It is important to revisit our plans and compare what was ideally targeted against what was actually achieved in implementation. In comparing the achievements with targets, strengths or weaknesses of established strat...It is important to revisit our plans and compare what was ideally targeted against what was actually achieved in implementation. In comparing the achievements with targets, strengths or weaknesses of established strategies can be accepted or corrections implemented since a plan also outlines some strategies for achieving the targets set. In this study, achievements in production and export of industrial forest products, i.e., sawn wood, plywood, chipboard and fibreboard, paper and paperboard and industrial round wood, are compared against targeted figures for 1996 for Tanzania. Discrepancies were obtained by subtracting targeted from achieved values and expressed both as absolute and relative differences in terms of the targeted values, with a negative sign for pro- duction where achievements were less than targets and a positive sign when achievements were higher than targets. Values achieved ranged from 4%-100% of the targeted values, depending on the product, and were only higher than the targeted value for industrial round wood. Possible causes of the discrepancies are inefficiency of parastatal companies, low private investment, sub-maximal in- dustrial operation and plant inefficiencies. Discrepancies could also result from unrealistic data used in planning due to difficulty in data availability and poor intra- and inter-sectoral coordination. The implications of these discrepancies are low contributions of the wood-based industry to the national economy, increased import substitution of wood-based products, increased socio-economic and environmental degradation and decreased integrity in planning and policy making.展开更多
An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis sugges...An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.展开更多
This study focused on identifying factors affecting the benefits of Participatory Forestry Management (PFM) income generating activities in Upper Imenti Forest and whether they are dependent on status of participation...This study focused on identifying factors affecting the benefits of Participatory Forestry Management (PFM) income generating activities in Upper Imenti Forest and whether they are dependent on status of participation in forest management through membership of Community Forest Association (CFA) or not. Cross-sectional survey research design was applied for collecting quantitative data using a semi-structured questionnaire administered to 384 households stratified on the basis of PFM participation status. Qualitative data was collected through focused group discussions using a checklist and key informant interviews using an interview schedule. Using Statistical Package for Social Sciences version 25, Binomial regression with Wald Chi-square was analyzed to identify factors perceived to be significantly influencing benefits for PFM participants and Pearson Chi-square to compare factors perceived to be affecting PFM and non-PFM participants. CFA members participation in PFM was significantly and positively affected by benefits of PFM income generating activities and forest products accessed in the forest. Benefits linked to Plantation Establishment for Livelihood Improvement System (PELIS) for CFA members were significantly reduced by enforcement of moratorium policy since February 2018, diseases and pests, poor PELIS guideline adherence and animal damage. Benefits related to state forest access for firewood by the CFA members were negatively influenced by the moratorium policy. Diseases and pests affected benefits associated with bee keeping significantly. Comparing factors under different PFM participation status, crop production was significantly affected by policy changes, pest and diseases, animal damage and PELIS guideline adherence for CFA members than for Non-CFA members. Policy changes also affected the CFA members significantly in firewood collection and access to fodder in the state forest than the Non-CFA members. Hence, sustainable community participation in Upper Imenti Forest management requires: increasing PFM benefits, addressing factors reducing benefits and enhancing active participation of CFA members in PFM related decision-making processes.展开更多
Background: The quantitative impact of forest management on forests' wood resource was evaluated for Picea and Fagus mixed forests. The effects on the productivity of tendering operations, thinnings and rotation len...Background: The quantitative impact of forest management on forests' wood resource was evaluated for Picea and Fagus mixed forests. The effects on the productivity of tendering operations, thinnings and rotation length have seldom been directly quantified on landscape scale. Methods: Two sites of similar fertility but subject to contrasted forest management were studied with detailed inventories: one in Germany, the other in Romania, and compared with the respective national forest inventories. In Romania, regulations impose very long rotations, low thinnings and a period of no-cut before harvest. In contrast, tending and thinnings are frequent and intense in Germany. Harvests start much earlier and must avoid clear cutting but maintain a permanent forest cover with natural regeneration. While Germany has an average annual wood increment representative for Central Europe, Romania represents the average for Eastern Europe. Results: The lack of tending and thinning in the Romanian site resulted in twice as many trees per hectare as in the German site for the same age. The productivity in Romanian production forests was 20 % lower than in Germany despite a similar fertility. The results were supported by the data from the national forest inventory of each country, which confirmed that the same differential exists at country scale. Furthermore, provided the difference in rotation length, two crops are harvested in Germany when only one is harvested in Romania. The losses of production due to a lower level of management in Romania where estimated to reach 12.8 million m3.y-1 in regular mountain production forests, and to 15 million m3.y-1 if managed protection forest is included. Conclusions: The productivity of Picea and Fagus mountain forests in Romania is severely depressed by the lack of tending and thinning, by overly long rotations and the existence of a 25-years no-cut period prior to harvest. The average standing volume in Germany was 50 % lower than in Romania, but the higher harvesting rate resulted in more than doubling wood production. Considering the mitigation effects of climate change by forests, it emerges that the increase in standing volume of forests in Romania is smaller than the additional harvest in Germany which serves fossil fuel substitution.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
Wild mushrooms are recognized as important non-wood forest products in mountainous ecosystems, but their real potential for generating rural economies has not been fully evaluated due to the difficulties in obtaining ...Wild mushrooms are recognized as important non-wood forest products in mountainous ecosystems, but their real potential for generating rural economies has not been fully evaluated due to the difficulties in obtaining reliable productivity data, minimizing their true potential as contributor to rural economies. Mushroom yield models based on large data series from Pinus forest ecosystems in the region of Catalonia(Spain), combined with data from the Spanish National Forest Inventory allow us to estimate the potential mushroom productivity by forest ecosystems. The results of 24,500 tons/yr of mushrooms of which 16,300 tons are classified as edible and 7,900 tons are commonly marketed demonstrate the importance of mushroom productions in Catalonian pine forests, mostly located in mountainous areas where the development of agricultural activities is limited. Economic mushroom value is estimated at 48 million € for the edible mushroom and 32 million € for those corresponding to marketable yields, confirming the potential of this non-wood forest product. These production results and corresponding economic values provide a basis for the incorporation of wild mushrooms as significant non-wood forest products in the development of forest policies in mountainous areas.展开更多
Background:This contribution evaluates the effect of forest structure and tree species diversity on plot productivity and individual tree growth in the unique Knysna forests in Southern Africa using mapped tree data ...Background:This contribution evaluates the effect of forest structure and tree species diversity on plot productivity and individual tree growth in the unique Knysna forests in Southern Africa using mapped tree data from an observational study that has been re-measured over a period of 40 years.Methods:The effects of tree species diversity and forest structure on tree growth and forest production are evaluated on three levels of resolution:a) the forest community(canopy,sub-canopy species),b) the subplots(number of trees per ha,skewness of the diameter distribution,diameter coefficient of variation) and c) the immediate neighborhood of selected reference trees("Mingling","Dominance",Aggregation" and "Size Variation").Results:An analysis of the community level identified two distinct clusters,one including dominant/canopy species with the highest growth rates and a greater variation of growth,and another cluster which includes the remaining subcanopy species which have a smaller maximum size and lower rates of growth.The area-based structure variables on plot level have a highly significant effect on total basal area growth.However,the effects of forest density and species richness on productivity were not straight forward.Maximum basal area production of about 0.75 m^2/ha/year is achieved at medium levels of richness(around 20 species per ha) and medium levels of density(around 30 m^2/ha basal area) using percentile regression estimates.The relative "Dominance" of a selected reference tree had a highly significant effect on individual tree growth on all investigated species.Other neighbourhood structure variables were only occasionally significant or not significant at all.Conclusion:This contribution presents a new theoretical framework for analysing natural forests that includes community,plot and neighborhood variables of forest structure and diversity,and a first specific analysis of the structure and dynamics of the Knysna Afromontane Forest,based on a unique set of longterm observations.The species-area(SAR) model developed in this study,represents a new general approach that can be used to derive a common standard of tree species diversity for different plot sizes,the species richness per hectare.展开更多
This paper uses an input-output table of China's provinces(2007-2016) to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML) index with expected and undesired outputs,and an absolute...This paper uses an input-output table of China's provinces(2007-2016) to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML) index with expected and undesired outputs,and an absolute β convergence and a conditional β convergence model,to conduct an in-depth analysis of dynamic changes and spatial convergence.Carbon emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Tibet are decreasing.The main contributing factors of carbon emission efficiency in three major regions vary over time.Further,carbon emission efficiency in the eastern,central,and western regions all have absolute β convergence and conditional β convergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in place.Finally,this paper proposes according recommendations.展开更多
The palm Euterpe edulis was historically very exploited by humans and even today, many individuals are cut down by collectors to harvest the edible palm hearts. The ecological aspects of this anthropogenic pressure an...The palm Euterpe edulis was historically very exploited by humans and even today, many individuals are cut down by collectors to harvest the edible palm hearts. The ecological aspects of this anthropogenic pressure and its related effects are poorly understood. Here we investigate if linear canopy openings in a fragment of Brazilian Atlantic Forest can cause edge effects and facilitate predatory harvesting by humans. We sampled in Tinguá Biological Reserve (Southeastern Brazil) native palm populations at forest edges adjacent to two linear canopy openings, and in the forest interior far from any edge. Our 8-year monitoring showed that the linear canopy openings negatively affected the palm populations reducing its density and regeneration mainly on edges, but no local extinction was observed. Thus, the direct human impact from harvesting, adverse survival conditions on edges and interspecific competition causes population declines with no local extinction, so this suggests that E. edulis may resist even under strong anthropogenic pressure.展开更多
Individual tree models(ITMs)are classified as growth and production models for projecting current and future forest stands.ITMs are more complex than other growth and production models,show a higher level of detail an...Individual tree models(ITMs)are classified as growth and production models for projecting current and future forest stands.ITMs are more complex than other growth and production models,show a higher level of detail and,consequently,produce a better modeling resolution.However,the accuracy and efficiency of ITMs have not been properly assessed to date.In this study,we estimated the growth in height,diameter,and individual tree volume of a Eucalyptus urophylla plantation by applying an ITM.We used a continuing forest inventory dataset in which 1554 individual trees within 29 permanent plots were measured in the field over a 6-year period(24 to 72 months).Each individual tree volume was estimated for future tree age.To achieve this,we adjusted the model to predict the height and diameter growth,and the probability of mortality as a function of the competition index.The ITM accuracy was assessed based on the analysis of variance results and,subsequently,the multiple mean comparison test at the 5%significance level.The tree volumes predicted by the ITM for the forest stand aged 72 months,beginning at ages 24,36,48,and 60 months,were compared to the field measured tree volume acquired from the 72-month forest inventory that was used as the reference age.Estimated and observed tree volumes were similar when the estimation was based on the 48-month forest plots.These results might help to reduce financial costs of forest inventory because the ITM produces accurate future predictions of forest stand stocks.Our estimated ITM for Eucalyptus plantations using measurement intervals up to 2 years is recommended because it significantly reduced the projected volume discrepancy compared to the field measurements.展开更多
Plantation forests are established,and expanding,to satisfy increasing global demand for timber products.Shifting societal values,such as safety,productivity,environmental,quality and social are influencing the planta...Plantation forests are established,and expanding,to satisfy increasing global demand for timber products.Shifting societal values,such as safety,productivity,environmental,quality and social are influencing the plantation forestry sector.This is primarily driven through an ever increasing world population,which in turn influences the way nations view the value systems by which they live.More people require more resources-also forest products.Also,the availability of information is influencing the pace of technological development.These changes could result in a difference in the management of plantations that could affect the forest engineering systems of the future.This review aimed to summarize the current status of plantation forests;summarize future developments and possible scenarios in forest plantation management for the various products;and assess whether these developments in a plantation environment could affect the harvesting systems used.Factors influencing the form of plantations include the type and nature of the plantation owner;the change in demand for different and new forest products;climate change factors,including the use of biomass for energy,carbon sequestration and trading;ecosystem services and other products and services;and sustainability certification of forest management.The impact and influence of these factors were summarised into a series of key drivers that will influence the technology used in harvesting machines,as well as the choice of harvesting machines,systems and methods.These drivers were the effect of variations in tree size,the expansion of plantation areas onto more difficult terrain,diversity in plantation design,increased attention towards site impacts and the increased use of biomass for energy.Specific information is provided regarding how the harvesting systems could be affected.展开更多
Background:Forests perform various important ecosystem functions that contribute to ecosystem services.In many parts of the world,forest management has shifted from a focus on timber production to multi-purpose forest...Background:Forests perform various important ecosystem functions that contribute to ecosystem services.In many parts of the world,forest management has shifted from a focus on timber production to multi-purpose forestry,combining timber production with the supply of other forest ecosystem services.However,it is unclear which forest types provide which ecosystem services and to what extent forests primarily managed for timber already supply multiple ecosystem services.Based on a comprehensive dataset collected across 150 forest plots in three regions differing in management intensity and species composition,we develop models to predict the potential supply of 13 ecosystem services.We use those models to assess the level of multifunctionality of managed forests at the national level using national forest inventory data.Results:Looking at the potential supply of ecosystem services,we found trade-offs(e.g.between both bark beetle control or dung decomposition and both productivity or soil carbon stocks)as well as synergies(e.g.for temperature regulation,carbon storage and culturally interesting plants)across the 53 most dominant forest types in Germany.No single forest type provided all ecosystem services equally.Some ecosystem services showed comparable levels across forest types(e.g.decomposition or richness of saprotrophs),while others varied strongly,depending on forest structural attributes(e.g.phosphorous availability or cover of edible plants)or tree species composition(e.g.potential nitrification activity).Variability in potential supply of ecosystem services was only to a lesser extent driven by environmental conditions.However,the geographic variation in ecosystem function supply across Germany was closely linked with the distribution of main tree species.Conclusions:Our results show that forest multifunctionality is limited to subsets of ecosystem services.The importance of tree species composition highlights that a lack of multifunctionality at the stand level can be compensated by managing forests at the landscape level,when stands of complementary forest types are combined.These results imply that multi-purpose forestry should be based on a variety of forest types requiring coordinated planning across larger spatial scales.展开更多
We identified 67 and 21 NTFP-yielding plant and animal species, respectively, in a reserve forest in Cachar district of Assam. We recorded globally threatened species listed by IUCN as Critically Endangered (plant sp...We identified 67 and 21 NTFP-yielding plant and animal species, respectively, in a reserve forest in Cachar district of Assam. We recorded globally threatened species listed by IUCN as Critically Endangered (plant species Dipterocarpus turbinatus), Vulnerable (plant species Aquillaria malaccensis), Endangered (animal species Hoolock hoolock, Indotestudo elongata and Manis pentadactyla), and Vulnerable (animal species Nilssonia hurum and Rusa unicolor). The whole plant or animal and/or their various parts were used as food or medicine, in house construction, magico-religious activities and others. While some NTFPs were harvested throughout the year, others were harvested seasonally. A comprehensive NTFP policy, along with scientific measures for regen- eration, restoration and augmentation of NTFP-yielding plants and animals, would help in addressing the conflicting demands of conservation and livelihood in the forests of this area.展开更多
Uncontrolled harvesting of non-timber forest products (NTFPs) poses a serious risk of extermination to several of these species in Nigeria. Yet, there is a paucity of information on the distribution, population stat...Uncontrolled harvesting of non-timber forest products (NTFPs) poses a serious risk of extermination to several of these species in Nigeria. Yet, there is a paucity of information on the distribution, population status and sustainable management of NTFPs in most of the tropical lowland rainforests. We, therefore, assessed the population, distribution and threats to sustainable management of NTFPs within the tropical lowland rainforests of Omo and Shasha Forest Reserves, south western Nigeria. Data were obtained through inventory surveys on five top priority species including: bush mango (Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill), African walnut (Tetracarpidium conophorum (Mull. Arg.) Hutch. & Dalziel syn. Plukenetia conophora), chew-stick (Massularia acuminata (G. Don) Bullock), fever bark (Annickia chlorantha Setten & P.J.Maas syn. Enantia chloranta) and bush pepper (Piper guineense Schumach. & Thonn.). Purposive and stratified random sampling techniques were used for the inventory. Each forest reserve was stratified into three, viz: less disturbed natural forest (for areas that have been rested for at least ten years), recently disturbed natural forest (for areas that have suffered one form of human perturbation or the other in the last five years), and plantation forest (for areas carrying forest plantation). Data were collected from eighteen 10 m × 500 m belt transects located in the above strata. The species were generally fewer in both plantation and recently disturbed natural forest than the less disturbed natural forest, suggesting that forest disturbances (habitat modification) for other uses may have an effect on the occurrence and densities of the NTFPs. Exceptions to this trend were found for P. guineense and T. conophorum, which were fairly common in both plantation and recently disturbed natural forest. Among three tree NTFP species (i.e. I. gabonensis, M. acuminata and A. chlorantha), only I. gabonensis showed a significant difference in overall DBH size classes for both reserves (t=?2.404; df =21; p=0.026). Three tree NTFP species in both reserves further showed differences from the regular patterns of distribution of trees. The fairly regular reverse J-shaped size class distribution observed for M. acuminata in the study sites, however, suggests a recuperating population. In general, destructive harvesting of species, logging operations, low population size, narrow distribution ranges and habitat degradation are the major threats to the population of NTFPs in the study area. The implications of our findings for sustainable management of NTFPs in the study area are discussed and recommendations are made for a feasible approach towards enhancing the status of the species.展开更多
Background: Forest management decisions are based on expectations of future developments. For sound decisions it is essential to accurately predict the expected values in future developments and to account for their i...Background: Forest management decisions are based on expectations of future developments. For sound decisions it is essential to accurately predict the expected values in future developments and to account for their inherent uncertainty,for example the impact of climate change on forests. Changing climatic conditions affect forest productivity and alter the risk profile of forests and forest enterprises. Intensifying drought stress is seen as one major risk factor threatening forest management in the north German lowlands. Drought stress reduces tree growth and vitality and might even trigger mortality. But so far, it is not possible to quantify effects of a persistent dryer climate on forest productivity at a level suitable for forest management.Methods: We apply a well-established single-tree forest growth simulator to quantify the effect of persistent dryer climates on future forest productivity. We analyse the growth of Scots pine(Pinus sylvestris L.), European beech(Fagus sylvatico L.) and oak(Quercus robur L. and Quercus petraea(Matt.) Liebl.) in two forest regions in the north German lowlands for a time interval of 60 years until 2070. The growth response under three different climate projections is compared to a baseline scenario.Results: The results show clear differences in volume increment to persistent dryer climates between tree species. The findings exhibit regional differences and temporal trends. While mean annual increment at biological rotation age of Scots pine and oak predominantly benefits from the projected climate conditions until 2070, beech might suffer losses of up to 3 m^3·ha^(-1)yr^(-1) depending on climate scenario and region. However, in the projection period2051 to 2070 the uncertainty ranges comprise positive as well as negative climatic effects for all species.Conclusions: The projected changes in forest growth serve as quantitative contributions to provide decision support in the evaluation of, for example, species future site suitability and timber supply assessments. The analysis of productivity changes under persistent dryer climate complements the drought vulnerability assessment which is applied in practical forestry in northwestern Germany today. The projected species' productivity has strong implications for forest management and the inherent uncertainty needs to be accounted for.展开更多
Background: Tropical forests play an important role in the global carbon(C) cycle.However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well...Background: Tropical forests play an important role in the global carbon(C) cycle.However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood.Montane forests are highly endangered due to logging, land-use and climate change.Our objective was to analyse how the carbon balance changes during forest succession.Methods: In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models.We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions(ravines and lower slopes vs upper slopes and ridges).Results: The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange(NEE) of 9.3 Mg C?(ha?yr)-1during its early successional stage(0–100 years).In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C?(ha?yr)–1.The simulated variability of the NEE was within the range of the field data.We discovered several forest attributes(e.g., basal area or the relative amount of pioneer trees) that can serve as predictors for NEE for young forest stands(0–100 years) but not for those in the late successional stage(500–1,000 years).In case of young forest stands these correlations are high, especially between stand basal area and NEE.Conclusion: In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity.To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests.With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes.These relationships promote a better understanding of the role of tropical montane forests in the context of global carbon cycle, which in future will become more relevant to a society under global change.展开更多
Non-timber forest products(NTFPs)play a significant role in the improvement of the forest-dependent people’s livelihoodsaround the world,strengthening protection for the sustainable use of forests.The purpose of this...Non-timber forest products(NTFPs)play a significant role in the improvement of the forest-dependent people’s livelihoodsaround the world,strengthening protection for the sustainable use of forests.The purpose of this research was to evaluate the influence of occupational category-wise(fuelwood collectors,farmers,small-scale businessmen,day labourers,and tea estate labourers)dependencyon NTFPsand the role of NTFPs on household income around the Khadimnagar National Park(KNP)in northeastern Bangladesh.In 2014,178purposively selected respondents from four villages(out of 22 villagesaround the KNP)were interviewed face-to-face using a semi-structured questionnaire.The study observed that these forest-dependent communities utilized resources of the KNP mainly for domestic energy supply,household income,and house construction.Results showed that income from NTFPs made a significant contribution to family income.Income data analysis indicated that small-scale businessmen earned relatively more income from NTFPs,followed by tea estate labourersand day labourers.The study revealed significant negative relationships of the distance of households from the forest with the amount of NTFPs collected(P<0.01)and monthly income from NTFPs(P<0.01).Positive significant relationships were found between the amount of NTFPs collected and the time spent in NTFP collection(P<0.001),as well as betweenmonthly income from NTFPs and family size(P<0.001).The fuelwood collectors and farmers collected significantly greater amounts of NTFPs per trip(P<0.001)than other occupational categories.The households that were moderately to highly dependent on NTFPs collected significantly higher amounts of NTFPs pertrip(P<0.01)than the households that were moderately dependent and less dependent on NTFPs.Community dependence on KNP’sresources,community’sappreciation of the KNP’s ecosystem services for villagers’livelihoods,and community’s high levels of concern for forest conservation provided a foundation for the sustainable management of the KNP.The study findings will be useful for designing an effective forest management plan and policy for NTFP management and forest conservation with the active involvement of the forest-dependent people in northeastern Bangladesh.展开更多
Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonber...Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonberry Vaccinium vitis-idaea is an important understory component of temperate and boreal forests and provider of valuable non-wood forest products.Here we studied effects of land use changes and introduction of Northern red oak Quercus rubra on lingonberry in mesic Scots pine forests(in central Poland).We measured lingonberry cover,height of shoots,biomass of stems and leaves,and fruit productivity.Shoots were collected within 200 research plots located in recent and ancient Scots pine forests,with and without Q.rubra.Results:We found that V.vitis-idaea reached lower cover,aboveground biomass and fruit production in recent than ancient forests and in forests with than without Q.rubra.The fruit production in recent pine forest was only 2%of that reported in ancient pine forest,and V.vitis-idaea did not reproduce generatively in forests with Q.rubra.Biomass and carbon sequestration of V.vitis-idaea in forests with alien(invasive)trees decreased by 75%compared to ancient pine forest.Effects were also clear at the individual shoot level–in less suitable conditions we found taller heights and higher biomass allocation into stems than foliage.Biomass allocation in fruiting and non-fruiting shoots in pine forests was also different–less of the dry biomass of fruiting shoots was allocated to leaves than to stems.Conclusions:In the age of high interest in ecosystem services and discussions about usage of alien tree species as alternatives in forest management,our results clearly indicate disruption of ecosystem services provided by V.vitisidaea in the presence of Q.rubra.Lingonberry benefited from the continuity of forest land use,however,regardless of land-use legacy,alien tree introduction led to decline in abundance of species crucial for ecosystem functioning.Therefore,to maintain valuable native species and for conservation of ecosystem services delivery,we suggest limiting the introduction of Q.rubra in areas with abundant V.vitis-idaea,especially in forests with continuous forest land-use history.展开更多
The forest sectors in many regions and countries are facing a need to change their structure, due to the development of new markets, emergence of new competitors, and shifts in production and consumption patterns for ...The forest sectors in many regions and countries are facing a need to change their structure, due to the development of new markets, emergence of new competitors, and shifts in production and consumption patterns for forest products. This article focuses on recent changes in the trade in these products, on imports and exports of four countries (USA, Sweden, Ukraine and, to a lesser extent, China) during the period from 1995 to 2011. For this purpose we use explanatory data analysis, time series analysis, benchmarking, meta-synthesis and content analysis of scientific and business publications concerning national and global trends in forest product industries. Data sources are various organizations’ databases of international trade in forest-based products in both monetary and physical terms (cubic meters and tons). The results show that the US and Swedish forest sectors are adversely affected by downturns in both their domestic and foreign markets during the study period, while the Ukrainian sector maintains exports of low value-added products at roughly constant levels (except that particle-board exports increase). China maintains production quantities of low value-added forest-based products, but also substantially increases exports of high-value added products. The results may facilitate efforts to forecast future trends and provide useful information and methodological approaches for future studies of interest to industry representatives, policy-makers and researchers.展开更多
Due to considerable deforestation in North Korea,there is a need to plan forest restoration programs based on scientific forest management.In this study,a methodology was developed for estimating the site index values...Due to considerable deforestation in North Korea,there is a need to plan forest restoration programs based on scientific forest management.In this study,a methodology was developed for estimating the site index values of six major tree species and the forest productivity potential.The site index values of these tree species were derived in South Korea using the Chapman-Richards equation.These values were used with data from the 6th National Forest Inventory,which included 20 types of edaphic,topographic,and climatic factors,and random forest analysis—a widely used machine learning technique for spatial prediction—to develop a new model for estimating the site index values of these species across South Korea.The prediction accuracy of this model was evaluated using the root mean square error.The results show that the prediction accuracy was high,with a root mean square error of~1m.Moreover,the importance of the variables related to climate and geography was generally high.The proposed site index estimation model for six tree species was applied across North Korea,and its effectiveness tested by comparing the estimated values with those reported in literature from North Korea.The differences between the model outputs and recorded data in the northern alpine regions were presumably due to the lack of data for high-altitude regions in South Korea.This model is based on the determination of the suitability of tree species in restoration efforts.Therefore,it can contribute to the evaluation of forest productivity in North Korea and may help plan efficient forest restoration programs.展开更多
文摘It is important to revisit our plans and compare what was ideally targeted against what was actually achieved in implementation. In comparing the achievements with targets, strengths or weaknesses of established strategies can be accepted or corrections implemented since a plan also outlines some strategies for achieving the targets set. In this study, achievements in production and export of industrial forest products, i.e., sawn wood, plywood, chipboard and fibreboard, paper and paperboard and industrial round wood, are compared against targeted figures for 1996 for Tanzania. Discrepancies were obtained by subtracting targeted from achieved values and expressed both as absolute and relative differences in terms of the targeted values, with a negative sign for pro- duction where achievements were less than targets and a positive sign when achievements were higher than targets. Values achieved ranged from 4%-100% of the targeted values, depending on the product, and were only higher than the targeted value for industrial round wood. Possible causes of the discrepancies are inefficiency of parastatal companies, low private investment, sub-maximal in- dustrial operation and plant inefficiencies. Discrepancies could also result from unrealistic data used in planning due to difficulty in data availability and poor intra- and inter-sectoral coordination. The implications of these discrepancies are low contributions of the wood-based industry to the national economy, increased import substitution of wood-based products, increased socio-economic and environmental degradation and decreased integrity in planning and policy making.
基金supported by the Sino-German Postdoc Scholarship Program of the China Scholarship Council(CSC)the German Academic Exchange Service(DAAD)+4 种基金supported in part by the National Natural Science Foundation of China(Nos.32071541,41971071)the Ministry of Science and Technology of China(Nos.2021FY100200,2021FY100702,2023YFF0805802)the Youth Innovation Promotion Association,CAS(No.2021392)the International Partnership Program,CAS(No.151853KYSB20190027)the“Climate Change Research Initiative of the Bavarian National Parks”funded by the Bavarian State Ministry of the Environment and Consumer Protection.
文摘An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.
文摘This study focused on identifying factors affecting the benefits of Participatory Forestry Management (PFM) income generating activities in Upper Imenti Forest and whether they are dependent on status of participation in forest management through membership of Community Forest Association (CFA) or not. Cross-sectional survey research design was applied for collecting quantitative data using a semi-structured questionnaire administered to 384 households stratified on the basis of PFM participation status. Qualitative data was collected through focused group discussions using a checklist and key informant interviews using an interview schedule. Using Statistical Package for Social Sciences version 25, Binomial regression with Wald Chi-square was analyzed to identify factors perceived to be significantly influencing benefits for PFM participants and Pearson Chi-square to compare factors perceived to be affecting PFM and non-PFM participants. CFA members participation in PFM was significantly and positively affected by benefits of PFM income generating activities and forest products accessed in the forest. Benefits linked to Plantation Establishment for Livelihood Improvement System (PELIS) for CFA members were significantly reduced by enforcement of moratorium policy since February 2018, diseases and pests, poor PELIS guideline adherence and animal damage. Benefits related to state forest access for firewood by the CFA members were negatively influenced by the moratorium policy. Diseases and pests affected benefits associated with bee keeping significantly. Comparing factors under different PFM participation status, crop production was significantly affected by policy changes, pest and diseases, animal damage and PELIS guideline adherence for CFA members than for Non-CFA members. Policy changes also affected the CFA members significantly in firewood collection and access to fodder in the state forest than the Non-CFA members. Hence, sustainable community participation in Upper Imenti Forest management requires: increasing PFM benefits, addressing factors reducing benefits and enhancing active participation of CFA members in PFM related decision-making processes.
基金support by a grant of the Romanian National Authority for Scientific Research,CNCS-UEFISCDI,project number PN-II-ID-PCE-2011-3-0781support by a grant of the Romanian National Authority for Scientific Research,CNCS-UEFISCDI,project number PN-II-RU-TE-2014-4-0017
文摘Background: The quantitative impact of forest management on forests' wood resource was evaluated for Picea and Fagus mixed forests. The effects on the productivity of tendering operations, thinnings and rotation length have seldom been directly quantified on landscape scale. Methods: Two sites of similar fertility but subject to contrasted forest management were studied with detailed inventories: one in Germany, the other in Romania, and compared with the respective national forest inventories. In Romania, regulations impose very long rotations, low thinnings and a period of no-cut before harvest. In contrast, tending and thinnings are frequent and intense in Germany. Harvests start much earlier and must avoid clear cutting but maintain a permanent forest cover with natural regeneration. While Germany has an average annual wood increment representative for Central Europe, Romania represents the average for Eastern Europe. Results: The lack of tending and thinning in the Romanian site resulted in twice as many trees per hectare as in the German site for the same age. The productivity in Romanian production forests was 20 % lower than in Germany despite a similar fertility. The results were supported by the data from the national forest inventory of each country, which confirmed that the same differential exists at country scale. Furthermore, provided the difference in rotation length, two crops are harvested in Germany when only one is harvested in Romania. The losses of production due to a lower level of management in Romania where estimated to reach 12.8 million m3.y-1 in regular mountain production forests, and to 15 million m3.y-1 if managed protection forest is included. Conclusions: The productivity of Picea and Fagus mountain forests in Romania is severely depressed by the lack of tending and thinning, by overly long rotations and the existence of a 25-years no-cut period prior to harvest. The average standing volume in Germany was 50 % lower than in Romania, but the higher harvesting rate resulted in more than doubling wood production. Considering the mitigation effects of climate change by forests, it emerges that the increase in standing volume of forests in Romania is smaller than the additional harvest in Germany which serves fossil fuel substitution.
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funded by the research project AGL2012-40035-C03-01 (Ministerio de Economía y Competitividad of Spain, Secretaría de Estado de Investigación, Desarrollo e Innovación)the Micosylva+project (Interreg IVB ProgramPO SUDOE SOE3/P2/E533)the Departament d’Agricultura, Ramaderia, Pesca, Alimentació i Medi Natural de la Generalitat de Catalunya
文摘Wild mushrooms are recognized as important non-wood forest products in mountainous ecosystems, but their real potential for generating rural economies has not been fully evaluated due to the difficulties in obtaining reliable productivity data, minimizing their true potential as contributor to rural economies. Mushroom yield models based on large data series from Pinus forest ecosystems in the region of Catalonia(Spain), combined with data from the Spanish National Forest Inventory allow us to estimate the potential mushroom productivity by forest ecosystems. The results of 24,500 tons/yr of mushrooms of which 16,300 tons are classified as edible and 7,900 tons are commonly marketed demonstrate the importance of mushroom productions in Catalonian pine forests, mostly located in mountainous areas where the development of agricultural activities is limited. Economic mushroom value is estimated at 48 million € for the edible mushroom and 32 million € for those corresponding to marketable yields, confirming the potential of this non-wood forest product. These production results and corresponding economic values provide a basis for the incorporation of wild mushrooms as significant non-wood forest products in the development of forest policies in mountainous areas.
文摘Background:This contribution evaluates the effect of forest structure and tree species diversity on plot productivity and individual tree growth in the unique Knysna forests in Southern Africa using mapped tree data from an observational study that has been re-measured over a period of 40 years.Methods:The effects of tree species diversity and forest structure on tree growth and forest production are evaluated on three levels of resolution:a) the forest community(canopy,sub-canopy species),b) the subplots(number of trees per ha,skewness of the diameter distribution,diameter coefficient of variation) and c) the immediate neighborhood of selected reference trees("Mingling","Dominance",Aggregation" and "Size Variation").Results:An analysis of the community level identified two distinct clusters,one including dominant/canopy species with the highest growth rates and a greater variation of growth,and another cluster which includes the remaining subcanopy species which have a smaller maximum size and lower rates of growth.The area-based structure variables on plot level have a highly significant effect on total basal area growth.However,the effects of forest density and species richness on productivity were not straight forward.Maximum basal area production of about 0.75 m^2/ha/year is achieved at medium levels of richness(around 20 species per ha) and medium levels of density(around 30 m^2/ha basal area) using percentile regression estimates.The relative "Dominance" of a selected reference tree had a highly significant effect on individual tree growth on all investigated species.Other neighbourhood structure variables were only occasionally significant or not significant at all.Conclusion:This contribution presents a new theoretical framework for analysing natural forests that includes community,plot and neighborhood variables of forest structure and diversity,and a first specific analysis of the structure and dynamics of the Knysna Afromontane Forest,based on a unique set of longterm observations.The species-area(SAR) model developed in this study,represents a new general approach that can be used to derive a common standard of tree species diversity for different plot sizes,the species richness per hectare.
文摘This paper uses an input-output table of China's provinces(2007-2016) to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML) index with expected and undesired outputs,and an absolute β convergence and a conditional β convergence model,to conduct an in-depth analysis of dynamic changes and spatial convergence.Carbon emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Tibet are decreasing.The main contributing factors of carbon emission efficiency in three major regions vary over time.Further,carbon emission efficiency in the eastern,central,and western regions all have absolute β convergence and conditional β convergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in place.Finally,this paper proposes according recommendations.
文摘The palm Euterpe edulis was historically very exploited by humans and even today, many individuals are cut down by collectors to harvest the edible palm hearts. The ecological aspects of this anthropogenic pressure and its related effects are poorly understood. Here we investigate if linear canopy openings in a fragment of Brazilian Atlantic Forest can cause edge effects and facilitate predatory harvesting by humans. We sampled in Tinguá Biological Reserve (Southeastern Brazil) native palm populations at forest edges adjacent to two linear canopy openings, and in the forest interior far from any edge. Our 8-year monitoring showed that the linear canopy openings negatively affected the palm populations reducing its density and regeneration mainly on edges, but no local extinction was observed. Thus, the direct human impact from harvesting, adverse survival conditions on edges and interspecific competition causes population declines with no local extinction, so this suggests that E. edulis may resist even under strong anthropogenic pressure.
基金supported by the Coordination for the Improvement of Higher Education Personnel(CAPES)the Brazilian National Council of Science and Technology(CNPQ)。
文摘Individual tree models(ITMs)are classified as growth and production models for projecting current and future forest stands.ITMs are more complex than other growth and production models,show a higher level of detail and,consequently,produce a better modeling resolution.However,the accuracy and efficiency of ITMs have not been properly assessed to date.In this study,we estimated the growth in height,diameter,and individual tree volume of a Eucalyptus urophylla plantation by applying an ITM.We used a continuing forest inventory dataset in which 1554 individual trees within 29 permanent plots were measured in the field over a 6-year period(24 to 72 months).Each individual tree volume was estimated for future tree age.To achieve this,we adjusted the model to predict the height and diameter growth,and the probability of mortality as a function of the competition index.The ITM accuracy was assessed based on the analysis of variance results and,subsequently,the multiple mean comparison test at the 5%significance level.The tree volumes predicted by the ITM for the forest stand aged 72 months,beginning at ages 24,36,48,and 60 months,were compared to the field measured tree volume acquired from the 72-month forest inventory that was used as the reference age.Estimated and observed tree volumes were similar when the estimation was based on the 48-month forest plots.These results might help to reduce financial costs of forest inventory because the ITM produces accurate future predictions of forest stand stocks.Our estimated ITM for Eucalyptus plantations using measurement intervals up to 2 years is recommended because it significantly reduced the projected volume discrepancy compared to the field measurements.
文摘Plantation forests are established,and expanding,to satisfy increasing global demand for timber products.Shifting societal values,such as safety,productivity,environmental,quality and social are influencing the plantation forestry sector.This is primarily driven through an ever increasing world population,which in turn influences the way nations view the value systems by which they live.More people require more resources-also forest products.Also,the availability of information is influencing the pace of technological development.These changes could result in a difference in the management of plantations that could affect the forest engineering systems of the future.This review aimed to summarize the current status of plantation forests;summarize future developments and possible scenarios in forest plantation management for the various products;and assess whether these developments in a plantation environment could affect the harvesting systems used.Factors influencing the form of plantations include the type and nature of the plantation owner;the change in demand for different and new forest products;climate change factors,including the use of biomass for energy,carbon sequestration and trading;ecosystem services and other products and services;and sustainability certification of forest management.The impact and influence of these factors were summarised into a series of key drivers that will influence the technology used in harvesting machines,as well as the choice of harvesting machines,systems and methods.These drivers were the effect of variations in tree size,the expansion of plantation areas onto more difficult terrain,diversity in plantation design,increased attention towards site impacts and the increased use of biomass for energy.Specific information is provided regarding how the harvesting systems could be affected.
基金funded through the project‘Bio Holz’(grant no.01LC1323A)in the funding program‘Research for the Implementation of the National Biodiversity Strategy(F&U NBS)’by the German Federal Ministry for Education and Research(BMBF)and the German Federal Agency for Nature Conservation(Bf N)with funds provided by the German Federal Ministry for the Environment,Nature Conservation,Building and Nuclear Safety(BMUB)supported by the DFG Priority Program 1374‘Infrastructure-Biodiversity-Exploratories’。
文摘Background:Forests perform various important ecosystem functions that contribute to ecosystem services.In many parts of the world,forest management has shifted from a focus on timber production to multi-purpose forestry,combining timber production with the supply of other forest ecosystem services.However,it is unclear which forest types provide which ecosystem services and to what extent forests primarily managed for timber already supply multiple ecosystem services.Based on a comprehensive dataset collected across 150 forest plots in three regions differing in management intensity and species composition,we develop models to predict the potential supply of 13 ecosystem services.We use those models to assess the level of multifunctionality of managed forests at the national level using national forest inventory data.Results:Looking at the potential supply of ecosystem services,we found trade-offs(e.g.between both bark beetle control or dung decomposition and both productivity or soil carbon stocks)as well as synergies(e.g.for temperature regulation,carbon storage and culturally interesting plants)across the 53 most dominant forest types in Germany.No single forest type provided all ecosystem services equally.Some ecosystem services showed comparable levels across forest types(e.g.decomposition or richness of saprotrophs),while others varied strongly,depending on forest structural attributes(e.g.phosphorous availability or cover of edible plants)or tree species composition(e.g.potential nitrification activity).Variability in potential supply of ecosystem services was only to a lesser extent driven by environmental conditions.However,the geographic variation in ecosystem function supply across Germany was closely linked with the distribution of main tree species.Conclusions:Our results show that forest multifunctionality is limited to subsets of ecosystem services.The importance of tree species composition highlights that a lack of multifunctionality at the stand level can be compensated by managing forests at the landscape level,when stands of complementary forest types are combined.These results imply that multi-purpose forestry should be based on a variety of forest types requiring coordinated planning across larger spatial scales.
文摘We identified 67 and 21 NTFP-yielding plant and animal species, respectively, in a reserve forest in Cachar district of Assam. We recorded globally threatened species listed by IUCN as Critically Endangered (plant species Dipterocarpus turbinatus), Vulnerable (plant species Aquillaria malaccensis), Endangered (animal species Hoolock hoolock, Indotestudo elongata and Manis pentadactyla), and Vulnerable (animal species Nilssonia hurum and Rusa unicolor). The whole plant or animal and/or their various parts were used as food or medicine, in house construction, magico-religious activities and others. While some NTFPs were harvested throughout the year, others were harvested seasonally. A comprehensive NTFP policy, along with scientific measures for regen- eration, restoration and augmentation of NTFP-yielding plants and animals, would help in addressing the conflicting demands of conservation and livelihood in the forests of this area.
文摘Uncontrolled harvesting of non-timber forest products (NTFPs) poses a serious risk of extermination to several of these species in Nigeria. Yet, there is a paucity of information on the distribution, population status and sustainable management of NTFPs in most of the tropical lowland rainforests. We, therefore, assessed the population, distribution and threats to sustainable management of NTFPs within the tropical lowland rainforests of Omo and Shasha Forest Reserves, south western Nigeria. Data were obtained through inventory surveys on five top priority species including: bush mango (Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill), African walnut (Tetracarpidium conophorum (Mull. Arg.) Hutch. & Dalziel syn. Plukenetia conophora), chew-stick (Massularia acuminata (G. Don) Bullock), fever bark (Annickia chlorantha Setten & P.J.Maas syn. Enantia chloranta) and bush pepper (Piper guineense Schumach. & Thonn.). Purposive and stratified random sampling techniques were used for the inventory. Each forest reserve was stratified into three, viz: less disturbed natural forest (for areas that have been rested for at least ten years), recently disturbed natural forest (for areas that have suffered one form of human perturbation or the other in the last five years), and plantation forest (for areas carrying forest plantation). Data were collected from eighteen 10 m × 500 m belt transects located in the above strata. The species were generally fewer in both plantation and recently disturbed natural forest than the less disturbed natural forest, suggesting that forest disturbances (habitat modification) for other uses may have an effect on the occurrence and densities of the NTFPs. Exceptions to this trend were found for P. guineense and T. conophorum, which were fairly common in both plantation and recently disturbed natural forest. Among three tree NTFP species (i.e. I. gabonensis, M. acuminata and A. chlorantha), only I. gabonensis showed a significant difference in overall DBH size classes for both reserves (t=?2.404; df =21; p=0.026). Three tree NTFP species in both reserves further showed differences from the regular patterns of distribution of trees. The fairly regular reverse J-shaped size class distribution observed for M. acuminata in the study sites, however, suggests a recuperating population. In general, destructive harvesting of species, logging operations, low population size, narrow distribution ranges and habitat degradation are the major threats to the population of NTFPs in the study area. The implications of our findings for sustainable management of NTFPs in the study area are discussed and recommendations are made for a feasible approach towards enhancing the status of the species.
基金funded by the German Federal Ministry of Fducation and Research under research grant 033L029H and is part of the interdisciplinary research project"Sustainable land-use management in the North German lowlands"
文摘Background: Forest management decisions are based on expectations of future developments. For sound decisions it is essential to accurately predict the expected values in future developments and to account for their inherent uncertainty,for example the impact of climate change on forests. Changing climatic conditions affect forest productivity and alter the risk profile of forests and forest enterprises. Intensifying drought stress is seen as one major risk factor threatening forest management in the north German lowlands. Drought stress reduces tree growth and vitality and might even trigger mortality. But so far, it is not possible to quantify effects of a persistent dryer climate on forest productivity at a level suitable for forest management.Methods: We apply a well-established single-tree forest growth simulator to quantify the effect of persistent dryer climates on future forest productivity. We analyse the growth of Scots pine(Pinus sylvestris L.), European beech(Fagus sylvatico L.) and oak(Quercus robur L. and Quercus petraea(Matt.) Liebl.) in two forest regions in the north German lowlands for a time interval of 60 years until 2070. The growth response under three different climate projections is compared to a baseline scenario.Results: The results show clear differences in volume increment to persistent dryer climates between tree species. The findings exhibit regional differences and temporal trends. While mean annual increment at biological rotation age of Scots pine and oak predominantly benefits from the projected climate conditions until 2070, beech might suffer losses of up to 3 m^3·ha^(-1)yr^(-1) depending on climate scenario and region. However, in the projection period2051 to 2070 the uncertainty ranges comprise positive as well as negative climatic effects for all species.Conclusions: The projected changes in forest growth serve as quantitative contributions to provide decision support in the evaluation of, for example, species future site suitability and timber supply assessments. The analysis of productivity changes under persistent dryer climate complements the drought vulnerability assessment which is applied in practical forestry in northwestern Germany today. The projected species' productivity has strong implications for forest management and the inherent uncertainty needs to be accounted for.
基金financial support of the German Research Foundation(DFG,Research Unit 816)for initializing the forest plots and the plot census as well as a first model parameterisationthe Helmholtz Alliance:Remote Sensing and Earth System Dynamics for financing the work on the further parameterisation of the model and analysis of the data
文摘Background: Tropical forests play an important role in the global carbon(C) cycle.However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood.Montane forests are highly endangered due to logging, land-use and climate change.Our objective was to analyse how the carbon balance changes during forest succession.Methods: In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models.We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions(ravines and lower slopes vs upper slopes and ridges).Results: The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange(NEE) of 9.3 Mg C?(ha?yr)-1during its early successional stage(0–100 years).In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C?(ha?yr)–1.The simulated variability of the NEE was within the range of the field data.We discovered several forest attributes(e.g., basal area or the relative amount of pioneer trees) that can serve as predictors for NEE for young forest stands(0–100 years) but not for those in the late successional stage(500–1,000 years).In case of young forest stands these correlations are high, especially between stand basal area and NEE.Conclusion: In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity.To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests.With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes.These relationships promote a better understanding of the role of tropical montane forests in the context of global carbon cycle, which in future will become more relevant to a society under global change.
文摘Non-timber forest products(NTFPs)play a significant role in the improvement of the forest-dependent people’s livelihoodsaround the world,strengthening protection for the sustainable use of forests.The purpose of this research was to evaluate the influence of occupational category-wise(fuelwood collectors,farmers,small-scale businessmen,day labourers,and tea estate labourers)dependencyon NTFPsand the role of NTFPs on household income around the Khadimnagar National Park(KNP)in northeastern Bangladesh.In 2014,178purposively selected respondents from four villages(out of 22 villagesaround the KNP)were interviewed face-to-face using a semi-structured questionnaire.The study observed that these forest-dependent communities utilized resources of the KNP mainly for domestic energy supply,household income,and house construction.Results showed that income from NTFPs made a significant contribution to family income.Income data analysis indicated that small-scale businessmen earned relatively more income from NTFPs,followed by tea estate labourersand day labourers.The study revealed significant negative relationships of the distance of households from the forest with the amount of NTFPs collected(P<0.01)and monthly income from NTFPs(P<0.01).Positive significant relationships were found between the amount of NTFPs collected and the time spent in NTFP collection(P<0.001),as well as betweenmonthly income from NTFPs and family size(P<0.001).The fuelwood collectors and farmers collected significantly greater amounts of NTFPs per trip(P<0.001)than other occupational categories.The households that were moderately to highly dependent on NTFPs collected significantly higher amounts of NTFPs pertrip(P<0.01)than the households that were moderately dependent and less dependent on NTFPs.Community dependence on KNP’sresources,community’sappreciation of the KNP’s ecosystem services for villagers’livelihoods,and community’s high levels of concern for forest conservation provided a foundation for the sustainable management of the KNP.The study findings will be useful for designing an effective forest management plan and policy for NTFP management and forest conservation with the active involvement of the forest-dependent people in northeastern Bangladesh.
基金financially supported by the Faculty of Biology and Environmental Protection,University of Lodz and the Institute of Dendrology,Polish Academy of Sciences,Kórnik,Poland。
文摘Background:Multi-purpose use of forests in a sustainable way forces a recognition of how introduction of alien woody species in forests with different land use histories affect native plants other than trees.Lingonberry Vaccinium vitis-idaea is an important understory component of temperate and boreal forests and provider of valuable non-wood forest products.Here we studied effects of land use changes and introduction of Northern red oak Quercus rubra on lingonberry in mesic Scots pine forests(in central Poland).We measured lingonberry cover,height of shoots,biomass of stems and leaves,and fruit productivity.Shoots were collected within 200 research plots located in recent and ancient Scots pine forests,with and without Q.rubra.Results:We found that V.vitis-idaea reached lower cover,aboveground biomass and fruit production in recent than ancient forests and in forests with than without Q.rubra.The fruit production in recent pine forest was only 2%of that reported in ancient pine forest,and V.vitis-idaea did not reproduce generatively in forests with Q.rubra.Biomass and carbon sequestration of V.vitis-idaea in forests with alien(invasive)trees decreased by 75%compared to ancient pine forest.Effects were also clear at the individual shoot level–in less suitable conditions we found taller heights and higher biomass allocation into stems than foliage.Biomass allocation in fruiting and non-fruiting shoots in pine forests was also different–less of the dry biomass of fruiting shoots was allocated to leaves than to stems.Conclusions:In the age of high interest in ecosystem services and discussions about usage of alien tree species as alternatives in forest management,our results clearly indicate disruption of ecosystem services provided by V.vitisidaea in the presence of Q.rubra.Lingonberry benefited from the continuity of forest land use,however,regardless of land-use legacy,alien tree introduction led to decline in abundance of species crucial for ecosystem functioning.Therefore,to maintain valuable native species and for conservation of ecosystem services delivery,we suggest limiting the introduction of Q.rubra in areas with abundant V.vitis-idaea,especially in forests with continuous forest land-use history.
基金support of a grant from the Swedish InstituteFinancial support has also been given from The Swedish Foundation for International Cooperation in Research and Higher Education
文摘The forest sectors in many regions and countries are facing a need to change their structure, due to the development of new markets, emergence of new competitors, and shifts in production and consumption patterns for forest products. This article focuses on recent changes in the trade in these products, on imports and exports of four countries (USA, Sweden, Ukraine and, to a lesser extent, China) during the period from 1995 to 2011. For this purpose we use explanatory data analysis, time series analysis, benchmarking, meta-synthesis and content analysis of scientific and business publications concerning national and global trends in forest product industries. Data sources are various organizations’ databases of international trade in forest-based products in both monetary and physical terms (cubic meters and tons). The results show that the US and Swedish forest sectors are adversely affected by downturns in both their domestic and foreign markets during the study period, while the Ukrainian sector maintains exports of low value-added products at roughly constant levels (except that particle-board exports increase). China maintains production quantities of low value-added forest-based products, but also substantially increases exports of high-value added products. The results may facilitate efforts to forecast future trends and provide useful information and methodological approaches for future studies of interest to industry representatives, policy-makers and researchers.
基金supported by the National Institute of Forest Science(Project No.FM0800-2019-05)。
文摘Due to considerable deforestation in North Korea,there is a need to plan forest restoration programs based on scientific forest management.In this study,a methodology was developed for estimating the site index values of six major tree species and the forest productivity potential.The site index values of these tree species were derived in South Korea using the Chapman-Richards equation.These values were used with data from the 6th National Forest Inventory,which included 20 types of edaphic,topographic,and climatic factors,and random forest analysis—a widely used machine learning technique for spatial prediction—to develop a new model for estimating the site index values of these species across South Korea.The prediction accuracy of this model was evaluated using the root mean square error.The results show that the prediction accuracy was high,with a root mean square error of~1m.Moreover,the importance of the variables related to climate and geography was generally high.The proposed site index estimation model for six tree species was applied across North Korea,and its effectiveness tested by comparing the estimated values with those reported in literature from North Korea.The differences between the model outputs and recorded data in the northern alpine regions were presumably due to the lack of data for high-altitude regions in South Korea.This model is based on the determination of the suitability of tree species in restoration efforts.Therefore,it can contribute to the evaluation of forest productivity in North Korea and may help plan efficient forest restoration programs.