园林绿化中大树移栽技术

大树是指胸径15厘米以上的常绿乔木或胸径20厘米以上的落叶乔木。移栽期间的乔木多数正处于树木生长发育的旺盛期,这时的适应性和再生能力都较强。大树能移植成活,便能在最短的时间内改变当地环境的自然面貌,充分发挥绿色景观效果,这对新兴工业园区建设尤为重要。一、移植技术移植前准备。在大树移植前必须掌握以下几点:一是树种、树龄、定植时间、移植后的养护管理情况、其生长情况、根系生长情况及病虫害防治情况等。二是树木对周围环境的适应情     

北方园林树木移植技术

<正>现对多年来对园林树木移植中的关键技术进行总结。1树木移植的时期严格地讲,只要树木根系带土,一年四季均可移植,并随着带土体积的增大,可移植的时间范围也增长。一般地讲,在早春,树木芽萌动以前移植最好,适用绝大多数的树种;针叶树均需带土移植,但是,云杉、杜松在新梢快速生长期,樟子松在顶芽萌动后,一般不宜移植;雨季移植,樟子松高生长停止后的雨季非常适合,其它树种在北方一般雨季不移植;秋季也是树木移植的好时期,但在北方樟子松、杜松不宜在秋季移植。对树体大小的不同,移植时期也有所不同,一般树体越大,移植的时期要求越严格。2树木移植时对树体的技术处理     

浅谈大树移植技术

在现代园林绿化中 ,为加快园林绿化速度 ,及时发挥园林树木的绿化功能和艺术效果 ,经常要进行大树移植 ,所以 ,大树移植已成为园林植物栽植的经常性工作。现根据多年的工作实践及经验 ,谈一谈对大树移植的特点及技术。大树移植的特点大树移植成活困难 ,主要有以下几个原因 :１．树龄大 ,阶段发育老 ,细胞再生能力弱 ,挖掘和移植过程中 ,根系损伤多 ,恢复慢 ,新根再生能力弱。２．大树在生长过程中 ,根系扩展范围广 ,不仅超过主枝的伸展范围 ,而且扎入土层深。在移植时土球不能很大 ,而且在一般带土范围内 ,吸收根较少 ,且根系多木栓化 ,所以…     

树木的排水方法

正排水对于树木生长非常重要,它是防涝保树的主要措施。树木生长的土壤水分过多,氧气就会不足,将抑制根系呼吸,减退树木吸收机能。当缺氧严重时,树木根系进行无氧呼吸,容易积累酒精使蛋白质凝固,引起根系死亡。对于耐水力差的树种,更应该抓紧时间及时排水。排     

谈大树移栽成活的关键

大树入城是提高城市绿化品位，改善人居环境的一条重要而有效的途径。大树在城市绿地中起着举足轻重的作用，是城市绿化的骨架，直接关系到城市绿化的景观效果。因此，移栽大树逐渐成为当前园林植物栽植的经常性工作，如何提高大树引进、种植的成活率，直接影响生态效应和景观效果，必需掌握以下几个关键要点。一、提高大树成活的原理大树一般是指胸径在１５cm以上的树木。大树的移栽，较之一般规格苗木的移栽，成活率较低。其原因是大树年龄大，阶段发育老、细胞的再生能力较弱，根系恢复慢，新根发生能力较弱。植物的生境原理和树势平衡原理对树木移植有着直接指导意义。树木的生态环境主要包括小气候、土壤等，如生境类同就可提高成活率，移栽后的生境优于原生境的，移栽成活率更高。此外，保持移植树木地上、地下部分的生理平衡，特别是树体吸收与蒸腾水分的平衡，是确保大树移植成活的又一技术关键。在技术措施上需要掌握适宜的移栽时间，减少根系损伤，进行合理的修剪，栽后及时浇水等。以调整树木地上与地下部之间的生理平衡，促进根系与枝叶的快速恢复和生长，提高大树移栽的成活率。二、大树种植前期准备工作大树移植与一般树木移植相似，但大树的来源多数是零星散生在各处，甚至荒山野地，环...     

苗木移植能提高造林成活率

植物的吸收功能和同化作用,与根量和叶量的关系是非常密切的。根量的减少,会明显地影响幼苗的成活率以及根的吸收作用。在移植苗木过程中,必须保护好苗木根系组织,还要使根系组织有迅速恢复再生的能力,移植后的苗木既或暂时生存,如果不     

红火蚁对不同树种侵染及影响因子研究

以红火蚁在树木根部筑巢作为侵染树木的标准,对广州市南沙开发区一苗圃的树木进行了调查和试验。发现侵染与树种有关;影响侵染的因素包括树木遮蔽度、根系表层发达程度和根系粉碎物对红火蚁的吸引力等。     

乔灌木树种根系的研究

根是构成植物体的主要部分之一,它不仅是吸收和输送水分与营养物质的器官,而且是使物质形成、贮藏和进行繁殖的器官。不同的树木种类,它的根系有不同的形态和构造,虽同一树种,由于生长地条件不同,根系发育情况也不一样。所以当选择造林树种及研究树木的混交时,不仅要调查各种树种的地上部生长,而且也要了解地下部根系在土壤中的结构特性和彼此互间的关     

白杄大苗木移植技术

白杄树形优美,材质优良,不仅是一个优良的用材树种,还是一个优良的绿化树种。白杄大苗移植再生能力较弱,从移植时间、苗木选择、移植方法等方面介绍了白杄大苗木移植技术。     

11个园林绿化树种根系对SO2胁迫的反应特性

用开顶式熏气装置对11种2年生园林绿化苗木进行3种不同浓度的SO2胁迫,并对其根系TTC还原力和根系吸收面积进行了测定,研究了参试树种根系对SO2胁迫的反应。结果表明:在SO2胁迫条件下,大多数树种的根系TTC还原力、根系体积、根系活跃吸收面积、比吸收面积和根系活跃比表面积等指标均出现下降趋势,下降幅度因树种和SO2浓度不同而有较大差异;树种的抗污指数分别与根系TTC还原力、比吸收面积、根系活跃比表面积存在显著正相关关系。     

Approaches to modelling the uptake of water and nutrients in agroforestry systems

This review presents information about root systems of crops and trees and describes approaches that have been used to model uptake of water and nutrients in crops that may have application to agroforestry systems. Only a few measurements of the distribution of tree roots in agroforestry systems have been published and these are predominantly in alley cropping systems with young trees. Therefore, a major limitation to developing water and nutrient uptake models for trees is the lack of adequate measurements and conceptual models for describing the distribution of roots spatially and temporally. Most process-based modelling approaches to water and nutrient uptake integrate the activities of a single root over the whole root system. Several difficulties can be foreseen with applying these approaches to roots of older trees including the presence of mycorrhizal associations so that the root surface is not the site of uptake, the uncertainty as to whether all tree roots are active in taking up water and nutrients, and the fact that, unlike annual crops, trees have substantial reserves of nutrients that can be mobilised to support growth so that the notion of a plant demand regulating uptake may prove difficult to define. The review concludes that a programme of experimental measurements is required together with modelling using approaches both in which roots are implicit, and in which process-based models with roots allow competitive ability to be assessed.     

Water and nutrient dynamics and tree growth

The balance in the investment of assimilate at any time into leaves and roots may depend on whether water, nutrients or radiation are limiting to growth. Also, for the same investment of assimilate into roots, the root configuration may range from intensive to extensive in both space and time, to take best advantage of the distribution and amount of water and nutrients. Intensive root configurations, which include mycorrhizas and proteoid roots, assist in the uptake of nutrients (such as phosphorus) which are rate-limiting in soil. Mycorrhizas may assist in water uptake in dry or coarse textured soils with low unsaturated hydraulic conductivities.

Adaptations which assist trees to survive in dry and nutrient-deficient environments are discussed. These mechanisms may reduce, maintain or increase growth. In production forestry, it is desirable to exploit those mechanisms which increase growth. When soil water and nutrients limit tree growth, productivity may be improved by increasing the amount of uptake of water and nutrients, or by increasing the efficiency by which they are used in growth. Maximizing water-use efficiency when soil water supply is limiting may be dependent on whether the trees are in mixed stands or in monoculture. Selecting trees with relatively less root may improve productivity in monocultures when weeds are controlled and fertilizer is added. It is well known that trees can ‘re-use’ nutrients by retranslocating them within the tree to zones of demand. Relatively little is known, though, about differences in the biochemical involvement of nutrients at the cellular and subcellular level which contribute to differences in nutrient-use efficiency in trees.     

公路绿化中大树移植与养护技术

结合安宁市的自然条件与昆安公路绿化的实际,探讨大树移植技术措施,包括起挖大树前断根、修剪,起挖、包装、运输,栽植技术等.保持树体水分代谢平衡是移植大树养护管理的关键,采取包干、喷水、遮荫等办法保持移植大树地上部分湿润,移栽后做好控水、生长素处理,保护新芽,保持土壤通气性,促发新根.     

园林大树夏季全冠移植的几项关键技术

园林大树夏季全冠移植是现阶段园林绿化建设的常用手段,通过分析大树移栽的几个关键技术,认为铁勾网包扎可代替木箱移植,抗蒸腾剂技术应深入研究推广,成熟后可用于代替全光喷雾技术。易积水的移栽地可使用根部土壤透气技术。营养液滴注技术使用时应注意输液孔处病虫害的侵袭。文章总结提出了断根处理、树干钉板、根部固定和浇水节律等配套技术,可为园林大树夏季全冠移植工作提供参考。     

Exploring below ground complementarity in agroforestry using sap flow and root fractal techniques

Indices of shallow rootedness and fractal methods of root system study were combined with sapflow monitoring to determine whether these ‘short-cut’ methods could be used to predict tree competition with crops and complementarity of below ground resource use in an agroforestry trial in semi-arid Kenya. These methods were applied to Grevillea robusta Cunn., Gliricidia sepium (Jacq.) Walp., Melia volkensii Gürke and Senna spectabilis syn. Cassia spectabilis aged two and four years which were grown in simultaneous linear agroforestry plots with maize as the crop species. Indices of competition (shallow rootedness) differed substantially according to tree age and did not accurately predict tree:crop competition in plots containing trees aged four years. Predicted competition by trees on crops was improved by multiplying the sum of proximal diameters squared for shallow roots by diameter at breast height², thus taking tree size into account. Fractal methods for the quantification of total length of tree root systems worked well with the permanent structural root system of trees but seriously underestimated the length of fine roots (less than 2 mm diameter). Sap flow measurements of individual roots showed that as expected, deep tap roots provided most of the water used by the trees during the dry season. Following rainfall, substantial water uptake by shallow lateral roots occurred more or less immediately, suggesting that existing roots were functioning in the recently wetted soil and that there was no need for new fine roots to be produced to enable water uptake following rainfall. This revised version was published online in June 2006 with corrections to the Cover Date.     

利用Minirhizotron技术监测火炬松新根生长动态

利用Minirhizotron技术 ,研究了位于美国路易斯安那州的 19年生的火炬松新根生长动态。结果表明 ,火炬松新根的根量密度随时间呈增长趋势 ,在生长季末的 1、2月份达到最大。经过林地土壤干旱处理 (通过建立穿透雨隔离系统 ,阻止雨水到达地面 )的树木的根量密度自 9.3cm处 ,随土壤深度增加呈下降趋势 ,未经干旱处理的树木在离土表 80　 10 0cm深处仍有较高的根量密度 ,达 3.4 8　5 .12条·m- 1,是经干旱处理树木对应土壤层次中根量密度的 10多倍。火炬松从 3月份开始发生新根 ,随后迅速增加 ,至 6月份发生最多 ,然后缓慢减少 ,5　 7月的新根发生数占总量的 4 1.8% ,大部分新根发生在离土表 30cm以内的土壤中。 11个月的干旱处理显著地降低火炬松的根量密度 (1 1条·m- 1,未经干旱处理的为 3 2 7条·m- 1)和新根发生数 (5 7条·株- 1,未经干旱处理的为 15 6条·株 - 1) ,干旱处理还可导致新根推迟 1 0　 1.5个月发生。 5a前在土表撒施化肥似乎对新根的发生和生长没有明显影响     

Planting stress in newly planted jack pine and white spruce. 1. Factors influencing water uptake

Bareroot jack pine (Pinus banksiana Lamb.) seedlings (2 + 0) and bareroot white spruce (Picea glauca (Moench) Voss) transplants (1 1/2 + 1 1/2) were taken from cold storage and planted on a clearcut forest site in northeastern Ontario on several dates between May 6 and June 5 during which period soil temperature at 15 cm depth increased from 0 to 18 degrees C. Additional cold-stored trees were transferred to a greenhouse where they were grown in pots for 0, 7 or 28 days and then placed with their roots in aerated water maintained at one of a range of constant temperatures between 0 and 22 degrees C. In both species, daytime xylem pressure potentials (Psi(x)) and needle conductances (g(wv)) decreased with decreasing soil or water temperature. At all root temperatures, g(wv) was lower, and Psi(x) higher, in jack pine than in white spruce. After 28 days in the greenhouse, g(wv) of jack pine seedlings, and Psi(x) of white spruce, was higher than in plants just removed from cold storage. In both species, water-flow resistance through the soil-plant-atmosphere continuum (RSPAC) increased as root temperature decreased. At all root temperatures, RSPAC was higher in plants just removed from cold storage than in plants grown in the greenhouse for 28 days, during which time many new unsuberized roots were formed. At root temperatures above 10 degrees C, RSPAC of both species was higher in trees newly planted in mineral soil than in trees with roots in aerated water; presumably because the roots of planted trees had limited hydraulic contact with the soil. On the day following removal from cold storage, relative plant water flow resistance increased, in both species, more rapidly with declining root temperature than could be accounted for by the change with temperature in the viscosity of water, thus indicating an effect of temperature on root permeability. The same effect was evident in jack pine seedlings, but not white spruce transplants, that had been grown for 28 days in the greenhouse after removal from cold storage.     

Hydraulic conductivity in roots of ponderosa pine infected with black-stain (Leptographium wageneri) or annosus (Heterobasidion annosum) root disease

Roots from healthy and diseased mature ponderosa pine, Pinus ponderosa Laws., trees were excavated from a site near Burns, Oregon. The diseased trees were infected with black-stain root disease, Leptographium wageneri Kendrick, or annosus root disease, Heterobasidion annosum (Fr.) Bref., or both. Axial hydraulic conductivity of the roots was measured under a positive head pressure of 5 kPa, and the conducting area was stained with safranin dye to determine specific conductivity (k(s)). In diseased roots, only 8-12% of the cross-sectional xylem area conducted water. Resin-soaked xylem completely restricted water transport and accounted for 13-16% of the loss in conducting area. In roots with black-stain root disease, 17% of the loss in conducting area was associated with unstained xylem, possibly resulting from occlusions or embolisms. Based on the entire cross-sectional area of infected roots, the k(s) of roots infected with black-stain root disease was 4.6% of that for healthy roots, whereas the k(s) of roots infected with annosus root disease was 2.6% of that for healthy roots. Although these low values were partly the result of the presence of a large number of diseased roots (72%) with no conducting xylem, the k(s) of functional xylem of diseased roots was only 33% of that for healthy roots. The low k(s) values of functional xylem in diseased roots may be caused by fungus induced occlusions preceding cavitation and embolism of tracheids. The k(s) of disease-free roots from diseased trees was only 70% of that for healthy roots from healthy trees. The disease-free roots had the same mean tracheid diameter and tissue density as the healthy roots, suggesting that the lower k(s) in disease-free roots of diseased trees may also have been caused by partial xylary occlusions.     

Ein Beitrag zur Regeneration und zur Infektion von Douglasienwurzeln (Pseudotsuga menziesii [Mirb.] Franco) durch Pilze aus dem Boden1

On the regeneration and infection of roots of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) by fungi present in the soil. 167 roots in 4 stands were severed 40–60 cm from the base of the tree. At the proximal cut ends of the thick roots of the 40 years old trees on loamy sand, either replacement roots or callous tissue were formed (only a small percentage of those roots was invaded by rot causing Basidiomycetes), or no new roots and no callus were formed and root rot fungi (Fomes annosus, Coniophora puteana, Resinicium bicolor) had invaded the root sections from the soil. On the root sections of the 35 and 55 years old Douglas firs on sand, with the exception of 2 roots, neither replacement roots nor callus were formed; Fomes and Coniophora had invaded the thicker roots of the older trees from the soil.     

Growth patterns and morphology of fine roots of size-controlling and invigorating peach rootstocks

We compared growth patterns and morphology of fine roots of size-controlling and invigorating peach (Prunus persica (L.) Batsch) rootstocks. Peach trees were grafted on five rootstocks: a vigorous control (Nemaguard), three intermediate vigor rootstocks (K119-50, P30-135 and Hiawatha), and a semi-dwarfing rootstock (K146-43). Minirhizotron tubes were installed at the base of trees on each rootstock and root images captured with a minirhizotron digital camera system. Number, visible length, and diameter of new roots were recorded at fixed soil depths from April 19, 2000 to December 19, 2001. Root diameter, specific root length, root tissue density and root length density were also measured periodically for each rootstock on roots collected from in-growth cores. Rootstocks had similar seasonal patterns of new root production. Fine root production was lowest in winter and appeared to decline during the final stages of fruit growth. A rootstock with almond in its genetic background (K119-50) produced the greatest quantity of fine roots and had the greatest number of new roots below 69 cm, whereas there were no differences among the other four rootstocks in the total number of roots produced. Rootstock K146-43 had thicker fine roots than the other rootstocks. Independent of rootstock, fine roots produced during spring had greater specific root length than those produced later in the season. The seasonal pattern of fine root production did not appear to be associated with the previously reported effects of these dwarfing rootstocks on shoot growth and stem water potential early in the growing season.