Submit to Forests Review for Forests Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Urban Forestry Measurements

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Forests (ISSN 1999-4907). This special issue belongs to the section "Urban Forestry".

Deadline for manuscript submissions: closed (30 May 2023) | Viewed by 18802

Share This Special Issue

Special Issue Editors

Prof. Dr. Richard Hauer

E-Mail Website
Guest Editor

College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, WI 54481, USA
Interests: street trees; urban forests; greenspace; land surveying; risk assessment
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Bryant Scharenbroch

E-Mail Website
Guest Editor

College of Natural Resources, University of Wisconsin - Stevens Point, Stevens Point, WI 54481-3897, USA
Interests: urban soil; street tree; urban forest; forest landscapes

Special Issue Information

Dear Colleagues,

Urban tree and forest data can provide valuable information for urban foresters, arborists, researchers, and others. Measurements of the urban forest vary across space and time. Urban forest measurements are made across the continuum of space from cellular to global scales. Longitudinal or repeated measures data are invaluable for the monitoring of urban trees and forests in response to disturbance, management, and other factors impacting urban forests. Methods of urban forest measurement also vary by the personnel performing the measurement. Practitioners have different goals and resources to measure the urban forest compared to researchers. This Special Issue will publish research on the various methods for which we measure urban forests.

Potential topics include but are not limited to:

Tree measurements
Urban forest measurements
Urban site descriptions
Tree growth and longevity
Urban tree canopy
Urban forest inventory and analysis
Measuring trees and storm impacts
Ecosystem services
Quantifying aesthetics and scenic beauty
Other papers related to quantifying urban trees and forests

Prof. Dr. Richard Hauer
Prof. Dr. Bryant Scharenbroch
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Forests is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

urban forest measurements
urban tree canopy
longitudinal
tree growth and longevity
urban forest inventory and analysis

Published Papers (11 papers)

Download All Papers

Research

14 pages, 4433 KiB

Open AccessArticle

Tree Health Condition in Urban Green Areas Assessed through Crown Indicators and Vegetation Indices

by Luis Manuel Morales-Gallegos, Tomás Martínez-Trinidad, Patricia Hernández-de la Rosa, Armando Gómez-Guerrero, Dionicio Alvarado-Rosales and Luz de Lourdes Saavedra-Romero

Forests 2023, 14(8), 1673; https://0-doi-org.brum.beds.ac.uk/10.3390/f14081673 - 18 Aug 2023

Cited by 2 | Viewed by 1316

Abstract

The urban environment induces stress on trees and its impact can be identified by observing the condition of the crown. The aim of this study is to correlate the variables of crown density (Cdn), crown transparency (Ctr) and dieback (Cdie) with the following vegetation indices: the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), blue-normalized difference vegetation index (BNDVI), green-normalized difference vegetation index (GNDVI), green–red vegetation index (GRVI) and red–green–blue vegetation index (RGBVI) of the crowns of trees located in urban green areas, as well as chlorophyll fluorescence (Fv/Fm) as an indirect indicator of the overall tree health condition. A total of 549 trees were evaluated, represented in 24 families, 36 genera and 53 species; the variables had average values of 67.96% for Cdn, 35.19% for Ctr and 1% for Cdie. Correlations were found between Fv/Fm, NDVI and BNDVI. NDVI and BNDVI correlated with variables such as Cdn and Ctr, mainly in species such as Ligustrum lucidum, Jacaranda mimosifolia and Fraxinus uhdei. Therefore, it is possible to evaluate the tree health condition of trees in urban green environments through the identification of unfavorable conditions at the crown level by using vegetation indices for some of the species studied. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

18 pages, 1065 KiB

Open AccessArticle

Learning from Forest Trees: Improving Urban Tree Biomass Functions

by Christian Vonderach and Adrienne Akontz

Forests 2023, 14(7), 1473; https://0-doi-org.brum.beds.ac.uk/10.3390/f14071473 - 18 Jul 2023

Viewed by 1005

Abstract

Trees are one of the few carbon sinks in urban areas. Different methods are available to assess the biomass of urban trees, one of these being allometric biomass functions. Biomass functions are well investigated, reliable and easy to apply if the required information is available. Our goal is to use biomass functions to enhance urban forest management tools with information on stored biomass and carbon. In this study, we test several approaches to estimate new species-specific biomass functions. We include data from urban and traditional forest trees since both origins can be modeled by the allometric relationship solely giving different parameter estimates. The tested models include mixed allometric models for urban trees only, the adjustments of available forest tree biomass models and a cross-classified mixed model (CCMM) using both data from urban and forest trees. We then show by cross validation that the CCMM, statistically separating the data into different species and origins, shows greater improvement over the simpler models. Hence, we state that the inclusion of forest tree data improves the performance on biomass predictions for urban trees: the urban tree biomass functions “learned from forest trees”. The CCMM is also compared against the predictions of the above-ground biomass functions applied in the German National Forest Inventory. Comparable RMSE and slightly lower BIAS values are found, both for deciduous and coniferous tree species. With the approach of a cross-classified model, we also enable predictions for non-observed conifers in urban space, assuming comparable growth differences between deciduous and conifer species in forest stands and urban areas. A sample application using the CCMM model shows results for a small subset of data of an urban tree inventory, collected in a residential area in the city of Munich, Germany. It is applied to estimate carbon storage at two points in time and, hence, carbon fluxes in the period under consideration. Such information can help in the decision making and management of urban trees. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

14 pages, 8548 KiB

Open AccessArticle

Tree Species Identification in Urban Environments Using TensorFlow Lite and a Transfer Learning Approach

by Diego Pacheco-Prado, Esteban Bravo-López and Luis Ángel Ruiz

Forests 2023, 14(5), 1050; https://0-doi-org.brum.beds.ac.uk/10.3390/f14051050 - 19 May 2023

Viewed by 1903

Abstract

Building and updating tree inventories is a challenging task for city administrators, requiring significant costs and the expertise of tree identification specialists. In Ecuador, only the Trees Inventory of Cuenca (TIC) contains this information, geolocated and integrated with the taxonomy, origin, leaf, and crown structure, phenological problems, and tree images taken with smartphones of each tree. From this dataset, we selected the fourteen classes with the most information and used the images to train a model, using a Transfer Learning approach, that could be deployed on mobile devices. Our results showed that the model based on ResNet V2 101 performed best, achieving an accuracy of 0.83 and kappa of 0.81 using the TensorFlow Lite interpreter, performing better results using the original model, with an accuracy and kappa of 0.912 and 0.905, respectively. The classes with the best performance were Ramo de novia, Sauce, and Cepillo blanco, which had the highest values of Precision, Recall, and F1-Score. The classes Eucalipto, Capuli, and Urapan were the most difficult to classify. Our study provides a model that can be deployed on Android smartphones, being the beginning of future implementations. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

20 pages, 6339 KiB

Open AccessArticle

Allometric Growth of Common Urban Tree Species in Qingdao City of Eastern China

by Jinming Yang, Mengfan Zhang, Jian Zhang, Huicui Lu and Richard J. Hauer

Forests 2023, 14(3), 472; https://0-doi-org.brum.beds.ac.uk/10.3390/f14030472 - 26 Feb 2023

Cited by 2 | Viewed by 1543

Abstract

Allometric growth equations help to describe the correlation between the variables of tree biological characteristics (e.g., diameter and height, diameter and canopy width) and estimate tree dynamics at a given tree dimension. Allometric models of common tree species within urban forests are also important to relate ecosystem services to common urban tree measurements such as stem diameter. In this study, allometric growth models were developed for common tree species used for urban greening on the streets of seven municipal districts in Qingdao city of eastern China. A sampling survey was constructed on an urban–rural gradient to obtain the data of tree diameter, crown width, height to live crown base, and tree height. From these measurements, the crown volume and crown projection area of tree species were calculated. The allometric relationship between two variables was established using quantile regression models (95%, 50%, and 5%) to explore its correlation and the influence of tree species characteristics on urban tree allometry. Our results showed that the correlation of allometric growth of different tree species varied largely due to their own characteristics, and the allometric growth of the same tree species was significantly different as well under the fitting of different quantiles. We found that the relationship between crown width and diameter was stronger than that between tree height and diameter. Moreover, the allometric relationship between crown projection area–diameter and crown width–diameter showed similar fitting. The allometric relationship analysis provide theoretical models and a way to use common field data to support urban forestry management and for the subsequent evaluation and prediction of tree functions and ecosystem services. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

13 pages, 5453 KiB

Open AccessArticle

Estimating Stormwater Infiltration and Canopy Interception for Street Tree Pits in Manhattan, New York

by Nandan Hara Shetty

Forests 2023, 14(2), 216; https://0-doi-org.brum.beds.ac.uk/10.3390/f14020216 - 23 Jan 2023

Viewed by 2357

Abstract

Estimates of the amount of stormwater captured by urban trees have focused on the rainfall intercepted by leaves and branches, while the amount of stormwater runoff that flows into a tree pit from the surrounding sidewalk has not been well quantified. This study estimated the amount of stormwater that infiltrates into a tree pit by first calculating the tributary drainage area that drains to street tree pits of varying sidewalk widths and slopes. With Manhattan, New York, as a case study, the study used i-Tree software to find that for street trees in Manhattan, stormwater infiltration greatly exceeded canopy interception, by a ratio of 3 to 1: stormwater infiltration averaged 6842 L/yr, while canopy interception averaged 2228 L/yr. The results contradict prior research that asserted that canopy interception is the primary means by which street trees provide stormwater control. The study also provides a method to calculate street tree drainage areas that would improve estimates of the amount of stormwater captured by street trees, by highlighting the dominant role played by sidewalk widths and slopes. Infiltration averaged 4221 L/yr for a sidewalk width of 3 m and 14774 L/yr for a sidewalk width of 10 m. Infiltration also averaged 5607 L/yr for a street slope of 0.5% and 18,383 L/yr for a street slope of 10%. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

12 pages, 8507 KiB

Open AccessCommunication

Observation of External Wounding on Green Ash (Fraxinus pennsylvanica Marshall) Trees Associated with Tree Injection Systems

by Richard J. Hauer, John J. Ball and Eric North

Forests 2022, 13(11), 1802; https://0-doi-org.brum.beds.ac.uk/10.3390/f13111802 - 29 Oct 2022

Cited by 2 | Viewed by 1406

Abstract

Field observations of external wounds associated with two common tree injection methods compared open (plug-less) and sealed (plug) systems in green ash (Fraxinus pennsylvanica Marshall) trees. A wound from any cause within 1.37 m above the ground was common with 28.8% of all trees. The open system had statistically fewer (p < 0.001) trees with at least one wound (11.6% of trees) than the sealed system (47.4% of trees). The open system had fewer (p < 0.001) wounds (0.17, 0.04 SE) per tree and a smaller (p < 0.001) total wound area (25.5 cm², 8.7 SE) per tree, compared to the sealed system wounds (1.14, 0.13 SE) per tree and the total wound area (99.7 cm², 16.2 SE) per tree. The incidence of a tree with a wound(s) within 1.37 m above the ground was 7.2 times more likely with trees treated though the sealed system. Wounds in the sealed system were observed to appear to have a high rate of improper application of plugs, which was associated in 77% of the cases to explain the wounds. Implications of study results are further provided to best protect ash trees, while at the same time reducing the incidence external wounding on ash trees. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

16 pages, 2110 KiB

Open AccessArticle

Antioxidant Responses and Adaptation Mechanisms of Tilia tomentosa Moench, Fraxinus excelsior L. and Pinus nigra J. F. Arnold towards Urban Air Pollution

by Slaveya Petrova, Iliana Velcheva, Bogdan Nikolov, Tonka Vasileva and Veselin Bivolarski

Forests 2022, 13(10), 1689; https://0-doi-org.brum.beds.ac.uk/10.3390/f13101689 - 14 Oct 2022

Cited by 5 | Viewed by 1247

Abstract

The aim of this study was to assess the antioxidant response towards urban air pollution of three widespread ornamental species—Tilia tomentosa, Fraxinus excelsior and Pinus nigra. Saplings were planted in four urban plots with different anthropogenic impacts, and periodic observations were performed on their development. Three types of biochemical markers, representing plant responses by three different mechanisms, were analyzed: photosynthetic pigments, free proline and guaiacol peroxidase activity. Our study confirmed that plant responses and adaptation to the environment are complex biological processes including physiological and biochemical changes. As a whole, these experiments revealed that the studied trees react by specific mechanisms towards urban air pollution, and antioxidant responses are significantly correlated with the enhancement of traffic (p < 0.05). Fraxinus excelsior was assessed as being very suitable for urban landscaping due to the significant tolerance to environmentally stressful conditions. Tilia tomentosa was also evaluated as a suitable ornamental species as it demonstrated good development in the urban environment. Pinus nigra was proven as more sensitive to the urban air pollution versus the other two studied trees. These findings could be very useful as a scientific basis for the landscaping practice in terms of the sustainable development and management of urban forestry. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

19 pages, 4308 KiB

Open AccessArticle

Estimating Carbon Stocks and Biomass Expansion Factors of Urban Greening Trees Using Terrestrial Laser Scanning

by Linlin Wu, Yongjun Shi, Fanyi Zhang, Yufeng Zhou, Zhentian Ding, Shixin Lv and Lin Xu

Forests 2022, 13(9), 1389; https://0-doi-org.brum.beds.ac.uk/10.3390/f13091389 - 31 Aug 2022

Cited by 3 | Viewed by 1718

Abstract

Urban forest carbon sequestration represents an important component of the global forest carbon pool; however, accurate measurements are limited by the inability of existing field stand models to match the specificity of urban greening species. Herein, canopy volume, carbon stock, and the biomass expansion factor (BEF) of 30 Koelreuteria paniculate trees were measured based on terrestrial laser scanning (TLS) and compared to the results of existing wood volume and carbon stock model measurements. The findings revealed that (1) TLS point cloud data were highly reproducible and accurate (root mean square error of tree height and diameter at breast height were ±0.35 m and ±0.33 cm, respectively). (2) Owing to human interference and cluttered urban environments, the BEF of urban greening tree species fluctuated irregularly, considerably different from that of natural forest stands. (3) Leaf carbon stocks were influenced by the size of the voxel. (4) Different tree measurement factors maintained variable degrees of influence on BEF (height under branch, volume of thick branch, crown width, and projected areas of tree-crown produced correlation coefficients of −0.64, 0.54, 0.45, and 0.43, respectively). Accordingly, the carbon stock and BEF of urban greening tree species can be accurately calculated via TLS without damage. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

24 pages, 2434 KiB

Open AccessArticle

An Evaluation of National Park System Pilot Area Using the AHP-Delphi Approach: A Case Study of the Qianjiangyuan National Park System Pilot Area, China

by Qianda Zhuang, Lin Wang and Guoquan Zheng

Forests 2022, 13(8), 1162; https://0-doi-org.brum.beds.ac.uk/10.3390/f13081162 - 22 Jul 2022

Cited by 3 | Viewed by 1514

Abstract

With the national park as an important measure of ecological protection, China has started 10 national park system pilot areas. However, the research on the comprehensive evaluation of national park construction and development is insufficient. The main purpose of this study was to establish a comprehensive evaluation index system for the pilot area of the national park system. The method of the Analytic Hierarchy Process combined with the Delphi method by ten relevant experts was used. The comprehensive evaluation index system for the national park system pilot areas was composed of the objective level and the criteria level which includes three items: natural resource conditions; research, education and recreation functions; and protection and management conditions. The indicator level involved seven items and the factor level included 31 items. Furthermore, the weight of each item in these levels was obtained through the Delphi method by the judgement of selected experts. The Qianjiangyuan National Park System Pilot Area (QNPSPA) was selected as the study case for empirical research. The score of the comprehensive evaluation of the QNPSPA was 90.801, which belongs to Grade I in the five catalogues, indicating its comprehensive construction level was very high and its protection and management measures were efficient. However, significant deficiencies also existed in the area suitability, recreation facilities and production, natural resource property rights, human landscape value and ecosystem integrity. To address these problems, five suggestions were proposed. For example, strengthening cross-administrative cooperation and communication, improving the construction of recreational facilities, etc. The evaluation framework proposed in this study could play a positive role in the construction evaluation of the pilot areas of national parks in China and is conducive to promoting the evaluation research of national parks in China and promoting the development of conservation and construction. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

12 pages, 2100 KiB

Open AccessArticle

Comparative Research on Typical Measure Methods of the Carbon Sequestration Benefits of Urban Trees Based on the UAV and the 3D Laser: Evidence from Shanghai, China

by Xiaoyan Ma, Qinghua Zou, Ming Liu and Jun Li

Forests 2022, 13(5), 640; https://0-doi-org.brum.beds.ac.uk/10.3390/f13050640 - 20 Apr 2022

Cited by 3 | Viewed by 1834

Abstract

The Carbon Sequestration Benefits (CSB) of vegetation and forest have received more and more attention with the increase in CO₂ density in the atmosphere. The evaluation of the CSB of existing vegetation and forest has also become one of the important research topics in urban ecology. In the existing research, the evaluation of CSB methods can be categorized into a two-dimension index and three-dimension index. The two-dimension index mainly focuses on leaf area method and leaf area index method. Additionally, the three-dimension index mostly focuses on the Three-Dimension Green Quantity (3DGQ) method which further includes Approximate Geometry Model (AGM), Point Cloud (PC) method using 3D laser, and Point Cloud Convex Hull Slicing (PCCHS) method, etc. In this paper, we take Shanghai as the study area, and address the top 15 species with each species having 30 trees of the same age from Shanghai to calculate the average annual CSB of the 15 species using the two-dimension index and three-dimension index. Through this, we analyze the difference of the same species in different indexes in the same categories and in different categories. The research results provide a research basis for the in-depth exploration of the three-dimensional spatial pattern of urban green space and ecological benefit evaluation. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

11 pages, 2398 KiB

Open AccessArticle

Rapidly Quantifying Interior Greenery Using 360° Panoramic Images

by Junzhiwei Jiang, Cris Brack, Robert Coe and Philip Gibbons

Forests 2022, 13(4), 602; https://0-doi-org.brum.beds.ac.uk/10.3390/f13040602 - 12 Apr 2022

Viewed by 1560

Abstract

Many people spend the majority of their time indoors and there is emerging evidence that interior greenery contributes to human wellbeing. Accurately capturing the amount of interior greenery is an important first step in studying its contribution to human well-being. In this study, we evaluated the accuracy of interior greenery captured using 360° panoramic images taken within a range of different interior spaces. We developed an Interior Green View Index (iGVI) based on a K-means clustering algorithm to estimate interior greenery from 360° panoramic images taken within 66 interior spaces and compared these estimates with interior greenery measured manually from the same panoramic images. Interior greenery estimated using the automated method ranged from 0% to 34.19% of image pixels within the sampled interior spaces. Interior greenery estimated using the automated method was highly correlated (r = 0.99) with interior greenery measured manually, although we found the accuracy of the automated method compared with the manual method declined with the volume and illuminance of interior spaces. The results suggested that our automated method for extracting interior greenery from 360° panoramic images is a useful tool for rapidly estimating interior greenery in all but very large and highly illuminated interior spaces. Full article

(This article belongs to the Special Issue Urban Forestry Measurements)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Urban Forestry Measurements

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (11 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI