浅谈我国林地资源概况及可持续利用策略

本文以全国森林资源数据为基础,分析现有林地资源的数量、质量格局,提出现有林地资源的可持续利用策略与具体目标.     

大同市园林树种资源及开发利用前景

丰富的园林绿化树种是城市园林绿化重要的物质基础。在简要介绍大同市立地情况的基础上,针对大同市现有园林树种资源的利用现状及存在问题,提出了充分利用现有树种资源、引进外地园林绿化树种、大力开发利用野生树种资源的开发利用对策。     

宣化县黄羊滩原生植被资源调查分析评价及保护利用

宣化县黄羊滩原生植被的初步鉴定显示,现有植物共计77科、224属、389种,该文对现有资源进行优势科、优势属、植物生活型、生态型和资源分类进行分析评价,提出黄羊滩植物资源的开采利用及保护措施。     

河南银杏资源的保护与持续利用

根据河南银杏资源特点，提出了银杏资源持续利用的保护措施和发展对策：认真做好现有资源的优良单株调查，保护现有古树，对实生大树进行高接改良和人工授粉；提高良种苗木繁殖技术，提高对现有银杏资源保护和持续利用的认识；树立人口－资源－经济－环境相互协调持纽利用的整体观念，使银杏朝着生态经济化方向发展；建立银杏资源数量，质量的监测，预报系统，加强国际合作与交流，加速限杏产品开发，不断提高银杏的经济价值。     

加快后备资源培育促进生态环境建设

文章以鄂伦春自治旗嘎仙沟经营林场现有资源为例 ,阐述了加快后备资源培育的重要性。     

安陆市树种资源的保护及开发利用

本文通过对安陆市树种资源现状概述,阐述了如何保护现有的树种资源,提出了其开发策略。     

福建省药用植物资源的保护和可持续利用

论述了福建省药用植物资源分布和特色以及现有资源保护和培育现状,指出存在的问题,提出福建省药用植物资源保护和可持续利用的对策。     

浅谈园林植物资源的开发利用

概述了我国园林植物资源开发利用的现状，分析了开发园林植物资源的必要性及可能性，并结合江苏的实际提出了充分开发利用现有植物资源的措施。     

南靖兰花栽培技术措施与保护对策

根据兰花生长发育适宜的条件,阐述南靖兰花栽培技术措施。依据全县兰花现有资源现状,提出保护南靖兰花资源的对策。     

蟒头山国家森林公园优质树种资源初探

介绍了蟒头山国家森林公园现有的优质树种资源,并对园区现有白皮松林、山杨林、白桦林、辽东栎林、山桃灌丛等5类主要植被群系和山花景观、白皮松景观、红叶景观等3个主要森林植物景观类型进行了论述和评价,同时对森林公园现有植物景观提出新的设计营造方案,对森林公园内优质树种资源保护和利用提出建设性意见.     

暴马榆1年生苗生长观测及苗期管理

通过对暴马榆1年生播种苗生长进行定期观测,采用Logist曲线对苗高生长过程进行拟合,建立生长模型,经对生长模型进行计算分析,结果表明:暴马榆1年生苗高生长相关系数达0.994 369,拟合效果显著。1年生暴马榆播种苗高生长过程可划为生长前期、速生期和生长后期。生长前期约35d,苗木累积生长量为15.3cm,累积生长率为23%;速生期约48d,苗木累积生长量为40.8cm,累积生长率为61.3%;生长后期约38d,苗木累积生长量为10.5cm,累积生长率为15.7%。     

色木槭、拧劲槭生长分析及生长阶段划分初探

以色木槭、拧劲槭天然林解析木为对象,用Logistic模型对树高、胸径、材积生长进行拟合,研究其生长规律。结果表明：树高、材积生长拟合效果良好。色木槭树高生长9 a前为生长前期,9～31 a为速生期,20 a为生长高峰年,31 a后为生长后期;材积生长25 a前为生长前期,25～38 a为速生期,32 a为生长高峰年,38 a后为生长后期。拧劲槭树高生长9 a前为生长前期,9～40 a为速生期,12 a为生长高峰年,40 a后为生长后期;材积生长28 a前为生长前期,28～43 a为速生期,36 a为生长高峰年,43 a后为生长后期。色木槭、拧劲槭树高、胸径生长在15 a前比较接近,15 a后色木槭明显高于拧劲槭;色木槭、拧劲槭材积生长在18 a前比较接近,18 a后色木槭明显高于拧劲槭。     

Environmental influences on juvenile shoot growth in Picea abies

Under certain environmental conditions, juvenile shoot growth characters might give early indications of adaptability and growth potential. Therefore, the reaction patterns of predetermined and free shoot growth were studied on Picea abies (L.) Karst, plants, which at different times during the growth period were treated by (1) application of nutrients, (2) defoliation, and (3) short days. Fertilization caused an increase in both predetermined and free growth, while defoliation and short day treatment caused a decrease in both forms of shoot growth and short days did not allow any free growth to occur. In the growth period following the treatments, fertilization caused more predetermined and less free growth to occur, while defoliation caused less predetermined and more free growth. Predetermined growth is explainable by the finite number of predetermined needle primordia. Free growth is initiated thereafter. It is influenced strongly by the environmental conditions and seems not to be influenced by the amount of preceding predetermined growth. Free growth enables young plants to utilize favourable growth conditions in summer for height growth precociously, which might increase their adaptability and competitive value. However, predetermined growth is the preferable mode of shoot growth because favourable conditions in successive growth periods induce more predetermined than free growth. Predetermined and free growth are well integrated forms of shoot growth giving no supporting evidence to the hypothesis that free and predetermined growth are inherited independently of each other. Rank changes in provenance development are probably not explainable by a loss in height growth when free growth occurs no more due to age, but by other causes.     

Tree growth as indicator of tree vitality and of tree reaction to environmental stress: a review

The intensive monitoring plots (Level II) of ICP Forests serve to examine the effects of air pollution and other stress factors on forest condition, including tree vitality. However, tree vitality cannot be measured directly. Indicators, such as tree growth or crown transparency, may instead be used. Tree growth processes can be ranked by order of importance in foliage growth, root growth, bud growth, storage tissue growth, stem growth, growth of defence compounds and reproductive growth. Under stress photosynthesis is reduced and carbon allocation is altered. Stem growth may be reduced early on as it is not directly vital to the tree. Actual growth must be compared against a reference growth, such as the growth of trees without the presumed stress, the growth of presumed healthy trees, the growth in a presumed stress-free period or the expected growth derived from models. Several examples from intensive monitoring plots in Switzerland illustrate how tree-growth reactions to environmental stresses may serve as vitality indicator. Crown transparency and growth can complement each other. For example, defoliation by insects becomes first visible in crown transparency while stem growth reaction occurs with delay. On the other hand, extreme summer drought as observed in large parts of Europe in 2003 affects stem growth almost immediately, while foliage reduction becomes only visible months later. Residuals of tree growth models may also serve as indicators of changed environmental conditions. Certain stresses, such as drought or insect defoliation cause immediate reactions and are not detectable in five-year growth intervals. Therefore, annual or inter-annual stem growth should be assessed in long-term monitoring plots. An erratum to this article can be found at     

一平浪林场云南松单株木生长规律初步研究

通过对一平浪林区云南松的林分调查以及树干解析,分析了林分的树高、直径生长过程,结果表明,云南松生长发育过程可划分为苗木生长初期.树高速生期、直径速生期、速生后期和成熟期5个生长阶段.前5年为苗木生长初期,5～10 a是林分开始郁闭.高生长明显加快,10～25 a期间,云南松直径生长量也开始达高峰期,需要加强抚育管理措施;25～45 a期间,直径旺盛生长,树高保持一定生长量,而材积生长量保持最大,其后云南松进入速生后期,生长渐趋于缓慢,但仍保持较高的生长量.表明云南松速生期较长,可作长轮伐期经营,是培育大径材的理想树种.     

林木调查因子生长率之间的关系研究

以湖南省会同县的杉木为例，研究了直径生长率与树高生长率、材积生长率的相关关系。采用生长量修正法建立了杉木单木竞争生长量模型，回归拟合出树高生长指数κ的相关模型作为中介模型，推手出了杉木直径生长率、树高生长率、材积生长率的预估模型。     

濒危植物白桂木种子繁殖苗年生长规律研究

通过白桂木播种育苗,研究白桂木1年生苗在苗期的生长规律。经定期观测和回归分析,模拟苗木生长与时间的数学模型。结果表明：采用有序样品聚类法将生长期划分为3个时期：生长初期、生长盛期、生长后期,生长盛期生长量占总生长量的60％-70％;用幂函数模型来模拟白桂木1年生苗各生长时期苗高和地径的生长情况的相关系数和拟合度最高。     

Variation of growth rhythm among families and correlation between growth rhythm and growth Rate in Betula pendula roth

Growth rhythm, including growth initiation, growth cessation, growth period, and growth rate for Betula pendula were observed on two full‐sib trials of reciprocal recurrent selection and polycross. The results indicate that most of the characters of growth rhythm show significant differences among families and mating patterns. The variations of the characters of growth rhythm are more strongly under genetic control than those of growth rate. The correlations between most characters of growth rhythm and growth rate are highly significant.     

引种元宝枫抽梢年生长规律研究

对云南引种的元宝枫生长情况在定点观测的基础上进行数据分析,结果表明:元宝枫大树和留床苗3～4 月份是高生长的主要时段。1 a中,高增长量呈单峰曲线,粗增长量呈双峰曲线;当年播种苗和移栽苗在3～5月份生长缓慢,6～7月份生长迅速;有长枝和短枝的分化,短枝在5月底停止高生长,高度不超过30 cm,长、短枝粗增长保持同步,呈双峰曲线。     

Modelling annual individual-tree growth and mortality of Scots pine with data obtained at irregular measurement intervals and containing missing observations

An individual-tree growth model was developed with data from 54 permanent plots of Scots pine (Pinus sylvestris L.) located in Galicia (northwestern Spain). The study involved two model fitting approaches, one considering constant growth and mortality rates in the period between two consecutive inventories, and another considering variable growth and mortality rates in the same period. The individual-tree growth model was based on annual basal area growth, height growth and survival probability. The model included variables from groups pertaining to tree size, competition and age. Weighted regression was used as a tool for dealing with missing height observations in model fitting. Evaluation of the model via simulation of growth and mortality in the period between inventories showed that the variable growth rate approach provided slightly better results than the constant growth rate approach. The final model was consistent with expected diameter growth, height growth, dominant height growth, stand basal area growth and reduction in number of stems per hectare.