大树移植技术及注意事项

在现代城市的建设当中,大树移植逐渐成为推进城市绿化的重要手段。在城市绿化过程中如何保证大树的成活率成为一个关键问题。本文主要从大树的选择、大树移植前的准备工作、大树移植和移植后的养护管理几个方面介绍了大树移植技术,以期为大树的移植和养护提供一定的参考。     

浅谈大树移植技术

长期以来,城市园林绿化的树种相对比较单一。当大树移植兴起之后,日益丰富了城市园林的绿化树种,改善了城市居住环境。在当前的城市绿化过程中,大树移植的作用日益重要。本文就大树移植时间,移植大树的准备工作,挖掘、包装、吊运方法,大树的栽植及养护等方面阐述了大树移植技术,以期科学运用大树移植技术。     

国槐大树移植技术

总结蓟县国槐大树移植的关键技术,包括国槐大树移植前的准备工作、移栽大树的方法和国槐大树定植后的养护管理。     

浅析全冠大树移植成活率低的原因及对策

目前各种景观设计、园林工程都涉及到全冠大树移植方面的工作。提高大树移植的成活率,就必须了解大树的生长习性,遵循植物的生长规律。我国各个地区在大树移植的工作上都存在一些技术上的欠缺。针对大树移植中容易出现的问题,笔者在文章中,根据多年的大树移植经验,结合实践,分析了全冠大树移植成活率低的原因,提出相应的对策措施,以供参考。     

城镇绿化大树移植技术要点

随着时代的发展和城市的进步,城镇的绿化建设问题逐渐被人们所关注,而在园林绿化中常用的手段就是将大树进行移植和栽培。因为大树移植可以使绿化在短时间内达到目的,但在城镇大树移植时存在一些问题,导致大树死亡,成活率低等。本文主要针对大树在城镇绿化中的移植进行研究和探讨,并根据大树移植死亡的原因进行分析,提出合理的建议和对策,以确保大树移植后健康的生长。     

浅析大树移植技术

为了保证大树移植正常成活,本文主要通过对移植树木的选择、土壤选择与处理、大树预先断根、大树修剪、大树起挖运输技术、大树栽植技术、大树养护管理等大树移植技术措施的阐述,以提高大树移植成活率。同时对大树移植存在的弊端进行探讨,并提出参考建议。     

园林绿化中大树移植技术分析

园林绿化工作有利于改善城市的环境质量,优化城市形象,对城市的发展具有关键性作用。大树是园林绿化中的关键元素,街道两旁、广场、建筑物旁边等都有大树的踪影,注重对大树移植技术的掌控非常关键。就园林绿化中大树移植技术进行了分析与探究。     

大树移植技术探讨

在园林绿化工程中,为了迅速达到绿化、美化的景观效果,经常需要移植大树,但是在大树移植过程中由于技术措施应用不当往往造成移植大树成活率较低。本文从大树移植前准备、移植过程、移植后的养护等方面阐述大树移植的技术措施,以期提高大树移植成活率提供理论参考。     

大规格树木移植过程中的问题与方法

大树移植在园林绿化工程中见效快、效果好。文章主要阐述大树移植过程中需注意的问题,如大树移植时间、移植前准备、起苗包装方法、大树吊运、定植、后期养护管理等,以及在每一个环节中新技术、新方法的应用。     

当前大树移植存在问题及解决办法

<正>1当前大树移植存在的问题近年来,大树移植已成为一种时尚,景观绿地中,若种植大树,绿量迅速提高,景观效果立竿见影,对提高绿地质量,增加城市绿量确实起到了很好的作用。而大树在生态效益方面更是功不可没,绿色是城市之"肺"。大树吸收二氧化碳、制造氧     

园林大树移植树皮复原保活技术

介绍了园林大树移植过程中树皮复原的应用范围及其相应的植皮技术,以期对园林大树的移植养护管理起到指导作用。     

Assessing the structure and stability of street trees in Lhasa,China

Street trees can provide important environmental services to residents living in high-altitude cities. Nevertheless the performance of street trees in this unique environment is largely unknown. This article examines the impact of high-altitude environments on the growth of street trees through a case study in Lhasa, China. The structure, species composition, and health condition of street trees in Lhasa were surveyed using a representative sampling approach. The history of street tree programs and factors that affect the health of street trees was also analyzed. The results showed that there were 24 species and cultivars in 2032 sampled street trees. The street tree population in Lhasa contained a significant number of small trees, which was due to the large-scale planting program initiated in recent years. The street tree population in Lhasa was not very stable due to the uneven age distribution. The health conditions of street trees were affected by climatic factors as well as by management practices. We concluded that unfavorable environmental conditions in high-altitude cities may affect the sustainability of street tree populations to some degree but that human management of the street tree population is a more significant factor.     

一个数学模型在果树栽培学中的应用

假设树冠为一仅由连续叶片组成的密度均匀的曲面体,通过计算单位土地面积上的果树树冠的总表面积和总容积发现,树形相似时,封行后矮化密植与常规种植果树的树冠总表面积相等,而矮化密植果树树冠的总容积相对较小;通过计算单位土地面积上不同树形树冠的表面积,发现他们差异悬殊。进而研究树冠的表面积和容积与栽植密度和树形之间的关系,为矮化密植高产、优质及树形选择提供新的理论依据和参考。     

苹果苗木类型和栽植时间对幼树生长特性的影响

【目的】为了研究不同栽植时间下不同苗木类型的生长特性,【方法】以3 a生‘长富2号’/‘M26’/八棱海棠为试材,测定3个栽植时间(2010年3月10日、4月10日和5月10日)下分枝苗、去分枝苗和单干苗生长特性相关指标。【结果】5月份栽植植株的生长势弱于3、4月栽植的植株;单干苗生长势弱于分枝苗和去分枝苗。栽植后第2年,3、4月栽植植株的株高、主干粗度显著大于5月栽植的植株。去分枝苗和单干苗株高显著大于分枝苗。3种苗木类型主干粗度依次为分枝苗>去分枝苗>单干苗,且相互差异显著。分枝苗和去分枝苗冠径显著大于单干苗。栽植后第3年,分枝苗的花芽数显著高于去分枝苗和单干苗。【结论】苹果苗木在冷藏条件下,4月栽植是可行的,本试验中3月份栽植较为适宜。分枝苗有利于促进幼树提早开花结果。     

Influence of rate and method of application of superphosphate on the growth and nutrient status of newly planted peach trees

A field experiment was carried out with newly planted peach trees to determine the influence of both rate and method of application of superphosphate on tree growth and nutrient status during the first growing season. Superphosphate was applied at planting at rates ranging from ¼ to 9 lb per tree, and applications were made either to the soil surface, in the planting hole, under tree roots, or in a band around the tree at a depth of 6 inches. Trees were grown under straw mulch and were irrigated as required.

Results showed that, in this soil of low initial ? content, trees receiving 9 lb superphosphate on the soil surface or in a ring band grew significantly larger than trees receiving ¼ lb superphosphate per tree (this applied for butt circumference only on surface-treated trees), but high rates of superphosphate in the planting hole or under tree roots resulted in tree death. No significant differences in growth were recorded at harvest between surface and ring-banded treatments at any phosphate rate, but leaf analysis in midsummer and tree analysis at harvest showed that the phosphate status of surface-treated trees was significantly higher than that of ring-banded trees.

At low rates of superphosphate (¼ and 1 lb per tree), surface treatment tended to give larger trees at the end of the growing season than band treatment, but differences were not significant. It is thought that this differential response occurred because the phosphate-fixing potential of the soil increased sharply with depth and hence band applications were inefficient unless very high rates of superphosphate were used.

The tree damage observed when high rates of superphosphate were applied in the planting hole or under tree roots was probably due to a combination of osmotic stress, acidity damage to the roots and possibly toxic nutrient levels in tree tissues. Hence high rates of superphosphate should not be placed close to tree roots at planting.

Leaf analysis in midsummer and tree analysis at harvest showed that the main effect of superphosphate application was on the ? status of the trees, and maximum tree growth in the surface and band treatments corresponded to a value of approximately 0.28% ? (dry weight basis) in the leaves. The efficiency of uptake of applied superphosphate was very low at all rates of application and was especially so at high rates. However, positive growth responses were recorded to 9 lb superphosphate per tree in surface and banding treatments. It is suggested that, although most of the applied superphosphate could not be utilized, tree growth rate was proportional to the concentration of ? in the soil zone which could be exploited by the roots.     

Twelve-year change in tree diversity and spatial segregation in the Mediterranean city of Santiago,Chile

Tree diversity is one of the most important components of urban ecosystems, because it provides multiple ecological benefits and contributes to human well-being. However, the distribution of urban trees may be spatially segregated and change over time. To provide insights for a better distribution of tree diversity in a socially segregated city, we evaluated spatial segregation in the abundance and diversity of trees by socioeconomic group and their change over a 12-year period in Santiago, Chile. Two hundred vegetation plots were sampled across Santiago in 2002 and 2014. We found that overall abundance and diversity of urban trees for the entire city were stable over 12 years, whereas species richness and abundance of native tree species increased. There was segregation in tree species richness and abundance by socioeconomic group, with wealthier areas having more species and greater abundance of trees (for all tree species and native species) than poorer ones. Tree community composition and structure varied with socioeconomic group, but we found no evidence of increased homogenization of the urban forest in that 12 years. Our findings revealed that although tree diversity and abundance for the entire city did not change in our 12-year period, there were important inequities in abundance and diversity of urban trees by socioeconomic group. Given that 43% of homes in Santiago are in the lower socioeconomic areas, our study highlights the importance of targeting tree planting, maintenance and educational programs in these areas to reduce inequalities in the distribution of trees.     

Modelling the spread of tree pests and pathogens in urban forests

Understanding the potential dynamics of tree pests and pathogens is a vital component for creating resilient urban treescapes. Epidemiologically relevant features include differences in environmental stress and tree management between street and garden trees, and variation in the potential for human-mediated spread due to intensity of human activity, traffic flow and buildings. We extend a standard spatially explicit raster-based model for pest and pathogen spread by dividing the urban tree population into roadside trees and park/garden trees. We also distinguish between naturally-driven radial spread of pests and pathogens and human-mediated linear spread along roads. The model behaviour is explored using landscape data for tree locations in an exemplar UK town. Two main sources of landscape data were available: commercially collated aerial data, which have high coverage but no information on species; and, an urban tree inventory, with low, non-random, coverage but with some species data. The data were insufficient to impute a species-specific host landscape accurately; however, by combining the two data sources, and applying either random or Matérn cluster point process driven selection of a subset of all trees, we create two sets of potential host landscapes. We find that combining the two mechanisms of dispersal has a non-additive effect, with the enhanced linear dispersal enabling new foci of infection to be established more rapidly than with radial dispersal alone; and clustering of trees by species slows down the expansion of epidemics when compared with random distribution of tree species within known host locations.     

Updating urban forest inventories: An example of the DISMUT model

Canberra is a unique city in Australia where the trees on public land that dominate the urban forest were planned for at the city's inception. In the mid-1990s, a 100% census of street and park trees was completed, and together with simple health, growth and yield models, this database formed the basis of a decision information system to support the management of the urban trees – DISMUT. The accuracy of the models was evaluated in a study in 2005 where models to predict total tree height were found to be unbiased and precise, tree crown dimension were under-estimated for small trees, and tree health was over-estimated. The over-estimate of health may be due to the relatively poor rainfall conditions over the past 10 years while the biases in crown dimension predictions are more likely due to a too simple model form. However, the existence of DISMUT predictions over all streets and parks in Canberra means that statistically efficient two-phase sampling approaches can be used to correct for any bias in the mean estimates of tree numbers and size, and also to predict the mean value of other environmental, economic or social parameters of interest that are correlated to tree size.     

Restoration of the urban forests of Tokyo and Hiroshima following World War II

The urban forests of Tokyo and Hiroshima were devastated by American bombing during World War II. Approximately 160 km² of Tokyo were burned by more than 100 fire bombings, while an area of 12 km² was leveled and burned by one atomic bomb in Hiroshima. Tokyo's street tree population was reduced from 105,000 to approximately 42,000 by the end of the war. In the years immediately following the war, the street tree population dropped to 35,000 in Tokyo due to a combination of further tree mortality and the cutting of trees for fire wood. No estimates of pre-war street tree populations are available for Hiroshima. Examination of pre- and post-atomic bombing photographs of Hiroshima suggests an even higher percentage of the trees in the city were destroyed. Post-war reconstruction of the urban forests of each city developed along different pathways. Plans for the redevelopment of Tokyo were rejected by the general public who wanted a return to pre-war conditions. Few streets were widened to accommodate traffic and allow for new street tree planting. Plans for new parks were shelved or only partially achieved. Some streets were replanted by private citizens. Initial survival rates of replanting were low. Trees in Tokyo's municipal tree nurseries, which had not been converted to vegetable gardens during the war, were often larger than the optimal size for transplanting, but were used as no other trees were available. A more concerted effort to reconstruct the urban forest came following the 1959 decision to site the 1964 Olympic Games in Tokyo. Many streets were widened and planted with trees. New tree-lined boulevards were also created. In contrast, Hiroshima sponsored an international competition for the design of a Peace Park and a major tree-lined boulevard. Several wide streets were built with space for street trees. Major plans were also drawn to create greenways along the rivers and to build additional parks. Trees were initially donated by local farmers and nearby towns for planting the parks and the boulevard since municipal tree nurseries had been converted to vegetable gardens during the war. Survival rates were very low due to the rubble content of the soil and difficulties in watering the transplanted trees. Strong support from the mayors of Hiroshima contributed to the success of urban forest reconstruction in Hiroshima. The historical significance of the destruction caused by the first atomic bomb to be dropped on an urban area also contributed to Hiroshima citizens' will to reconstruct both the city and its urban forest. Species and location of trees determined the survival of trees after war in both cities. Species with strong resprouting ability and thick bark survived the bombing and fire. In Tokyo trees located in open areas avoided the fire, while in Hiroshima trees standing behind tall concrete buildings were shielded from radiation and the heat wave. In addition to the difficulties faced during the city-wide replanning process, constraints of urban forest recovery included severe financial restriction, short supply of proper large-sized trees for planting and lack of labor for planting and post-planting tree care. Hiroshima used public participation and community involvement to restore the urban greenery successfully and, until today, has maintained a program to conserve the trees that survived the atomic bomb.     

Redeveloping the urban forest: The effect of redevelopment and property-scale variables on tree removal and retention

The effects of urbanization on urban forest canopy cover has received significant consideration at broad scales, but little research has explored redevelopment-related influences on individual tree removal at a property scale. This study explores the effect of residential property redevelopment on individual trees in Christchurch, New Zealand. The study monitored 6966 trees on 450 residential properties between 2011 and 2015/16. Of the 450 properties, 321 underwent complete redevelopment during that time, while 129 were not redeveloped. The percentage of trees removed on redeveloped and non-redeveloped properties differed markedly, being 44% and 13.5%, respectively. A classification tree (CT) analysis was used to examine the effects of different combinations of 27 explanatory variables, describing land cover, spatial relationships, economic, and resident and household variables, on tree removal or retention on the properties. The best model included land cover, spatial, and economic variables (accuracy = 73.4%). The CT of the corresponding model shows that trees were most likely to be removed if they were within 1.4 m of a redeveloped building on a property with a capital value less than $1,060,000 NZ. The strongest predictor of tree retention was that the property was not redeveloped. The model predicted that trees were over three times as likely to be removed from a redeveloped property relative to a property that was not redeveloped. None of the seven resident and household variables were selected by the CT as important explanatory variables for tree removal or retention. These results provide insights into the factors that influence tree removal during redevelopment on residential properties, and highlight the need for effective tree protection during redevelopment.