm with ages of 120 to 250 years. The Latham index calculated for trees within the sample plot highlighted a multilayered canopy with a dominant layer of largeliving trees(age > 120 years). The size-class distribution of stems had a reverse-J shape, and basal area was 52 m^2 ha^(-1). Deadwood was exclusively constituted by standing dead trees and CWD and its volume was on average 31 m^3 ha^(-1). Pure Italian maple forests are generally rare in Europe, and it was unexpected to find a forest stand characterized by a so complex structure with old growth attributes. The study of complex forest stand, even if small, could give precious information on the forest evolution, clarifying also diverse auto-ecological traits of tree species that usually are not common in our forests.
基金supported by research grants from the Korea Forest Service(S121314L130100)
文摘Tropical forests play a critical role in mitigating climate change because they account for large amount o terrestrial carbon storage and productivity.However,there are many uncertainties associated with the estimation o carbon dynamics.We estimated forest structure and carbon dynamics along a slope(17.3°–42.8°)and to assess the relations between forest structures,carbon dynamics,and slopes in an intact lowland mixed dipterocarp forest,in Kuala Belalong,Brunei Darussalam.Living biomass,basa area,stand density,crown properties,and tree family composition were measured for forest structure.Growth rate,litter production,and litter decomposition rates were also measured for carbon dynamics.The crown form index and the crown position index were used to assess crown properties,which we categorized into five stages,from very poor to perfect.The living biomass,basal area and stand density were 261.5–940.7 Mg ha^(-1),43.6–63.6 m^2ha^(-1)and 6,675–8400 tree ha^(-1),respectively.The average crown form and position index were 4,which means that the crown are mostly symmetrical and sufficiently exposed for photosynthesis.The mean biomass growth rate,litter production,litter decomposition rate were estimated as11.9,11.6 Mg ha^(-1)a^(-1),and 7.2 g a^(-1),respectively.Biomass growth rate was significantly correlated with living biomass,basal area,and crown form.Crown form appeared to strongly influence living biomass,basal area and biomass growth rate in terms of light acquisition.However,basal area,stand density,crown properties,and biomass growth rate did not vary by slope or tree family composition.The results indicate that carbon accumulation by tree growth in an intact lowland mixed dipterocarp forest depends on crown properties.Absence of any effect of tree family composition on carbon accumulation suggests that the main driver of biomass accumulation in old-growth forests of Borneo is not species-specific characteristics of tree species.
基金This study is supported by National Key Research and Development Program(2016YFC0501603).
文摘Understanding the interaction between canopy structure and the parameters of interception loss is essential in predicting the variations in partitioning rainfall and water resources as affected by changes in canopy structure and in implementing water-based management in semiarid forest plantations.In this study,seasonal variations in rainfall interception loss and canopy storage capacity as driven by canopy structure were predicted and the linkages were tested using seasonal filed measurements.The study was conducted in nine 50 m×50 m Robinia pseudoacacia plots in the semiarid region of China’s Loess Plateau.Gross rain-fall,throughfall and stemflow were measured in seasons with and without leaves in 2015 and 2016.Results show that measured average interception loss for the nine plots were 17.9% and 9.4% of gross rainfall during periods with leaves (the growing season) and without leaves, respectively. Average canopy storage capacity estimated using an indirect method was 1.3 mm in the growing season and 0.2 mm in the leafless season. Correlations of relative interception loss and canopy storage capacity to canopy variables were highest for leaf/wood area index (LAI/WAI) and canopy cover, fol-lowed by bark area, basal area, tree height and stand density. Combined canopy cover, leaf/wood area index and bark area multiple regression models of interception loss and canopy storage capacity were established for the growing season and in the leafless season in 2015. It explained 97% and 96% of the variations in relative interception loss during seasons with and without leaves, respectively. It also explained 98% and 99% of the variations in canopy storage capacity during seasons with and without leaves, respectively. The empiri-cal regression models were validated using field data col-lected in 2016. The models satisfactorily predicted relative interception loss and canopy storage capacity during seasons with and without leaves. This study provides greater under-standing about the effects of changes in tree canopy structure (e.g., dieback or mortality) on hydrological processes.
基金Supported by the National Natural Science Foundation of China (No. 60174046).
文摘The bottleneck analysis of the minimum coat problem for the generalized netwok(MCPGN) is discussed.The analysis is based on the network simplex algorithm,which gains negative cost graphs by constructing augmented forest structure,then augments flows on the negative cost graphs until the optimal revolution is gained Bottleneck structure is presented after analyzing the augmented forest structure.The negative cost augmented graphs are constructed with the bottleneck structure.The arcs that block the negative cost augmented graph are the elements of the bottleneck.The bottleneck analysis for the generalized circulation problem,the minimum circulation problem and the circulation problem are discussed respectively as the basal problems,then that for MCPGN is achieved.An example is presented at the end.
文摘The present study was carried out at two different gradients of unburnt and burnt Anogeissus latifolia forest sites in the Garhwal region, India. At each gradient, the unburnt and burnt forest sites were further categorized into three different elevations, i.e., lower (700 m), middle (850 m) and upper (1000 m). At each elevation, the density of trees, saplings and seedlings was higher at the unburnt sites except for trees at the upper elevation which was higher at the burnt sites. The total basal area of each layer of forest was also higher at the unburnt sites. The study revealed that the lower number of saplings and seedlings at the burnt forest sites might be due to the effect of fire. Most trees in the lower dbh classes were affected by forest fire at the burnt sites which reduced the total density and total basal area of the trees compared to the unburnt sites. The diversity of trees increased with increasing elevation. However, the diversity of saplings and seedlings reduced with increasing elevation.
基金the National Natural Science Foundation of China(32201338)Science Technology Program from the Forestry Administration of Guangdong Province(2021KJCX017)+1 种基金Guangzhou Municipal Science and Technology Bureau Program(2023A04J0086)Shenzhen Key Laboratory of Southern Subtropical Plant Diversity。
文摘As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic spaces.Previous studies note that vegetation structure is a key factor influencing bird sounds in urban forests;hence,adjusting the frequency composition may be a strategy for birds to avoid anthropogenic noise to mask their songs.However,it is unknown whether the response mechanisms of bird vocalizations to vegetation structure remain consistent despite being impacted by anthropogenic noise.It was hypothesized that anthropogenic noise in urban forests occupies the low-frequency space of bird songs,leading to a possible reshaping of the acoustic niches of forests,and the vegetation structure of urban forests is the critical factor that shapes the acoustic space for bird vocalization.Passive acoustic monitoring in various urban forests was used to monitor natural and anthropogenic noises,and sounds were classified into three acoustic scenes(bird sounds,human sounds,and bird-human sounds)to determine interconnections between bird sounds,anthropogenic noise,and vegetation structure.Anthropogenic noise altered the acoustic niche of urban forests by intruding into the low-frequency space used by birds,and vegetation structures related to volume(trunk volume and branch volume)and density(number of branches and leaf area index)significantly impact the diversity of bird sounds.Our findings indicate that the response to low and high frequency signals to vegetation structure is distinct.By clarifying this relationship,our results contribute to understanding of how vegetation structure influences bird sounds in urban forests impacted by anthropogenic noise.
基金funded by the Guangxi Natural Science Foundation Program (2022GXNSFAA035583 and 2020GXNSFAA159108)National Natural Science Foundation of China (32060305)+2 种基金Foundation of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University)Ministry of Education, China (ERESEP 2021Z06)Chinese Forest Biodiversity Monitoring Network
文摘Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.
基金the Special Projects for the Central Government to guide the development of local science and technology(ZY20B15)the Key Research&Development Program funding project of Heilongjiang Province(GA21C030)the Research Funds of Provincial Research Institutes of Heilongjiang Province(ZNBZ2022ZR07)。
文摘Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The succession patterns of methanotrophic communities and functions in Wudalianchi volcano forest soils could provide a basis for the study of evolutionary mechanisms between soil microorganisms,the environment,and carbon cycling of temperate forest ecosystems under climate change.In this study,the characteristics and drivers of methanotrophic community structure and function of two volcanic soils at different stages of development are analyzed,including an old volcano and a new volcano,which most recently erupted 300 years and 17-19×10^(5)years ago,respectively,and a non-volcano hills as control,based on space for time substitution and Miseq sequencing and bioinformation technology.The results showed that CH_(4) fluxes were significantly higher in old-stage volcano forest soils than new-stage forest soils and non-volcano forest soils.There were significant differences in the community composition and diversity of soil methanotrophs from different volcano forest soils.Methylococcus was the dominant genus in all soil samples.Additionally,the relative abundance of Methylococcus,along with Clonothrix,Methyloglobulus,Methylomagum,Methylomonas and Methylosarcina,were the important genera responsible for the differences in methanotrophic community structure in different volcano forest soils.The relative abundance of methanotroph belonging toγ-proteobacteria was significantly higher than that belonging toα-proteobacteria(P<0.05).Chao1,Shannon and Simpson indices of soil methanotrophic community were significantly lower in new-stage volcanos and were significantly affected by bulk density,total porosity,p H,nitrate,dissolved organic carbon and dissolved organic nitrogen.There were significant differences in community structure between new-stage and old-stage volcanoes.Bulk density and p H are important soil properties contributing to the divergence of methanotrophs community structure,and changes in soil properties due to soil development time are important factors driving differences in methanotrophs communities in Wudalianchi volcanic soils.
