Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion...Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.展开更多
Vertical forest structure is closely linked to multiple ecosystem characteristics,such as biodiversity,habitat,and productivity.Mixing tree species in planted forests has the potential to create diverse vertical fores...Vertical forest structure is closely linked to multiple ecosystem characteristics,such as biodiversity,habitat,and productivity.Mixing tree species in planted forests has the potential to create diverse vertical forest structures due to the different physiological and morphological traits of the composing tree species.However,the relative importance of species richness,species identity and species interactions for the variation in vertical forest structure remains unclear,mainly because traditional forest inventories do not observe vertical stand structure in detail.Terrestrial laser scanning(TLS),however,allows to study vertical forest structure in an unprecedented way.Therefore,we used TLS single scan data from 126 plots across three experimental planted forests of a largescale tree diversity experiment in Belgium to study the drivers of vertical forest structure.These plots were 9–11years old young pure and mixed forests,characterized by four levels of tree species richness ranging from monocultures to four-species mixtures,across twenty composition levels.We generated vertical plant profiles from the TLS data and derived six stand structural variables.Linear mixed models were used to test the effect of species richness on structural variables.Employing a hierarchical diversity interaction modelling framework,we further assessed species identity effect and various species interaction effects on the six stand structural variables.Our results showed that species richness did not significantly influence most of the stand structure variables,except for canopy height and foliage height diversity.Species identity on the other hand exhibited a significant impact on vertical forest structure across all sites.Species interaction effects were observed to be site-dependent due to varying site conditions and species pools,and rapidly growing tree species tend to dominate these interactions.Overall,our results highlighted the importance of considering both species identity and interaction effects in choosing suitable species combinations for forest management practices aimed at enhancing vertical forest structure.展开更多
The forest headwater streams are important hubs for connecting terrestrial and aquatic ecosystems,with plant litter and sediments as the major carriers for material migrations;however,until now we knew little about th...The forest headwater streams are important hubs for connecting terrestrial and aquatic ecosystems,with plant litter and sediments as the major carriers for material migrations;however,until now we knew little about the dynamics of trace elements such as iron(Fe)and aluminum(Al)in forest headwater streams.Here,we quantitatively identified the spatiotemporal dynamics of Fe and Al storages in plant litter and sediments and their influencing factors in a subtropical forest headwater stream,and assessed the potential pollution risk.The results showed that:(1)the mean concentrations of Fe and Al in plant litter(sediments)were 5.48 and 8.46(7.39 and 47.47)g·kg^(-1),and the mean storages of Fe and Al in plant litter(sediments)were 0.26 and 0.43(749.04 and 5030.90)g·m^(-2),respectively;(2)the storages of Fe and Al in plant litter and sediments significantly fluctuated from January to December,and showed a decreasing pattern from the source to mouth;and(3)storages of Fe and Al had no significant correlation with riparian forest type and the present of tributary and the Fe and Al storages in plant litter were mainly affected by water temperature and water alkalinity,and their storages in sediments were mainly affected by water temperature and frequency of rainfall;and(4)there were no anthropogenic pollution in Fe and Al in the forest headwater stream.Our study revealed the primary factors of concentrations and storages of Fe and Al in plant litter and sediments in a forest headwater stream,which will improve our understanding of the role of headwater streams in forest nutrient storage and cycling along with hydrological processes.展开更多
Ethiopia is one of the countries in the world endowed with rich biological resources. However, due to human impacts, the forest cover in Ethiopia has been decreasing rapidly. The study was carried out with the purpose...Ethiopia is one of the countries in the world endowed with rich biological resources. However, due to human impacts, the forest cover in Ethiopia has been decreasing rapidly. The study was carried out with the purpose of finding out the Regeneration Status, Population Structure and Floristic composition of Woody Plant Species in Sheleko Medihanialem Natural Forest in Gondar, North West Ethiopia, from October 2019 to September 2020. The systematic vegetation sampling method was used to collect data from Fifty plots of 20 m × 20 m (400 m2) along five line transects. In addition, five, 5 m × 5 m subplots were laid within the main plot to sample seedlings and saplings. The floristic composition and population structure of woody individuals of trees and shrubs with a diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 2 m were measured. DBH ≤ 2.5 cm and less than 1 m height were considered as seedlings and DBH ≥ 2.5 cm and height of 1 - 2 m as saplings. Vegetation data of density, frequency, basal area, and importance value index were computed. A total of 65 woody plant species in 54 genera and 34 plant families were recorded. Fabaceae, Moraceae and Euphorbiaceae were the dominant families in terms of species richness. Woody species densities for mature individuals were 2202.5 stems∙ha−1, seedling 2419.2 stems∙ha−1 and sapling 1737.6 stems∙ha−1. The forest was dominated by small-sized/young trees and shrubs, indicating the status of secondary growth and/or regeneration.展开更多
Natural forests and stands subjected to little to moderate human impact are continuously declining worldwide and with these,their biodiversity and ecosystem services.Many Nothofagus forests in the south of the South A...Natural forests and stands subjected to little to moderate human impact are continuously declining worldwide and with these,their biodiversity and ecosystem services.Many Nothofagus forests in the south of the South American continent are in a pristine state or only moderately impacted by humans.Forest grazing by livestock,in the past and still today often practiced in a non-sustainable way is,however,increasingly under discussion to meet current environmental and socio-economic challenges.Accordingly,we investigate the regeneration of Nothofagus dombeyi,a keystone species of the Patagonian Andes,in secondary forests in Argentinian northern Patagonia,particularly addressing the role of disturbance through grazing by livestock at various intensities.We test the hypothesis that the regeneration of this tree species is favored by grazing impact and,thus,disturbance of the herb layer and soil surface.In support of our hypothesis,Nothofagus dombeyi regeneration was significantly higher in terms of individuals and height classes in moderately grazed forests.Multivariate analysis shows significant positive effects of moderate grazing pressure,herb layer cover,and the occurrence of bare soil on the regeneration of Nothofagus dombeyi.Our results show that an integration of livestock grazing and forest regeneration is possible and that agroforestry systems can be an adequate management option for stakeholders in the region.A grazing management can also be part of a forest fire prevention strategy.However,the regeneration success and grazing pressure should be continuously monitored.展开更多
Thinning is a widely used forest management tool but systematic research has not been carried out to verify its eff ects on carbon storage and plant diversity at the ecosystem level.In this study,the eff ect of thinni...Thinning is a widely used forest management tool but systematic research has not been carried out to verify its eff ects on carbon storage and plant diversity at the ecosystem level.In this study,the eff ect of thinning was assessed across seven thinning intensities(0,10,15,20,25,30 and 35%)in a low-quality secondary forest in NE China over a ten-year period.Thinning aff ected the carbon storage of trees,and shrub,herb,and soil layers(P<0.05).It fi rst increased and then decreased as thinning intensity increased,reaching its maximum at 30%thinning.Carbon storage of the soil accounted for more than 64%of the total carbon stored in the ecosystem.It was highest in the upper 20-cm soil layer.Thinning increased tree species diversity while decreasing shrub and herb diversities(P<0.05).Redundancy analysis and a correlation heat map showed that carbon storage of tree and shrub layers was positively correlated with tree diversity but negatively with herb diversity,indicating that the increase in tree diversity increased the carbon storage of natural forest ecosystems.Although thinning decreased shrub and herb diversities,it increased the carbon storage of the overall ecosystem and tree species diversity of secondary forest.Maximum carbon storage and the highest tree diversity were observed at a thinning intensity of 30%.This study provides evidence for the ecological management of natural and secondary forests and improvement of ecosystem carbon sinks and biodiversity.展开更多
Background:Chinese pine(Pinus tabuliformis Carr.)is one of the major afforestation species in northern China and plays a key role in restoring forest ecosystems and preserving soil and water.However,most Chinese pine ...Background:Chinese pine(Pinus tabuliformis Carr.)is one of the major afforestation species in northern China and plays a key role in restoring forest ecosystems and preserving soil and water.However,most Chinese pine plantations are experiencing ecological problems such as the low diversity of understory plants and difficulty in natural regeneration.Thinning has been widely used to maintain and improve a variety of forest ecosystem services from plantations.To date,however,few studies have been conducted to systematically determine the effects of thinning on understory plant diversity and the regeneration of Chinese pine in plantations.Methods:We conducted a literature search,and selected 22 publications covering a total of 83 treatments related to thinning effects on the species richness of understory plants and 15 publications covering a total of 43 treatments related to thinning effects on the regeneration of Chinese pine,in tree plantations of northern China.The data from the literature were synthesized and evaluated with meta-analysis approach to determine the treatment effects.Results:Compared with the control stands,thinning increased the species richness of shrubs and herbs by an average of 25.3%and 26.5%,respectively.While the varying thinning intensities all had significantly positive effects on the species richness of understory plants,only moderate thinning(30%–50%)had a positive effect on the density of regenerating seedlings and saplings of Chinese pine(60.2%).The species richness of understory plants was greatest after 14 years of thinning with an increase of 36.3%,whereas the density of regenerating Chinese pine seedlings and saplings reached a maximum after≥11 years of thinning with an increase of 76.5%,compared to that of the unthinned stands.Thinning in the half-mature plantations had the greatest effects on the understory shrub richness(44.1%)and the density of regenerating Chinese pine seedlings and saplings(86.5%).Both single and multiple thinning were found to significantly promote the species richness of understory plants and the density of regenerating Chinese pine seedlings and saplings,and the positive effects of thinning were greater in areas with a humidity index(HI)<30 than in areas with an HI≥30.In general,age group,planting density and recovery time were prominent factors affecting the species richness of understory plants,whereas the slope,HI and recovery time were the dominant controls of the density of regenerating Chinese pine seedlings and saplings,indicating differential effects of thinning on the species richness of understory plants and the regeneration capacity of Chinese pine in plantations.Conclusion:Thinning appears to be a feasible management measure to improve the understory plant diversity and regeneration capacity of Chinese pine in plantations.We postulate that moderate thinning in half-mature forest stands with an HI<30 can help effectively promote the species diversity of understory plants and the natural regeneration of Chinese pine,thereby maintaining a more resilient stand structure and the development of Chinese pine plantations.展开更多
The Afromontane forests of Ethiopia have been under a serious degradation threat. Assessment of floristic diversity and species composition in Biteyu forest of Gurage mountain chain in the central Ethiopia was conduct...The Afromontane forests of Ethiopia have been under a serious degradation threat. Assessment of floristic diversity and species composition in Biteyu forest of Gurage mountain chain in the central Ethiopia was conducted to examine the pattern of forest structure. Thirty plots of 30 m×30 m were used to record the vegetation and environmental data using systematic sampling technique. The local name, plant scientific names, DBH, height,species abundance and percentage canopy cover of plant species were recorded. Shannon diversity index and Sorensen's coefficients was used for comparison among communities and similar forests in the country. Threats to the forest biodiversity in Biteyu were determined by counting cattle interference and wood stumps as disturbance indicators. Relative Euclidean Distance measures by using Ward's method(linkage) was applied for cluster analysis. Environmental variables were also recorded in each plot. Woody species population structure, basal area and importance value index were analyzed using spreadsheet programs. Data on species distribution and environmental variables in the forest were analyzed by canonical correspondence analysis. A total of 190 species in 154 genera under 73 families were identified. Twenty species were found to be endemic taxa to the Flora Area. Only three plant community types were identified from the cluster analysis due to the high human influence. The Sorensen's coefficient showed the resemblance of the Biteyu forest with other Dry Evergreen Afromontane forests in the country. Moreover, altitude and slope strongly affect the species composition and structure of Biteyu forest. Given the high anthropogenic influence, high endemism, high dependence of the local community on the forest resources, forest conservation and restoration measures should be done by stakeholders.展开更多
Increasing field experiments have been conducted in forests to better understand the response of plant growth and photosynthesis to climatic warming. However,it is still unknown whether there is a general pattern in r...Increasing field experiments have been conducted in forests to better understand the response of plant growth and photosynthesis to climatic warming. However,it is still unknown whether there is a general pattern in relation to how and to what extent warming impacts woody plants in forests. In this study, a meta-analysis was conducted to investigate the warming effects. When temperatures increased between 0.3 and 10 ℃, specific leaf area(SLA) was significantly increased by 5.9%, plant height by 7.8%, biomass by 21.9%, foliar calcium(Ca) and manganese(Mn) concentrations by 20.7% and 39.6% and net photosynthetic rate(Pn) by 9.9%. Enhanced growth and Pn may have a relationship with changing SLA, efficiency of PSⅡ(photosystem Ⅱ), photosynthetic pigment concentrations and foliar nutrients. The results will be useful to understand the underlying mechanisms of forests responding to global warming.展开更多
Carbon (C), nitrogen (N), and phosphorous (P) levels and their stoichiometry in plant components (leaves, branch trunks, roots) of trees in a karst forest and non-karst forest are compared. The results show that the C...Carbon (C), nitrogen (N), and phosphorous (P) levels and their stoichiometry in plant components (leaves, branch trunks, roots) of trees in a karst forest and non-karst forest are compared. The results show that the C contents, C:N and C:P ratios of dominant species in the karst forest were lower than those in the non-karst forest, but the N and P and the N:P ratio were higher;C:N:P ratios in plant organs of trees in the karst forest were in the order of trunks>roots>branches>leaves. However, C:N:P ratio in the non-karst forest trees were trunks>branches>roots>leaves. Moreover, ratio of C:N:P in trunks was highest and lowest in leaves in both forests. In non-karst forest trees, N:P was in the order of leaves> roots>branches>trunks. There were no significant differences in the ratio of N:P in different plant components of trees in the karst forest. However, in karst and non-karst forest trees, the ratio of N:P in leaves was highest;positive correlations between N and P contents, and N and N:P ratios were observed in both karst and non-karst forests (p<0.001). Negative correlations between P and N:P ratios (p<0.05) were observed in karst forest trees, while positive correlations were observed in non-karst forest trees.展开更多
The main species composition drivers in temperate deciduous forests are environmental conditions, a stand?s age and the site history, e.g., the succession stage and past land use, as well as disturbance regime and cur...The main species composition drivers in temperate deciduous forests are environmental conditions, a stand?s age and the site history, e.g., the succession stage and past land use, as well as disturbance regime and current management. We compared plant species diversity and composition in late successional and ancient forests, cooccurring on the same small river island applying species accumulation curves and nonmetric multidimensional scaling, respectively. Given the island?s geomorphological characteristics, we expected these to be very similar before human intervention in the past. The forests experienced differing disturbance regimes in the past, while over the last 30 years, human intervention has been the same and reduced to a minimum. The ancient forest in this study had two major characteristics defining it as old, mature forest: continuity of presence for more than 200years and specific composition. The late successional forest experienced major disturbance in the 20th century and was allowed natural regeneration by bordering on the ancient forest, representing a potential species pool,and by decades of minimum human intervention. Our results showed that, even though there was no difference in species richness, we could still detect differences between the forests, particularly in the abundance and species composition of the understorey, among which geophytes had the most indicative importance. To make our results useful on a broader scale, we composed from the literature a species list of plants indicative for ancient forest and tested its application. These results are important for distinguishing between old and mature secondary stands and particularly for identifying old forest stands, which should be conserved and, in the case of fragmented landscapes, included in a network connecting forest fragments.展开更多
The severe and rapid attack on the Caicos pine Pinus caribaea var. bahamensis(Pinaceae) by the nonnative invasive pine tortoise scale, Toumeyella parvicornis, has resulted in the death of most of the trees in the Turk...The severe and rapid attack on the Caicos pine Pinus caribaea var. bahamensis(Pinaceae) by the nonnative invasive pine tortoise scale, Toumeyella parvicornis, has resulted in the death of most of the trees in the Turks and Caicos Islands(TCI) in just over a decade. Local and international conservation efforts have enabled the necessary multi-disciplinary research, data gathering, and monitoring to develop and implement a restoration strategy for this endemic tree from the Bahaman archipelago. The native plant nursery established on North Caicos and horticultural expertise acquired throughout the years were crucial to the successful rescue of Caicos pine saplings from the wild populations and cultivation of new saplings grown from locally sourced seeds. These saplings have been used to establish six Restoration Trial Plots on Pine Cay and a seed orchard on North Caicos in TCI. Core Conservation Areas(CCAs) for the Caicos pine forests have been identified and mapped. To date, forest within the Pine Cay CCA has been supplemented by planting more than 450 pine trees, which have survived at a high(>80%)rate.展开更多
Despite the widely accepted view that planted forests are valuable habitat for wildlife species,there is a lack of empirical evidence showing the suitability of this novel habitat,especially in relation to plantations...Despite the widely accepted view that planted forests are valuable habitat for wildlife species,there is a lack of empirical evidence showing the suitability of this novel habitat,especially in relation to plantations of exotic tree species.Furthermore,little is known about the effects of forest management on the ecology and dynamics of wild populations in the Neotropics.During the breeding season,the migrant flycatcher White-crested Elaenia is the most abundant bird species in forested landscapes in Chile.For several years we have studied different aspects of these artificial forests in the coastal range of south-central Chile as habitat for the species,particularly in contrast to the native forest.In general,our results indicate that plantation forests offer a poorer quality habitat,where the density of the species tends to be lower than in the native forest,although a significant edge effect suggests that its quality can be mitigated by planting as a matrix mosaic with native forest.Furthermore,compared to native forests,populations in plantations contained a higher proportion of younger adult individuals maintaining larger territories,and showing poorer body condition.We suggest that these differences could also have an impact on the birds'longevity and survival.展开更多
Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.M...Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.Moreover,it is unknown whether forest phenology changes with the proximity to forest edge.Methods:This study examined the green-up dates,dormancy dates,time-integrated NDVI(LiNDVI,a measure of vegetation productivity in growing season),and their sensitivities to climatic factors along the gradients of distance(i.e.proximity)to forest edge(0–2 km)in China's natural forests(NF)and planted forests(PF).For the analysis,field-surveyed data were integrated with Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI from 2000 to 2022.Results:Our results reveal that PF had earlier green-up dates,later dormancy dates,and higher LiNDVI than NF.However,green-up sensitivities to temperature were higher at the edges of NF,whereas no such pattern was observed in PF.Conversely,the sensitivity of dormancy dates remains relatively stable from the inner to the edge of both NF and PF,except for a quadratic change in dormancy date sensitivity to precipitation found in NF.Additionally,we found that the green-up sensitivity to temperature increased with decreasing proximity to edge in NF evergreen forests,while it showed the opposite trend in PF evergreen forests.Furthermore,we observed that the precipitation impact on green-up dates shifts from postponing to advancing from the inner to the edge of NF,whereas precipitation dominantly postpones PF's green-up dates regardless of the proximity to edge.The LiNDVI exhibits higher sensitivity to precipitation at the edge areas,a phenomenon observed in NF but not in PF.Conclusions:These results suggest that the responses of forests to climate change vary with the distance to the edge.With increasing edge forests,which results from fragmentation caused by global changes,we anticipate that desynchronized phenological events along the distance to the edge could alter biogeochemical cycles and reshape ecosystem services such as energy flows,pollination duration,and the tourism industry.Therefore,we advocate for further investigations of edge effects to improve ecosystem modelling,enhance forest stability,and promote sustainable tourism.展开更多
Urban forest soil infiltration, affected by various factors, is closely related with surface runoff. This paper studied the effect of urban forest types, vegetation configuration and soil properties on soil infiltrati...Urban forest soil infiltration, affected by various factors, is closely related with surface runoff. This paper studied the effect of urban forest types, vegetation configuration and soil properties on soil infiltration. In our study, 191 typical plots were sampled in Changchun City, China to investigate the soil infiltration characteristics of urban forest and its influencing factors. Our results showed that the steady infiltration rates of urban forest soil were highly variable. High variations in the final infiltration rates were observed for different vegetation patterns and compaction degrees. Trees with shrubs and grasses had the highest infiltration rate and trees with bare land had the lowest infiltration rate. In addition, our results showed that the soil infiltration rate decreased with an increase in the bulk density and with a reduction in the soil organic matter content and non-capillary porosity. The soil infiltration rate also had significantly positive relationships with the total porosity and saturated soil water content. Urban soil compaction contributed to low soil infiltration rates. To increase the infiltration rate and water storage volume of urban forest soil, proper techniques to minimize and mitigate soil compaction should be used. These findings can provide useful information for urban planners about how to maximize the water volume of urban forest soil and decrease urban instantaneous flooding.展开更多
Available light under forest canopies includes two components, diffuse light and direct light (sunflecks), and is characterized as low and highly dynamic. Understory habitats under different forest types experience di...Available light under forest canopies includes two components, diffuse light and direct light (sunflecks), and is characterized as low and highly dynamic. Understory habitats under different forest types experience different light conditions. Sunflecks as a critical resource for understory plants have great importance on carbon gain of understory plants. Under the light-limiting habitat, understory plants exhibit a high light utilization efficiency attributed by a post-illumination CO2 uptake. Although different species have different photosynthetic responses, shade plants appear to be acclimated to respond more quickly and efficiently to sunflecks. This acclimation includes a faster induction, relatively lower rate of induction loss, lower photosynthetic compensation point, and higher water use efficiency. The process that shade plants harvest light energy is not well known. Studies of photosynthetic responses to sunflecks in natural conditions are rare. Little is known about constraints on sunfleck utilization, which may change seasonally. Extensive field studies in conjunction with laboratory investigations will be needed to further understand potential and actual constraints on sunfleck utilization. Most studies on photosynthetic responses to fluctuating light condition were done in the level of leaves. Fluctuating light utilization on the basis of whole plants and populations presents future challenges to ecologists.展开更多
In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferou...In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferous tree planting had been conducted to accelerate forest restoration.To study the long term effect of these activities on forest recovery,we used a simulation modeling approach to study long-term(300 years) forest dynamics under current planting and natural regeneration scenarios.Results indicate that under tree planting scenario in the severely burned area,the dominant species Dahurian larch(Larix gmelinii) can reach pre-fire level(60% of the area) within 20 years and the maximum abundance can reach nearly 90% within 100 years.While under natural regeneration scenario,it needs about 250 years to reach its pre-fire level.From the perspective of timber production,tree planting can bring twice as much timber volume as that under natural regeneration within 300 years,which is the average longevity of L.gmelinii.It needs about 70 years to reach the timber volume of pre-fire level under the planting scenario,whereas it requires at least 250 years to reach the timber volume of pre-fire level under natural regeneration scenario.Another dominant species Asian White birch(Betula platyphylla) responded negatively to the planting of coniferous species.In general,tree planting of coniferous species after fire can greatly accelerate forest restoration in terms of species abundance and target timber volume,with desirable ecological and economic returns.展开更多
Background:Non-timber forest products(NTFPs)are an important part of forest biodiversity,and the subsistence and trade of local people,especially in less developed countries.Because of the high ecological and economic...Background:Non-timber forest products(NTFPs)are an important part of forest biodiversity,and the subsistence and trade of local people,especially in less developed countries.Because of the high ecological and economic value,NTFPs have faced the problem of over-exploitation,and the key to solve this problem is to determine the feasible way of sustainable utilization of NTFPs.Harvest intensity is one of the most important and easily controlled utilization factors,which can greatly influence the plant individual survival,growth and reproductive performances,and even the population structure and dynamics.Therefore,we chose two common and important NTFPs species with different marketable parts(i.e.,Acanthopanax senticosus with tender leaves and Aralia elata with tender buds)as our study objects.Aiming to determine the optimum harvest intensity for sustainably utilizing both NTFPs species,five levels of harvest intensity treatments(i.e.,control,light,medium,high and severe)were designed to assess the effects of harvest intensity on their marketable organ yield,plant growth and reproductive performances.Results:The biomass growth rates of marketable organ and plant growth of A.senticosus under light harvest intensity treatment were significantly higher than those under other harvest intensities.The plant height growth and 1000-seed weight of A.elata under severe harvest intensity treatment were significantly lower than those under control treatment.Conclusions:The light harvest intensity with 25% leaf removal and the high harvest intensity with all terminal buds harvested are the optimum harvest intensity to maintain the sustainable utilization of A.senticosus and A.elata,respectively.These findings could provide managers with basic but practical guidance for making decisions about the sustainable harvest management plan for the cultivated NTFPs species,and further provide a theoretical basis for managers to establish the harvest regulations for wild NTFPs species.Consequently,the local residents or communities can improve their income while ensure the sustainable development of wild NTFPs.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
Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully...Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully exploited.To extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast China.Spectral and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant species.The results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source independently.Similarly,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was accurate.Including terrain factors and removing spatial correlation from NFRI sample points further improved the recognition accuracy.The optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,respectively.The high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant species.Visualizing the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.展开更多
基金funded by the National Natural Science Foundation of China (No.32360418)the Guizhou Provincial Basic Research Program (Natural Science)(No.QianKeHeJiChu-ZK[2024]YiBan022)。
文摘Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.
基金Mengxi Wang holds a doctoral scholarship from the China scholarship council(CSC:202003270025)。
文摘Vertical forest structure is closely linked to multiple ecosystem characteristics,such as biodiversity,habitat,and productivity.Mixing tree species in planted forests has the potential to create diverse vertical forest structures due to the different physiological and morphological traits of the composing tree species.However,the relative importance of species richness,species identity and species interactions for the variation in vertical forest structure remains unclear,mainly because traditional forest inventories do not observe vertical stand structure in detail.Terrestrial laser scanning(TLS),however,allows to study vertical forest structure in an unprecedented way.Therefore,we used TLS single scan data from 126 plots across three experimental planted forests of a largescale tree diversity experiment in Belgium to study the drivers of vertical forest structure.These plots were 9–11years old young pure and mixed forests,characterized by four levels of tree species richness ranging from monocultures to four-species mixtures,across twenty composition levels.We generated vertical plant profiles from the TLS data and derived six stand structural variables.Linear mixed models were used to test the effect of species richness on structural variables.Employing a hierarchical diversity interaction modelling framework,we further assessed species identity effect and various species interaction effects on the six stand structural variables.Our results showed that species richness did not significantly influence most of the stand structure variables,except for canopy height and foliage height diversity.Species identity on the other hand exhibited a significant impact on vertical forest structure across all sites.Species interaction effects were observed to be site-dependent due to varying site conditions and species pools,and rapidly growing tree species tend to dominate these interactions.Overall,our results highlighted the importance of considering both species identity and interaction effects in choosing suitable species combinations for forest management practices aimed at enhancing vertical forest structure.
基金financially supported by the National Natural Science Foundation of China(32271633)founded by the National Natural Science Foundation of China(32201342)+1 种基金Natural Science Foundation of Fujian Province(2022J01642)supported by the National Natural Science Foundation of China(32171641)。
文摘The forest headwater streams are important hubs for connecting terrestrial and aquatic ecosystems,with plant litter and sediments as the major carriers for material migrations;however,until now we knew little about the dynamics of trace elements such as iron(Fe)and aluminum(Al)in forest headwater streams.Here,we quantitatively identified the spatiotemporal dynamics of Fe and Al storages in plant litter and sediments and their influencing factors in a subtropical forest headwater stream,and assessed the potential pollution risk.The results showed that:(1)the mean concentrations of Fe and Al in plant litter(sediments)were 5.48 and 8.46(7.39 and 47.47)g·kg^(-1),and the mean storages of Fe and Al in plant litter(sediments)were 0.26 and 0.43(749.04 and 5030.90)g·m^(-2),respectively;(2)the storages of Fe and Al in plant litter and sediments significantly fluctuated from January to December,and showed a decreasing pattern from the source to mouth;and(3)storages of Fe and Al had no significant correlation with riparian forest type and the present of tributary and the Fe and Al storages in plant litter were mainly affected by water temperature and water alkalinity,and their storages in sediments were mainly affected by water temperature and frequency of rainfall;and(4)there were no anthropogenic pollution in Fe and Al in the forest headwater stream.Our study revealed the primary factors of concentrations and storages of Fe and Al in plant litter and sediments in a forest headwater stream,which will improve our understanding of the role of headwater streams in forest nutrient storage and cycling along with hydrological processes.
文摘Ethiopia is one of the countries in the world endowed with rich biological resources. However, due to human impacts, the forest cover in Ethiopia has been decreasing rapidly. The study was carried out with the purpose of finding out the Regeneration Status, Population Structure and Floristic composition of Woody Plant Species in Sheleko Medihanialem Natural Forest in Gondar, North West Ethiopia, from October 2019 to September 2020. The systematic vegetation sampling method was used to collect data from Fifty plots of 20 m × 20 m (400 m2) along five line transects. In addition, five, 5 m × 5 m subplots were laid within the main plot to sample seedlings and saplings. The floristic composition and population structure of woody individuals of trees and shrubs with a diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 2 m were measured. DBH ≤ 2.5 cm and less than 1 m height were considered as seedlings and DBH ≥ 2.5 cm and height of 1 - 2 m as saplings. Vegetation data of density, frequency, basal area, and importance value index were computed. A total of 65 woody plant species in 54 genera and 34 plant families were recorded. Fabaceae, Moraceae and Euphorbiaceae were the dominant families in terms of species richness. Woody species densities for mature individuals were 2202.5 stems∙ha−1, seedling 2419.2 stems∙ha−1 and sapling 1737.6 stems∙ha−1. The forest was dominated by small-sized/young trees and shrubs, indicating the status of secondary growth and/or regeneration.
基金supported by funds of the Federal Ministry of Food and Agriculture (BMEL) based on a decision of the Parliament of the Federal Republic of Germany via the Federal Office for Agriculture and Food (BLE,grant No.281-042-01)
文摘Natural forests and stands subjected to little to moderate human impact are continuously declining worldwide and with these,their biodiversity and ecosystem services.Many Nothofagus forests in the south of the South American continent are in a pristine state or only moderately impacted by humans.Forest grazing by livestock,in the past and still today often practiced in a non-sustainable way is,however,increasingly under discussion to meet current environmental and socio-economic challenges.Accordingly,we investigate the regeneration of Nothofagus dombeyi,a keystone species of the Patagonian Andes,in secondary forests in Argentinian northern Patagonia,particularly addressing the role of disturbance through grazing by livestock at various intensities.We test the hypothesis that the regeneration of this tree species is favored by grazing impact and,thus,disturbance of the herb layer and soil surface.In support of our hypothesis,Nothofagus dombeyi regeneration was significantly higher in terms of individuals and height classes in moderately grazed forests.Multivariate analysis shows significant positive effects of moderate grazing pressure,herb layer cover,and the occurrence of bare soil on the regeneration of Nothofagus dombeyi.Our results show that an integration of livestock grazing and forest regeneration is possible and that agroforestry systems can be an adequate management option for stakeholders in the region.A grazing management can also be part of a forest fire prevention strategy.However,the regeneration success and grazing pressure should be continuously monitored.
基金supported by the Applied Technology Research and Development program of Heilongjiang Province(GA19C006)the Innovation Foundation for Doctoral Program of Forestry Engineering of Northeast Forestry University(LYGC202112).
文摘Thinning is a widely used forest management tool but systematic research has not been carried out to verify its eff ects on carbon storage and plant diversity at the ecosystem level.In this study,the eff ect of thinning was assessed across seven thinning intensities(0,10,15,20,25,30 and 35%)in a low-quality secondary forest in NE China over a ten-year period.Thinning aff ected the carbon storage of trees,and shrub,herb,and soil layers(P<0.05).It fi rst increased and then decreased as thinning intensity increased,reaching its maximum at 30%thinning.Carbon storage of the soil accounted for more than 64%of the total carbon stored in the ecosystem.It was highest in the upper 20-cm soil layer.Thinning increased tree species diversity while decreasing shrub and herb diversities(P<0.05).Redundancy analysis and a correlation heat map showed that carbon storage of tree and shrub layers was positively correlated with tree diversity but negatively with herb diversity,indicating that the increase in tree diversity increased the carbon storage of natural forest ecosystems.Although thinning decreased shrub and herb diversities,it increased the carbon storage of the overall ecosystem and tree species diversity of secondary forest.Maximum carbon storage and the highest tree diversity were observed at a thinning intensity of 30%.This study provides evidence for the ecological management of natural and secondary forests and improvement of ecosystem carbon sinks and biodiversity.
基金supported by Natural Science Basic Research Program of Shaanxi(2021JQ-155)National Natural Science Foundation of China(32101511)Chinese Universities Scientific Fund(2452020137 and 2452021073)。
文摘Background:Chinese pine(Pinus tabuliformis Carr.)is one of the major afforestation species in northern China and plays a key role in restoring forest ecosystems and preserving soil and water.However,most Chinese pine plantations are experiencing ecological problems such as the low diversity of understory plants and difficulty in natural regeneration.Thinning has been widely used to maintain and improve a variety of forest ecosystem services from plantations.To date,however,few studies have been conducted to systematically determine the effects of thinning on understory plant diversity and the regeneration of Chinese pine in plantations.Methods:We conducted a literature search,and selected 22 publications covering a total of 83 treatments related to thinning effects on the species richness of understory plants and 15 publications covering a total of 43 treatments related to thinning effects on the regeneration of Chinese pine,in tree plantations of northern China.The data from the literature were synthesized and evaluated with meta-analysis approach to determine the treatment effects.Results:Compared with the control stands,thinning increased the species richness of shrubs and herbs by an average of 25.3%and 26.5%,respectively.While the varying thinning intensities all had significantly positive effects on the species richness of understory plants,only moderate thinning(30%–50%)had a positive effect on the density of regenerating seedlings and saplings of Chinese pine(60.2%).The species richness of understory plants was greatest after 14 years of thinning with an increase of 36.3%,whereas the density of regenerating Chinese pine seedlings and saplings reached a maximum after≥11 years of thinning with an increase of 76.5%,compared to that of the unthinned stands.Thinning in the half-mature plantations had the greatest effects on the understory shrub richness(44.1%)and the density of regenerating Chinese pine seedlings and saplings(86.5%).Both single and multiple thinning were found to significantly promote the species richness of understory plants and the density of regenerating Chinese pine seedlings and saplings,and the positive effects of thinning were greater in areas with a humidity index(HI)<30 than in areas with an HI≥30.In general,age group,planting density and recovery time were prominent factors affecting the species richness of understory plants,whereas the slope,HI and recovery time were the dominant controls of the density of regenerating Chinese pine seedlings and saplings,indicating differential effects of thinning on the species richness of understory plants and the regeneration capacity of Chinese pine in plantations.Conclusion:Thinning appears to be a feasible management measure to improve the understory plant diversity and regeneration capacity of Chinese pine in plantations.We postulate that moderate thinning in half-mature forest stands with an HI<30 can help effectively promote the species diversity of understory plants and the natural regeneration of Chinese pine,thereby maintaining a more resilient stand structure and the development of Chinese pine plantations.
基金Addis Ababa university,Rufford Foundation and IFS(Sweden)
文摘The Afromontane forests of Ethiopia have been under a serious degradation threat. Assessment of floristic diversity and species composition in Biteyu forest of Gurage mountain chain in the central Ethiopia was conducted to examine the pattern of forest structure. Thirty plots of 30 m×30 m were used to record the vegetation and environmental data using systematic sampling technique. The local name, plant scientific names, DBH, height,species abundance and percentage canopy cover of plant species were recorded. Shannon diversity index and Sorensen's coefficients was used for comparison among communities and similar forests in the country. Threats to the forest biodiversity in Biteyu were determined by counting cattle interference and wood stumps as disturbance indicators. Relative Euclidean Distance measures by using Ward's method(linkage) was applied for cluster analysis. Environmental variables were also recorded in each plot. Woody species population structure, basal area and importance value index were analyzed using spreadsheet programs. Data on species distribution and environmental variables in the forest were analyzed by canonical correspondence analysis. A total of 190 species in 154 genera under 73 families were identified. Twenty species were found to be endemic taxa to the Flora Area. Only three plant community types were identified from the cluster analysis due to the high human influence. The Sorensen's coefficient showed the resemblance of the Biteyu forest with other Dry Evergreen Afromontane forests in the country. Moreover, altitude and slope strongly affect the species composition and structure of Biteyu forest. Given the high anthropogenic influence, high endemism, high dependence of the local community on the forest resources, forest conservation and restoration measures should be done by stakeholders.
基金funded by the National Natural Science Foundation of China(NSFC No.31500416)Research Funds for the Introduction of Talents of Shanghai Science and Technology Museum
文摘Increasing field experiments have been conducted in forests to better understand the response of plant growth and photosynthesis to climatic warming. However,it is still unknown whether there is a general pattern in relation to how and to what extent warming impacts woody plants in forests. In this study, a meta-analysis was conducted to investigate the warming effects. When temperatures increased between 0.3 and 10 ℃, specific leaf area(SLA) was significantly increased by 5.9%, plant height by 7.8%, biomass by 21.9%, foliar calcium(Ca) and manganese(Mn) concentrations by 20.7% and 39.6% and net photosynthetic rate(Pn) by 9.9%. Enhanced growth and Pn may have a relationship with changing SLA, efficiency of PSⅡ(photosystem Ⅱ), photosynthetic pigment concentrations and foliar nutrients. The results will be useful to understand the underlying mechanisms of forests responding to global warming.
基金supported by the National Natural Science Foundation of China(31360123)National Key Scientific Research Project(2013CB956701)Applied and Basic Research Program of Guizhou Province([2014]200208)
文摘Carbon (C), nitrogen (N), and phosphorous (P) levels and their stoichiometry in plant components (leaves, branch trunks, roots) of trees in a karst forest and non-karst forest are compared. The results show that the C contents, C:N and C:P ratios of dominant species in the karst forest were lower than those in the non-karst forest, but the N and P and the N:P ratio were higher;C:N:P ratios in plant organs of trees in the karst forest were in the order of trunks>roots>branches>leaves. However, C:N:P ratio in the non-karst forest trees were trunks>branches>roots>leaves. Moreover, ratio of C:N:P in trunks was highest and lowest in leaves in both forests. In non-karst forest trees, N:P was in the order of leaves> roots>branches>trunks. There were no significant differences in the ratio of N:P in different plant components of trees in the karst forest. However, in karst and non-karst forest trees, the ratio of N:P in leaves was highest;positive correlations between N and P contents, and N and N:P ratios were observed in both karst and non-karst forests (p<0.001). Negative correlations between P and N:P ratios (p<0.05) were observed in karst forest trees, while positive correlations were observed in non-karst forest trees.
基金financial support within the research programs P1-0403 and J1-2457, funded by the Slovenian Research Agency。
文摘The main species composition drivers in temperate deciduous forests are environmental conditions, a stand?s age and the site history, e.g., the succession stage and past land use, as well as disturbance regime and current management. We compared plant species diversity and composition in late successional and ancient forests, cooccurring on the same small river island applying species accumulation curves and nonmetric multidimensional scaling, respectively. Given the island?s geomorphological characteristics, we expected these to be very similar before human intervention in the past. The forests experienced differing disturbance regimes in the past, while over the last 30 years, human intervention has been the same and reduced to a minimum. The ancient forest in this study had two major characteristics defining it as old, mature forest: continuity of presence for more than 200years and specific composition. The late successional forest experienced major disturbance in the 20th century and was allowed natural regeneration by bordering on the ancient forest, representing a potential species pool,and by decades of minimum human intervention. Our results showed that, even though there was no difference in species richness, we could still detect differences between the forests, particularly in the abundance and species composition of the understorey, among which geophytes had the most indicative importance. To make our results useful on a broader scale, we composed from the literature a species list of plants indicative for ancient forest and tested its application. These results are important for distinguishing between old and mature secondary stands and particularly for identifying old forest stands, which should be conserved and, in the case of fragmented landscapes, included in a network connecting forest fragments.
基金The Meridian ClubPine Cay Homeowners Association for their support to research and restoration efforts on Pine Cay+1 种基金the John Ellerman FoundationDarwin Plus grant (DPLUS016) for financial support for different elements of the overall Caicos Pine Recovery Project between 2014 and 2016
文摘The severe and rapid attack on the Caicos pine Pinus caribaea var. bahamensis(Pinaceae) by the nonnative invasive pine tortoise scale, Toumeyella parvicornis, has resulted in the death of most of the trees in the Turks and Caicos Islands(TCI) in just over a decade. Local and international conservation efforts have enabled the necessary multi-disciplinary research, data gathering, and monitoring to develop and implement a restoration strategy for this endemic tree from the Bahaman archipelago. The native plant nursery established on North Caicos and horticultural expertise acquired throughout the years were crucial to the successful rescue of Caicos pine saplings from the wild populations and cultivation of new saplings grown from locally sourced seeds. These saplings have been used to establish six Restoration Trial Plots on Pine Cay and a seed orchard on North Caicos in TCI. Core Conservation Areas(CCAs) for the Caicos pine forests have been identified and mapped. To date, forest within the Pine Cay CCA has been supplemented by planting more than 450 pine trees, which have survived at a high(>80%)rate.
基金Comisión Nacional de Investigación Científica y Tecnológica CONICYT,Gobierno de Chile,for funding his graduate studiesFondo Nacional de Desarrollo Científico y Tecnológico FONDECYT,Gobierno de Chile,supported this research through the proyect Id:1120314。
文摘Despite the widely accepted view that planted forests are valuable habitat for wildlife species,there is a lack of empirical evidence showing the suitability of this novel habitat,especially in relation to plantations of exotic tree species.Furthermore,little is known about the effects of forest management on the ecology and dynamics of wild populations in the Neotropics.During the breeding season,the migrant flycatcher White-crested Elaenia is the most abundant bird species in forested landscapes in Chile.For several years we have studied different aspects of these artificial forests in the coastal range of south-central Chile as habitat for the species,particularly in contrast to the native forest.In general,our results indicate that plantation forests offer a poorer quality habitat,where the density of the species tends to be lower than in the native forest,although a significant edge effect suggests that its quality can be mitigated by planting as a matrix mosaic with native forest.Furthermore,compared to native forests,populations in plantations contained a higher proportion of younger adult individuals maintaining larger territories,and showing poorer body condition.We suggest that these differences could also have an impact on the birds'longevity and survival.
基金supported by National Science Foundation of China(Nos.32001166,32371663)the Forestry Peak Discipline Construction Project of Fujian Agriculture and Forestry University,China(No.72202200205).
文摘Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.Moreover,it is unknown whether forest phenology changes with the proximity to forest edge.Methods:This study examined the green-up dates,dormancy dates,time-integrated NDVI(LiNDVI,a measure of vegetation productivity in growing season),and their sensitivities to climatic factors along the gradients of distance(i.e.proximity)to forest edge(0–2 km)in China's natural forests(NF)and planted forests(PF).For the analysis,field-surveyed data were integrated with Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI from 2000 to 2022.Results:Our results reveal that PF had earlier green-up dates,later dormancy dates,and higher LiNDVI than NF.However,green-up sensitivities to temperature were higher at the edges of NF,whereas no such pattern was observed in PF.Conversely,the sensitivity of dormancy dates remains relatively stable from the inner to the edge of both NF and PF,except for a quadratic change in dormancy date sensitivity to precipitation found in NF.Additionally,we found that the green-up sensitivity to temperature increased with decreasing proximity to edge in NF evergreen forests,while it showed the opposite trend in PF evergreen forests.Furthermore,we observed that the precipitation impact on green-up dates shifts from postponing to advancing from the inner to the edge of NF,whereas precipitation dominantly postpones PF's green-up dates regardless of the proximity to edge.The LiNDVI exhibits higher sensitivity to precipitation at the edge areas,a phenomenon observed in NF but not in PF.Conclusions:These results suggest that the responses of forests to climate change vary with the distance to the edge.With increasing edge forests,which results from fragmentation caused by global changes,we anticipate that desynchronized phenological events along the distance to the edge could alter biogeochemical cycles and reshape ecosystem services such as energy flows,pollination duration,and the tourism industry.Therefore,we advocate for further investigations of edge effects to improve ecosystem modelling,enhance forest stability,and promote sustainable tourism.
基金Under the auspices of Excellent Young Scholars of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.DLSYQ 13004)Chinese Academy of Sciences/State Administration of Foreign Experts Affairs International Partnership Program for Creative Research Teams(No.KZZD-EW-TZ-07-09)Strategic Priority Research Program of Chinese Academy of Sciences(No.KFZD-SW-302-03)
文摘Urban forest soil infiltration, affected by various factors, is closely related with surface runoff. This paper studied the effect of urban forest types, vegetation configuration and soil properties on soil infiltration. In our study, 191 typical plots were sampled in Changchun City, China to investigate the soil infiltration characteristics of urban forest and its influencing factors. Our results showed that the steady infiltration rates of urban forest soil were highly variable. High variations in the final infiltration rates were observed for different vegetation patterns and compaction degrees. Trees with shrubs and grasses had the highest infiltration rate and trees with bare land had the lowest infiltration rate. In addition, our results showed that the soil infiltration rate decreased with an increase in the bulk density and with a reduction in the soil organic matter content and non-capillary porosity. The soil infiltration rate also had significantly positive relationships with the total porosity and saturated soil water content. Urban soil compaction contributed to low soil infiltration rates. To increase the infiltration rate and water storage volume of urban forest soil, proper techniques to minimize and mitigate soil compaction should be used. These findings can provide useful information for urban planners about how to maximize the water volume of urban forest soil and decrease urban instantaneous flooding.
文摘Available light under forest canopies includes two components, diffuse light and direct light (sunflecks), and is characterized as low and highly dynamic. Understory habitats under different forest types experience different light conditions. Sunflecks as a critical resource for understory plants have great importance on carbon gain of understory plants. Under the light-limiting habitat, understory plants exhibit a high light utilization efficiency attributed by a post-illumination CO2 uptake. Although different species have different photosynthetic responses, shade plants appear to be acclimated to respond more quickly and efficiently to sunflecks. This acclimation includes a faster induction, relatively lower rate of induction loss, lower photosynthetic compensation point, and higher water use efficiency. The process that shade plants harvest light energy is not well known. Studies of photosynthetic responses to sunflecks in natural conditions are rare. Little is known about constraints on sunfleck utilization, which may change seasonally. Extensive field studies in conjunction with laboratory investigations will be needed to further understand potential and actual constraints on sunfleck utilization. Most studies on photosynthetic responses to fluctuating light condition were done in the level of leaves. Fluctuating light utilization on the basis of whole plants and populations presents future challenges to ecologists.
基金Under the auspices of National Natural Science Foundation of China (No 30270225, 40871245, 40331008, 40671013)
文摘In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferous tree planting had been conducted to accelerate forest restoration.To study the long term effect of these activities on forest recovery,we used a simulation modeling approach to study long-term(300 years) forest dynamics under current planting and natural regeneration scenarios.Results indicate that under tree planting scenario in the severely burned area,the dominant species Dahurian larch(Larix gmelinii) can reach pre-fire level(60% of the area) within 20 years and the maximum abundance can reach nearly 90% within 100 years.While under natural regeneration scenario,it needs about 250 years to reach its pre-fire level.From the perspective of timber production,tree planting can bring twice as much timber volume as that under natural regeneration within 300 years,which is the average longevity of L.gmelinii.It needs about 70 years to reach the timber volume of pre-fire level under the planting scenario,whereas it requires at least 250 years to reach the timber volume of pre-fire level under natural regeneration scenario.Another dominant species Asian White birch(Betula platyphylla) responded negatively to the planting of coniferous species.In general,tree planting of coniferous species after fire can greatly accelerate forest restoration in terms of species abundance and target timber volume,with desirable ecological and economic returns.
基金supported by grants from the National Key R&D Program of China(2016YFC0500302)the National Natural Science Foundation of China(U1808201)+1 种基金Strategic Leading Science&Technology Programme,CAS(XDA23070100)the Liaoning Revitalization Talents Program(XLYC1807102).
文摘Background:Non-timber forest products(NTFPs)are an important part of forest biodiversity,and the subsistence and trade of local people,especially in less developed countries.Because of the high ecological and economic value,NTFPs have faced the problem of over-exploitation,and the key to solve this problem is to determine the feasible way of sustainable utilization of NTFPs.Harvest intensity is one of the most important and easily controlled utilization factors,which can greatly influence the plant individual survival,growth and reproductive performances,and even the population structure and dynamics.Therefore,we chose two common and important NTFPs species with different marketable parts(i.e.,Acanthopanax senticosus with tender leaves and Aralia elata with tender buds)as our study objects.Aiming to determine the optimum harvest intensity for sustainably utilizing both NTFPs species,five levels of harvest intensity treatments(i.e.,control,light,medium,high and severe)were designed to assess the effects of harvest intensity on their marketable organ yield,plant growth and reproductive performances.Results:The biomass growth rates of marketable organ and plant growth of A.senticosus under light harvest intensity treatment were significantly higher than those under other harvest intensities.The plant height growth and 1000-seed weight of A.elata under severe harvest intensity treatment were significantly lower than those under control treatment.Conclusions:The light harvest intensity with 25% leaf removal and the high harvest intensity with all terminal buds harvested are the optimum harvest intensity to maintain the sustainable utilization of A.senticosus and A.elata,respectively.These findings could provide managers with basic but practical guidance for making decisions about the sustainable harvest management plan for the cultivated NTFPs species,and further provide a theoretical basis for managers to establish the harvest regulations for wild NTFPs species.Consequently,the local residents or communities can improve their income while ensure the sustainable development of wild NTFPs.
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.
基金supported by the National Technology Extension Fund of Forestry,Forest Vegetation Carbon Storage Monitoring Technology Based on Watershed Algorithm ([2019]06)Fundamental Research Funds for the Central Universities (No.PTYX202107).
文摘Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable information.However,the potential of GEE for forest resource management has not been fully exploited.To extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast China.Spectral and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant species.The results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source independently.Similarly,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was accurate.Including terrain factors and removing spatial correlation from NFRI sample points further improved the recognition accuracy.The optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,respectively.The high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant species.Visualizing the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.