台湾肖楠幼苗移植技术研究

对台湾肖楠幼苗的移植时间、移植密度等进行对比试验.结果 表明:移植密度对台湾肖楠幼苗移植的保存率影响不显著,而移植时间对保存率有极显著影响,其中4月份移植保存率最高;不同移植时间、移植密度及其两者交互作用下的台湾肖楠幼苗的地径、苗高、全株干生物量、根茎比均存在极显著差异.综合比较台湾肖楠幼苗移植的保存率、地径、苗高、干...     

大型树木移植的技术要点与管理措施

本文从移植的大型树木选择、移植、移植后的管理等方面介绍了大型树木移植的技术要点和管理措施。     

园林绿化大树移植技术

根据永州地区气候与土壤条件,从大树选择、定植地选择、移栽时间选择、移植与移植后的养护,以及移植过程中移植档案的建立等6个方面综述了园林绿化大树的移植技术。使用该技术在永州地区移植绿化大树,成活率达50%~95%,其中1~3月或11~12月移植成活率达85%~95%。     

多季树木移植器的研究与应用

树木移植，它包括大树和幼苗的移植，有几千年的历史，是绿化的最基本工作和方法。树木移植，在理论上是可行的，只要树木的移植地和被移植地环境相对一致，树木伤根、失水少，任何树木在任何季节移植都是没有问题的。环境相对一致不变，它包括大气候和小气候、土壤的理化性质等。但树木移植后环     

油松大苗移植技术

大苗移植是加快造林绿化步伐的有效途径,但是大苗移植难以成活.从油松形态特征和生物学特性、移植苗木的选择、苗圃地选择以及移植方法等方面,介绍了油松大苗移植技术.     

樟子松、油松换床移植苗培育技术

樟子松、油松二年生留床苗换床移植后,移植的苗木不仅侧根主根长比留床苗均有增长而且根茎粗壮,侧根发育均称,生长量相对提高。移植地最好选在前茬育过松苗的土地,移植前需要整地、施肥、化垄。移植时间应选在春季土壤解冻达到30 cm时,移植方法采取高垄双行移植。移植苗的管理主要是保持土壤湿润,适时追肥,加强松土除草,越冬覆土。     

园林苗木的培育和管理

从育苗和苗木移植两个环节详细介绍了园林苗木的培育和管理技术。对容器育苗和温室育苗两种方式进行了分别探讨。对移植前期准备、移植时期、移植方法和移植苗木的管理进行了介绍。     

红松优质壮苗培育技术的研究

文章在红松优质壮苗的培育研究中,对平圃地常规移植、平圃地非常规移植、山地移植所生产的苗木,将其苗高、地径、一级侧根数量进行比较,结果表明,平圃地非常规移植、山地移植所生产的苗木的一级苗率好于平圃地常规移植所生产的苗木。     

樟子松移植大苗造林试验

针对樟子松移植大苗造林存在的问题 ,应用正交试验设计的方法 ,较为系统地研究了移植时间、使用的移植器规格和苗木高度范围 ,通过 4年的调查测定 ,总结确定了移植造林的时间、移植器规格和苗木高度     

园林苗木的培育和管理

从育苗和苗木移植两个环节详细介绍了园林苗木的培育和管理技术.对容器育苗和温室育苗两种方式进行了分别探讨.对移植前期准备、移植时期、移植方法和移植苗木的管理进行了介绍.     

Availability of standing trees for large cavity-nesting birds in the eastern boreal forest of Québec,Canada

Large cavity-nesting birds depend on large-diameter trees for suitable nest sites. The increased spatial extent of commercial timber harvesting is modifying forest structure across the land base and may thus compromise the availability of large trees at the landscape scale. In this study, our objectives were to (1) characterize the availability of large living and dead trees in old-growth stands dominated by different tree species and surficial deposits that encompass the range of natural cover types of eastern Québec's boreal forest; (2) analyze the distribution of trees among decay-classes; and (3) compare the availability of large trees in unharvested, remnant, and harvested stands for the entire range of decay-classes. A total of 116 line transects were distributed across unharvested forests, remnant linear forests, and cutblocks in cutover areas. Unharvested forest stands (black spruce [Picea mariana], balsam fir [Abies balsamea]–black spruce, balsam fir–white spruce [Picea glauca] and balsam fir) reflected a gradient of balsam fir dominance. The remnant forests selected were isolated for 5–15 years. Analyses were performed at two diameter cut-off values. Trees with DBH ≥20 cm were considered for availability of total trees whereas trees with DBH ≥30 cm were considered for availability of large trees. Forest stands comprised high proportions of standing dead trees (33% of all stems, 8% were large dead stems). Availability of total and large standing trees increased with the dominance of balsam fir in stands. Forest stands located on thick surficial deposits showed higher densities of large dead trees for every stand type suggesting a higher productivity on those sites. Availability of stems according to decay-classes showed a dome-shaped distribution with higher densities of snags in intermediate decay stages. However, for large stems, black spruce stands showed a significantly lower availability that was consistent across all decay-classes. In linear remnant forests, pure balsam fir stands were absent. Remnant stands thus showed a much lower availability in large trees when compared with unharvested balsam fir stands. Clearcuts had the lowest densities of dead trees across sampled stands. Current even-aged management practices clearly affect availability and recruitment of large trees, therefore forest-dwelling wildlife relying on these structures for breeding is likely to be affected by large-scale harvesting in coniferous boreal forests.     

Characteristics of hollow-bearing trees occupied by arboreal marsupials in the montane ash forests of the Central Highlands of Victoria, south-east Australia

A total of 1125 hollow-bearing trees was observed for the presence of arboreal marsupials in the montane ash forests of the Central Highlands of Victoria, south-east Australia. Different species of arboreal marsupials exhibited preferences for hollow-bearing trees with different characteristics. Gymnobelideus leadbeateri (Leadbeater's possum) selected short, fat trees with numerous holes and a large quantity of dense surrounding vegetation. Very large hollow-bearing trees were favoured as nest sites by Petauroides volans. Petaurus breviceps preferred trees with a large number of fissures, whereas trees favoured by Antechinus stuartii were tall and thin. Trees selected as nest sites by Trichosurus caninus were typically short and fat with few holes. Our results provide evidence of resource partitioning of hollow-bearing trees amongst arboreal marsupials. Clear-felling of montane ash forest on an 80–120-year rotation will have a highly detrimental effect on arboreal marsupials by substantially reducing the number and range of types of hollow-bearing trees required to support the complete diversity of species. The 80–120-year interval between logging operations will result in trees being harvested well before they develop characteristics which make them suitable nest sites for arboreal marsupials.     

广州城区公园风景游憩林径级和高度级结构分布

【目的】探明广州风景游憩林群落结构现状以及存在的问题,进一步为城市风景游憩林群落结构调整和配置优化提供理论依据。【方法】以900 m^2样方为单元分别在广州发展公园风景游憩林群落样地设置样方15个,华南农业大学风景游憩林群落样地设置样方25个,火炉山森林公园风景游憩林群落样地设置样方20个,采用群落生态学的方法,研究了不同生态位风景游憩林径级和高度级结构分布。【结果】1)3个样地风景游憩林径级结构呈现一定差异:广州发展公园以大、中径级乔木占绝对优势,华南农业大学样地风景游憩林小径级乔木相对优势明显,火炉山样地风景游憩林群落以中、小径级乔木占绝对优势。2)根据群落中个体的胸径和树高呈现不同的相关关系表明:广州发展公园样地风景游憩林大径级树木开始出现衰退现象;华南农业大学样地风景游憩林由于存在大量小径级的速生树种,导致胸径—树高曲线在初期迅速增高;火炉山样地风景游憩林结构配置拟自然化,胸径—树高曲线增长较为平稳。【结论】根据高度级比重、相对频度和分布均匀度分析结果得出:广州发展公园样地风景游憩林中、大高度级树木比重较大,且分布更为集中,华南农业大学样地风景游憩林的小、中高度级的树木所占比重较高,小高度级树木分布更为集中;火炉山样地风景游憩林小高度级比重,且分布更为集中。建议通过人工择伐、补植特定树种的方式,调控城市风景游憩林群落的径级和高度级结构分布,促进风景游憩林的逐步稳定。     

林木干形变化规律的研究

利用450株桦树标准木和63株落叶松标准木材料对林木的干形进行了研究,旨在探索林木干形的变化规律,为林木材积的测算提供理论依据。结果表明,林木的各干形指标均因径阶的不同而不同,并且胸高形数和胸高形率均随直径的增大而又变小的趋势。     

Relationship between the incidence of pine wilt disease and the drainage area

We examined the relationship between the incidence of pine wilt disease and moisture conditions in the stand level ofPinus densiflora Sieb. et Zucc. forests in the warm-temperate zone of the western part of Japan. For this analysis, pine trees killed by pine wilt disease were distinguished from the suppressed trees by their position in the layer of the pine forest stand. The drainage area, which is small in the upper part and large in the lower part of the slope, was adopted for representing the moisture conditions in the soil of the slope. The percentage of the pine trees killed by pine wilt disease increased as the size of the drainage area increased. This result suggested that the incidence of pine wilt disease tended to be high in areas with moist conditions. Pine trees attacked by the pinewood nematode die from extensive water deficit due to tracheid cavitations. Pine wilt disease mainly emerges in the summer when the soil water conditions become especially severe, and the radical water stress is thought to accelerate the disease. It was assumed that pine trees in the plots with the small drainage area resisted the influence of the attack of the pinewood nematode because pine trees in the plots with the small drainage area encountered long-term water stress and acquired drought tolerance. Pine trees in the plots with the large drainage area were presumed to be well established in the moist conditions and not to have acquired drought tolerance. The drought tolerance of pine trees was thought to be an important factor in resistance to pine wilt disease.     

广东榕属古树分布及历史文化研究

广东省榕属Ficus古树数量大、种类多,占广东古树总数的29.1%,包括榕树F. microcarpa、雅榕F. concinna等21种。通过分析榕属古树的组成和分布特征,探究影响其保存和保护的历史文化成因。结果表明,在榕属古树中,三级古树占90.2%,粤北地区一级古树数量较多;榕树数量最多,占81.8%。榕属古树在珠三角核心区和粤东、粤西两翼分布密度较大,粤北地区分布密度较小,总体呈现沿海向内陆递减的趋势;村落和寺庙宗祠是集中分布点。榕属古树的分布除了受本属生物学特征和自然地理条件约束,更受到乡村民俗文化、儒释道文化和士大夫文化等文化要素的影响。这些要素既是区域生态文化的体现,也是古树保护与利用的价值所在。传承区域生态文化是保护古树资源的重要途径。     

秦岭西段锐齿栎群落林木个体大小分布特征及物种多样性

对秦岭西段小陇山林区腹地和林缘区的锐齿栎群落的大小分布和多样性进行了分析,结果表明:林区腹地分布区锐齿栎群落的个体较多,锐齿栎成年林木树高频度分布的峰值出现在7 - 19 m间,占总数的73.54%, 3 m以下的幼苗幼树占总数的18.43%,锐齿栎幼苗的萌发受中成林木、灌木的影响较大。在林缘分布区内,小于3 m以下的幼苗幼树与林区腹地分布相类似,但3 m以上各树高阶的数量都很少,特别是成熟林木较少,群落处于不稳定状态。林区腹地锐齿栎群落不同层次的物种组成丰富,物种数均高于林缘区,林区腹地锐齿栎群落多样性灌木层>草本层>乔木层,林缘区锐齿栎群落多样性草本层>灌木层>乔木层。     

Accuracy of the Rotfinder instrument in detecting decay on Norway spruce (Picea abies) trees

Rotfinder is a non-destructive decay-sensing apparatus based on resistance measurements in standing trees. The accuracy of Rotfinder in detecting decay was evaluated in 500 standing trees in three Norway spruce (Picea abies) plots. Trees were measured at three heights, 0.30, 0.66 and 1.30 m. Sections were later inspected for the presence of decay and reaction zones. Inspected trees were mostly infected by Heterobasidion annosum and showed a large variation in the amount of decay present, ranging from 0.1% to 88.0% of the section. Correctly and incorrectly classified trees were compared in terms of ion and element concentration, density and moisture. Measurements at stump level (0.30 m) were more accurate than measurements at breast height (1.30 m) where the reaction zone and decay columns showed lower moisture content. The accuracy of Rotfinder increased when trees with small decay columns were regarded as ‘non-decayed’. When only trees with more than 15% of the section decayed were regarded as ‘decayed’, Rotfinder had an accuracy of 0.86 when performing assessments at stump level. False negatives, as opposed to true positives, corresponded to trees with smaller and drier decay columns, drier reaction zones and lower K⁺ (potassium) concentration in the decay column. False positives corresponded to trees with large sapwood and high sodium content in the sapwood. Rotfinder represents an alternative to the standard method of using increment core observations to assess decay in living trees.     

Mycorrhizal associations in the rain forest of South Cameroon

Mycorrhizal associations of important tree species were investigated within the research area of the Tropenbos Cameroon Programme (TCP), situated on the western portion of the Atlantic Biafrean forest of south Cameroon. Ninety-seven tree species of economic, social, and ecological importance, and three lianas were selected in three sites that differed in altitude, soil clay content, and soil pH. In each site plots were laid out in undisturbed forest. In each plot, seedlings, saplings, juvenile, and mature trees were identified to species level and counted; girth at breast height measured and basal area calculated; root samples were taken and examined for mycorrhizal type and extent of mycorrhizal colonization.

All 100 species investigated were mycorrhizal. Tree of 74 species formed exclusively arbuscular mycorrhizas (AM); 23 trees and three Gnetum species formed ectomycorrhizas (ECM). Five of these ECM plants also harbored AM structures. Extent of mycorrhizal root colonization showed large differences for various AM trees; however, colonization of more than half of these trees was less than 25%. Colonization of ECM trees was often higher than 75%. The contribution of ECM trees to basal area varied between 19 and 35%. ECM trees often occurred in small to large clumps. In sustainable forest management plans, existing ECM forest clumps should be given special conservation value.     

Characteristics of tree damage by the grey red-backed vole (<Emphasis Type="Italic">Myodes rufocanus bedfordiae</Emphasis>) in a deciduous forest in Hokkaido,Japan

In deciduous forests, tree seeds and seedlings are frequently exposed to high predation by small rodents, and this predation can have an important effect on forest regeneration. However, damage to large trees by small rodents has not been studied, except for damage observed during timber production. To determine factors affecting damage to large trees by the grey red-backed vole (Myodes rufocanus bedfordiae), the characteristics and spatial patterns of tree damage by voles at vole wintering sites were examined over 3 years in a deciduous forest in Hokkaido. This study found that the location of damaged trees was related to vole wintering sites. Vole damage was affected by tree species. Damaged trees were heavily concentrated in small areas. Leaning trees and trees that had suffered previous damage were more likely to be damaged. However, the diameter at breast height was not significantly related to vole damage. These differences in susceptibility to vole damage may result in different tree mortality.