论我国珍贵用材树种资源的培育(续)

珍贵用材树种资源是我国重要的战略资源。文章探讨了珍贵用材树种的定义,及开展珍贵用材树种资源培育工作的意义和面临的问题,并提出了相应的政策措施和技术路线。加快珍贵树种的培育,除采取集约经营、定向改培、适当加大初植密度、加强抚育管理等技术措施外,要考虑与现有的林业重点工程相结合,与林下种养殖业相结合,与城市绿化相结合。     

论我国珍贵用材树种资源的培育

珍贵用材树种资源是我国重要的战略资源。文章探讨了珍贵用材树种的定义,及开展珍贵用材树种资源培育工作的意义和面临的问题,并提出了相应的政策措施和技术路线。加快珍贵树种的培育除采取集约经营、定向改培、适当加大初植密度、加强抚育管理等技术措施外,要考虑与现有的林业重点工程相结合,与林下种养殖业相结合,城市绿化相结合。     

土默川平原高标准农田防护林规划设计研究

对土默川平原的自然环境状况和农田林网现状进行科学分析和认真调查后 ,提出了该区建设高标准农田林网的目标路线、技术路线 ;并给出了该区林带建设的供选树种和病虫害防治的林业预防措施 ;研究设计了适合该区林网建设的十种农防林优化模式。     

专用纸浆材遗传育种现状及思考

当今,纸浆材树种由过去的针叶树种为主体转向针、阔树种协调发展;良种选育由过去只注重提高纤维产量向产量与制浆品质并重方向发展;育种技术向杂交育种和基因工程方向发展。作者在综述国内外纸浆材遗传育种现状和我国发展纸浆材基地政策基础上,提出了短周期优质纸浆材育种策略、育种程序、技术路线、研究内容和育种指标。     

油松近自然育林差别化经营关键技术

为精准提升我国北方主要树种油松的森林质量,选取了中村林场4种油松(Pinus tabuliformis)典型林分开展近自然差别化经营,并建设示范林。经营模式包括:目标树全林经营、目标树经营、油松低效纯林转化培育混交林、交通沿线培育景观林。通过探索油松林经营技术路线并付诸实践,显著提升森林资源的质量,取得了良好的经营效果,以期为本区域乃至全省油松森林可持续经营提供可参考、可复制的技术示范。     

江门市白水带风景区风景林改造设计及效果分析

根据江门市白水带风景区的现状,提出了风景林林分改造的技术路线和措施;初步分析了林分改造各树种生长情况及林分改造效果。     

试论哈尔滨市开展造林树种固碳能力研究的意义

环境保护背景下,优良固碳树种引种培育可丰富树种资源、提高绿化水平、促进碳汇交易发展,有着社会、经济、生态三大效益,固碳树种的培育与推广关系到未来低碳社会的建设与发展。文章介绍了哈尔滨市固碳树种研究的背景,分析了研究区的自然条件、树种来源、技术路线,并对树种引进结果与意义进行了评价,希望能为东北地区碳汇林的培植发展提供帮助。     

夏橡等大规格珍稀、彩叶良种苗木标准化生产要点及应用

在新疆玛纳斯县平原林场进行夏橡、水曲柳、美国黑核桃、金叶白蜡、核桃楸5个大规格珍稀、彩叶良种的培育,通过不同株行距和切根试验对比提高苗木生长量和质量,总结技术路线,凝练出标准化生产方案,为新疆园林树木的丰富提供了树种资源,同时也丰富了新疆园林植物的色彩,并为新型防护林树种的选育提供了储备树种.     

杨树同龄级、同树种不同密度、不同树种同密度暨抚育技术的研究

在同样的立地条件下对同龄级、同树种不同密度、不同树种同密度,将每个树种均按4种抚育技术措施进行试验。试验地面积各160亩,经5年的观测,生长差异显著,取得了明显效果。     

国外松嫁接技术试验初报

无产阶级文化大革命以来,我所先后开展了湿地松、火炬松造林对比试验。经过近十年的观察,实践证明,这两种松树具有适应性强、生长快、干村通直、抗性强等优点,是我省低丘地区较为理想的造林树种。可是,过去由于刘少奇、林彪反革命修正主义路线的干扰与破坏,使这一优良用材树种得不到发展与推广。文化大革命摧毁了刘、林反革命司令部,毛主席革命路线得到全面贯彻,特别是近两年来,学理论、抓路线,林业生产与科学试验也     

东北林区过伐林生态系统研究概述

从过伐林类型、群落结构、分布格局、林木生长、生物多样性和经营等方面对东北林区过伐林的研究简要概述,提出今后应加强过伐林动态模拟、结构与功能优化、定向恢复、多功能评价等方面的研究,以期为过伐林的深入研究、加快阔叶红松林恢复进程提供科学依据。     

关于发展人工林与建立人工林业问题探讨

全世界森林面积为 34 5 4× 1 0 8hm2 ,其中 3%是人工林。人工林是重要的森林生态系统 ,在木材生产、环境保护和景观建设中具有重要功能和作用。人工林在生产功能方面的补偿作用 ,使天然林可以更好地发挥生态环境价值、森林娱乐和生物多样性保护功能。人工林可持续经营的前提是遗传材料的正确选择与营林实践艺术的结合以及保证这种结合的林业政策。愈来愈多地使用外来树种营建人工林是全球趋势。人工林对于环境和生物多样性的影响 ,可以通过合理的规划和经营措施得到解决。林木育种与遗传改良和经营制度的技术创新是不断提高人工林生态系统生产力的动力。人工林的可持续经营是一个十分复杂的问题 ,中国人工林实现可持续经营面临技术和体制两方面的挑战 ,但是 ,根本出路在于林业经济体制的改革 ,象农业那样 ,在市场经济环境中实行人工林产业化经营 ,建立人工林业 (Forestplantationindustry)。     

广西雅长林场防火林带树种选择与密度确定方法

营建生物防火林带是预防森林火灾蔓延、减少经济损失的有效方法，科学地选择防火树种和合理确定林带密度则是营建生物防火林带的关键。以广西国有雅长林场为研究对象，提出了基于理想点评价方法的防火树种选择和地理信息系统支持下的防火林带密度确定方法，结果表明：借助于现代决策方法与地理信息系统技术，可使防火树种的选择和林火阻隔网合理密度确定更为科学、客观、合理。     

Ecological and Historical Evidence of Anthropogenic Forest Transformations in Eastern Cape Breton Island

Abstract

Farmers cleared approximately one third of settled forest areas within the boreal-temperate ecotone of eastern Cape Breton Island in the 19th century. Temperate hardwoods were prime settlement areas but land ownership patterns and technological dependence of saw milling on stream waters also influenced the clearing and fragmentation of hardwood areas. In the 20th century, boreal tree species invaded abandoned fields thus confounding the natural edaphic-topographic specificity of forest vegetation in ecotonal landscapes. The anthropogenic expansion of boreal tree species sustained comparable levels of wood production while reducing compositional and structural diversity of the tree stratum on original hardwood sites. Industrial forestry accelerated the transformation of the entire boreal-temperate ecotone of eastern Cape Breton Island in the 20th century.     

茅荆坝林区森林类型划分及评价*

次生林是我国重要的后备森林资源,在维护生态平衡中起着重要作用。但我国次生林区立地条件复杂,林分类型不仅多样,而且质量差异很大。为了更好地经营次生林,提高森林生产力和森林生态效益,本文对河北省茅荆坝林区进行了森林类型划分,并对各类型的自然特性及生产力进行了评价,为茅荆坝次生林区乃至华北次生林区今后的森林经营工作提供了一定的依据。     

森林工程与森林生态系统保护

森林工程体系的基本框架包括木材采伐工程、迹地更新造林工程、抚育采伐工程、低效林改造工程、林内路桥工程和装备系统工程。策划和实施森林工程时应遵循的两个基本原则,一是森林工程活动将森林生态系统保护置于首要位置,二是森林工程工艺系统要与作业区域的生态系统保持一致。由于森林生态系统群落结构及其生态过程决定森林生态系统功能,所以森林工程实施时,森林生态系统群落结构保护要着眼于群落结构的连续性和多样性,生物多样性保护要着眼于目的树种、珍稀濒危物种保护和生境保护,森林生态系统环境保护要着眼于水土流失、土壤和地质性灾害。     

The possibility analysis of natural poplar-birch forest recovery to broad-leaf Korean pine forest through the method of life table in the Xioaxing’an Mountains

The basic principle of life table method is described, and the method of tree height instead of tree age in static life table is suggested, and it is also discussed that the possibility of natural poplar-birch forest recover to broad-leaf Korean pine forest on low pitches in the Xiaoxing’an Mountains by this method. If there is no particular situation, Korean pines after high than 5m under natural Poplar-birch forest will basically survive and make their way into dominant canopy accompanied by climax broad-leaf species.     

What can tree plantations do for forest birds in fragmented forest landscapes? A case study in southern Brazil

Despite the fact that tree plantations are not able to completely replace the ecological function of natural forests, the present study proposes to evaluate for which bird species or avian groups tree plantations act as habitat in fragmented landscape in southern Brazil. We compared the richness and abundance of bird species in a natural forest to adjacent plantations of Araucaria, a native tree species and of pine, an exotic plant in South America. Moreover, we evaluated the impact of tree plantations on richness of avian groups with different levels of dependence on forest habitat, feeding habits and foraging strata as well as on threatened species. The fixed 100 m radius point-counts method was used. A total of 114 bird species were recorded in all areas. Of those, 93 occurred in natural forest, 87 in Araucaria plantations and 81 in pine plantations. These results indicate that richness and abundance were lower in the pine plantations than in the natural forest and in the Araucaria plantations. Araucaria plantations can be used by a high number of bird species and their richness was not significantly lower than that observed in the adjacent natural forest. Our results suggest that Araucaria plantations could act as habitat for a large number of bird species, especially for forest-dependents species, insectivores, frugivores and species at different threat categories.     

Effects of Different Management Practices on Stand Composition and Species Diversity in Subtropical Forests in Nepal: Implications of Community Participation in Biodiversity Conservation

In this article, we compared the structure, composition, and diversity of trees, shrubs and saplings, seedlings and herbaceous species of community- and government-managed forests in the lowlands of eastern Nepal. Results suggest that among the trees, the community forest was dominated by a single species, Shorea robusta. However, Shorea robusta and Terminalia myriocarpa were codominant in the government forest. Tree density and basal area were higher in the government forest, but shrub/sapling density and basal area were higher in the community forest, suggesting a positive effect of community management on tree regeneration. Overstory species assemblages showed an obvious compositional difference between the forests, but understory species assemblages were less obvious. Plot-level tree and shrub/sapling species richness was higher in the government forest than the community forest. However, seedling-herbaceous species richness was higher in the community forest. The dominance of Shorea robusta trees in the community forest suggests that people involved in managing forests may be more interested in a limited number of economically valuable species while removing less important trees. Such preferential management practices may increase resource heterogeneity within a forest and maintain species diversity in the understory. Thus, community participation in forest management should be encouraged, with guided management techniques and exercises, to achieve maximum forest recovery, provide sustainable ecosystem services, and maintain forest diversity.     

THE POSSIBILITY ANALYSIS OF NATURAL POPLAR-BIRCH FOREST RECOVERY TO BROAD-LEAF KOREAN PINE FOREST THROUGH THE METHOD OF LIFE TABLE IN THE XIOAXING''''AN MOUNTAINS

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