关于大兴安岭林区造林工作的几点建议

关于大兴安岭林区造林工作的几点建议罗刚（内蒙古第二林业勘察设计院乌兰浩特１３７４００）通过对大兴安岭次生林区的森林经理二类调查，与近年来的新成林验收工作及森林资源监测工作，发现目前大兴安岭地区的人工造林树种选择极其单一，其中９０％以上的造林地都是营造...     

物种的存亡与天然林保护工程

论述了物种存在的意义，分析了保护物种多样性和实施天然林保护工程的关联性。     

黑龙江省西部半干旱地区引进班克松的可行性

在林业建设中如何搞好树种引种工作,对于增加物种多样性,改善森林结构,提高森林质量,加快造林绿化速度,都具有十分重要的意义.尤其在树种资源匮乏,针叶树种单一的干旱、半干旱区显得尤 为重要,一旦引种成功,其意义将十分深远[1].     

优良乡土树种的现状与开发利用

乡土树种在森林生态网络建设、水土保持、丰富物种多样性、改善农村生态等方面起着非常重要的作用.近年来,随着国家退耕还林工程建设的开展,长丰县林业发展进入了一个崭新时期,全县造林规模不断增长,造林模式不断增多,森林资源得到了快速增长,生态得到了极大改善.     

生态产业接续“木头产业”的历史抉择——关于大兴安岭天保工程发展接续产业的调查

面对我国林业由以木材生产为主向以生态建设为主发展战略的转变，长期以木材生产为主的国有林区如何适应这一转变，实现可持续发展，成为新时期国有林区的历史性选择。大兴安岭林业集团公司紧紧抓住天然林保护工程契机，     

关于大兴安岭林区森林科学经营的建议

大兴安岭林区是中国最北、纬度最高的边境地区,素有"高寒禁区"之称。由于独特的地理位置和丰富的森林资源,大兴安岭林区成为我国东北粮仓和呼伦贝尔草原的天然生态屏障,也是国家重要的生态安全保障区和木材资源战略储备区,在国家生态战略全局中具有特殊地位。大兴安岭巨大的山体     

建立国家湿地公园对提高鸟类物种多样性的影响与建议——以湖南泸溪武水国家湿地公园为例

2014年12月,湖南泸溪武水国家湿地公园获批国家湿地公园试点。通过8年持续有效的湿地保护和管理,截至2022年,湖南泸溪武水国家湿地公园的生态环境质量改善明显,良好生境为鸟类提供了优质栖息地、繁殖场所,鸟类物种数持续增加。为了解湖南泸溪武水国家湿地公园鸟类物种多样性增加的具体情况,应用中国观鸟中心记录软件,通过样线法和固定样地法相结合的方法,于2019—2021年对湖南泸溪武水国家湿地公园中的鸟类进行了实地调查。调查过程中共记录鸟类17目55科162种,相较于2014年建立国家湿地公园之前,鸟类物种数量增加了77种,增加的鸟类中包括黄胸鹀、黑冠鹃隼和黄腿渔鸮等8种国家重点保护鸟类。此外,分析了湖南泸溪武水国家湿地公园生态环境面临的问题,并提出湿地公园鸟类保护的路径,为未来国家湿地公园的建设与管理提供了有益借鉴。     

选择不同造林树种与经济效益关系的研究

在相同立地条件下,选择不同的造林树种,所获的经济效益不同,只有选择适宜树种,才会获得最佳的经济效益。     

濮阳市优良绿化树种生态适应性试验研究

根据引种驯化树种选择原则和驯化成功标准,对100个绿化树种进行苗木引种,通过物候期观察、不同抗逆性试验,结果筛选出了适合濮阳市的优良绿化树种63种,其中29个为新增添树种。       

加强保护与培育珍贵树种资源的建议

由于经济社会发展的大量需求而进行的过度开发利用,导致珍贵树种资源的数量和质量持续下降,造成后备资源匮乏。因此,保护好现有的珍贵树种资源,积极培育和发展珍贵树种,增加森林资源总量和质量,对现代经济社会的发展具有重要意义。     

Estimating tree species diversity across geographic scales

The relationship between number of species and area observed has been described using numerous approaches and has been discussed for more than a century. The general objectives of our study were fourfold: (1) to evaluate the behaviour of species–area curves across geographic scales, (2) to determine sample sizes necessary to produce acceptably precise estimates of tree species diversity, (3) to evaluate relationships among estimates of tree species diversity for local to large geographic scales, and (4) to determine whether the proportion of native tree species may be precisely estimated using sample sizes smaller than those necessary to estimate total tree species diversity. Such investigations are necessary to improve biodiversity monitoring at large scales. The analytical approaches included Monte Carlo bootstrap simulations and two geospatial methods and relied on a database populated with data for more than 12,000 national forest inventory plots (NFI) from 16 regional units, 13 European countries and three ecoprovinces of the United States of America (USA). Four primary results were obtained. First, tree species diversity may be precisely estimated using observations for a random subsample of 2,000–4,000 NFI plots. Second, large sample sizes are necessary to estimate tree species diversity for regional units or forest categories, except possibly for boreal forests for which the number of tree species is small. Third, estimates of the proportion of native tree species may be precisely estimated using tree species information for a random sample of approximately 30 NFI plots. Finally, our estimated species–area curves show that the curve shapes and relationships among estimates of tree species diversity at large scales clearly depend on the relative geographic location of the anchor regional unit (a European country or ecoprovince of the USA) relative to the other regional units. None of the well-known models for species–area curves adequately describes our results. The conclusion was that the uncertainties of the estimates reflect the unfavourable state of global biodiversity monitoring of species groups. The total numbers of tree species in our regional units, which cannot be adequately estimated, are small relative to other tree species-rich regions. Consequently, monitoring of tree species diversity is currently a highly uncertain enterprise at large scales.     

关于树种发展战略问题的探讨

随着社会经济的发展，林业已成为备受社会关注的行业，参与林业发展的越来越多，树种发展问题一时成为人们关注的焦点。本文介绍了树种发展的制约因子，从理论、实践剖析了树种发展应坚持的几个原则，强调了树种发展的基本思路和应采取的措施。     

Patterns of genetic diversity in Australian tree species

Australia has a large endemic tree flora with many of the genera largely confined to the southern hemisphere. The two dominant genera are Eucalyptus and Acacia. Isozyme studies of patterns of genetic diversity in populations of these species are reviewed. Generally, Australian tree species have high levels of allozyme variation with most of this variation within rather than between populations. The species with the most genetic differentiation between populations are those with regional distributions but with small disjunct populations. Many of the species show no discernible relationship between current population sizes and genetic diversity. A number of species with widespread distributions exhibit similar clusters of populations both on isozymes and other traits. Such clusters often correspond to large geographic regions. This pattern suggests that preliminary low intensity isozyme surveys could help to define more efficient sampling strategies for intensive seed collections and subsequent field trials of many tree species.     

密度对华北落叶松人工林树高、胸径和物种多样性的影响

以河北省木兰围场国有林场管理局克勒沟林场华北落叶松人工林为研究对象,对标准地内保留密度为400株/hm2、600株/hm2、900株/hm2、1 100株/hm2的华北落叶松在上坡位、中坡位、下坡位的树高和胸径以及物种多样性进行了调查分析,结果表明:在保留密度为600株/hm2时,林木生长最好,树高最大;保留密度小于600株/hm2时,树高随着密度的增大而增大,但大于600株/hm2时,树高会随着密度的增大而呈现降低的趋势;胸径会随着保留密度的增大而减小;对不同密度样地中的植物重要值及物种多样性指数进行了计算,林下草本层植物的数量、多样性指数在保留密度为600株/hm2时达到最大值,之后随着密度的增加均呈递减的趋势。     

Farmer-led approaches to increasing tree diversity in fields and farmed landscapes in Ethiopia

Agroforestry Systems - Increasing tree cover and managing trees better on farms in Ethiopia supports livelihoods and the environment but most tree-planting schemes promote only a few species. This...     

试论森林树种生物多样性保护的遗传学理论基础

森林树种生物多样性的保护是当代全球关切的问题之一。要保存森林资源,也就要保存森林物种,更重要的是保存构成森林主体的树木。而要保存树种,首先要保存树种内性状的多样性,因为种内多样性消失是物种消失的先导。同名性状多样性,是决定或控制同名性状的等位基因决定的,因此与保存多种多样的基因资源联系在一起。现就森林树种生物多样性保护与遗传学中的变异等理论关系作以简述。１　生物多样性和森林树种资源 生物多样性是人类赖以生存的各种有生命资源的总汇和未来工农业、医药业发展的基础,为人类提供了食物、能源、材料等基本需…     

Tree-root systems and herbaceous species-characteristics under tree species introduced into grazing lands in subhumid Cameroon

The effect of tree species on the characteristics of the herbaceous stratum, during the first five years of a fallow, was evaluated in the North of Cameroon (average annual temperature 28.2 °C, total annual rainfall 1050 mm). Treatments included a natural grazed herbaceous fallow, a natural ungrazed herbaceous fallow and three planted tree fallows (Acacia polyacantha Willd. ssp. campylacantha (Hochst. ex A. Rich.), Senna siamea Lam. and Eucalyptus camaldulensis Dehnh.), which were protected against grazing. Because tree species influenced light interception in different ways, as well as having different root patterns, they had different effects on the herbaceous stratum in terms of species composition and biomass. The grazed herbaceous fallow maintained the greatest species richness. Protection against grazing or the introduction of tree species associated with the absence of grazing induced both a progressive evolution to a particular species composition. The ungrazed herbaceous fallow consisted mainly of Andropogon gayanus Kunth, which provided the greatest biomass (8 t dry matter ha^–1 at the end of the fallow period). E. camaldulensis provided little shade and the lowest fine root mass in the top layer allowing the growth of A. gayanus and thus a greater herbaceous biomass (3.5 t DM ha^–1) than that found under the other tree species. Under the heavy shade of A. polyacantha, the herbaceous stratum consisted mainly of annual Pennisetum spp. (2.2 t DM ha^–1) and showed the greatest N concentration (1.3%), probably due to N₂ fixation by the tree species. After the fourth year, despite the relatively open tree canopy, S. siamea, which showed the highest fine root mass, had a strong depressive effect on the herbaceous stratum. This revised version was published online in June 2006 with corrections to the Cover Date.