scholarly journals Urban tree pests and natural enemies respond to habitat at different spatial scales

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Sarah E Parsons ◽  
Steven D Frank
Keyword(s):  
Natural Enemies ◽  
Spatial Scales ◽  
Structural Complexity ◽  
Urban Environments ◽  
Urban Trees ◽  
Urban Habitat ◽  
Urban Tree ◽  
Impervious Cover ◽  
Enemies Hypothesis ◽  
The City

Abstract Trees provide many ecosystem services in our urban environments. However, city trees are often stressed by pests that are typically higher than those in nearby natural areas. Our research highlights a potential mismatch in scale between the habitat elements that affect the densities of pests and their natural enemies on city trees. We tested a well-known ecological concept, the enemies hypothesis, in the city, where relationships of pests and their enemies have not been thoroughly studied. To test our hypothesis that natural enemies and aphid predation services on urban trees increase with more local structural complexity around trees, we collected data on crape myrtle trees on NC State University’s campus from 2016 to 2017. We measured local structural complexity of vegetation around study trees, quantified impervious cover among other urban habitat elements, collected crape myrtle aphids (Tinocallis kahawaluokalani) and their natural enemies on trees, and performed predation experiments. We found that aphid abundance was positively correlated with more impervious cover within 100 m of crape myrtle trees. Alternatively, greater local structural complexity within the 10 × 10 m area around crape myrtles correlated with a higher abundance of natural enemies. Aphid predation was mostly predicted by local structural complexity and impervious cover within 20 m of crape myrtle trees. Together, these findings suggest that although the impervious nature of our cities may mean higher densities of some pests, local landscapes around trees can play an important role in maintaining natural enemies and predation services that help regulate pest populations.

scholarly journals A Review of Spatial Variation of Allergenic Tree Pollen Within Cities

2015 ◽  
Vol 41 (2) ◽  
Author(s):  
Kate Weinberger ◽  
Patrick Kinney ◽  
Gina Lovasi
Keyword(s):  
Spatial Variation ◽  
Metropolitan Areas ◽  
Spatial Scales ◽  
Allergic Sensitization ◽  
Urban Environments ◽  
Urban Trees ◽  
Tree Planting ◽  
Health Impacts ◽  
Tree Pollen ◽  
Urban Tree

Urban trees provide a range of environmental and public health benefits. However, urban trees may also have an adverse effect on human health by increasing exposure to pollen. Many types of tree pollen are considered to be allergens and have been linked to various manifestations of allergic disease, including allergic sensitization, exacerbation of allergic rhinitis, and exacerbation of allergic asthma. An emerging body of literature suggests that the amount of pollen deposited annually varies widely over small spatial scales. While the health impacts of spatial variation in tree pollen within metropolitan areas could be large, the current literature has not been systematically reviewed. To fill this gap in knowledge, this review synthesizes existing evidence on how tree pollen is distributed on an intra-urban spatial scale. A better understanding of the spatial distribution of allergenic tree pollen within urban environments and its relation to health could inform increasingly common urban tree planting programs.

scholarly journals Prediction limits of mobile phone activity modelling

2017 ◽  
Vol 4 (2) ◽  
pp. 160900 ◽  
Author(s):  
Dániel Kondor ◽  
Sebastian Grauwin ◽  
Zsófia Kallus ◽  
István Gódor ◽  
Stanislav Sobolevsky ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Spatial Scales ◽  
Urban Environments ◽  
Full Spectrum ◽  
Left Behind ◽  
Social Events ◽  
Prediction Limits ◽  
Spatio Temporal ◽  
City Structure ◽  
The City

Thanks to their widespread usage, mobile devices have become one of the main sensors of human behaviour and digital traces left behind can be used as a proxy to study urban environments. Exploring the nature of the spatio-temporal patterns of mobile phone activity could thus be a crucial step towards understanding the full spectrum of human activities. Using 10 months of mobile phone records from Greater London resolved in both space and time, we investigate the regularity of human telecommunication activity on urban scales. We evaluate several options for decomposing activity timelines into typical and residual patterns, accounting for the strong periodic and seasonal components. We carry out our analysis on various spatial scales, showing that regularity increases as we look at aggregated activity in larger spatial units with more activity in them. We examine the statistical properties of the residuals and show that it can be explained by noise and specific outliers. Also, we look at sources of deviations from the general trends, which we find to be explainable based on knowledge of the city structure and places of attractions. We show examples how some of the outliers can be related to external factors such as specific social events.

scholarly journals Woody Surface Area Measurements with Terrestrial Laser Scanning Relate to the Anatomical and Structural Complexity of Urban Trees

2021 ◽  
Vol 13 (16) ◽  
pp. 3153
Author(s):  
Georgios Arseniou ◽  
David W. MacFarlane ◽  
Dominik Seidel
Keyword(s):  
Surface Area ◽  
Laser Scanning ◽  
Structural Complexity ◽  
Terrestrial Laser Scanning ◽  
Urban Trees ◽  
Box Dimension ◽  
Urban Tree ◽  
Sensing Technology ◽  
Path Lengths ◽  
And Function

Urban forests are part of the global forest network, providing important benefits to human societies. Advances in remote-sensing technology can create detailed 3D images of trees, giving novel insights into tree structure and function. We used terrestrial laser scanning and quantitative structural models to provide comprehensive characterizations of the woody surface area allometry of urban trees and relate them to urban tree anatomy, physiology, and structural complexity. Fifty-six trees of three species (Gleditsia triacanthos L., Quercus macrocarpa Michx., Metasequoia glyptostroboides Hu & W.C. Cheng) were sampled on the Michigan State University campus. Variations in surface area allocation to non-photosynthesizing components (main stem, branches) are related to the fractal dimension of tree architecture, in terms of structural complexity (box-dimension metric) and the distribution of “path” lengths from the tree base to every branch tip. The total woody surface area increased with the box-dimension metric, but it was most strongly correlated with the 25th percentile of path lengths. These urban trees mainly allocated the woody surface area to branches, which changed with branch order, branch-base diameter, and branch-base height. The branch-to-stem area ratio differed among species and increased with the box-dimension metric. Finally, the woody surface area increased with the crown surface area of the study trees across all species combined and within each species. The results of this study provide novel data and new insights into the surface area properties of urban tree species and the links with structural complexity and constraints on tree morphology.

scholarly journals Assessing Lisbon Trees’ Carbon Storage Quantity, Density, and Value Using Open Data and Allometric Equations

Information ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 133
Author(s):  
Miguel de Castro Neto ◽  
Pedro Sarmento
Keyword(s):  
Co2 Emissions ◽  
Carbon Storage ◽  
Tree Species ◽  
Large Scale ◽  
Open Data ◽  
Urban Trees ◽  
Allometric Equations ◽  
Urban Tree ◽  
Density Values ◽  
The City

Urban population has grown exponentially in recent years, leading to an increase of CO2 emissions and consequently contributing on a large scale to climate change. Urban trees are fundamental to mitigating CO2 emissions as they incorporate carbon in their biomass. It becomes necessary to understand and measure urban tree carbon storage. In this paper is studied the potential of open data to measure the quantity, density, and value of carbon stored by the seven most represented urban trees in the city of Lisbon. To compute carbon storage, the seven most represented urban tree species were selected from an open database acquired from an open data portal of the city of Lisbon. Through allometric equations, it was possible to compute the trees’ biomass and calculate carbon storage quantity, density, and value. The results showed that the tree species Celtis australis is the species that contributes more to carbon storage. Central parishes of the city of Lisbon present higher-density values of carbon storage when compared with the border parishes despite the first ones presenting low-to-medium values of carbon storage quantity and value. Trees located in streets, present higher values of carbon storage, when compared with trees located in schools and green areas. Finally, the potential usage of this information to build a decision-support dashboard for planning green infrastructures was demonstrated.

scholarly journals Mapping and studying an urban red fox (Vulpes vulpes) population using social media

2016 ◽  
Author(s):  
Ahsennur Soysal ◽  
Linda M Hooper-Bui ◽  
Edward A Laws
Keyword(s):  
Social Media ◽  
Citizen Science ◽  
Baton Rouge ◽  
Urban Environments ◽  
Urban Habitat ◽  
Story Map ◽  
Local Residents ◽  
Trail Cameras ◽  
The Many ◽  
The City

Foxes are timid yet resourceful animals that are integrated into many urban environments. Because they are elusive, collecting information about the number of urban foxes, their diet and spatial distribution, their interactions with the ecological community in their urban habitat, as well as residents’ response to them, is difficult. Involving stakeholders to participate in the data collection on wildlife via citizen science on social media is one way to overcome this complication, while simultaneously engaging residents in the ecology happening around them. Therefore, we used social media as the platform to engage the public to document and map the foxes in Baton Rouge, LA. Local residents were asked to post sightings and/or photographs of foxes they observed, with the location, onto our Facebook Page at Fox Finders of Baton Rouge, on Twitter at @FoxFindersBR, or on Twitter and Instagram with the hashtag #findfoxlsu. This information was added onto an ArcGIS story map. Types of public responses and engagement over time were also measured. The authors clarified people’s misconceptions about foxes when questions were asked on our Facebook Page. On-site observations and trail cameras were also used in common locations to monitor the urban foxes. While we received only one fox sighting via Instagram and Twitter each, our Facebook Page generated 1132 “likes” and an average of 14% Page Engagement Rate during the first eight months. Along with Baton Rouge, people from 384 different cities and 16 countries have engaged with the page. In addition, 180 sightings of about 140 different foxes—including 61 photographs and eight videos—were submitted, with eight of the sightings coming from areas surrounding the city—outside the study area. Seven common fox locations in the city were identified, all of which were adjacent to a source of water. Results showed that urban foxes have become habituated to the urban environment and may serve as an umbrella species. From the many positive and enthusiastic feedback we have received on our Facebook Page, our research model successfully promoted citizen science by easily connecting residents to science, enabling them to engage with our team and local residents directly to learn about the wildlife around them, efficiently documented and mapped many local urban foxes, and provided a preliminary count of foxes for benchmark data for future studies.

scholarly journals Mapping and studying an urban red fox (Vulpes vulpes) population using social media

2016 ◽  
Author(s):  
Ahsennur Soysal ◽  
Linda M Hooper-Bui ◽  
Edward A Laws
Keyword(s):  
Social Media ◽  
Citizen Science ◽  
Baton Rouge ◽  
Urban Environments ◽  
Urban Habitat ◽  
Story Map ◽  
Local Residents ◽  
Trail Cameras ◽  
The Many ◽  
The City

Foxes are timid yet resourceful animals that are integrated into many urban environments. Because they are elusive, collecting information about the number of urban foxes, their diet and spatial distribution, their interactions with the ecological community in their urban habitat, as well as residents’ response to them, is difficult. Involving stakeholders to participate in the data collection on wildlife via citizen science on social media is one way to overcome this complication, while simultaneously engaging residents in the ecology happening around them. Therefore, we used social media as the platform to engage the public to document and map the foxes in Baton Rouge, LA. Local residents were asked to post sightings and/or photographs of foxes they observed, with the location, onto our Facebook Page at Fox Finders of Baton Rouge, on Twitter at @FoxFindersBR, or on Twitter and Instagram with the hashtag #findfoxlsu. This information was added onto an ArcGIS story map. Types of public responses and engagement over time were also measured. The authors clarified people’s misconceptions about foxes when questions were asked on our Facebook Page. On-site observations and trail cameras were also used in common locations to monitor the urban foxes. While we received only one fox sighting via Instagram and Twitter each, our Facebook Page generated 1132 “likes” and an average of 14% Page Engagement Rate during the first eight months. Along with Baton Rouge, people from 384 different cities and 16 countries have engaged with the page. In addition, 180 sightings of about 140 different foxes—including 61 photographs and eight videos—were submitted, with eight of the sightings coming from areas surrounding the city—outside the study area. Seven common fox locations in the city were identified, all of which were adjacent to a source of water. Results showed that urban foxes have become habituated to the urban environment and may serve as an umbrella species. From the many positive and enthusiastic feedback we have received on our Facebook Page, our research model successfully promoted citizen science by easily connecting residents to science, enabling them to engage with our team and local residents directly to learn about the wildlife around them, efficiently documented and mapped many local urban foxes, and provided a preliminary count of foxes for benchmark data for future studies.

Minimetrò in Perugia as leverage for urban regeneration

TERRITORIO ◽  
2020 ◽  
pp. 148-163
Author(s):  
Luca Fondacci
Keyword(s):  
Urban Regeneration ◽  
Urban Environments ◽  
Low Carbon ◽  
Sustainable Mobility ◽  
Field Surveys ◽  
Peripheral Area ◽  
Alternative Means ◽  
Considerable Impact ◽  
The City ◽  
Historical Centre

In the 1970s, the fragile historical centre of the city of Perugia was a key area where the binomial of sustainable mobility and urban regeneration was developed and applied. At the turn of the xxi century, the low carbon automatic people-mover Minimetrò broadened that application from the city's historical centre to the outskirts, promoting the enhancement of several urban environments. This paper is the outcome of an investigation of original sources, field surveys and direct interviews, which addresses the Minimetrò as the backbone of a wide regeneration process which has had a considerable impact on the economic development of a peripheral area of the city which was previously devoid of any clear urban sense. The conclusion proposes some solutions to improve the nature of the Minimetrò as an experimental alternative means of transport.

scholarly journals Towards sustainable management of the stock and ecosystem services of urban trees. From theory to model and application

Trees ◽  
2021 ◽  
Author(s):  
H. Pretzsch ◽  
A. Moser-Reischl ◽  
M. A. Rahman ◽  
S. Pauleit ◽  
T. Rötzer
Keyword(s):  
Ecosystem Services ◽  
Carbon Sequestration ◽  
Leaf Area ◽  
Ecosystem Service ◽  
Sustainable Management ◽  
Environmental Changes ◽  
Urban Trees ◽  
Urban Tree ◽  
Age Class ◽  
Sustainable Planning

Abstract Key message A model for sustainable planning of urban tree stocks is proposed, incorporating growth, mortality, replacement rates and ecosystem service provision, providing a basis for planning of urban tree stocks. Abstract Many recent studies have improved the knowledge about urban trees, their structures, functions, and ecosystem services. We introduce a concept and model for the sustainable management of urban trees, analogous to the concept of sustainable forestry developed by Carl von Carlowitz and others. The main drivers of the model are species-specific tree diameter growth functions and mortality rates. Based on the initial tree stock and options for the annual replanting, the shift of the distribution of the number of trees per age class can be predicted with progressing time. Structural characteristics such as biomass and leaf area are derived from tree dimensions that can be related to functions such as carbon sequestration or cooling. To demonstrate the potential of the dynamic model, we first show how different initial stocks of trees can be quantitatively assessed by sustainability indicators compared to a target stock. Second, we derive proxy variables for ecosystem services (e.g. biomass for carbon sequestration, leaf area for deposition and shading) from a given distribution of the number of trees per age class. Third, we show by scenario analyses how selected ecosystem services and functions may be improved by combining complementary tree species. We exercise one aspect (cooling) of one ecosystem service (temperature mitigation) as an example. The approach integrates mosaic pieces of knowledge about urban trees, their structures, functions, and resulting ecosystem services. The presented model makes this knowledge available for a sustainable management of urban tree stocks. We discuss the potential and relevance of the developed concept and model for ecologically and economically sustainable planning and management, in view of progressing urbanization and environmental changes.

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