scholarly journals Tree Species Diversity and Socio-economic Perspectives of the Urban (Food) Forest of Accra, Ghana

Author(s):  
Bertrand Nero ◽  
Nana Afranaa Kwapong ◽  
Raymond Jatta ◽  
Oluwole Fatunbi

In Africa, 80% of households in urban areas are food insecure and is coupled with a dramatically changing urban food culture towards increased consumption of sugary and fatty foods. Consequently, incidences of obesity and undernourishment in many African cities are becoming escalating. Urban and peri-urban forestry emerges as a complementary measure to contribute towards elimination of urban hunger and improved nutritional security. However, there is scanty knowledge about the composition, diversity and socioeconomic contributions of urban food trees in African cities and this hinders policy discussions integrating urban forestry into the food security discourse. This paper examines the diversity and composition of the urban forest and food trees of Accra and sheds light on perceptions of urbanites regarding food tree cultivation and availability in the city. Using a mixed methods approach, about 105 respondents in six neighbourhoods of Accra were interviewed while over 200 100-m2 plots were surveyed across five land use types. Twenty-two out of the 70 woody species in Accra are edible. The food tree abundance in the city is about half of the total number of trees enumerated. The species richness and abundance of the edible trees and all trees in the city were significantly different among land use types (p<0.0001) and neighbourhood types (p<0.0001). The diversity of food bearing tree species was much higher in the poorer neighbourhoods than in the wealthier neighbourhoods. Respondents in wealthier neighbourhoods indicated that tree and fruit tree cover of the city was generally low and showed greater interests in cultivating fruit trees and expanding urban forest cover than poorer neighbourhoods. These findings demonstrate the need for urban food policy reforms that integrate urban grown tree foods in the urban food system/culture.

2018 ◽  
Vol 10 (10) ◽  
pp. 3417 ◽  
Author(s):  
Bertrand Nero ◽  
Nana Kwapong ◽  
Raymond Jatta ◽  
Oluwole Fatunbi

Urban and peri-urban forestry has emerged as a complementary measure to contribute towards eliminating urban hunger and improved nutritional security. However, there is scanty knowledge about the composition, diversity, and socioeconomic contributions of urban food trees in African cities. This paper examines the diversity and composition of the urban forest and food trees of Accra and sheds light on perceptions of urbanites regarding food tree cultivation and availability in the city. Using a mixed methods approach, 105 respondents in six neighborhoods of Accra were interviewed while over 200 plots (100-m2 each) were surveyed across five land use types. Twenty-two out of the 70 woody species in Accra have edible parts (leaves, fruits, flowers, etc.). The food-tree abundance in the city is about half of the total number of trees enumerated. The species richness and abundance of the food trees and all trees in the city were significantly different among land use types (p < 0.0001) and neighborhood types (p < 0.0001). The diversity of food-bearing tree species was much higher in the poorer neighborhoods than in the wealthier neighborhoods. Respondents in wealthier neighborhoods indicated that tree and food-tree cover of the city was generally low and showed greater interest in cultivating food (fruit) trees and expanding urban forest cover than poorer neighborhoods. These findings demonstrate the need for urban food policy reforms that integrate urban-grown tree foods in the urban food system/culture.


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.


2016 ◽  
Vol 9 ◽  
Author(s):  
Mélanie LeBlanc ◽  
Guillaume Fortin

Changes in land use, which threaten ecosystems and habitats, have an impact on run-off and water quality on urban areas. Using a GIS program we have classified the land use of the Humphreys Brook watershed and quantified the changes that have occurred using landscape metrics. A rapid growth of the city emerges from our results. All land use types of urban nature have seen an increase in surface areas to the detriment of natural land uses. Moreover the landscape indices are showing signs of rectangularity, where humans have introduced straight edges, and other common processes of transformation to the landscape.


Author(s):  
Md. Sultan Mahmud ◽  
Rony Basak

Noise pollution is a silent villain as it’s quite easy for being ignored by us. Urban areas are more exposed to this deadly agenda as the density of population and their belongings are excessive in there. This study differentiated noise levels of Sylhet City Corporation, a growing city of Bangladesh into different types according to the land use purpose of the city like residential, silent etc. One hundred and sixty-eight noise level readings, taken at 14 different positions during the morning, afternoon, evening, and night of selective weekdays which are categorized as busy days, typical days and weekends were utilized for this research. Results put the average noise level readings in the city centers at between 45 dB(A) and 95 dB (A), dissented from the permissible limits of the World Health Organization (WHO) as well as national standardization organization: Department of Environment (DOE) in all the land use types, with the highest noise pollution levels recorded for transportation, commercial and silent typed areas. The result of the one-way ANOVA test completed where the dependent variable was noise and the independent variable was land use types uncovers a factually huge mean noise levels over the study area (F (4,115) = 9.52, p = 1.1079). Tukey’s HSD method also carried away which showed the uneven difference of noise levels between the land types. The study represents noise pollution auditing, and the immediate needs to control urban noise pollution with convenient and effective policies some of which is recommended at the end of the study.


Land ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 101 ◽  
Author(s):  
Janis Arnold ◽  
Janina Kleemann ◽  
Christine Fürst

Urban ecosystem services (ES) contribute to the compensation of negative effects caused by cities by means of, for example, reducing air pollution and providing cooling effects during the summer time. In this study, an approach is described that combines the regional biotope and land use data set, hemeroby and the accessibility of open space in order to assess the provision of urban ES. Hemeroby expresses the degree of naturalness of land use types and, therefore, provides a differentiated assessment of urban ES. Assessment of the local capacity to provide urban ES was conducted with a spatially explicit modeling approach in the city of Halle (Saale) in Germany. The following urban ES were assessed: (a) global climate regulation, (b) local climate regulation, (c) air pollution control, (d) water cycle regulation, (e) food production, (f) nature experience and (g) leisure activities. We identified areas with high and low capacity of ES in the urban context. For instance, the central parts of Halle had very low or no capacity to provide ES due to highly compact building styles and soil sealing. In contrast, peri-urban areas had particularly high capacities. The potential provision of regulating services was spatially limited due to the location of land use types that provide these services.


2019 ◽  
Vol 46 (1) ◽  
pp. 67-78
Author(s):  
Septian Eka Prayoga ◽  
Arif Kusumawanto

Surface materials that turn into hard surface material and lack of vegetations are some of the effects of rapid development that can affect the micro climate in urban areas. This happened on Cik Ditiro corridor in the city of Yogyakarta which had quite dense activities, this was marked by various functions of land use and human activities throughout the day. The method is simulation method that uses the EnviMET 4.0 software and the empirical measurements. This method is to simulate the value of each climate variable in existing conditions and ideal conditions. The results of this research show that the condition of the Cik Ditiro corridor still belongs to the heat which is uncomfortable thermal conditions. Recommendations result of this research is to make better thermal comfort on corridor. The result of this research to give recommendations in terms of improving better for thermal comfort.


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 ◽  
Author(s):  
Long Ho ◽  
Ruben Jerves-Cobo ◽  
Matti Barthel ◽  
Johan Six ◽  
Samuel Bode ◽  
...  

Abstract. Rivers act as a natural source of greenhouse gases (GHGs) that can be released from the metabolisms of aquatic organisms. Anthropogenic activities can largely alter the chemical composition and microbial communities of rivers, consequently affecting their GHG emissions. To investigate these impacts, we assessed the emissions of CO2, CH4, and N2O from Cuenca urban river system (Ecuador). High variation of the emissions was found among river tributaries that mainly depended on water quality and neighboring landscapes. By using Prati and Oregon Indexes, a clear pattern was observed between water quality and GHG emissions in which the more polluted the sites were, the higher were their emissions. When river water quality deteriorated from acceptable to very heavily polluted, their global warming potential (GWP) increased by ten times. Compared to the average estimated emissions from global streams, rivers with polluted water released almost double the estimated GWP while the proportion increased to ten times for very heavily polluted rivers. Conversely, the GWP of good-water-quality rivers was half of the estimated GWP. Furthermore, surrounding land-use types, i.e. urban, roads, and agriculture, significantly affected the river emissions. The GWP of the sites close to urban areas was four time higher than the GWP of the nature sites while this proportion for the sites close to roads or agricultural areas was triple and double, respectively. Lastly, by applying random forests, we identified dissolved oxygen, ammonium, and flow characteristics as the main important factors to the emissions. Conversely, low impact of organic matter and nitrate concentration suggested a higher role of nitrification than denitrification in producing N2O. These results highlighted the impacts of land-use types on the river emissions via water contamination by sewage discharges and surface runoff. Hence, to estimate of the emissions from global streams, both their quantity and water quality should be included.


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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