scholarly journals Application of Paclobutrazol to Mitigate Environmental Stress of Urban Street Trees

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 355
Author(s):  
Bert Cregg ◽  
Dana Ellison-Smith
Keyword(s):  
Gas Exchange ◽  
Tree Growth ◽  
Leaf Size ◽  
Net Photosynthesis ◽  
Urban Environments ◽  
Street Trees ◽  
Urban Street ◽  
Pear Trees ◽  
Callery Pear ◽  
Control Tree

Paclobutrazol is a tree growth regulator that is frequently applied by arborists to control tree growth in utility rights of way. Paclobutrazol is also marketed to mitigate tree stresses associated with urban environments. In this study we applied paclobutrazol as a soil drench to honeylocust (Gleditsia triacanthos L var. inermis (L.) Zab.) and Callery pear (Pyrus calleryiana Decne.) trees planted as street trees on two sites in Lansing, Michigan USA. We evaluated physiological and morphological responses for two years after treatment. Application of paclobutrazol increased SPAD chlorophyll index of trees of both species in both years, compared to untreated control trees. Application of paclobutrazol increased leaf water potential of trees on one study site (Downtown) but not the other (Old Town). Paclobutrazol increased gas exchange (net photosynthesis and stomatal conductance) of Callery pear trees on one of four measurement dates (gas exchange was not measured on honeylocust trees). Leaf size of Callery pear trees was reduced following paclobutrazol application whereas leaf size of honeylocust trees was unaffected by paclobutrazol. These results indicate that paclobutrazol can help to reduce stress of trees and improve physiological function under urban conditions. However, paclobutrazol should be viewed as part of a suite of options for arborists and landscapers to manage trees on stressful sites, rather than as a replacement for proper overall care.

scholarly journals Responses of gas-exchange rates and water relations to annual fluctuations of weather in three species of urban street trees

2014 ◽  
Vol 34 (10) ◽  
pp. 1056-1068 ◽  
Author(s):  
Y. Osone ◽  
S. Kawarasaki ◽  
A. Ishida ◽  
S. Kikuchi ◽  
A. Shimizu ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Exchange Rates ◽  
Water Relations ◽  
Street Trees ◽  
Urban Street

Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

1994 ◽  
Vol 24 (5) ◽  
pp. 954-959 ◽  
Author(s):  
L.J. Samuelson ◽  
J.R. Seiler
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Soil Fertility ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Red Spruce ◽  
Fertility Treatment ◽  
Sink Strength ◽  
Growth Enhancement ◽  
Growing Seasons

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

Photosynthesis and Transpiration in Damaged and Undamaged Spruce Trees

1996 ◽  
Vol 51 (3-4) ◽  
pp. 200-210 ◽  
Author(s):  
Aloysius Wild ◽  
Peter Sabel ◽  
Lucia Wild-Peters ◽  
Ursula Schmieden
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Natural Habitat ◽  
Late Summer ◽  
Net Photosynthesis ◽  
Diurnal Course ◽  
Physiological Homeostasis ◽  
Use Efficiency ◽  
Needle Loss ◽  
Light Saturation Curves

Abstract The investigations presented here focus on the CO2/H2O gas exchange in damaged and undamaged spruce trees while using open-air measurements as well as measurements under defined conditions in the laboratory. The studies were performed at two different sites in the Hunsrück and the Westerwald mountains. In the laboratory the CO2/H2O gas exchange was measured on detached branches under controlled conditions in the course of two years. CO2 saturation curves were also generated. In addition CO2 compensation points were deter­ mined employing a closed system. In the natural habitat diurnal course measurements of photosynthesis and transpiration as well as light-saturation curves for photosynthesis were performed. In parallel with the photosynthesis and transpiration measurements, measurements of the water potential were taken at both locations. The photosynthetic capacity and transpiration rate show a typical annual course with pronounced maxima in spring and late summer and minima in summer and winter. The needles of the damaged trees exhibit higher transpiration rates and a distinct reduction in photosyn­ thesis than the needles of the undamaged trees during two seasons. The diurnal course measurements of net photosynthesis and transpiration show a maximum in photosynthesis and transpiration in the afternoon in May and September, but a characteristic midday depression in July. Photosynthesis was markedly lower and transpiration higher in the needles of the damaged trees. The damaged trees show a lower increase in the light and CO2 saturation curves and higher CO2 compensation points as compared to the undamaged trees. The water potential reaches much lower values during the course of the day in needles of the dam­ aged trees. The reduction of the photosynthetic rate on one hand and the increase in transpiration on the other hand result in an extreme lowering of the water use efficiency in photosynthesis. The damage to the thylakoid membranes and to the guard cells obviously results in a pro­ found disturbance of the physiological homeostasis of the needles and could thus lead to premature needle loss.

Quantifying the shape of urban street trees and evaluating its influence on their aesthetic functions based mobile lidar data

2022 ◽  
Vol 184 ◽  
pp. 203-214
Author(s):  
Tianyu Hu ◽  
Dengjie Wei ◽  
Yanjun Su ◽  
Xudong Wang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Lidar Data ◽  
Street Trees ◽  
Urban Street

Effects of varying establishment approaches on the growth of urban street trees

2018 ◽  
Vol 40 (4) ◽  
pp. 201-209 ◽  
Author(s):  
Lai Fern Ow ◽  
Subhadip Ghosh ◽  
Yusof Mohamed Lokman Mohd.
Keyword(s):  
Street Trees ◽  
Urban Street

scholarly journals Physiological responses of beet plants irrigated with saline water and silicon application

2020 ◽  
Vol 11 ◽  
pp. E3113
Author(s):  
José Sebastião de Melo Filho ◽  
Toshik Iarley da Silva ◽  
Anderson Carlos de Melo Gonçalves ◽  
Leonardo Vieira de Sousa ◽  
Mario Leno Martins Véras ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Concentration ◽  
Saline Water ◽  
Block Design ◽  
Essential Element ◽  
Net Photosynthesis ◽  
Crop Productivity ◽  
Experimental Unit ◽  
Randomized Block Design

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.

scholarly journals Advanced GPR Signal Processing Techniques for Root Detection in Urban Environments

2020 ◽  
Author(s):  
Livia Lantini ◽  
Fabio Tosti ◽  
Iraklis Giannakis ◽  
Kevin Jagadissen Munisami ◽  
Dale Mortimer ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Root Systems ◽  
Urban Environments ◽  
Street Trees ◽  
Destructive Testing ◽  
Root Detection ◽  
Charitable Trust ◽  
Ground Penetrating ◽  
Processing Techniques ◽  
Non Destructive

<p>Street trees are widely recognised to be an essential asset for the urban environment, as they bring several environmental, social and economic benefits [1]. However, the conflicting coexistence of tree root systems with the built environment, and especially with road infrastructures, is often cause of extensive damage, such as the uplifting and cracking of sidewalks and curbs, which could seriously compromise the safety of pedestrians, cyclists and drivers.</p><p>In this context, Ground Penetrating Radar (GPR) has long been proven to be an effective non-destructive testing (NDT) method for the evaluation and monitoring of road pavements. The effectiveness of this tool lies not only in its ease of use and cost-effectiveness, but also in the proven reliability of the results provided. Besides, recent studies have explored the capability of GPR in detecting and mapping tree roots [2]. Algorithms for the reconstruction of the tree root systems have been developed, and the spatial variations of root mass density have been also investigated [3].</p><p>The aim of this study is, therefore, to investigate the GPR potential in mapping the architecture of root systems in street trees. In particular, this research aims to improve upon the existing methods for detection of roots, focusing on the identification of the road pavement layers. In this way, different advanced signal processing techniques can be applied at specific sections, in order to remove reflections from the pavement layers without affecting root detection. This allows, therefore, to reduce false alarms when investigating trees with root systems developing underneath road pavements.</p><p>In this regard, data from trees of different species have been acquired and processed, using different antenna systems and survey methodologies, in an effort to investigate the impact of these parameters on the GPR overall performance.</p><p> </p><p><strong>Acknowledgements</strong></p><p>The authors would like to express their sincere thanks and gratitude to the following trusts, charities, organisations and individuals for their generosity in supporting this project: Lord Faringdon Charitable Trust, The Schroder Foundation, Cazenove Charitable Trust, Ernest Cook Trust, Sir Henry Keswick, Ian Bond, P. F. Charitable Trust, Prospect Investment Management Limited, The Adrian Swire Charitable Trust, The John Swire 1989 Charitable Trust, The Sackler Trust, The Tanlaw Foundation, and The Wyfold Charitable Trust. This paper is dedicated to the memory of our colleague and friend Jonathan West, one of the original supporters of this research project.</p><p> </p><p><strong>References</strong></p><p>[1] J. Mullaney, T. Lucke, S. J. Trueman, 2015. “A review of benefits and challenges in growing street trees in paved urban environments,” Landscape and Urban Planning, 134, 157-166.</p><p>[2] A. M. Alani, L. Lantini, 2019. “Recent advances in tree root mapping and assessment using non-destructive testing methods: a focus on ground penetrating radar,” Surveys in Geophysics, 1-42.</p><p>[3] L. Lantini, F. Tosti, Giannakis, I., Egyir, D., A. Benedetto, A. M. Alani, 2019. “A Novel Processing Framework for Tree Root Mapping and Density Estimation using Ground Penetrating Radar,” In 10th International Workshop on Advanced Ground Penetrating Radar, EAGE.</p>

A Communitys Urban Rejuvenation - The Cabarets Trouper

2021 ◽  
Author(s):  
◽  
Connie Smith
Keyword(s):  
Online Shopping ◽  
Urban Environments ◽  
Living Room ◽  
Retail Sector ◽  
Urban Street ◽  
Big Box ◽  
Retail Shopping ◽  
Residential Space ◽  
Community Space ◽  
Competitive Nature

<p>The 1990s brought innovation to retail shopping, enabling consumers to begin to shop from the comfort of their own home. Today, Online shopping continues to revolutionise the industry, creating a highly competitive market space while advancing “convenience shopping”. As customers can now purchase anything at their fingertips, those that choose to shop in-store find their desires are also competitively meet. Evolution within the retail industry has meant that many stores have become a part of “big box” developments. These facilities provide customers with readily stocked merchandise and the in-store experience of “convenience shopping”.  Online shopping and Big Box stores will continue to lure people away from what once were vibrant urban retail environments posing various adverse effects on our streets, city centres and local businesses. Broadway Avenue, Palmerston North is one of many streets that have fallen victim to these developments creating unpleasant retail experiences for the community. This thesis argues how interior architecture can assist rejuvenating desolate urban environments. It proposes that by applying selected interior principles to an urban street it can create a space that begins to challenge the current programme encouraging the street to adapt for the community.  This design based research proposes to create a community space ‘living room’ by treating the street as though it is a residential space within a retail environment. It aims to preserve and maintain a sense of history and diversity within the cityscape. The existing site attributes will be used to create a set of design rules and regulations within the shopping environment to encourage internal and external spaces to feed off one another adapting frequently to cope with the competitive nature of the retail sector.</p>

scholarly journals Constrained tree growth and gas exchange of seawater‐exposed forests in the Pacific Northwest, USA

2019 ◽  
Vol 107 (6) ◽  
pp. 2541-2552 ◽  
Author(s):  
Wenzhi Wang ◽  
Nate G. McDowell ◽  
Nicholas D. Ward ◽  
Julia Indivero ◽  
Cailene Gunn ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Pacific Northwest ◽  
Tree Growth ◽  
The Pacific
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