GARDEN SHOWS: THE DRIVING FORCE FOR LANDSCAPE MANAGEMENT, URBAN DEVELOPMENT AND INDUSTRY

Luise Preisler-Holl*

Summary

The role of international, federal, state and regional garden shows in the promotion of landscape management, urban development, and industry within Germany is reviewed and discussed.

Since the post Second World War period, Germany has developed a tradition of garden shows as the impetus for ecological, cultural and economic development of urban areas and their environs. Initially, garden shows were used to stimulate the regeneration of bombed areas by restoring devastated urban parks and public amenities and by controlling dust and pests. From the late 1950's onwards, the focus shifted towards urban regeneration with the creation of green spaces and green corridors in densely populated areas. In the 1980's, the debate on ecological aspects of green areas started and this is now a focal point of all regeneration projects.

Currently there is debate as to the future of garden shows in Germany. The requirements of strategies to continue the tradition of garden shows are discussed.

LANDFILL LEACHATE NUTRIENT RECOVERY BY WILLOW SHORT ROTATION COPPICE I. YIELD, TISSUE COMPOSITION AND WOOD QUALITY

Andrew Godley*, Gillian Alker*, John Hallett*, Richard Marshall** and Drusilla Riddell-Black***

Summary

Landfill leachate is composed of a variety of organic and inorganic components that require treatment before it can be discharged to natural waters. Landfill operators are seeking to develop sustainable cost effective methods for landfill leachate management particularly for remote or abandoned sites with leachates having low concentrations of contaminants. This study evaluated the application of willow short rotation coppice (SRC) as a leachate treatment option. The results indicated that the willow SRC could effectively treat the leachate significantly attenuating the leachate contamination reducing the environmental burden of the discharged leachate. Additionally the willow benefited from the fertiliser value of the leachate components increasing the willow yield without detriment to the wood quality. Therefore willow SRC acts to beneficially recover value from the leachate contaminants rather than simply remove them to another medium as in other wastewater systems.

THE EFFECTS OF PROGRESSIVE ROOT REMOVAL PRIOR TO PLANTING ON SHOOT AND ROOT GROWTH OF BETULA PENDULA Roth.

D. Marcus Bellett-Travers* David E.B. Higgs** and Clive R. Ireland***

Summary

Root loss during transplanting of bare rooted nursery stock is thought to limit water uptake during establishment. An initial investigation into the effects on growth under well watered conditions of progressive removal of root material from dormant trees of Betula pendula Roth. was set up in spring 1994. Trees with roots £ 1 mm removed (40% removal by mass) and with roots £ 5 mm removed (84% removal by mass) were compared to controls. Some limited measurements of water relations were also made.

Shoot and root growth were increasingly limited by progressive root removal. Root regrowth was apparently proportional to the amount of old root material left behind after transplanting. In addition, the most severe treatment (roots £ 5 mm were removed) limited root growth in favour of shoot growth. Direct measurements of water relations proved to be difficult and inconclusive, however, increases in stem diameter, an indirect measurement of changes in water relations, indicated that progressive root removal subtly increased water stress in the trees.

Alternative hypotheses for the observed of changes in growth based on limitations in sugar physiology and hormone imbalance are also discussed.

THE CHALLENGES OF PLANNING FOR SUSTAINABLE ENVIRONMENTS IN THE UK†

Dealga P. O'Callaghan*

Summary

The UK approach to planning is explained. The evolution of the planning system and its central role in the provision of sustainable environments is set out. The UK approach to the preservation and protection of trees and the establishment of major community and urban forestry initiatives is shown as a major step towards achieving the goal of sustainability. Other areas of ensuring that sustainable environments are achieved, include nature conservation, landscape issues and protection of hedgerows. Matching the demand for housing while providing for sustainable environments is shown as a major challenge for the modern planning system. Examples are provided of 'best practice' from both private and public sectors, together with a description of what is perceived to be a threat to sustainability in Britain.

COMMUNITY PERCEPTIONS ON ADDED VALUES AND CONSERVATION OF TREES IN THE UNIVERSITY OF IBADAN, NIGERIA

B.O. Agbeja* and P.O. Adesoye

Summary

This study examines community perceptions on added values and conservation of trees in the University of Ibadan, Nigeria with a view to determining the importance of trees on campus. Data for the exercise were obtained from a stratified random sampling of 238 respondents in four categories through a structured questionnaire.
The results showed that 63.4 per cent respondents affirmed that the trees on campus produce a multitude of services such as shade, aesthetics, protection of the watershed, etc. while 36.6 per cent ascertained their awareness of goods obtainable from campus trees such as poles, firewood and fruits. Socio?economic values of trees revealed that over 70 per cent respondents affirmed that trees on campus directly and indirectly provide employment and income to the school leavers. On average, a photographer on campus using the green tree canopy as background for snapshots realizes more than N60,000 on monthly basis. The results on conservation revealed that 89.5 per cent of respondents affirmed that conservation of trees on campus has for a number of years been inadequate due to sporadic funding, lack of personnel and equipment for campus tree management. The shade width model revealed a strong positive linear correlation (R2 = 0.950) between the shade width and total height of Albizia saman. The shade width increases with increase in total height.
The Department of Forest Resources Management, University of Ibadan should of necessity be accorded the role to chart development objectives for campus tree management which relate to the declarations of interrelated goals obtainable from different tree species located on the 1032 hectares of land in University of Ibadan.

Keywords:  added value, conservation, management, urban trees

EFFECT OF WATER STRESS ON INFECTION BY SPECIES OF HONEY FUNGUS (ARMILLARIA MELLEA AND A. GALLICA)

T.O.S. Popoola*† and R.T.V. Fox

Summary

Isolates of Armillaria mellea and A. gallica that differed in virulence to healthy blackcurrant, strawberry, Lawson cypress and privet were used to inoculate plants exposed to different watering regimes. Host plants from which water had either been withheld or their roots kept constantly flooded with water, both showed increased susceptibility compared to those plants, which had been watered regularly. At the end of the period of stress, roots from randomly selected plants from each treatment were harvested. Following chemical analysis of the roots for protein, lipids, and carbohydrates including starch, in vitro assays were carried out with these substances. The increased amounts of these nutrients in both groups of stressed plants are sufficient to stimulate the growth of both A. mellea and A. gallica and enhance their virulence.

Keywords:   Armillaria spp., waterlogging, drought, stress.

REGENERATIVE ABILITY IN FUNGALLY INFECTED ANCIENT COMMON BEECH (FAGUS SYLVATICA L.)

J.R. Packham*

Summary

  

NON-DESTRUCTIVE TECHNIQUES FOR DETECTING DECAY IN STANDING TREES

Djamel Ouis*

Summary

This paper reviews the different techniques used to investigate whether the trunk of a standing tree is hosting rot or not. The most widespread and efficient techniques may in general be classified under two wide classes depending on the signal used for investigating the tree trunk. The first category includes the vibro-acoustical techniques using either vibrations at frequencies within the acoustical bandwidth or sound waves at acoustical or ultrasonic frequencies. The second class of techniques uses various methods based on electromagnetic radiation. There are furthermore some other techniques which are more or less destructive, and which are also presented in the current work. These techniques are destructive, but to a lesser extend than the well known fully destructive ones inasmuch as only a small sample is extracted from the tree trunk to be submitted to test.

Keywords:  acoustic tests, decay detection, Densitomat, electromagnetic radiation, Fractometer,
       non-destructive testing, Pilodyn, Shigometer, ultrasound, vibration monitoring

THERMOGRAPHY REVEALS HIDDEN TREE DECAY

Alessandra Catena*

Summary

The detection of hidden cavities and/or rotten tissue in trees has now become of major interest for plant pathologists, curators of historic gardens and arboriculturalists. A damaged tree poses a threat to public safety, if part or all of the tree is allowed to fail.
Currently available diagnostic systems are generally time-consuming and require the presence of a team of personnel if parts of a tree to be examined cannot be reached from the ground. Many systems are invasive, requiring that holes be made in the tree that can then become the access and spread routes for pathogens. Some methods use radioisotopes or X-ray sources which give the perception to the public that they are unsafe to use.
The use of a hand-held infrared (IR) camera allows the presence and size of internal cavities/damage to be identified. This includes aerial parts of large trees that can be assessed from the ground and in real time. The apparatus can also detect the presence of damage in the root system, simply by examining the plant collar. The method proposed is non-invasive and totally harmless to people. It is a quick, safe and user-friendly system of investigation that provides images of the internal condition of trees.
Repeated image capture over a period of time can monitor the progress of the pathology and is advantageous over other methods.

Keywords:nbsp; cavities in trees; infrared (IR) camera; thermography; tree decay; tree hazard evaluation; tree safety assessment; urban trees; Visual Tree Assessment (VTA)

THE INFLUENCE OF BIOSTIMULANTS ON GROWTH AND VITALITY OF THREE URBAN TREE SPECIES FOLLOWING TRANSPLANTING

Gillian A. Fraser and Glynn C. Percival*

Summary

Four commercially available, biostimulants sold under the trade names 'Generate', 'Crop Set', 'Fulcrum' and 'Redicrop 2000' were applied either as a root drench or foliar spray to three transplant?sensitive tree species, red oak (Quercus rubra), birch (Betula pendula) and beech (Fagus sylvatica) post transplanting. The short and long?term efficacy of the biostimulants on growth was quantified by recording root and shoot vigour at week 8 and 20. In addition, improvements in tree vitality were assessed by measurement of a chlorophyll a performance index based on leaf chlorophyll fluorescence emissions. Irrespective of species, no significant effect of mode of application (foliar spray versus root drench) was recorded on growth and vitality. The biostimulants Generate and Fulcrum increased growth of all three tree species. No significant effects on growth and chlorophyll fluorescence of birch and beech were recorded following applications of the biostimulants Crop Set and Redicrop 2000, however, significant increase in growth of red oak was recorded. Only the biostimulant Generate increased chlorophyll fluorescence values of all test species. Results show use of biostimulants can improve root and shoot vigour following transplanting. However, selection of an appropriate biostimulant is critical as effects on growth and vitality can vary widely between tree species possibly as a result of the differing active ingredient used in the formulation of the product.

AN AUDIT OF WOODLAND PERFORMANCE ON RECLAIMED LAND IN ENGLAND

Andy J. Moffat¹ and James Laing²

Summary

A survey of woodlands on 27 sites reclaimed after mineral working or landfilling in England was carried out to assess performance in relation to published reclamation and aftercare guidance. There appeared piecemeal uptake of the guidance at many of the sites, with consequent negative effects on tree survival, growth and health. Many of the problems identified were considered to be preventable, and suggest a level of ignorance or disinterest by the managers of the land on which woodland is established. Recommendations for improvement in restoration and aftercare practices are presented..

Keywords:  brownfield land; woodland performance; reclamation standards.

GANODERMA ON TREES-DIFFERENTIATION OF SPECIES AND STUDIES OF INVASIVENESS

F.W.M.R. Schwarze* and D. Ferner**

Summary

The relative abilities of Ganoderma applanatum, G. resinaceum and G. adspersum to overcome the reaction zone (R-zone) of Platanus x acerifolia were assessed under controlled conditions using wood blocks containing naturally induced R-zones. Also, the effect of physically damaging the R-zone on fungal spread was examined. During incubation, fungal entry into each block was controlled by coating it with paraffin wax, so as to leave only one side available for colonisation. The results were examined mainly in the context of the different colonisation strategies and wood-degrading mechanisms of these fungi. In order to allow for possible intra-specific differences, two isolates of each fungus were used.
There were clear differences between the fungi, on the basis of both histological criteria and drilling resistance measurements, as determined after four and eight weeks' incubation. Both G. adspersum and G. resinaceum breached the R-zone, but the G. adspersum was more aggressive in this respect (Figure 11). On the other hand, G. applanatum did not breach the R-zone, due to an inability to modify the defensive compounds in this region.
When wood blocks were drilled before incubation, so as to breach the R-zones physically, G. applanatum was able to colonise and degrade the adjacent sapwood. This pre-treatment also enhanced the ability of G. resinaceum and G. adspersum to enter the sapwood. Ganoderma resinaceum preferentially exploited the sapwood before starting to degrade the polyphenolic barrier of the R-zone, whereas G. adspersum began to degrade this barrier at an early stage.
Within control blocks, containing no R-zones, G. applanatum caused the most rapid loss of cell wall structure, followed by G. resinaceum and G. adspersum. These results were confirmed by weight loss data..

Keywords:  Ganoderma spp.; London plane; reaction zone; invasiveness; 'IML-Resi'

A UNIQUE TECHNIQUE FOR STREET TREE PLANTING IN BEIJING

Jun Yang* and Joe McBride**

Summary

This paper presents a unique technique that urban foresters in Beijing used to plant more street trees. This technique involves the transplanting of heavily pruned, relatively large size trees into sidewalk cuts along major streets. The benefits and the disadvantages of this type of planting are discussed. A long term, well-designed field test is recommended before this new planting technique is applied on a large scale.

Keywords:  street trees; transplanting.