一种确定林业发展项目的有效工具(英文)

在云南省绿春县的有些村庄,由砍柴造成的森林破坏是造成环境退化的主要原因。在黑河流域的上游,不断加剧的水土流失和河床抬升对下游上百万的人们构成威胁。尽管人们对森林破坏和土地的可持续利用、社区可持续发展之间的关系不是不了解,但当生存压力存在的时候就会忽略由此造成的对未来的影响。对于村民来说,他们已经意识到了他们的生存状况,并讨论解决的有效途径,而不是单纯等待外界的援助和干预。问题的关键是如何将这些变化和影响以一种直观和形象的方式向村民解释,并且让包括文盲在内的所有人都能理解。从这方面考虑,图形的东西比文字和数字分析更有优势。本文采用MIGIS(移动交互式地理信息系统的英文缩写,它包括两部分的内容,即PLA-参与式学习和行动和GIS-地理信息系统)在云南省绿春县哈尼族村寨来协助进行村民自发的造林规划。图6表1参16。     

Collection of urban tree products by households in poorer residential areas of three South African towns

The high rates of urban in-migration and poverty common in many developing country towns potentially increases the reliance of urban populations on the direct benefits provided by trees. Yet understanding of the extent of such use and the sources of these tree products is limited. Here we report on the extent of use of urban tree products by 450 households in the poorer areas of three towns along a rainfall gradient based on household questionnaires. We considered the proportion of households making use of each of several tree products and the collection or purchasing frequency which we disaggregated by source of the product, including trees in homesteads, urban spaces, edges of towns and via purchase from traders. Most households (91%) used firewood, which was most frequently collected from the urban fringe or purchased, although one-third at times also collected firewood from trees on their home plot. All households used fruits, most commonly sourced through purchase (98%), but nearly half of whom also supplemented by harvesting fruits from their home plot. Other products used included wood for building, fencing and utensils, herbal medicines, planting material and mulch. Collection of products from urban homestead trees was highest amongst households in the informal settlements and least in the more established townships. Residents of new low-cost housing areas made extensive use of urban tree products harvested in urban spaces because they had fewer homestead trees than residents of informal areas or townships. Overall, urban residents made use of a wide array of tangible products from trees which they sourced from a variety of places, including their homestead plot. This urges that planning agencies ensure that homestead plot sizes or other urban spaces that provide tree products are large enough to support the direct needs of poorer urban residents.     

Nitrogen fixation,biomass production,and nutrient uptake by annual Sesbania species in an alkaline soil

Summary In three field trials conducted during the summer season of 1986, 1987 and 1989 in an alkaline soil, 17 accessions of annual Sesbania spp. were evaluated for nodulation, N₂ fixation (acetylene reduction assay), dry weight of roots and shoots, woody biomass production, and nutrient uptake. At 50 days after sowing all the accessions were effectively nodulated (average 36.4 root nodules plant^-1) with a high nodule score (3.4). There was a lot of variation in nodule volume and mass and in acetylene reduction activity but not in N content (5.2%). N uptake in shoots, roots and nodules averaged 639, 31, and 13 mg plant^-1, respectively, and much of the fixed N remained in shoots. Accessions of S. cannabina complex performed better than others. S. rostrata had poor root nodulation but exhibited excellent stem nodulation (300 nodules plant^-1) even though not inoculated with Azorhizobium sp. Average concentrations of N, P, K, S, Ca, and Mg in the shoots were high, at 3.2, 0.28, 1.5, 0.28, 1.5, and 0.4% respectively, and Na was low (0.15%), reflecting the usefulness of Sesbania spp. as an integrated biofertilizer source. Green matter production was 26.0 Mg ha^-1 (5.9 Mg dry matter) and N uptake was 158 kg ha^-1, 54 days after sowing. Average woody biomass of six accessions at maturity, 200 days after sowing, was high (19.9 Mg ha^-1), showing its potential for shortterm firewood production. Total nutrient uptake for production of woody biomass (200 days of growth) was no more demanding than growing the plant to the green-manuring stage of 50–60 days' growth.     

东北三省薪炭林区划

为指导农村能源建设,并为其提供科学依据。本文对东北三省内的森林资源、薪材资源和农村能源状况,以及自然地理条件等进行研究,提出了薪炭林区划的原则和依据,将东北三省区划为3个类型区(一级区):薪炭林不发展区(Ⅰ)、薪炭林一般发展区(Ⅱ)和薪炭林重点发展区(Ⅲ)。根据类型区划和自然地理区划、行政区划相结合的原则,在一级区划的基础上,划分了11个二级区:大兴安岭山地区(Ⅰ_1)、小兴安岭山地区(Ⅰ_2)、长白山中部山地区(Ⅰ_3)、长白山北部山地区(Ⅱ_1)、吉林省中部丘陵区(Ⅱ_2)、辽东中低山地区(Ⅱ_3)、松嫩平原区(Ⅲ_1)、三江平原区(Ⅲ_2)、辽河中下游平原区(Ⅲ_3)、辽西低山丘陵区(Ⅲ_4)、辽东半岛低山丘陵区(Ⅲ_5)。并提出了各区薪炭林发展规划。     

元阳县薪材树种生物量的初步研究

元阳薪材树种生物量（地方部分）的研究，为云南地区薪炭林的发展提供了理论依据。     

生物质能在农村能源中的地位与薪炭林建设

生物质能一直是我国农村能源的主体 ,多能互补虽然弥补了薪炭林的不足 ,但薪炭林具备了可再生、少污染、成本低、易贮藏、较安全等优点 ,仍被人们青睐。薪炭林不仅提供燃料 ,还可提供饲料、化工原料、建筑材料等 ,有利于经济发展和环境保护。薪炭林作为 5大林种之一的地位应予肯定 ,它的发展趋势良好 ,前景广阔     

Use and conservation of forest resources in the municipality of San Agustin Loxicha,Sierra Madre del Sur,Oaxaca, Mexico

The Sierra Madre del Sur, Oaxaca is considered an area with high diversity of ecosystems, and low levels of fragmentation due to human disturbance. An indigenous people, the Zapotecs, have inhabited this area for centuries and Zapotec communities have used and continue to make use of local resources for their subsistence. Agroforestry systems provide timber, firewood, and non-timber forest products to local communities. Despite the ecological and cultural relevance of this region, basic information about local practices of management and harvesting are lacking. Little is known about the possible effects of these practices on biodiversity conservation. The objectives of this study were: to determine the local uses of forest wood resources in the municipality of San Agustín Loxicha, to determine the tree species most used by the inhabitants of this municipality and to discuss the implications of this management in the conservation of plant cover in this Priority Terrestrial Region. The reported main use of tree species was firewood, obtained by gathering dry branches and bark, as well as by felling dead trees. To a lesser extent, tree species are used to build houses and make furniture. Local people collect trees from the surrounding vegetation, so the richness and abundance of tree species in the area surrounding each community will always influence the ability of the communities to meet their needs. These practices do not have drastic effects on plant cover, mainly in areas of established forests. These traditional practices are involved in an empirical strategy to conserve and manage local resources.     

A bioeconomic analysis of carbon sequestration in farm forestry: a simulation study of Gliricidia sepium

Trees provide many environmental services including improved soil fertility and soil structure, which often leads to increased productivity and sustainability of the land. Trees also increase the average carbon stocks of land-use systems. Under the Clean Development Mechanism of the Kyoto Protocol, landholders may receive payments for the carbon-sequestration services provided. This study is the first of a series aimed at assessing the appropriateness of tree-based land-use systems as alternatives to continuous cropping and/or Imperata-fallow systems. The performance of a Gliricidia sepium woodlot, grown over 25 years and under various pruning and harvesting regimes, was assessed through modelling. The assessment was based on the system’s ability to sequester and store carbon, maintain land productivity, and be financially profitable for landholders. It was found that the system was profitable under most management regimes tested. Profits were maximised by pruning and harvesting as much biomass as possible when no carbon payments were available, but this strategy decreased system productivity and profitability in the long run. Carbon-sequestration payments encouraged landholders to adopt less intensive practices since net revenues were higher with carbon payments. It was also shown that the carbon pools included in a carbon-trading scheme were sensitive to carbon-measuring costs. For example, if the annual cost of measuring soil carbon was greater than US$1.19 ha⁻¹ it would not be economical to account for this pool in a carbon-sequestration project.     

Plant growth, biomass production and nutrient accumulation by slash/mulch agroforestry systems in tropical hillsides of Colombia

Planted fallow systems under ‘slash and mulch’ management were compared with natural fallow systems at two farms (BM1 and BM2) in the Colombian Andes. The BM1 site was relatively more fertile than the BM2 site. Planted fallow systems evaluated included Calliandra calothyrsus CIAT 20400 (CAL), Indigofera constricta (IND) or Tithonia diversifola (TTH). During each pruning event slashed biomass was weighed, surface-applied to the soil on the same plot and sub-samples taken for chemical analyses. While Indigofera trees consistently showed significantly greater (p < 0.05) plant height and collar diameter than Calliandra trees at both study sites, only collar diameter in Indigofera was significantly affected at all sampling times by differences between BM1 and BM2. After 27 months, TTH presented the greatest cumulative dry weight biomass (37 t ha^–1) and nutrient accumulation in biomass (417.5 kg N ha^–1, 85.3 kg P ha^–1, 928 kg K ha^–1, 299 kg Ca ha^–1 and 127.6 kg Mg ha^–1) among planted fallow systems studied at BM1. Leaf biomass was significantly greater (P < 0.05) for CAL than IND irrespective of site. However, CAL and IND biomass from other plant parts studied and nutrient accumulation were generally similar at BM1 and BM2. At both sites, NAT consistently presented the lowest biomass production and nutrient accumulation among fallow systems. Planted fallows using Calliandra and Indigofera trees had the additional benefit of producing considerable quantities of firewood for household use. This revised version was published online in June 2006 with corrections to the Cover Date.     

Variation in stem-growth and branch-wood traits among provenances of Calycophyllum spruceanum Benth. from the Peruvian Amazon

Calycophyllum spruceanum Benth. is an important tree for timber, charcoal and firewood in the Peruvian Amazon. The first provenance trial was established on farms in three zones located in one watershed in the Peruvian Amazon. The three zones differ in soil fertility and rainfall. Seven provenances from the Peruvian Amazon were tested in all three zones. Variation in four stem-growth traits (height, diameter, number of nodes and branches) and two branch-wood traits (basic density, heat content) was analyzed 18 months after establishment. There were significant differences in stem height and number of stem nodes among provenances in the analysis across zones. Provenance-related variation in stem-growth traits was most significant in the zone with the most fertile soils and highest rainfall. Branch-wood traits did not vary significantly among provenances in the analysis across zones or within zones. Branch-wood heat content was correlated with latitude, increasing from north to south, but this was only observed in a zone with low soil fertility and intermediate rainfall. Branch-wood density was correlated positively with stem diameter in the driest zone, but negatively with stem nodes in the intermediate zone and with stem height in the wettest zone. Results illustrate the potential for selection of fast-growing provenances, and the importance of replicating trials on different test environments to detect variation among provenances.