谈德国林业政策和经营模式对伊春林区林业发展的几点启示

通过分析德国森林资源和生态环境保护与建设的特点,深入了解了德国林业相关的法规及政策,保护与发展森林资源的政府资助以及德国森林经营管理理论、技术与方法,结合伊春林区实际,提出对伊春林区森林经营管理模式和经营理念进行改进的几点建议.     

伊春林区生态产业建设的探讨

生态产业建设，是全面实现小康社会的战略举措，是社会经济可持续发展的本质要求，是科学发展观的重要实践。从伊春林区现有状况入手，简要论述了该地区进行生态产业建设的必要性及可行性，用新的举措发展生态产业及开发生态产业中存在的问题，最后对伊春林区如何进行生态产业建设提出了几点建议。     

伊春林区:建立森林病虫害预测预警系统

黑龙江省伊春林区林业有害生物发生面积居高不下,外来有害生物对该市林业生态安全威胁加大,如何真正有效控制林业有害生物及应对外来有害生物对全市林业生态的安全威胁,是伊春林区林业有害生物防治工作面临的严峻问题,本文从建立和完善伊春林业有害生物预测预警系统方面阐述了建立科学、完备的伊春林区林业有害生物预测预警系统建设具体措施。     

浅议大兴安岭东部林区旅游生态环境保护与建设规划

文章阐述了大兴安岭东部林区旅游生态环境的现状,论述了大兴安岭东部林区旅游生态环境保护与建设目标及主要内容,提出了大兴安岭东部林区生态环境保护的对策与措施。     

伊春林区绿色经济发展研究

文章分析了伊春林区绿色经济的发展概况以及绿色经济在节约能源、保护生态、提高经济效益等方面给伊春带来的巨大推动作用,同时,也对伊春林区绿色经济存在的问题与挑战提出了一些建议和对策。     

伊春林区主要乡土观赏树种的开发利用

主要介绍了伊春本地区可用于绿化的观赏树种,并对这些观赏树种进行了生态适生性、观赏用途及绿化功能分类,旨在为伊春林区在园林建设中对本地树种的应用提供基本依据。     

林区野生榛林改培技术

伊春林区的林业已从传统林业向生态林业方向转变。资源型城市经济转型,发展非林替代产业,特别是林区广大林改户发展林下经济,都迫切需要符合实际的经营项目与技术支持。伊春林区野生榛资源丰富,进行野生榛林改培,成本低,收入可观,是林区职工增加经营林地收益的好方法。     

浅谈林区公路建设与生态环境保护

概述了林区公路建设对生态环境的影响,并就在林区公路建设中实施生态环境保护,提出了若干建议。     

基于生态区位测度的伊春林区森林生态服务功能价值评估

在构建伊春林区森林生态区位测度指标体系的基础上,测度不同等级森林的生态区位系数,按照寒温带针叶林、温带落叶阔叶林、温带红松阔叶混交林等不同林分,对伊春林区森林的涵养水源、固定CO2和释放O2、保育土壤、营养物质循环和储藏、净化大气环境、生物多样性保护等6种生态服务功能形式的价值进行评估,使得评估结果更加合理.本文可为伊春林区森林可持续发展政策的制定提供参考依据,同时对该区域森林资源保护和开发利用具有重要的意义.     

林区公路建设中的生态环境保护问题

概述了林区公路建设对生态环境的影响，并就在林区公路建设中实施生态环境保护，提出了若干建议。     

林火与水土流失

本文综述了林地用火与水土流失关系, 阐明在北方及南方平原林地"规定用火"或"迹地用火"后, 土壤渗透性能得到改善, 水土流失较为轻微; 而在南方山区, 强度火烧后水土流失较为严重, 陡坡地段可蚀性较强的土壤水土流失尤为严重。根据火后土壤生境特点及用火现状, 指出林业用火与耕作制度有机组合, 形成特定的"农林业系统", 将为南方林业生产带来重大改革。     

Water and nutrient dynamics and tree growth

The balance in the investment of assimilate at any time into leaves and roots may depend on whether water, nutrients or radiation are limiting to growth. Also, for the same investment of assimilate into roots, the root configuration may range from intensive to extensive in both space and time, to take best advantage of the distribution and amount of water and nutrients. Intensive root configurations, which include mycorrhizas and proteoid roots, assist in the uptake of nutrients (such as phosphorus) which are rate-limiting in soil. Mycorrhizas may assist in water uptake in dry or coarse textured soils with low unsaturated hydraulic conductivities.

Adaptations which assist trees to survive in dry and nutrient-deficient environments are discussed. These mechanisms may reduce, maintain or increase growth. In production forestry, it is desirable to exploit those mechanisms which increase growth. When soil water and nutrients limit tree growth, productivity may be improved by increasing the amount of uptake of water and nutrients, or by increasing the efficiency by which they are used in growth. Maximizing water-use efficiency when soil water supply is limiting may be dependent on whether the trees are in mixed stands or in monoculture. Selecting trees with relatively less root may improve productivity in monocultures when weeds are controlled and fertilizer is added. It is well known that trees can ‘re-use’ nutrients by retranslocating them within the tree to zones of demand. Relatively little is known, though, about differences in the biochemical involvement of nutrients at the cellular and subcellular level which contribute to differences in nutrient-use efficiency in trees.     

生态经济林与可持续发展

通过实地调查与资料收集，对生态经济树种及生态经济林进行了定义，分析了我国经济林的生产现状及发展生态经济林的意义。介绍了浙江省杨梅、山核桃、山茱萸、香榧等主要生态经济树种的经济效益与生态效益，并探讨了生态经济林纯林、混交林、立体经营及散生庭院式的栽培模式及规范化栽培，指出山地或坡地发展生态经济林应以混交林和立体经营为主，减少纯林栽培，提倡四旁、宅院种植经济林以增加收入、美化环境。同时指出生态经济林也是经济林生存和持续发展的根本问题。     

早实薄皮核桃品种引种筛选试验及综合评价

近年来,随着核桃产业的发展和早实薄皮核桃的推广应用,青海省河湟谷地也纷纷引种。由于引种前缺乏相关研究,引进品种杂乱,其表现良莠不齐,优少劣多现象突出。为了筛选出能适于该地区栽培的薄皮核桃品种,对引进的9个早实薄皮核桃品种开展了引种试验和观测分析,采用数据直观分析和主成分分析相结合的方法,对各品种果实的经济学性状进行了分析评价,筛选出了辽宁1号、中林5号为适于青海省栽培的优良品种,这两个品种可在该区域适度发展。     

国内外水土流失与土壤退化现状及特点分析

土壤侵蚀是土地退化的主要原因,全球约有1 965.0万km2的面积受到各种形式土壤退化的影响,水土流失与土地退化给人类的可持续发展带来了巨大的压力。我国水土流失尤为严重,根据最新第2次水土流失遥感调查结果表明,全国现有的水土流失面积为356.0万km2。轻度水蚀区主要分布在东中部,中度水蚀区绝大部分在中西部,强度及以上的水蚀区主要在西部地区。严重的水土流失使生态环境不断恶化,加剧土地资源危机,已成为严重的社会问题。     

德国 奥地利森林资源监测与经营管理的特点及启示

深入分析了德国在同一抽样体系下,实施森林资源及其生态状况监测的技术特点、永续利用的经营理念与近自然的经营管理方法,以及奥地利信息技术在森林资源监测中的应用特点与科技创新的发展措施,对比我国森林资源监测状况,提出了完善森林资源监测内容和指标体系,建立森林资源及生态状况综合监测体系,加强新技术的创新研究和应用,积极争取国家基础数据共享应用的建议。     

Radiation-use efficiency and gas exchange responses to water and nutrient availability in irrigated and fertilized stands of sweetgum and sycamore

We investigated how water and nutrient availability affect radiation-use efficiency (epsilon) and assessed leaf gas exchange as a possible mechanism for shifts in epsilon. We measured aboveground net primary production (ANPP) and annual photosynthetically active radiation (PAR) capture to calculate epsilon as well as leaf-level physiological variables (light-saturated net photosynthesis, Asat; stomatal conductance, gs; leaf internal CO2 concentration, Ci; foliar nitrogen concentration, foliar [N]; and midday leaf water potential, Psileaf) during the second (2001) and third (2002) growing seasons in sweetgum (Liquidambar styraciflua L.) and sycamore (Platanus occidentalis L.) stands receiving a factorial combination of irrigation and fertilization at the Savannah River Site, South Carolina. Irrigation and fertilization increased PAR capture (maximum increase 60%) in 2001 and 2002 for both species and annual PAR capture was well correlated with ANPP (mean r2 = 0.77). A decreasing trend in epsilon was observed in non-irrigated stands for sweetgum in 2001 and for sycamore in both years, although this was only significant for sycamore in 2002. Irrigated stands maintained higher gas exchange rates than non-irrigated stands for sweetgum in 2001 and for sycamore in both years, although foliar [N] and Psileaf were generally unaffected. Because Ci decreased in proportion to gs in non-irrigated stands, it appeared that greater stomatal limitation of photosynthesis was associated with decreased Asat. On several measurement dates for sweetgum in 2001 and for sycamore in both years, epsilon was positively correlated with gas exchange variables (Asat, gs, Ci) (r ranged from 0.600 to 0.857). These results indicate that PAR capture is well correlated with ANPP and that gas exchange rates modified by irrigation can influence the conversion of captured light energy to biomass.     

Forest and Forestry Research and Education in Mongolia

Since 1990, after the dramatic change in Mongolia's political and economic system, human impact on forest resources highly increased and became continuously degraded due to improper exploitation, forest fire, mining, pest and disease, uncontrolled grazing, and inadequate management which negatively affect its environmental conditions causing severe deforestation, desertification, and ecological stress in some regions of the country. Forestry research and education became fragmented in Mongolia. Several institutions and universities conducted vague and in some cases duplicating research topics. Hence, this article aims to understand the current status and issues as well as to formulate possible solutions in strengthening and developing forest and forestry research and education in the country.     

Root length and nitrate under Sesbania sesban: Vertical and horizontal distribution and variability

Measurements of root and nutrient distributions in agroforestry systems have often been obtained from unreplicated plots. We, therefore, measured the vertical and horizontal distribution of root length and soil nitrate in replicated plots of sesbania [Sesbania sesban (L.) Merr.] to assess plot-to-plot variation and identify appropriate sampling schemes. Sampling was on profile walls exposed from pits at two on-farm sites (Ochinga and Muange) in Kenya. At Ochinga, soil was sampled at 27 0.15-m depth intervals and eight 0.15-m-wide locations perpendicular to 2.25-m-wide rows of 19-month-old sesbania. At Muange, sampling was 18 months after establishment of sesbania from seedlings with a 1 m by 1 m spacing. Soil was sampled at 17 0.15-m depth intervals and nine 0.15-m-wide sampling locations – one exactly below the tree and four each on opposite sides of the tree. Root length density generally decreased with distance from sesbania and with soil depth. Soil nitrate, however, followed different trends in the four replications at Ochinga and the three replications at Muange. At Ochinga, nitrate above 2.5-m depth clearly increased with distance from the tree in two replications but followed no distinct trend in another replication. At Muange, nitrate above 1.2-m depth decreased with distance from the tree in one replication, increased with distance from the tree in another replication and followed no clear trend in another replication. The suitability of various sampling schemes for measuring root length and nitrate was accessed from percent bias between measured values at sampling locations in the scheme and actual values for an entire transect of sampling locations. Bias associated with selection of sampling locations tended to be higher within the 2.25-m-wide sesbania rows than the 1 m by 1 m sesbania spacing. Soil sampling in systems with rows of young trees should be at several locations along a transect perpendicular to tree rows in order to minimize bias. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date.     

城市树木养护与树艺学:欧美的做法及启示

城市树木是绿色基础设施的基本组成,是城市林业建设的基础,树木的管护水平决定了城市树木的生存质量。欧美城市树木养护和管理方面已形成专门的职业技术体系,并产生了树艺学(Arboriculture)学科。文中通过文献分析和研究,对欧美城市树木管理的教育、职业资格认证、职业要求情况进行总结分析,指出我国在城市树木管护方面应拓宽职业技术渠道,促进学科专业化发展;同时,要加强鼓励市民参与树木管理监督,扩大树木工作者权利范围,增加树木风险评估内容,规范职业资格认证与加强培训。