scholarly journals Rapid Assessment of Change and Hurricane Impacts to Houston’s Urban Forest Structure

2011 ◽  
Vol 37 (2) ◽  
pp. 60-66
Author(s):  
Christina Staudhammer ◽  
Francisco Escobedo ◽  
Alicia Lawrence ◽  
Mary Duryea ◽  
Pete Smith ◽  
...  

A subsample of 332, 0.06-hectare plots measured during 2001–2002 in Houston, TX, U.S., were relocated and measured in 2008 following Hurricane Ike. These 37 re-measured plots provide a unique opportunity to explore the effects of urbanization and hurricanes on the forest structure of coastal urban forests. Statistical analyses of growth, mortality, and in-growth were conducted using plot- and tree-level factors. In total, 305 trees were re-measured, of which 195 (63.9%) still remained on-site and 110 (36.1%) had been removed. Ninety-seven (31.8%) of these trees were determined to be removed due to urbanization and 13 trees (4.3%) were removed due to hurricane impacts. Results show an overall annual net loss in tree numbers and an increase in tree density during the analysis period. Average annual mortality and in-growth rates were 3.9% and 5.3%, respectively. Growth rates were significantly influenced by land cover type, tree stem diameter, crown width, and percent dieback (P < 0.05). Overall, Hurricane Ike resulted in the removal of 4.3% of all trees measured, with removal occurring on six (16%) of the 37 re-measured plots. These initial findings could be used to understand changes in forest structure in coastal urban areas, improve estimates of carbon sequestration, and develop management goals.

2008 ◽  
Vol 34 (6) ◽  
pp. 347-358
Author(s):  
David Nowak ◽  
Daniel Crane ◽  
Jack Stevens ◽  
Robert Hoehn ◽  
Jeffrey Walton ◽  
...  

To properly manage urban forests, it is essential to have data on this important resource. An efficient means to obtain this information is to randomly sample urban areas. To help assess the urban forest structure (e.g., number of trees, species composition, tree sizes, health) and several functions (e.g., air pollution removal, carbon storage and sequestration), the Urban Forest Effects (UFORE) model was developed. Data collection variables and model methods are detailed and urban forest structure results are compared among 14 United States cities with average tree density ranging between 22.5 trees/ha (9.1 trees/ac) in Casper, Wyoming, U.S. to 275.8 trees/ha (111.6 trees/ac) in Atlanta, Georgia, U.S. Advantages and disadvantages of this ground-based method of assessing urban forest structure, functions, and values are discussed.


2012 ◽  
Vol 38 (2) ◽  
pp. 58-63
Author(s):  
Nicholas Martin ◽  
Arthur Chappelka ◽  
Edward Loewenstein ◽  
Gary Keever ◽  
Greg Somers

Models that predict ecosystem services in urban areas are useful tools to urban forest managers. Predictive open-grown crown width equations were developed for three oak species common in urban forests in the southern United States. Tree crown form is an important component of these equations; however, there are few predictive equations available for urban, open-grown trees. The species used were Quercus lyrata Walt. (overcup oak), Quercus nuttallii Palmer (Nuttall oak), and Quercus phellos L. (willow oak). The study authors believe that these are the first predictive open-grown crown width equations developed for these species in the southern U.S. Diameter at breast height (DBH) (independent variable), DBH2 (independent variable), and average crown width (dependent variable) data were used to create the predictive crown width equations and yielded R2 values of 0.96, 0.94, and 0.91 for overcup, Nuttall, and willow oaks, respectively. These equations can aid urban landscape and utility planners by providing a means to predict crown dimensions at varying trunk diameters. Field time could also be minimized by reducing the need to measure crown width and with time, these equations could be used to validate species specific equations (e.g., leaf biomass) for these and other southern urban-planted tree species.


Author(s):  
Karolin Kokaz ◽  
Peter Rogers

Recent economic expansion and population growth in developing countries have had a big impact on the development of large cities like Delhi, India. Accompanied by Delhi’s rapid spatial growth over the last 25 years, urban sprawl has contributed to increased travel. The vehicle fleet projected at current growth rates will result in more than 13 million vehicles in Delhi in 2020. Planning and managing such a rapidly growing transport sector will be a challenge. Choices made now will have effects lasting well into the middle of the century. With such rapid transport growth rates, automobile emissions have become the fastest increasing source of urban air pollution. In India, most urban areas, including Delhi, already have major air pollution problems that could be greatly exacerbated if growth of the transport sector is managed unwisely. The transport plans designed to meet such large increases in travel demand will have to emphasize the movement of people, not vehicles, for a sustainable transportation system. Therefore, a mathematical model was developed to estimate the optimal transportation mix to meet this projected passenger-km demand while satisfying environmental goals, reducing congestion levels, and improving system and fuel efficiencies by exploiting a variety of policy options at the minimum overall cost or maximum welfare from transport. The results suggest that buses will continue to satisfy most passenger transport in the coming decades, so planning done in accordance with improving bus operations is crucial.


2021 ◽  
Vol 38 ◽  
pp. 00053
Author(s):  
Mariya Kazantseva ◽  
Sergei Artyomenko

There are 11 plant species of the Orchidaceae family in the city area of Tyumen; eight of them are protected in the Tyumen region, one species is included in the Red Book of Russia. Representatives of the family are found in the urban forest complex, roadside forest belts, on lawns and in public gardens of the central part of the city. Most species are represented locally by single specimens or small groups; three species – Epipactis helleborine, Platanthera bifolia and Neottianthe cucullata can form large complete coenopopulations. The main anthropogenous factors negatively affecting the condition of orchids in the city are: reconstruction of roads and plantations, regular mowing of grass in the habitats of plants. The protection of species requires coordinated efforts of municipal services for the improvement of urban areas and environmental organizations.


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.


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 630
Author(s):  
Peter Sang-Hoon Lee ◽  
Jincheol Park

The urban heat island effect has posed negative impacts on urban areas with increased cooling energy demand followed by an altered thermal environment. While unusually high temperature in urban areas has been often attributed to complex urban settings, the function of urban forests has been considered as an effective heat mitigation strategy. To investigate the cooling effect of urban forests and their influence range, this study examined the spatiotemporal changes in land surface temperature (LST) of urban forests and surrounding areas by using Landsat imageries. LST, the size of the urban forest, its vegetation cover, and Normalized Difference Vegetation Index (NDVI) were investigated for 34 urban forests and their surrounding areas at a series of buffer areas in Seoul, South Korea. The mean LST of urban forests was lower than that of the overall city, and the threshold distance from urban forests for cooling effect was estimated to be roughly up to 300 m. The group of large-sized urban forests showed significantly lower mean LST than that of small-sized urban forests. The group of urban forests with higher NDVI showed lower mean LST than that of urban forests with lower mean NDVI in a consistent manner. A negative linear relationship was found between the LST and size of urban forest (r = −0.36 to −0.58), size of vegetation cover (r = −0.39 to −0.61), and NDVI (r = −0.42 to −0.93). Temporal changes in NDVI were examined separately on a specific site, Seoul Forest, that has experienced urban forest dynamics. LST of the site decreased as NDVI improved by a land-use change from a barren racetrack to a city park. It was considered that NDVI could be a reliable factor for estimating the cooling effect of urban forest compared to the size of the urban forest and/or vegetation cover.


2020 ◽  
Vol 23 (4) ◽  
pp. 905-917
Author(s):  
James A. Westfall ◽  
David J. Nowak ◽  
Jason G. Henning ◽  
Tonya W. Lister ◽  
Christopher B. Edgar ◽  
...  

Author(s):  
Zemin Wu ◽  
Chenglin Huang ◽  
Wenyou Wu ◽  
Shaoujie Zhang

Author(s):  
Maria A. Cunha-e-Sá ◽  
Sofia F. Franco

Although forests located near urban areas are a small fraction of the forest cover, a good understanding of the extent to which —wildland-urban interface (WUI) forest conversion affects local economies and environmental services can help policy-makers harmonize urban development and environmental preservation at this interface, with positive impact on the welfare of local communities. A growing part of the forest resource worldwide has come under urban influence, both directly (i.e., becoming incorporated into the interface or located at the interface with urban areas) and indirectly (as urban uses and values have come to dominate more remote forest areas). Yet forestry has been rather hesitant to recognize its urban mandate. Even if the decision to convert land at the WUI (agriculture, fruit, timber, or rural use) into an alternative use (residential and commercial development) is conditional on the relative magnitude and timing of the returns of alternative land uses, urban forestry is still firmly rooted in the same basic concepts of traditional forestry. This in turn neglects features characterizing this type of forestland, such as the urban influences from increasingly land-consumptive development patterns. Moreover, interface timber production-allocated land provides public goods that otherwise would be permanently lost if land were converted to an irreversible use. Any framework discussing WUI optimal rotation periods and conversion dates should then incorporate the urban dimension in the forester problem. It must reflect the factors that influence both urban and forestry uses and account for the fact that some types of land use conversion are irreversible. The goal is to present a framework that serves as a first step in explaining the trends in the use and management of private land for timber production in an urbanizing environment. Our framework integrates different land uses to understand two questions: given that most of the WUI land use change is irreversible and forestry at this interface differs from classic forestry, how does urban forestry build upon and benefit from traditional forestry concepts and approaches? In particular, what are the implications for the Faustmann harvesting strategy when conversion to an irreversible land use occurs at some point in the future? The article begins with a short background on the worldwide trend of forestland conversion at the WUI, focusing mostly on the case of developed countries. This provides a context for the theoretical framework used in the subsequent analysis of how urban factors affect regeneration and conversion dates. The article further reviews theoretical models of forest management practices that have considered either land sale following clear-cutting or a switch to a more profitable alternative land use without selling the land. A brief discussion on the studies with a generalization of the classic Faustmann formula for land expectation value is also included. For completeness, comparative statics results and a numerical illustration of the main findings from the private landowner framework are included.


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