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辽西北地区通过“三北”防护林工程的建设,筑起了辽西北第一道绿色屏障,也促进了当地的榛子、仁用杏、核桃、大枣等经济林建设。本文结合辽宁省阜新市彰武县榛子和仁用杏生产现状,重点阐述当地榛子和仁用杏产业存在的主要问题和发展对策,以期为促进当地经济林产业快速发展和农民的脱贫致富提供一定的帮助和指导。 相似文献
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我国经济林资源的现状及其发展对策 总被引：2，自引：0，他引：2
分析了当前我国经济林资源发展的现状,面临的机遇和存在的不足,提出了新时期我国经济林发展的工作思路和目标,以及实现该目标应采取的加强引导、做好宏观指导和科学规划,加大经济林树种、品种结构调整步伐、促进经济林资源的合理布局,积极推广先进实用技术、努力提高管理水平,大力发展和改造油茶等木本粮油品种,在大力发展经济林的同时、应适度控制林业重点生态工程区域的经济林比例,加强经济林市场体系建设、促进经济林产品的生产、加工和销售协调发展等主要对策。 相似文献
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通过对全县果树经济林的调查分析,提出了县域果树经济林的发展方向和品种定向,可为整个辽源地区及至全省的果树经济林建设提供参考。 相似文献
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辽西北地区发展沙棘生态型经济林的可行性 总被引：4，自引：1，他引：3
论述了在辽西北地区大力发展抄棘生态型经济林的可行性问题，认为发展沙棘是辽西北地区农村产业结构调整、农民脱贫致富、全面建设小康社会和社会主义新农村的必然选择。 相似文献
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干果经济林发展离不开干果经济林苗木的及时供应,其品种、数量、质量不仅关系到经济林建设的速度、成活率和保存率,而且影响林木的生长发育和今后生态、社会和经济效益的发挥。 相似文献
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经济林产业现代化的思考 总被引：9，自引：1，他引：9
通过长期以来的努力 ,我国经济林产业已得到了很大的发展 ,成为林业产业的主要组成部分。在农村经济发展、农民增收和农业现代化建设及生态工程区经济发展中起到了重要的作用。但当前我国经济林产业仍然存在数量较大质量偏低、生产规模分散、采收及采后管理薄弱和产品消费群体单一、林种产品类同化、科研沿续性不足导致创新乏力等问题 ,困扰我国经济林产业现代化的健康发展。对于我国经济林产业化建设 ,今后更要重视在经营方向上逐步走向规模化和企业化 ;重视适地适树和品种区域化问题 ;实施生产品种良种化工程 ;分类推行经济林栽培技术 ,实施以产量为基础、质量为核心的栽培方式 ;提高经济林果品采后处理水平 ;加强名、特、优、稀、新经济林果品和产品的发展 ,加强新品种和新技术的引进力度 ;强化经济林科研稳定持续开展 ,健全经济林技术推广体系 相似文献
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通过对桑植县经济林产业化建设现状的分析,指出了存在的问题,如缺乏长期规划与科学指导;经济林造林分散,没有形成规模效益;品种单一,市场竞争力不强;管理水平低,科技投入少,技术服务不到位等。针对上述问题,提出了经济林产业化建设的对策及措施。 相似文献
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承德市林业有害生物发生状况和治理对策 总被引：1，自引：0，他引：1
承德市位于河北省东北部,东靠辽宁、北接内蒙,南临天津,西南与北京相连,国土总面积3．95万平方公里,近年来承德林业工作以为河北增资源、为农民拓财源、为京津阻沙源、保水源的“四源”林业建设为使命,实施依法治林、科技兴林、项目强林三大战略,初步构筑了沿边沿坝防风固沙林、低山丘陵水保经济林、川地河岸防护林、环城沿路窗口地带绿化美化风景林五大防护林体系。 相似文献
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C.W. Woodall C.M. Oswalt J.A. Westfall C.H. Perry M.D. Nelson A.O. Finley 《Forest Ecology and Management》2009
Changes in tree species distributions are a potential impact of climate change on forest ecosystems. The examination of tree species shifts in forests of the eastern United States largely has been limited to simulation activities due to a lack of consistent, long-term forest inventory datasets. The goal of this study was to compare current geographic distributions of tree seedlings (trees with a diameter at breast height ≤2.5 cm) with biomass (trees with a diameter at breast height > 2.5 cm) for sets of northern, southern, and general tree species in the eastern United States using a spatially balanced, region-wide forest inventory. Compared to mean latitude of tree biomass, mean latitude of seedlings was significantly farther north (>20 km) for the northern study species, while southern species had no shift, and general species demonstrated southern expansion. Density of seedlings relative to tree biomass of northern tree species was nearly 10 times higher in northern latitudes compared to southern latitudes. For forest inventory plots between 44° and 47° north latitude where southern tree species were identified, their biomass averaged 0.46 tonnes/ha while their seedling counts averaged 2600 ha−1. It is hypothesized that as northern and southern tree species together move northward due to greater regeneration success at higher latitudes, general species may fill their vacated niches in southern locations. The results of this study suggest that the process of northward tree migration in the eastern United States is currently underway with rates approaching 100 km/century for many species. 相似文献
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经济林不仅具有很高的经济价值、良好的生态效益,而且多数经济林树种集叶、花、果、形于一身,具有极高的观赏价值,在园林绿化和廊道绿化建设中具有广阔的应用前景。文章论述了经济林的园林和廊道绿化价值,经济林在国内外园林和廊道绿化建设中的应用现状、利用途径、树种选择的原则等,并提出了园林、廊道绿化建设中选用经济林树种应注意的问题。因地制宜合理选用经济林树种是园林和廊道绿化建设中的一条重要途径。 相似文献
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立足当前生态文明建设和林业发展,文中从产业结构转型、劳动力就业结构转型和生态环境建设3方面构建我国南方集体林区林业经济转型指标体系,基于2000—2019年面板数据,运用熵值法测算林业经济转型水平,采用固定效应模型实证探究促进林业经济转型的驱动因素。结果显示:1)南方集体林区林业经济转型水平总体呈上升趋势,转型平均水平从2000年的0.51升至2019年的0.90,林业产业结构和劳动力就业结构趋向合理化转变;2)影响南方集体林区林业经济转型的主要为林业投资、技术水平、森林资源和林业系统工资水平的积极驱动作用,以及林权制度改革的政策冲击和城镇水平提高所产生的一定阻碍作用;3)不同水平下林业经济转型的主要驱动因素存在差异,转型水平较低阶段主要受技术水平、森林资源、人才资源、经济水平、城镇水平和工资水平影响,转型水平较高阶段主要受制度创新、林业投资、森林资源和工资水平影响。森林资源的丰富程度对各方面均会产生影响,森林资源较少地区林业经济转型受制度创新和技术水平影响显著,森林资源较多地区则受技术水平、森林资源、城镇水平和工资水平影响显著。结合南方集体林区林业经济转型发展的现状及实证分析结果,提出应进一步完善林业改革制度配套措施、加快发展第三产业、拓宽资金渠道、提高林业劳动力供给质量等有利于推动林区林业经济转型的对策建议。 相似文献
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《Forest Ecology and Management》2002,155(1-3):257-270
We examined tree species responses under forest harvesting and an increased fire disturbance scenario due to climate warming in northern Wisconsin where northern hardwood and boreal forests are currently predominant. Individual species response at the ecosystem scale was simulated with a gap model, which integrates soil, climate and species data, stratified by ecoregions. Such responses were quantified as species establishment coefficients. These coefficients were used to parameterize a spatially explicit landscape model, LANDIS. Species response to climate warming at the landscape scale was simulated with LANDIS, which integrates ecosystem dynamics with spatial processes including seed dispersal, fire disturbance, and forest harvesting. Under a 5 °C annual temperature increase predicted by global climate models (GCM), our simulation results suggest that significant change in species composition and abundance could occur in the two ecoregions in the study area. In the glacial lake plain (lakeshore) ecoregion under warming conditions, boreal and northern hardwood species such as red oak, sugar maple, white pine, balsam fir, paper birch, yellow birch, and aspen decline gradually during and after climate warming. Southern species such as white ash, hickory, bur oak, black oak, and white oak, which are present in minor amounts before the warming, increase in abundance on the landscape. The transition of the northern hardwood and boreal forest to one dominated by southern species occurs around year 200. In the sand barrens ecoregion under warming conditions, red pine initially benefits from the decline of other northern hardwood species, and its abundance quickly increases. However, red pine and jack pine as well as new southern species are unable to reproduce, and the ecoregion could transform into a region with only grass and shrub species around 250 years under warming climate. Increased fire frequency can accelerate the decline of shade-tolerant species such as balsam fir and sugar maple and accelerate the northward migration of southern species. Forest harvesting accelerated the decline of northern hardwood and boreal tree species. This is especially obvious on the barrens ecoregion, where the intensive cutting regime contributed to the decline of red pine and jack pine already under stressed environments. Forest managers may instead consider a conservative cutting plan or protective management scenarios with limited forest harvesting. This could prolong the transformation of the barrens into prairie from one-half to one tree life cycle. 相似文献
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The productivity of traditional agrisilviculture system (agricultural crops + trees) was investigated in the northern and southern aspects of mid-hill situation in Garhwal Himalaya, Uttarakhand, India during the 2004-2006. A total of 19 tree species were studied in both northern and southern aspects, out of which 17 tree species were selected in northern aspect and 12 tree species in southern aspect for phytosociological characteristic analysis of trees in agrisilvicultural system. The most dominant tree species are Grewia optiva, Celtis australis and Melia azedarach and successively grown under traditional agrisilviculture system. The results show that the annual productivity of all tree species was 3775 kg·ha-1·a-1 in northern aspect (site-N) and 3101 kg·ha-1·a-1 in southern aspect (site-S). G. Optiva had the highest productivity in both site-N and site-S among the tree species, followed by M. Azedarach, Quercus leucotrichophora and C. Australis. The dominant agricultural crops were Eleusine coracana in summer cereals, Phaseolus vulgaris in summer pulses-oilseeds and Triticum aestivum in the winter season in the area. The average biological productivity of agricultural crops in northern aspect was about 16% higher than that in southern aspect under traditional agrisilviculture system. The sole agricultural crop productivity (without trees) in northern aspect was also higher than that in southern aspect. An obvious difference in annual productivity of trees and agriculture crops was observed between northern aspect and southern aspect. The overall productivity in traditional agrisilviculture system (crop + tree) was 24% (in northern aspect) and 21% (in southern aspect) higher than that in sole cropping system. 相似文献
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Conifer dominated plantations in central and northern Europe are associated with relatively low ecological values, and in some cases, may be vulnerable to disturbances caused by anthropogenic climate change. This has prompted the consideration of alternative tree species compositions for use in production forestry in this region. Here we evaluate the likely biodiversity costs and benefits of supplanting Norway spruce (Picea abies) monocultures with polycultures of spruce and birch (Betula spp.) in southern Sweden. This polyculture alternative has previously been evaluated in terms of economic, recreational, and silvicultural benefits. By also assessing the ecological implications we fill a gap in our understanding of the range of socio-ecological benefits that can be achieved from a single polyculture alternative. We project likely broad scale changes to species richness and abundance within production stands for five taxonomic groups including ground vegetation, tree-living bryophytes, lichens, saproxylic beetles, and birds. Our research leads us to three key findings. First, the replacement of spruce monocultures with spruce–birch polycultures in the managed forest landscapes of southern Sweden can be expected to result in an increase in biological diversity for most but not all taxa assessed, but it is unlikely to improve conditions for many red-listed forest species. Second, modification of other aspects of forest management (i.e. rotation length, dead wood and green tree retention, thinning regimes) is likely to contribute to further biodiversity gains using spruce–birch polycultures than spruce monocultures. Third, the paucity of empirical research which directly compares the biodiversity of different types of managed production stands, limits the extent to which policy relevant conclusions can be extracted from the scientific literature. We discuss the wider implications of our findings, which indicate that some climate change adaptation strategies, such as risk-spreading, can be readily integrated with the economic, environmental and social goals of multi-use forestry. 相似文献
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《Forest Policy and Economics》2000,1(1):27-40
This paper addresses the effects of economic transition policies on forestry in China. The effects of de-collectivization and market liberalization on the forest land area and timber harvest are studied using panel data from four provinces covering the period 1978–1995. Fixed effects ordinary least squares models for forest land cover and annual harvests per hectare are estimated, allowing for differences across provinces and prefectures in northern and southern China. The results show that land tenure reform in general has had a positive effect on forest land expansion, but the absolute size of the effects varies from province to province. The positive impact of the reform on timber harvesting has not taken place at the cost of forest land cover. The claim that market liberalization leads to over-harvesting of forest resources in developing countries is not supported by our results. 相似文献
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13种观赏竹种引种驯化研究 总被引：2，自引：2，他引：0
竹子喜温暖、湿润气候,主要分布于我国南方大部分地区。我国自20世纪60-70年代以来开展了大量的"南竹北移"工作,将一些抗性较强的竹种引种到黄河流域以北地区。但北方竹类仍存在品种单调、成林效果差等问题。为丰富北方观赏竹种类,从上海、江苏宿迁和山东淄博引入13个竹种,在山西农业大学苗圃内进行引种驯化研究。引种适应性研究结果显示,刚竹属的淡竹、早园竹、青竹、箬竹和赤竹属的菲白竹适合在引种地种植,而佛肚竹、观音竹和罗汉竹则不适合种植。 相似文献
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Armillaria spp. are some of the most important forest pathogens in mixed hardwood forests of southern New England, yet their role as prominent disturbance agents is still not fully appreciated. We investigated the distribution of Armillaria species across eight separate stands of northern hardwood and mixed oak forests in western Massachusetts. We were specifically interested in the Armillaria species distribution from live, symptomatic hosts and not in determining overall incidence in the forest. From 32 plots (16 within each forest type), 320 isolates were collected. Armillaria was routinely encountered causing disease of live trees. In total, 89% (286/320) of all isolations came from live hosts exhibiting symptoms of root and butt rot. Overall, A. gallica was the dominant species in each forest type, making up 88/160 (55%) isolates from northern hardwood and 153/160 (96%) of all isolations from mixed oak stands. However, northern hardwood forests showed much greater species diversity, as A. calvescens, A. gemina, A. ostoyae, and A. sinapina were all found. At one site, a northern hardwood forest surrounding a high elevation spruce-fir forest, A. ostoyae was the most abundant species encountered. All five Armillaria species were found causing disease of live hosts, including A. gemina, a species considered by some as weakly virulent. Armillaria gallica was found on 22/23 tree species’ sampled, and was found most often causing butt rot. 相似文献