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1.
异速模型评估森林植被生物量有机碳储量   总被引:3,自引:0,他引:3  
在孟加拉的吉大港南部森林地区,利用异速模型评估森林植被的有机碳的储量.异速模型被分别应用测试树木(被划分两个胸高直径级)、灌木和草本植物.采用基部面积估算胸高直径级为从> 5 cm 到 ≤ 15 cm 和> 15 cm树木的生物量有机碳储量模型最好,分别有很高的决定系数(胸高直径级> 5 cm 到 ≤ 15 cm 的r2 为0.73697,胸高直径级> 15 cm 的r2为0.87703),且回归系数(P = 0.000)显著.其它模型(包括采用树高,胸高直径,树高和胸高直径,以及综合树高、胸高直径和木材密度)的线性和对数关系都表现出很低的决定系数.分别建立了20种优势树种的异速模型,采用树木基部面积的模型都得到很高的决定系数值.单独采用灌木和草本植物总生物量的异速模型有较高的决定系数(灌木的r2 为0.87948,草本植物的r2 为0.87325),且回归(系数)性显著(P = 0.000).生物量有机碳的评估是复杂的和耗时的研究,本研究所建立的异速模型可以应用于孟加拉和其它热带(地区)国家的森林植被的有机碳储量的测算.  相似文献   

2.
Traditional approaches to conservation of Garcinia kola and Gnetum africanum were assessed by a survey of 15 villages (three per province) in the humid forest zone of southern Cameroon. Four major land use systems [evergreen forest, degraded forest, bush fallow (10 years and over) and food crop fields] were identified as major niches for the species. The distribution of the plant stands varied from province to province. Gnetum africanum is intensively harvested (up to four times per week throughout the year) and reported to generate substantial income (averaging US$2,630 per household per annum). Indigenous practices used by farmers to protect the species include selective clearing during land preparation for cropping, sustainable bark harvesting of stands in wild population, transplantation of wildings, artificial propagation and recognition of individual property ownership on certain wild stands of G. kola. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

3.
Malian Forest Service activities and policies have evolved since the beginning of colonialism under the assumption that forests and their products are the property of the government. Today the importance of involving local people in forest management is recognized. The purpose of this research was to determine the range of non-timber forest products local people use either for direct consumption or for income generation and to identify the trees/shrubs that yield these products in natural forests, fallow lands and crop fields. A gender analysis of the data was also conducted. The data were collected from face-to-face structured interviews using open-ended questions of 92 randomly sampled households in six Malian villages. One-half of the interviews were conducted with women and the other half were with men. The study identified 55 different non-timber forest products produced by 108 plant species. Almost all (99%) of the products identified are used for personal consumption, whereas 68% of the products are also used to generate income. Products such as firewood, leaves for sauces, shea nuts for oil/butter, seeds for condiments and nuts/seeds for soap are the most frequently mentioned products collected by women. Different categories of products like utensils/house materials, animal feed and construction materials (thatch, poles, mats) are the products most frequently collected by men. Ninety percent of the products collected are found in the natural forests; 63% are collected from trees on fallow lands and 51% from scattered trees in crop fields. Forest Service support of villagers using non-timber forest products would create an economic relationship between the forest and the local people. This is essential for the protection of the forest because people will safeguard their interests.  相似文献   

4.
Means have to be found for rural people to supply both their own needs and those of the urban dwellers, without further loss of natural resources. Some examples from around the humid tropics suggest that complex agroforests may be able to achieve this goal. In West Africa, the concepts of the cocoa (Theobroma cacao) farm and compound garden, coupled with the domestication of indigenous trees for the production of improved non-timber forest products, need to be developed. There are numerous candidate species both for domestication and for inclusion in multi-strata systems. Research is needed on the development of various forms of multi-strata agroforests, coupled with short-term tree fallows especially to rehabilitate degraded land. More ecologically-oriented studies are required to build sustainable and productive multi-strata agro-ecosystems, while domestication requires greater understanding of the needs of the food and pharmaceutical industries and the development of marketing infrastructures. Incentives are required to promote entreprenurism in rural communities, especially near urban centres. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

5.
我国非木质林产品资源现状及其分类体系的研究   总被引:2,自引:0,他引:2  
随着我国经济社会的发展和人民生活水平的日臻提高,开发和利用非木质林产品具有及其重要的现实意义。通过实际调研数据,以我国非木质林产品资源分布及开发利用现状为基础,参考大量的国内外相关文献,借鉴国内外非木质林产品分类经验,把我国非木质林产品资源以冯彩兰等分类方法为蓝本,分为菌类、动物及动物制品类、植物及植物产品类及生态景观和生态服务类等4个一级类,并在此基础上考虑其实用性,对类型较为复杂和运用极其广泛的植物及植物产品类划分为干果、水果、山野菜、茶和咖啡、林化产品、木本油料、苗木花卉、竹及竹制品、药用植物(含香料)、珍稀濒危植物、非木质的纤维材料和竹藤、软木及其他纤维材料等12个二级类。同时研究我国主要非木质林产品的资源分布状况及其开发利用现状,运用ArcGIS9.3生成主要产品产量产地分布图,并探讨我国非木质林产品目前存在的主要问题和解决对策,为我国即将开展的中国森林认证非木质林产品认证标准的制定工作提供前提条件,也为进一步开展非木质林产品的认证工作提供初步的研究基础。  相似文献   

6.
New initiatives in agroforestry are seeking to integrate into tropical farming systems indigenous trees whose products have traditionally been gathered from natural forests. This is being done in order to provide marketable products from farms that will generate cash for resource-poor rural and peri-urban households. This poverty-alleviating agroforestry strategy is at the same time linked to one in which perennial, biologically diverse and complex mature-stage agroecosystems are developed as sustainable alternatives to slash-and-burn agriculture. One important component of this approach is the domestication of the local tree species that have commercial potential in local, regional or even international markets. Because of the number of potential candidate species for domestication, one crucial first step is the identification of priority species and the formulation of a domestication strategy that is appropriate to the use, marketability and genetic potential of each species. For most of these hitherto wild species little or no formal research has been carried out to assess their food value, potential for genetic improvement or reproductive biology. To date their marketability can only be assessed by their position in the local rural and urban marketplaces, since few have attracted international commercial interest. To meet the objective of poverty alleviation, however, it is crucial that market expansion and creation are possible, hence for example it is important to determine which marketable traits are amenable to genetic improvement. While some traits that are relatively easy to identify do benefit the farmer, there are undoubtedly others that are important to the food, pharmaceutical or other industries that require more sophisticated evaluation. This paper presents the current thinking and strategies of ICRAF in this new area of work and draws on examples from our program. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

7.
This review describes the non-timber forest products (NTFPs) used for different aspects of beauty-care in Bangladesh on the basis of extensive literature survey. The diverse plant species, including used parts and using patterns for hair care, facial treatments and body care, were summarized in 13 tables. This paper accumulate the scattered knowledge regarding the use of plants in beauty-care in Bangladesh, to draw the extent of use of NTFPs in health care and to record the knowledge for assessing the possibilities of further implementation in herbal cosmetics industries. The structured knowledge can be used in policy making process for sustainable management of these valuable NTFPs leading to the conservation of the country's biological diversity. It is suggested that intensive field level research is necessary for securing sustainability of NTFPs.  相似文献   

8.
Summary

As people become more interested in personal health and family activities, demand for wild forest products has increased. This increased demand coupled with an increased concern for sustainable m anagement practices has focused attention on the variety of issues and products involved in the non-timber forest products industry. Forest management organizations have gradually increased funding for research and management of non-timber forest products over the past two decades. The broad categories of U.S. non-timber forest products include floral greens, Christmas greens, ornamentals and craft materials, wild edibles, medicinals, ceremonials/culturals, and native transplants. The increase in resource pressure has had many policy reactions, including restricted access, harvesting fees, and harvest limits. Opportunities for public input to policy decisions on federal, state and private land are often unclear or nonexistent. Researchers, managers, and policy makers are working to understand the multitude of issues surrounding non-timber forest products, including biology, management, public policy and equity issues.  相似文献   

9.
《Southern Forests》2013,75(3):183-193
Tree bark is commonly used for traditional medicine in southern Africa and further afield. Increasing demand and commercialisation have resulted in the overexploitation of many species, posing a major challenge to forest managers to develop mechanisms for sustainable resource use. An experimental bark harvesting research project was initiated in the southern Cape, South Africa, to inform best practices for bark harvesting based on tree response to bark stripping. The species selected for the study, Ocotea bullata, Curtisia dentata and Rapanea melanophloeos, are much sought after and well represented in southern Cape forests. The treatment entailed removing vertical strips of bark, 1 m in length and of different strip widths, covering the full range of tree size classes ≥10 cm DBH. The treatments were applied during two seasons, winter and summer. Evaluations were done every six months to assess tree response to bark stripping in terms of bark regrowth through phellogen edge and sheet development, and susceptibility to insect and fungal damage. The results show a differential response of tree species in terms of phellogen edge and sheet growth, as well as susceptibility to fungal and insect attack. Rapanea melanophloeos was the most vulnerable to fungal and insect damage and displayed little bark regrowth following wounding. Curtisia dentata showed best bark regrowth through sheet development. Only O. bullata, though, showed adequate bark regrowth (through edge development) to allow for sustainable strip harvesting. Bark regrowth is influenced by season of stripping, although this is difficult to define considering the wide range of environmental and other factors affecting tree response to bark removal. Smaller trees are more vulnerable to bark stripping, especially with a wide strip, with poorer bark regrowth than bigger trees.  相似文献   

10.
From 1988 to 1990, leaves fromAzadirachta indica andAlbizia lebbeck were used as mulch on sorghum (Sorghum bicolor) in semi-arid Burkina Faso. Five different application modes, each representing a different combination of application timing and mulch composition, were evaluated. In one of the modes leaves were combined with sorghum straw. Leaf quantities applied corresponded to dosages of 25, 50 and 75 kg N ha–1 in all five modes.Dosage had a significant influence on yield all three years. The mulching effect increased progressively over the years and was more pronounced the higher the dosage. Mean grain yields obtained with the highest dosage, relative to an unmulched control, were 203%, 364% and 422%, for the three years, respectively. Application timing had a significant influence on yields in 1988 and 1989, but the response was not consistent. Differences in response were attributed to variation in the rainfall distribution. Mulch composition did not have a significant influence on yield during any of the three years. Of the five modes evaluated, the ones producing the highest yields over the three-year period of study were azadirachta leaves applied (i) at sowing and (ii) 4–6 weeks after sowing. Yields decreased on both the treated and untreated plots between 1988 and 1989. On the treated plots, yield generally increased again in 1990. This increase was attributed to a residual effect of the mulch. The residual effect probably only explained part of the large difference in yield between treated and untreated plots. It is therefore suggested that most of the nutrients released from the mulch were used by the plants during the same season, which increased production. Furthermore, the mulch layer could have reduced evaporation and thus increased the retention of soil water.
Résumé De 1988 à 1990, des feuilles d'Azadirachta indica et d'Albizia lebbeck ont été utilisées comme mulch sur une culture de sorgho blanc (Sorghum bicolor) au Burkina Faso, en climat semi-aride. Cinq modes d'application ont été évalués, chacun répresentant une compinaison différente en temps d'application et composition de mulch. Dans un des modes, les feuilles ont été combinées avec des tiges de sorgho. Les quantités de feuilles utilisées ont été équivalentes aux dosages de 25, 50 et 75 kg N ha–1 et ceci dans tous les cinq modes.Le dosage a eu une influence significative sur la récolte pendant toutes les trois années. Leffet a augmenté progressivement d'année en année et a été plus prononcé pour le dosage le plus élevé. Les moyennes de rendement de graines par rapport au témoin sans mulch, obtenues avec la dose de 75 kg N ha–1, ont été 203% pour la première année, 364% pour la seconde et 422% pour la troisième. Le temps d'application a eu une influence significative en 1988 et 1989, mais les résultats ont varié entre les années. Les différents résultats ont été attribués à la variation en distribution de la pluie. La composition de mulch n'a pas eu d'influence significative sur aucune des trois années. Parmi les cinq modes évalués, les deux qui ont assurés les récoltes les plus élevées sur la période entière de trois ans, étaient les feuilles d'azadirachta appliquées (i) au semis et (ii) 4–6 semaines après le semis. Les rendements ont baissés entre 1988 et 1989, tant sur les parcelles traitées que sur les parcelles non-traitées. Sur les parcelles traitées, les rendements ont de nouveau augmentés en 1990. Cette augmentation a été attribuée a un effet résiduel du mulch. Cet effet résiduel probablement n'explique qu'une partie de la grande différence en rendement entre les parcelles traitées et non-traitées. Il paraît donc que la plupart des élements nutritifs libérés par le mulch ont été utilisés par les plantes au cours de la même saison, et qu'ils ont ainsi augmenté la production. De plus, la couche de mulch a probablement réduit l'évaporation, résultant en une augmentation de la rétention d'eau dans le sol.
  相似文献   

11.
Riparian forests are classified as endangered ecosystems in general,particularly in sahelian countries like Burkina Faso because of human-induced alterations and civil engineering works.The modification of this important habitat is continuing,with little attention being paid to the ecological or human consequences of these changes.The objective of this study is to describe the variation of woody species diversity and dynamic in riparian forests on different type of watercourse banks along phytogeographical gradient in Burkina Faso.All woody species were systematically measured in 90 sample plots with sides of 50 m × 20 m.Density,dominance,frequency and species and family importance values were computed to characterize the species composition.Different diver-sity indices were calculated to examine the heterogeneity of riparian forests.A total of 196 species representing 139 genera and 51 families were recorded in the overall riparian forests.The species richness of individuals with dbh ≥ 5cm increased significantly from the North to the South along the phytogeographical gradient and varied significantly between the different types of riparian forests.Similarity in tree species composition between riparian forests was low,which indicates high beta diversity and reflects differences in habitat conditions and topography.The structural characteristics varied significantly along the phyto-geographical gradient and between the different types of riparian forests.The diameter class distribution of trees in all riparian forests showed a reverse "J" shaped curve except riparian forest of stream indicating vegetation dominated by juvenile individuals.Considering the ecological importance of riparian forest,there is a need to delineate and classify them along watercourses throughout the country.  相似文献   

12.
The roots of American ginseng have been harvested from the hardwood forests of the eastern United States, alongside timber, since the mid-1700s. Very little is known about this non-timber commodity relative to timber, although significant volumes of ginseng root have been harvested from the same forests along with timber. The harvest of ginseng correlated positively and significantly with hardwood forest area, hardwood growing stock volume, and timber removals. Also, it correlated with hardwood growing stock on public forestlands in the region. The annual wholesale value of American ginseng was estimated at approximately $26.9 million compared to annual stumpage value of harvested hardwood timber of just over $1.27 billion. The volume of ginseng root harvested from natural forests represents substantial extraction of biomass, and the associated value represents substantial income for people living in an economically marginalized region. Co-management of eastern hardwood forests for timber and non-timber forest products could improve local economies and better conserve the biodiversity of these forests.  相似文献   

13.
Abstract

This study pertains to the density-diameter (d-d) curves, diameter class distribution of dominant species and protective value of temperate forests between 2000 and 3300 m amsl in Pinder catchment of the Central Himalaya. The identified forests were mixed deciduous-evergreen, alder (Alnus nepalensis), mixed evergreen-deciduous, maple (Acer cappadocium), burans (Rhododendron arboreum), silver-fir (Abies pindrow), kharsu oak (Quercus semecarpifolia)and birch (Betula utilis).The d-d curve was inverse curvilinear for all species in the entire study area. The curve assumed an inverse curvilinear slope for the stands of smaller mean diameter, linear for the stands of intermediate mean diameter and bell shaped for the stands of larger mean diameter. The curves for burans, kharsu oak and alder, mixed and silver-fir, and birch forests were slightly convex, bell shaped, curvilinear, straight line and linear, respectively. Two light demanding species, Q. semecarpifoliaand Aesculus indicahave been experiencing regeneration problem, whereas the other two light demanding species, A. nepaiensisand B. utilisexhibited moderate regeneration. Shade tolerant A. pindrow, A. cappado-ciumand R. arboreumexhibited satisfactory regeneration, but conversion of seedlings into trees was not satisfactory for A. pindrow.The relative protective value of 5 different forests was in the order: silver fir > kharsu oak > mixed deciduous-evergreen > mixed evergreen-deciduous > birch.  相似文献   

14.
15.
运用社会调查学、参与式农村调查评估(PRA)、林业快速评估(FRA)方法对澜沧江流域德钦县燕门乡4个村10个村民小组居民的非木材林产品的利用和保护情况作了调查,结论为社区群众利用非木材林产品种类有7大类上千种.依据各自生活条件和所处环境的不同,利用方式和特点各不相同,但存在原始性和过度性利用的特点.在非木材林产品的利用中虽有各级政府及职能部门的干预以及"村规民约"的管理模式,但仍存在许多问题难以实现有效的管理.针对存在的问题,提出了相应的对策和建议.  相似文献   

16.
Vascular epiphyte biomass is poorly studied in Congo Basin forest. The aim of this study was to develop a protocol to estimate epiphyte biomass. Epiphytes were collected on 77 phorophytes of diameter 57–169.5 cm, oven-dried for biomass. Allometric equations for epiphyte biomass were developed with diameter and phorophyte height as predictor variables using regression analysis. The mean epiphyte biomass was 24.48 kg/phorophyte with a standard deviation of ±49.99. Cylicodiscus gabunensis and Triplochiton scleroxylon hosted the greatest epiphyte biomass with a mean vascular epiphyte biomass of 71.65 and 62.3 kg/phorophyte, respectively. Kruskal–Wallis test (p = 0.005) showed that there was a significant difference between epiphyte biomass with respect to phorophyte species. The relationship found between epiphyte biomass and dendrometric variables of the phorophytes were intermediate (Adj.R2 < 0.630) meaning epiphyte biomass increased with increasing tree diameter. However, models with diameter input variables had greater prediction than input variables of total height. Based on the Akaike Information Criterion (AIC), the allometry lnY = ?21.37 + 5.21 x ln(D) ?0.35 x ln(H) with AIC (183) was the best equation for the prediction of epiphyte biomass. These findings shall contribute to REDD+ (Reducing Emissions from Deforestation and Forest Degradation) strategy for climate change mitigation in Congo Basin.  相似文献   

17.
分析了天保工程不同区域存在的基本矛盾和问题,从面临的众多问题中总结归纳出退化天然林恢复与重建、非木质林产品资源开发利用、天然林近自然采育更新和结构调整、工程区防灾减灾和森林健康状况保持、天然林资源动态时空分析与评价等5个重大而急需解决的技术问题;提出了推广应用现有技术成果、针对新问题设立课题研究和引进国际先进理论技术为工程服务的总体对策;并针对5大问题进行深入分析,提出了人工促进退化天然林恢复、森林近自然经营及健康状态监测等解决问题的关键理论和技术要点.  相似文献   

18.
分析了天保工程不同区域存在的基本矛盾和问题,从面临的众多问题中总结归纳出退化天然林恢复与重建、非木质林产品资源开发利用、天然林近自然采育更新和结构调整、工程区防灾减灾和森林健康状况保持、天然林资源动态时空分析与评价等5个重大而急需解决的技术问题;提出了推广应用现有技术成果、针对新问题设立课题研究和引进国际先进理论技术为工程服务的总体对策;并针对5大问题进行深入分析,提出了人工促进退化天然林恢复、森林近自然经营及健康状态监测等解决问题的关键理论和技术要点。  相似文献   

19.
《Southern Forests》2013,75(3):255-260
Natural forests are disappearing in many tropical countries, resulting in loss of biodiversity and erosion of forest-dependent livelihoods. The maintenance and restoration of forests as well as a search for alternative natural resources that can concurrently improve the environment and enhance incomes of local communities has become crucial. Bamboo is suggested as a resource, which could substitute trees for socio-economic and ecological purposes in developing countries in the (sub)tropics. However, the relative importance of bamboos and trees for socio-economic and ecological purposes in bamboo-growing communities is not yet studied. Here, we present a study conducted to compare the socio-economic and ecological benefits of bamboo and trees from the perspectives of three bamboo-growing communities in the Wassa East District of Ghana. The compared benefits were ranked on a five-point Likert scale and significance of differences was tested at the 95% confidence level. For socio-economic benefits, trees were ranked significantly higher than bamboo for domestic energy, medicinal use and commercial harvesting; however, furniture, building and construction were not significantly different. For ecological benefits, bamboo was ranked significantly higher than trees for erosion control and riverbank protection. Trees, on the other hand, were ranked significantly higher than bamboo for biodiversity conservation, carbon sequestration and oxygen generation. The results imply that transforming bamboo into suitable products to meet communities’ energy needs could alleviate pressure on trees in natural forests.  相似文献   

20.
Gmelina arborea Roxb. is a fast-growing, deciduous tree species native to Bangladesh. It has been widely planted since 1992 for commercial production of pulpwood in hilly areas of Bangladesh. The purpose of this study was to derive well-fitting allometric models for estimation of aboveground biomass, and carbon and nutrient (nitrogen, phosphorus and potassium) stocks in G. arborea to ensure sustainable production and management of this species. Eight linear models with 64 regression equations were tested for estimation of aboveground biomass, carbon and nutrient stocks in different parts (leaves, branches, bark and stem) of the plant. The best-fitting allometric models were selected in accordance with various relevant statistical criteria.  相似文献   

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