No generality in biodiversity-productivity relationships along elevation in temperate and subtropical forest landscapes

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.

Data cleaning method for the process of acid production with flue gas based on improved random forest

Acid production with flue gas is a complex nonlinear process with multiple variables and strong coupling.The operation data is an important basis for state monitoring,optimal control,and fault diagnosis.However,the operating environment of acid production with flue gas is complex and there is much equipment.The data obtained by the detection equipment is seriously polluted and prone to abnormal phenomena such as data loss and outliers.Therefore,to solve the problem of abnormal data in the process of acid production with flue gas,a data cleaning method based on improved random forest is proposed.Firstly,an outlier data recognition model based on isolation forest is designed to identify and eliminate the outliers in the dataset.Secondly,an improved random forest regression model is established.Genetic algorithm is used to optimize the hyperparameters of the random forest regression model.Then the optimal parameter combination is found in the search space and the trend of data is predicted.Finally,the improved random forest data cleaning method is used to compensate for the missing data after eliminating abnormal data and the data cleaning is realized.Results show that the proposed method can accurately eliminate and compensate for the abnormal data in the process of acid production with flue gas.The method improves the accuracy of compensation for missing data.With the data after cleaning,a more accurate model can be established,which is significant to the subsequent temperature control.The conversion rate of SO_(2) can be further improved,thereby improving the yield of sulfuric acid and economic benefits.

Population distribution and threats to sustainable management of selected non-timber forest products in tropical lowland rainforests of south western Nigeria

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.

Diversity of non-timber forest products in Cachar District, Assam, India

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.

Effects of harvest intensity on the marketable organ yield,growth and reproduction of non-timber forest products(NTFPs):implication for conservation and sustainable utilization of NTFPs

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.

Contribution of non-timber forest products to the livelihoods of the forest-dependent communities around the Khadimnagar National Park in northeastern Bangladesh

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.

Does ash dieback affect the reproductive ecology of Fraxinus excelsior L.?

Forest tree species reproduction is a key factor in maintaining the genetic diversity of future generations and the stability of forest ecosystems.The ongoing ash dieback disease could affect the reproductive ecology of Fraxinus excelsior L.and have a major impact on the quantity and quality of pollen and seeds.In this study,we investigated pollen production and viability of pollen and seeds of ash trees with different health status from 2018 to 2022.Inflorescences were collected from 105 trees(pollen production),pollen from 125 trees(pollen viability),and seeds from 53 trees(seed quality)in two seed orchards and in one floodplain forest in southern Germany.Not all parameters were examined at every site every year.The average pollen production per tree was estimated at 471.2±647.9 billion pollen grains.In addition,we found that a high number of inflorescences did not equate to high pollen production per inflorescence.Pollen production of healthy and diseased trees did not differ significantly,although only 47%of severely diseased male trees(vs.72%for healthy trees)produced flowers.With regards to pollen viability,the TTC test showed an average viability of 73%±17%.Overall,there was a slight tendency for diseased trees to have less viable pollen.However,a significant difference could only be calculated for trees in the floodplain forest.The percentage of germinable seeds in 2018 was 38%in the floodplain forest and 57%in one of the seed orchards.The percentage of viable seeds(TTC test)ranged from 17 to 22%in the orchards in 2020.Non-viable seeds were usually heavily infested by insects.In general,seed quality was not significantly different between healthy and diseased trees.Our results indicate that ash dieback affects flower formation and pollen viability but not pollen production or seed quality.Nevertheless,the fact that hardly any flowering was observed,especially for trees that were seriously affected,suggests a negative effect of ash dieback on reproductive performance.Thus,severely diseased trees will transfer their genes to a smaller extent to the next generation.

Market analysis for timber and forest products in China

This paper introduces the general condition of forestry resources of China and the demand and supply of timber and forest products. The market for timber and forest producls has borne dual pressure because of the population explosion and growth of the domestic economy. A major contemporary strategy for sustainable forestry includes the promotion of the Forest Products Industry (FPI), the substitution of other materials for timber,and the encouragement of imports of timber and forest products. The author analyzes the effect of these policies on the market for timber and forest products. In addition, the difficulties encountered by most mid-to large -scale state- owned forest enterprises during the transition from a centrally-planned economy to a market economy are examined. Finally, the author points out the countermeasures and means for reform of these old forest enterprises with a view toward future prosperity of the market for timber and forest products.

Assessing the role of forest resources in improving rural livelihoods in West Bengal of India

Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consumed locally,supporting numerous rural communities relying on forests for essential resources,such as firewood,timber,and NTFPs.This study focuses on two forest-dominant districts in West Bengal of India,namely,Jhargram District and Paschim Medinipur District.Furthermore,this study aims to enhance the understanding of forest-dependent communities by comparing the standard of living among different village classes.Thus,we categorized villages into three classes based on the distance from home to forests,including inner villages,fringe villages,and outer villages.Through focus group discussions and household surveys,we explored the sources of local economy,income sources of household,and reasons for economic diversification in different village classes.The study findings confirm that substantial variations existed in the income sources and the standard of living in these villages.Forest income varied dramatically among the three village classes,with inner villages having greater forest income than fringe villages and outer villages.Meanwhile,households in outer villages depended on forests and engaged in diverse economic activities for their livelihoods.Compared with inner and fringe villages,households in outer villages derived a significant portion of their income from livestock.This discrepancy can be attributed to challenges,such as inadequate transportation,communication,and underdeveloped market chains in inner villages.Moreover,these findings emphasize the need to develop sustainable forest management practices,create alternative income-generation opportunities,and improve infrastructure and market access in inner villages,as well as promote economic diversification in outer villages.Through targeted policy measures,these forest-rich regions can achieve improved livelihoods,enhanced standard of living,and increased resilience for their communities.

Investigation and Evaluation on Heavy Metal Content and Pesticide Residues of Three Edible Forest Products in Central Sichuan Province

Taking three mains edibles products(walnut, prickly ash and bamboo shoots) and origin soil in central area of Sichuan Province as the study objects, this research aimed at revealing the level of heavy metals and pesticide residue and comprehensive evaluation the soil heavy metal pollution in the region. The results showed that: ① Soil organic matter, total nitrogen, total phosphorus and heavy metal contents of mercury, arsenic in the south area were significant higher than that in the north area, while the heavy metal contents of lead and copper were significantly higher in the north area; ② The pollution index of six heavy metals of cadmium, mercury, arsenic, lead, chromium and copper in the producing area was less than 1.0. However, the integrated pollution index was at a warning level, and there was a potential risk of cadmium contamination; ③ The walnut samples exceeded the lead limit value over 75% in the north area and over 35% in the south area, and the same as 30% of bamboo shoot samples; ④ There was a significant negative correlation of mercury content between walnut samples and production soil, and a significant positive correlation of arsenic content between bamboo shoots and production soil. In addition, there is no significant correlation of heavy metal contents between prickly samples and production soil; ⑤ Fenthion residues were detected in walnuts, malathion samples were detected in prickly ash, and chlorothalonil, dimethoate and chlorpyrifos residues in bamboo shoots samples. None of theses pesticide residues exceeded the standard limit value. In general, the soil is in well sanitary condition and the edible forest products are not exposed to the contamination of pesticide residues in the study area. The quality and safety of the prickly ash is good while the walnut and bamboo shoots have certain risks in terms of high lead level.

Factors Impacting Benefits of Participatory Forest Management in Upper Imenti Forest, Meru County, Kenya

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.

Impacts of the Benefit Sharing Mechanism(BSM)Policy Implementation on Forest Protection and Sustainable Use of Non-timber Products at Bach Ma National Park

This study aimed to evaluate the impacts of the benefit sharing mechanism(BSM)pilot policy on sustainable use of non-timber forest products(NTFPs)and natural resources conservation in co-management forest of Bach Ma National Park.Evaluation methods were route and permanent plot survey,household interview,in-depth interview,village meeting,group discussion and workshop at commune level.Results showed that:(1)the BSM policy had brought favorable conditions for local people in sustainable use and development of the NTFPs,as well as minimised the threats to biodiversity in co-managed forest;(2)the harvest amounts of seven selected NTFPs after two years of the BSM policy implementation were higher than growth rate of every NTFP and the permitted harvest amounts of the benefit sharing plans(BSP);(3)although there was a risk of over-exploitation of the NTFPs,the annual yields in 2013 and 2014 were much lower,but more sustainable than that before the BSM implementation;(4)the forest protection status in the co-management areas was also better than before.Additionally,this study has also defined and recommended that in order to continue the BSM,it is necessary to ensure the sustainable exploitation of NTFPs,as well as implement more enforcement activities inside the co-management forest area.

Evaluating the Potential Contribution of Non-timber Forest Products (NTFPs) to Smallholder Farmers in Semi-arid and Arid Regions: A case of Chivi, Zimbabwe

Food insecurity in most dry regions in Zimbabwe has taught many people a lesson of using non timber forest products(NTFPs)to reduce food insecurity and improve livelihoods as well as poverty alleviation.The aim of the study was to evaluate the potential contribution of non-timber forest products to smallholder farmers in arid and semi-arid regions.The research was carried out as a survey and data was collected using interviews,questionnaires and focus group discussion.Data was analysed for descriptive statistics using IBM SPSS version 25.Results indicated that 64%were females and 36%were males with the majority of participants being married(57.6%)with only 8.8%being widowed.Results show that all respondents(100%)indicated that they obtain fruits from the forests as a major source of food during winter and rain season.Vegetables(84.2%),thatching grass(80.8%)and edible worms(62.5%)were also major non-timber forest products obtained from the forests by participants.All participants(100%)indicated that income generation,firewood and source of heat for brick moulding were major benefits they obtain from forest with vegetables(74.2%),brooms(91.7%)and improved nutrition(85.0%)being regarded as other important benefits enjoyed by local people from forests.Afforestation and reforestation were regarded as major sustainable forest management practices by all(100%)participants with agroforestry being indicated by only 12.5%since people had no knowledge about it.NTFPs has capacity of improving food security,human livelihoods and alleviate poverty.People are encouraged to harvest NTFPs sustainably to allow future use.Use of agroforestry can be a best way for managing forests sustainably,improve food security,crop yield,poverty alleviation and climate change mitigation.

Trends in Markets for Forest-Based Products and Consequences for Selected Countries

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.

Resolute Forest Products公司位于美国田纳西州Calhoun工厂的新卫生用纸生产线投产

Resolute Forest Products公司近日宣布，成功启动其位于美国田纳西州Calhoun工厂的新卫生纸机，并已正式生产出第一个生活用纸母卷。

Eco-certification of non-timber forest products in China:addressing income generation and biodiversity conservation needs

Non-timber forest products (NTFPs) can play a key role in sustainable rural development due to their ability to support rural livelihoods while contributing to environmental objectives, including biodiversity conservation. However, systematic understanding of their role and potential in conservation and development remains weak. Studies have pointed to important knowledge gaps that may lead to serious exploitation and unsustainable use of the natural resource "NTFP" in China, such as (1) lack of basic knowledge on germplasm and non-existing or incom-plete inventory, (2) no in-depth and long-term monitoring and institutional arrangements to ascertain sustainable extraction levels, (3) insufficient market transparency for communities, (4) incomplete knowledge of NTFP domesti-cation and its effects on product quality and price and the conservation of wild sources, and (5) no existing research on the full length of the commodity chain for major non-timber forest products and the various actors in the chain. This paper presents initiatives toward balancing poverty reduction and biodiversity conservation goals in China's remote mountain regions through the sustainable management of NTFPs. The potential and challenges of organic, ecological and Fairtrade certification schemes in the context of smallholder farmers are discussed in more detail.

Mushroom Production as an Alternative for Rural Development in a Forested Mountainous Area

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.

Variation of net primary productivity and its drivers in China’s forests during 2000-2018

Background:Net primary productivity(NPP)in forests plays an important role in the global carbon cycle.However,it is not well known about the increase rate of China’s forest NPP,and there are different opinions about the key factors controlling the variability of forest NPP.Methods:This paper established a statistics-based multiple regression model to estimate forest NPP,using the observed NPP,meteorological and remote sensing data in five major forest ecosystems.The fluctuation values of NPP and environment variables were extracted to identify the key variables influencing the variation of forest NPP by correlation analysis.Results:The long-term trends and annual fluctuations of forest NPP between 2000 and 2018 were examined.The results showed a significant increase in forest NPP for all five forest ecosystems,with an average rise of 5.2 gC·m-2·year-1 over China.Over 90%of the forest area had an increasing NPP range of 0-161 gC·m-2·year-1.Forest NPP had an interannual fluctuation of 50-269 gC.m-2·year-1 for the five major forest ecosystems.The evergreen broadleaf forest had the largest fluctuation.The variability in forest NPP was caused mainly by variations in precipitation,then by temperature fluctuations.Conclusions:All five forest ecosystems in China exhibited a significant increasing NPP along with annual fluctuations evidently during 2000-2018.The variations in China’s forest NPP were controlled mainly by changes in precipitation.