营林生产管理工作探析

做好营林生产管理工作,对于推进我国林业工程的可持续发展有着至关重要的作用,可以有效促进林业产业经济效益和社会效益的提升。然而,由于种种原因所限,我国目前的营林生产管理工作并不尽如人意,亟需改进。文章先分析目前营林生产管理工作的现状,接着提出一套有针对性的解决措施,以期能促进我国林业工作持续稳定的发展。     

森林培育措施对红松人工林径向生长性质的影响

对不同森林培育措施的红松人工林径向生长性质指标进行测试和分析.结果表明不同的森林培育措施(坡位、林分结构、初植密度、间伐)对红松人工林的生长率、生长轮宽度及生长轮密度有显著的影响,对晚材率的影响不明显;坡向对红松人工林的生长率、生长轮宽度有显著的影响,对晚材率、生长轮密度的影响不明显;修枝对红松人工林的生长率、晚材率有显著的影响,对生长轮宽度及生长轮密度的影响不明显;阴坡、坡下、三株一丛、2.0m×2.0m、适度间伐、适度修枝的林分林木生长率较高,可用于培育大径级的木材.     

鲁山县火炬松造林技术探讨

通过几年的育苗和造林试验,总结出了火炬松在北部分界上造林的关键技术措施和方法。     

油茶优良无性系造林及可配性测定的研究

经过对6种不同无性系测定,表明油茶优良无性系自然着果率高,优良无性系之间的可配性很强,各无性系之间正反交的成果率都较高,解决了优良无性系造林中许多技术问题。     

国有林场营林技术措施的探讨

分析了福建省国有林场营林现状及存在的问题 ,从培育目标、良种壮苗、造林抚育、抚育间伐、生态公益林经营等方面对国有林场的营林技术措施进行了探讨     

Can the impact of deer browsing on tree regeneration be mitigated by shelterwood cutting and strip clearcutting?

Silvicultural treatments creating large canopy openings failed to restore regeneration of balsam fir (Abies balsamea (L.) Mill.) due to browsing pressure from white-tailed deer (Odocoileus virginianus Zimmermann). Consequently, we tested two alternative silvicultural treatments aimed at improving balsam fir establishment on Anticosti Island (Québec, Canada). In 1998 and 1999, we set up shelterwood seed cutting using three harvest intensities (0, 25 and 40% of basal area) and strip clearcutting with scarification using three different strip widths (15, 30 and 45 m), both with fenced and unfenced regeneration plots, in balsam fir stands. After 8 years, shelterwood seed cutting did not allow the establishment of new balsam fir seedlings, nor the development of unbrowsed balsam fir seedlings. In the strip clearcutting, deer browsing suppressed growth of palatable species in all strip widths. This favoured the development of unpalatable species, especially white spruce (Picea glauca (Moench) Voss). Our study demonstrates that the use of silvicultural treatments alone is unlikely to restore balsam fir regeneration on Anticosti Island, as long as the deer population remains higher than 20 deer/km².     

印度紫檀山地造林技术与苗木的早期生长表现

[目的]大面积推广印度紫檀这一珍贵用材树种。[方法]研究和总结了印度紫檀的山地造林技术要点和苗木的早期表现。[结果]3年生幼林生长表现良好;提高造林措施和加强幼林的抚育管理可提高幼林的成活率和保存率;适当的施肥对幼林的生长具有促进作用。[结论]印度紫檀有较强的适应能力,能适应云南热区的气候与立地条件,但生产周期长,必须走复合经营的道路,以提高林农的营林积极性和林地的综合效益。     

Impact of slash removal,drag scarification,and mounding on lodgepole pine cone distribution and seedling regeneration after cut-to-length harvesting on high elevation sites

Excessive slash loading could pose a problem for the regeneration of the serotinous lodgpole pine especially in forests at higher elevation where soil temperature is limiting. In the past, these forests have commonly been harvested using full-tree harvesting where trees are processed at roadside; however, recently cut-to-length harvesting has become a more frequent harvesting method. In cut-to-length harvesting the harvested trees are processed in the block, as a result slash accumulation is much higher on these cutblocks. In an experimental field trial, the cone distribution, natural lodgepole pine regeneration, and the growth and establishment of planted lodgepole pine were evaluated in response to slash load, drag scarification, and mounding after cut-to-length harvesting of high elevation lodgepole pine stands in the Rocky Mountains. Twelve sites were established, each contained six plots which were randomly assigned to six treatment combinations of two slash removal (slash and slash removed) and three mechanical soil preparation treatments (no soil preparation, drag scarifying, and mounding). The slash removal reduced slash volume by more than 50% but also reduced the number of lodgepole pine cones available for regeneration by over 33%. However, soil mechanical treatments offset this effect as fewer cones were necessary to achieve high natural pine regeneration densities. Drag scarification of plots resulted in 12 times the number of pine seedlings compared to the non-prepared plots. Although slash removal did not have an effect on the number of naturally regenerated lodgepole pine seedlings, it had a positive effect on their growth performance. Conversely, planted pine seedlings had lower mortality and better growth in soils that had been mechanically prepared and had the slash removed; however, the growth effects became only apparent 4 years after planting. While slash removal and mechanical soil preparation did increase soil temperatures; the slash removal treatment had a more transient effect on soil temperatures than soil preparation. Differences in soil temperature decreased over time which appeared to be mostly driven by a warming of the soils in the plots with no soil preparation, likely a result of the decomposition of the finer slash and feathermosses. Overall, it appears that surface disturbance on these high elevation sites had a far greater effect on lodgepole pine regeneration and growth than the increased accumulation of slash as a result of cut-to-length harvesting.     

南方防火树种选择及其育苗造林技术研究概况

综述和讨论了当前我国南方防火树种的研究现状,包括概念和研究意义,主要防火树种及选择依据、阻火机理、育苗造林技术和运用防火树种营造防火林带和混交林技术,以指导南方开展多元化营造林和林业多种经营工作。     

Anthropogenic alterations of genetic diversity within tree populations: Implications for forest ecosystem resilience

Healthy forests provide many of the essential ecosystem services upon which all life depends. Genetic diversity is an essential component of long-term forest health because it provides a basis for adaptation and resilience to environmental stress and change. In addition to natural processes, numerous anthropogenic factors deplete forest genetic resources. Genetic losses could be particularly consequential now because robust resilience is needed to respond to a growing number, variety, and frequency of stress exposures. Silvicultural management that selectively removes trees (and their genes) from forests may be another force reshaping forest gene pools. Although data concerning the influence of silvicultural management on genetic resources in temperate forests is somewhat mixed, through the genetic assessment of long-term silvicultural treatments within an eastern hemlock (Tsuga canadensis) forest, and computer-based simulated harvests of a genetically mapped eastern white pine (Pinus strobus) stand, we found that the selective removal of trees can alter gene frequencies. Due to an association with phenotypic characteristics used to guide harvests, the frequencies of rare alleles appeared particularly vulnerable to manipulation. Depending on the selection criteria used, rare allele frequencies either remained steady, decreased, or increased relative to study controls. Although harvest-associated genetic losses are possible, our data suggests that management can also sustain or enhance genetic richness. Similar to studies within temperate ecosystems, recent research in tropical forests underscores the potential influence of harvesting on the genetics of tree populations. In addition to efforts to reduce controllable sources of ecosystem stress (e.g., high pollutant exposures), management options should be evaluated that may bolster forest ecosystem resilience by preserving levels of genetic diversity within forests.