scholarly journals Structural Stability of Urban Trees Using Visual and Instrumental Techniques: A Review

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1752
Author(s):  
Camila S. F. Linhares ◽  
Raquel Gonçalves ◽  
Luis M. Martins ◽  
Sofia Knapic

This review focuses on tree health assessment in urban forest, specifically on the methodologies commonly used to detect levels, dimensions, and location of wood deterioration. The acknowledged benefits to the urban forestry area from the application of assessment techniques are also addressed. A summary is presented of the different methodologies, such as visual analyses, acoustic tomography, and digital wood inspection drill, with the underlined importance of the biodeterioration of wood by fungi and termites.

Author(s):  
Kathleen L. Wolf ◽  
Sharon T. Lam ◽  
Jennifer K. McKeen ◽  
Gregory R.A. Richardson ◽  
Matilda van den Bosch ◽  
...  

The urban forest is a green infrastructure system that delivers multiple environmental, economic, social and health services, and functions in cities. Environmental benefits of urban trees are well understood, but no review to date has examined how urban trees affect human health. This review provides a comprehensive summary of existing literature on the health impacts of urban trees that can inform future research, policy, and nature-based public health interventions. A systematic search used keywords representing human health, environmental health, and urban forestry. Following screening and appraisal of several thousand articles, 201 studies were conceptually sorted into a three-part framework. Reducing Harm, representing 41% of studies, includes topics such as air pollution, ultraviolet radiation, heat exposure, and pollen. Restoring Capacities, at 31%, includes attention restoration, mental health, stress reduction, and clinical outcomes. Building Capacities, at 28%, includes topics such as birth outcomes, active living, and weight status. The studies that were reviewed show substantial heterogeneity in purpose and method yet indicate important health outcomes associated with people’s exposure to trees. This review will help inform future research and practice, and demonstrates why urban forest planning and management should strategically promote trees as a social determinant of public health.


2020 ◽  
Vol 9 (9) ◽  
pp. e451997478
Author(s):  
Debora Klingenberg ◽  
Adriana Maria Nolasco ◽  
Ananias Francisco Dias Júnior ◽  
Luana Candaten ◽  
Annie Karoline Lima Cavalcante ◽  
...  

Urban tropical forest species generate large amounts of wood waste by pruning and removing urban trees, which can be an accessible source of biomass that could be used to generate energy instead of being disposed of irregularly. The objective of this study was to evaluate the potential for energy production of the wood residue of seven species most used in urban forestry in the State of São Paulo, Brazil, by determining the physical, chemical and energetic characteristics. Wood waste of 7 common urban forests species in the State of São Paulo were collected in the city of Piracicaba, characterized (humidity, basic density and bulk density), chemically (extract content, volatile materials, fixed carbon and ash content) and energetically (higher, lower, useful calorific power, density energy and thermogravimetric analysis). The highest value of basic density was found in the species Cenostigma pluviosum (653.76 kg/m³), ​​all species had higher calorific values ​​greater than 19 MJ/kg and the energy density of the species varied between 4.45 to 10,80 GJ/m³. The use of these wood residues for direct combustion is a viable alternative and can be considered as a solution to replace the incorrect disposal, which is still a common practice in many cities in developing countries.


2020 ◽  
Author(s):  
Leslie A. Brandt ◽  
Cait Rottler ◽  
Wendy S. Gordon ◽  
Stacey L. Clark ◽  
Lisa O'Donnell ◽  
...  

The trees, developed green spaces, and natural areas within the City of Austin’s 400,882 acres will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of urban trees and natural and developed landscapes within the City Austin to a range of future climates. We synthesized and summarized information on the contemporary landscape, provided information on past climate trends, and illustrated a range of projected future climates. We used this information to inform models of habitat suitability for trees native to the area. Projected shifts in plant hardiness and heat zones were used to understand how less common native species, nonnative species, and cultivars may tolerate future conditions. We also assessed the adaptability of planted and naturally occurring trees to stressors that may not be accounted for in habitat suitability models such as drought, flooding, wind damage, and air pollution. The summary of the contemporary landscape identifies major stressors currently threatening trees and forests in Austin. Major current threats to the region’s urban forest include invasive species, pests and disease, and development. Austin has been warming at a rate of about 0.4°F per decade since measurements began in 1938 and temperature is expected to increase by 5 to 10°F by the end of this century compared to the most recent 30-year average. Both increases in heavy rain events and severe droughts are projected for the future, and the overall balance of precipitation and temperature may shift Austin’s climate to be more similar to the arid Southwest. Species distribution modeling of native trees suggests that suitable habitat may decrease for 14 primarily northern species, and increase for four more southern species. An analysis of tree species vulnerability that combines model projections, shifts in hardiness and heat zones, and adaptive capacity showed that only 3% of the trees estimated to be present in Austin based on the most recent Urban FIA estimate were considered to have low vulnerability in developed areas. Using a panel of local experts, we also assessed the vulnerability of developed and natural areas. All areas were rated as having moderate to moderate-high vulnerability, but the underlying factors driving that vulnerability differed by natural community and between East and West Austin. These projected changes in climate and their associated impacts and vulnerabilities will have important implications for urban forest management, including the planting and maintenance of street and park trees, management of natural areas, and long-term planning.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Han Zhi-Ying ◽  
Youn Yeo-Chang

This paper aims to investigate the Beijing resident’s preferences over various options of urban forest management strategies. The literature investigation and expert Delphi method were conducted to classify the ecosystem services of urban forests into six categories: (1) fresh water provision, (2) noise reduction, (3) moderation of extreme events, (4) air quality regulation, (5) species diversity and wildlife habitat, and (6) recreation and spiritual experience. To elicit the relative preferences to ecosystem service (hereafter referred to as ES) of Beijing residents, we employed the choice experiment method. The data were collected by interviews with questionnaires conducted in October 2017, and a total of 483 valid questionnaires were analyzed. The subjects of this experiment were residents older than 19 years old who have lived in Beijing for more than 1 year and have visited any one of the urban forests located in Beijing more than once during 2016. The results were as follows: Firstly, the air quality regulation ES was considered as the most important service for Beijing residents in terms of their choices of urban forest. In addition, Beijing residents regarded the fresh water provision ES as the second most important ES. Beijing residents were willing to pay up to 1.84% of the average monthly income of Chinese households annually to expand urban forest ecosystems in order to improve air quality. Secondly, apartment owners were willing to pay more municipality tax for forest ESs than residents who did not own an apartment. Thirdly, residents were more willing to pay for urban forest ESs as their income increases. The results indicated that Beijing residents were willing to pay more tax in support of urban forestry for air quality improvement. This research suggests that urban environmental policy makers in Beijing should pay more attention to the regulation function of forests (especially improving air quality) when designing and managing urban forests.


2018 ◽  
Vol 04 (04) ◽  
pp. 1850022 ◽  
Author(s):  
Benjamin A. Jones ◽  
John Fleck

Managing outdoor water use while maintaining urban tree cover is a key challenge for water managers in arid climates. Urban trees generate flows of ecosystem services in arid areas, but also require significant amounts of irrigation. In this paper, a bioeconomic-health model of trees and water use is developed to investigate management of an urban forest canopy when irrigation is costly, water has economic value, and trees provide ecosystem services. The optimal tree irrigation decision is illustrated for Albuquerque, New Mexico, an arid Southwest US city. Using a range of monetary values for water, we find that the tree irrigation decision is sensitive to the value selected. Urban deforestation is optimal when the value of water is sufficiently high, or alternatively starts low, but grows to cross a specific threshold. If, however, the value of water is sufficiently low or if the value of tree cover rises over time, then deforestation is not optimal. The threshold value of water where the switch is made between zero and partial deforestation is well within previously identified ranges on actual water values. This model can be applied generally to study the tradeoffs between urban trees and water use in arid environments.


2015 ◽  
Vol 41 (5) ◽  
Author(s):  
Rachel Clark ◽  
Kayla Boyes ◽  
Lori Morgan ◽  
Andrew Storer ◽  
Jordan Marshall

Emerald ash borer is a pest of North American ash that has caused significant mortality within its introduced range. The timeline for tree mortality, once infested by emerald ash borer, is variable for individual trees, with a small proportion surviving infestation. Using tree health assessments and signs of emerald ash borer infestation, researchers developed decision models to predict the probability of mortality. Two resulting models performed well at correctly predicting mortality (>83% correct) and significantly separating probability of mortality for those trees. Both models used diameter at breast height (DBH) and presence of bark splits, with one including percent crown dieback and the other including vigor rating (overall tree health assessment). A third model had reduced correct prediction of mortality, but was still potentially an effective model. Other tested models had shortcomings in prediction of mortality or in separation of probabilities of mortality. Using variables from three potential decision models, the year of mortality was modeled. However, specific year prediction was not as effective. Because of a wide range of external factors, prediction of a specific year of mortality may not be appropriate. Using DBH and rapid health and infestation assessment data, the authors were able to correctly predict ash mortality within a three-year period for the majority of trees within this study. Management strategies that use these models for developing hierarchical removal programs for infested ash may distribute financial and environmental costs over multiple years as opposed to mass removal of street and park trees.


2021 ◽  
Author(s):  
Daniele Magditsch

Trees planted along city streets and in urban parks are subject to many adversities that affect growth and can often result in mortality. The application of organic mulch to the rooting medium of newly planted urban trees has the potential to improve the soil chemical and physical properties necessary for tree root health. This study examined the difference in soil nutrient supply rates (μg/10cm2/28 days) between three areal treatments of wood chips (0.75 m, 1.0m and 1.5 m radii) and before mulch application versus after mulch application using Analysis of Covariance. PRSTM-Probes were inserted into the soil over six 28-day periods to measure the supply rate of bioavailable nutrients (NO3-, NH4+, P, K, S, Ca, Mg, and Cu). Meteorological data and other soil chemical and physical factors were measured and included as covariates in the statistical model. Results indicate that mulching had a significant effect (p<0.05) on P supply rates; supply rates were lower in the reference plots compared to the treatment plots post-mulching. S, Ca, Mg, and Cu supply rates decreased after mulch application; however, the decrease was observed in all plots, which is likely due to temporal variations in plant demand rather than mulching. The wood chips also had a significant impact on buffering fluctuating soil temperatures and reducing soil moisture loss compared to non-mulched plots. The knowledge obtained from this research can be used to improve urban forest management strategies by providing a more in-depth understanding of the prescriptive use of organic mulch.


Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 519 ◽  
Author(s):  
Bertrand Nero ◽  
Daniel Callo-Concha ◽  
Manfred Denich

Urban forestry has the potential to address many urban environmental and sustainability challenges. Yet in Africa, urban forest characterization and its potential to contribute to human wellbeing are often neglected or restrained. This paper describes the structure, diversity, and composition of an urban forest and its potential to store carbon as a means of climate change mitigation and adaptation in Kumasi. The vegetation inventory included a survey of 470,100-m2 plots based on a stratified random sampling technique and six streets ranging from 50 m to 1 km. A total of 3757 trees, comprising 176 species and 46 families, were enumerated. Tree abundance and species richness were left skewed and unimodally distributed based on diameter at breast height (DBH). Trees in the diameter classes >60 cm together had the lowest species richness (17%) and abundance (9%), yet contributed more than 50% of the total carbon stored in trees within the city. Overall, about 1.2 million tonnes of carbon is captured in aboveground components of trees in Kumasi, with a mean of 228 t C ha−1. Tree density, DBH, height, basal area, aboveground carbon storage, and species richness were significantly different among green spaces (p < 0.05). The diversity was also significantly different among urban zones (p < 0.0005). The DBH distribution of trees followed a modified reverse J-shaped model. The urban forest structure and composition is quite unique. The practice of urban forestry has the potential to conserve biological diversity and combat climate change. The introduction of policies and actions to support the expansion of urban forest cover and diversity is widely encouraged.


2020 ◽  
Vol 27 ◽  
pp. 77-90
Author(s):  
Maria Rosaria Guarini ◽  
Antonio Nesticò ◽  
Pierluigi Morano ◽  
Francesco Sica

Green areas in urban agglomerations are strategic resource for the sustainable city development. The implementation of Urban Forestry Projects (UFP) allows on the one hand to raise the environmental quality level, improving the microclimate and preserving biodiversity, on the other hand to promote urban regeneration and promote socio-economic development by creating eco-systemic s er vices for the population. The result is a more rational land use and an increase in real estate values. Although the EU Directives show the need to promote the sustainable territory growth through the recover y and redevelopment of the built environment, the implementation of investments based on eco-system logic is rarely counted as a priority action for the city, often preferring a different allocation of available resources. The present work aims first to define an indicators set useful to express the value components – financial, social, cultural and ecological- environmental – for the UFP. These indicator s are the reference terms for the characterization of an innovative protocol of multicriteria analysis for the public operator who wants to establish the optimal distribution of funds between UFP units in limited areas of the urban fabric. The protocol uses the algorithms of mathematical programming and is tested on a case study about urban areas to be redeveloped.


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