Role Of Urban Forests Research Articles

The Role of Urban Forests as Carbon Sink: A Case Study in the Urban Forest of Banda Aceh, Indonesia

Forests have a role as carbon sinks and come under the spotlight when the world is facing the climate change problem. Urban forests have functions as the most effective carbon sinks. Banda Aceh City only has 7.15 ha of urban forest, and the vegetation that grows in the urban forest is essential for carbon emissions reduction. This study aimed to determine the potential tree biomass and carbon sink value in the BNI Urban Forest, Banda Aceh City, Indonesia. This study used vegetation analysis by inventory method with the census sampling method. The diameter of all trees was measured, and tree biomass, carbon stocks, and carbon sequestration were calculated. This study identified 16 tree species in the BNI Urban Forest with a total of 318 individuals, showing Casuarina equisetifolia as the most dominant tree (163 trees). The above-ground biomass, carbon stock, and carbon sequestration by the vegetation in the BNI Urban Forest were 24.66 tons/ha, 11.59 tons/ha, and 42.51 tons/ha, respectively. This study presented the vegetation conditions and the potential of carbon sequestration, which can be used to monitor and evaluate the benefits of the existence of urban forests in Banda Aceh. Keywords: carbon sequestration, carbon stock, green open space, tree biomass, urban forest

Spatial variation analysis of urban forest vegetation carbon storage and sequestration in built-up areas of Beijing based on i-Tree Eco and Kriging

To explore available methods for assessing the orientation, magnitude, and role of urban forests in abating climate change, i-Tree Eco and Kriging interpolation were employed to quantify and map the carbon storage and sequestration capability of trees in urban forests. Specifically, urban tree field data were collected from 981 sample plots throughout five types of urban forests in the built-up area of Beijing, China, and used to estimate carbon storage and sequestration within each individual plot and the area as a whole. These data were subsequently subjected to Kriging interpolation to map carbon storage and sequestration within the study area. The results showed that the carbon storage and sequestration patterns in the urban forests in Beijing exhibit noticeable spatial heterogeneity, and that there is a clear, statistically significant distribution of high and low value areas. Furthermore, urban planning, the degree of urbanization, and the urban forest structure effect the carbon spatial distribution. This work provides a reference for prudent planning and construction of urban forests and will aid decision-makers in designing eco-friendly urban environments.

Magnetism and Grain-Size Distribution of Particles Deposited on the Surface of Urban Trees in Lanzhou City, Northwestern China.

Studies on the variation in the particulate matter (PM) content, Saturation Isothermal Remanent Magnetization (SIRM), and particle grain-size distribution at a high spatial resolution are helpful in evaluating the important role of urban forests in PM removal. In this study, the trees located in dense urban forests (T0) retained more PM than trees located in open spaces (T1–T4); the SIRM and PM weight of T0 were 1.54–2.53 and 1.04–1.47 times more than those of T1–T4, respectively. In addition, the SIRM and PM weight decreased with increasing distance to the road, suggesting that distance from pollution sources plays a key role in reducing the air concentration of PM. The different grain-size components were determined from frequency curve plots using a laser particle-size analyzer. A unimodal spectrum with a major peak of approximately 20 μm and a minor peak between 0.1 and 1 μm was observed, indicating that a large proportion of fine air PM was retained by the needles of the study trees. Additionally, more <2.5 μm size fraction particles were observed at the sampling site near the traffic source but, compared to a tree in a row of trees, the percentage of the >10 μm size fraction for the tree in the dense urban forest was higher, indicating that the particles deposited on the needle surface originating from traffic sources were finer than those from natural atmospheric dust. The exploration of the variation in the PM weight, SIRM, and grain size of the particles deposited on the needle surface facilitates monitoring the removal of PM by urban forests under different environmental conditions (e.g., in closed dense urban forests and in open roadside spaces), different distances to roads, and different sampling heights above the ground.

Tourism Economic Value of Bukit Pangonan Urban Forest, Lampung, Indonesia

The quite high community activities in urban areas have caused the Bukit Pangonan Urban Forest to become an alternative tourism spot easily accessible by urban communities. There is, however, the need for natural tourism development in regional planning and conservation towards increasing the economic value of these urban forests. Therefore, this study was conducted to analyze the economic value of nature tourism in Bukit Pangonan Urban Forest and its role in environmental conservation. This involved the selection of 100 respondents as samples through incidental sampling techniques. Data was collected using interviews and analyzed quantitatively with the travel cost method and descriptively. The results showed the economic value of the Bukit Pangonan Urban Forest is Rp 4,557,944,880 per year, with visitors having a surplus of Rp 119,433 per visitor per visit and spending Rp 96,630/person/visit with the highest on transportation. The role of urban forests in environmental conservation is quite significant in preventing environmental damage, and it is possible to enhance this through the addition and diversification of tree species, protection of biodiversity, selection of appropriate tree species, development of environmentally friendly tourism facilities, providing conservation education to visitors, and policy support from the government. Moreover, it is also possible for the government to use Bukit Pangonan Urban Forest as a model to develop urban forest tourism in other areas.

Review on Urban Forests and Trees as Nature-Based Solutions over 5 Years

As human living environments face increasing challenges with resilience, the concept of nature-based solutions (NBS) was proposed in recent years as a way to promote sustainable living in urban environments. Urban forests and trees play important roles in urban ecosystems, while their potential as an NBS is promising. A bibliometric analysis was first conducted to explore the research pattern of NBS in urban environments. Studies of urban forest and tree-based green infrastructure in NBS research were further investigated using a systematic literature review method. The initial studies on NBS have increased since 2015 with 493 documents published from 142 sources in over 70 countries and regions. Keyword analysis showed green infrastructure had a rather high frequency of utility and received considerable attention. As for urban forests as nature-based solutions (UF-NBS) research, the most prominent study approaches used at different scales and the main benefits and typologies of urban forest studied in the articles were identified. UF-NBS research is still relatively scarce at present. Despite the role of urban forest and trees in addressing environmental challenges being well recognized, UF-NBS studies still need to be conducted in a more comprehensive context, taking social and economic aspects into account.

Between Pocket Forest Wilderness and Restored Rural Arcadia: Optimizing the Use of a Feral Woodland Enclave in Urban Environment

An eight-hectare forest reserve in the centre of the metropolitan area in SE Poland was investigated for the effects of its management in relation to its purpose—protection of old Quercus robur L. trees. This local issue corresponds to a wider debate on the role of urban forests in contemporary societies. The study embraced (1) oak stand history—stand mapping and dendrochronology, historical maps’ analysis; (2) vegetation trends—undergrowth and ground layer analysis; and (3) visitors’ opinions on the reserve’s use—interview. The dendroecological analysis corroborates the landscape’s history emerging from the 1700s–1900s maps. The reserve is a feral park established in the early 1900s on the abandoned agricultural, partly wooded landscape. Under the current regime, shade-tolerant trees continue gaining advantage over older oaks, preventing their regeneration, whilst the herb layer, due to the reserve’s isolation remains poor and polluted by alien species. The non-intervention approach does not allow the reserve’s objective to be met. We recommend the restoration of features of semi-open silvopastoral landscape. This would correspond with both local eco-history and the dominating preference of the interviewed visitors. Such “bio-cultural refugia” should become key knowledge centres of the natural, cultural, and economic importance of the “working rural landscape”, fostering urban care for the countryside.

Urban Forests and Carbon Sequestration

Climate change amidst rapid unplanned urbanisation and unsustainable development has taken centre stage amongst the most prominent challenges in today's world, with greater impacts on the society and economy of developing countries such as India. Forestry activities have gained traction due to huge pollution mitigating potentials which have become a focal point of intergovernmental agencies. Nonetheless, despite studies suggesting that forests play significant mitigation roles, the role of urban forests has not assumed equal significance despite their significant role in sequestering carbon and other various social-economic-cultural-aesthetic benefits. This review primarily focuses on carbon sequestration potentials and methodologies for urban forests. The author(s) reveal that urban forests in general and urban educational institutional campuses in particular can make significant contributions in maintaining and managing GHG emissions and sequestrations to ensure sustainability. These results can provide future direction and ample knowledge for academics, urban planners and policy makers.

Relationships between air particulate matter capture efficiency and leaf traits in twelve tree species from an Italian urban-industrial environment

Air pollution in the urban environment is widely recognized as one of the most harmful threats for human health. International organizations such as the United Nations and the European Commission are highlighting the potential role of nature in mitigating air pollution and are now funding the implementation of Nature-Based Solutions, especially at the city level. Over the past few decades, the attention of the scientific community has grown around the role of urban forest in air pollution mitigation. Nevertheless, the understanding on Particulate Matter (PM) retention mechanisms by tree leaves is still limited. In this study, twelve tree species were sampled within an urban park of an industrial city. Two techniques were used for leaf analysis: Vacuum/Filtration and Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy, in order to obtain a quali-quantitative analysis of the different PM size fractions. Results showed that deposited PM loads vary significantly among species. Different leaf traits, including micro and macromorphological characteristics, were observed, measured and ranked, with the final aim to relate them with PM load. Even if no significant correlation between each single leaf characteristic and PM deposition was observed (p > 0.05), multivariate analysis revealed relationships between clusters of leaf traits and deposited PM. Thus, by assigning a score to each trait, an Accumulation index (Ai) was calculated, which was significantly related to the leaf deposited PM load (p ≤ 0.05).

A tale of three cities: Mercury in urban deciduous foliage and soils across land-uses in Poughkeepsie NY, Hartford CT, and Springfield MA USA.

Mercury is a global pollutant that harms human and wildlife health through chronic exposure. The role of urban forests in Hg biogeochemistry has been understudied in cities without historical mining or current coal combustion. This study aimed to quantify total Hg concentrations and pools in urban forests to determine whether adjacent land-use impacts Hg accumulation. Three cities in the northeastern United States were studied: Hartford, Connecticut; Poughkeepsie, New York; and Springfield, Massachusetts. We identified ~20 urban forests sites in a ~10km by ~10km grid for each city and sampled foliage and soil at each site. Foliage from Populus exhibited significantly lower Hg concentrations (15.6±2.1ngg-1) than mean foliar Hg concentrations (23.7±0.6ngg-1) but most deciduous genera had comparable concentrations. Average forest floor Hg concentrations (195±21ngg-1) and Hg pools (1.9±0.5mgm-2) were similar to previous, non-urban studies in the region. Average A horizon (182±19ngg-1) and B horizon (125±14ngg-1) Hg concentrations were double those of regional forest soils. Mineral soil Hg pools for the top 30cm (49±6mgm-2) averaged two to ten times higher than rural, montane forests in the region. Soil pH, LOI, and %clay were poorly correlated with mineral soil Hg concentrations. Instead, highest foliar and soil Hg concentrations and pools were in urban forests adjacent to high and medium intensity developed areas in Springfield and Hartford. To differentiate the impact of land-uses not captured by the National Land Cover Database (NLCD) system, we implemented new land-use categories. Industrial areas had highest foliar and soil Hg concentrations and pools of any land use. Our results show increasing land-use increases Hg accumulation in urban forests.

Estimating Environmental Contamination and Element Deposition at an Urban Area of Central Italy

Air quality monitoring in many urban areas is based on sophisticated and costly equipment to check for the respect of environmental quality standards, but capillary monitoring is often not feasible due to economic constraints. In such cases, the use of living organisms may be very useful to complement the sparse data obtained by physico-chemical measurements. In this study, the bioaccumulation of selected trace elements (Al, As, Cd, Ce, Cr, Cu, Fe, Ni, Pb, S, Sb, Zn) in lichen samples (Evernia prunastri) transplanted for three months at an urban area of Central Italy was investigated to assess the main environmental contaminants, their sources, and the fluxes of element depositions. The results pinpointed Cu and Sb as the main contaminants and suggested a common origin for these two elements from non-exhaust sources of vehicular traffic, such as brake abrasion. Most study sites were, however, found to be subjected to low or moderate environmental contamination, and the lowest contamination corresponded to the main green areas, confirming the important protective role of urban forests against air pollution. Ranges of estimated mean annual element deposition rates in the study area were similar or lower than those reported for other urban areas.

West African Sahelian cities as source of carbon stocks: Evidence from Niger

The need for sustainable cities under a changing climate calls for intensive research on the role of urban forests in climate change mitigation. This study estimated the carbon stocks and carbon emission factors in Niamey and Maradi. Stratified random sampling approach was used for the urban forests inventory. Biomass was estimated using the generalized model. Stock-difference method was used for the carbon emission factor. Focusing on woody plants with a diameter at breast height > 5 cm, 2,027 stems (78 species) were measured in Niamey and 2,456 stems (90 species) were measured in Maradi. The mean carbon stock was 31.63 (15.63, 47.64) in Niamey and 58.30 (13.10, 103.50) t/ha in Maradi. The mean carbon stock was significantly different in each city (p < 0.05) across land use types. The results show that the conversion of peri-urban forests into the urban forest in any of the land use types is associated with carbon gain. This study illustrated the potential benefits of accounting for urban forest carbon stocks within Sahel cities under rapid urbanization. This study recommends that the urban forest carbon stocks should be included in climate change mitigation in Niger.

Tree agency and urban forest governance

Purpose – The role of urban forests and urban trees in creating vibrant and resilient cities is widely recognised. Urban forest governance as the strategic decision and rule making for urban tree resources is no longer solely the domain of governmental actors, but occurs rather often as network governance also involving businesses and civic society. However, governance theory usually does not consider the role of non-human agency, which can be considered problematic due to, for example, the important role of urban trees in place making. The purpose of this paper is to provide further insight into the importance of considering tree agency in governance. Design/methodology/approach – Taking an environmental governance and actor network theory perspective, the paper presents a critical view of current urban forest governance, extending the perspective to include not only a wide range of human actors, but also trees as important non-human actors. Findings – Urban forest governance has become more complex and involves a greater range of actors and actor networks. However, the agency of trees in urban forest governance is seldom well developed. Trees, in close association with local residents, create places, something which needs to be better recognised in governance. Case studies show that this type of non-reflexive agency of urban trees often has emerged in the case of acute threats to urban trees or woodlands. New approaches such as those of biophilic urbanism and biocultural diversity can assist with better integration of tree agency in governance. Originality/value – Urban forest governance is an emerging field of research which has seldom addressed tree agency. Thus the perspective on urban forest governance is enriched, beyond the dominant post-neoliberal and anthropocentric perspective.

Multiple use patterns of medicinal trees in an urban forest in Nairobi, Kenya

Medicinal plants support the healthcare needs of the most vulnerable human populations, including the rapidly increasing urban poor in developing countries. However, little is known about the role of urban forests in supplying traditional herbal remedies compared to those in rural areas. Different parts of medicinal species could be used to supply different forest products, and multiple uses may exacerbate impacts to the species. We focused on the debarking and cutting of woody species harvested for medicine and fuelwood in an urban forest in Nairobi, Kenya. Since informal harvest was common, we surveyed the signs of harvest (i.e., stem debarking and cutting) in the forest rather than conducting household interviews. The survey covered a total of 14,993 stems of 93 species, of which 9169 were standing and 5824 were cut. Among those standing, 172 stems of nine species were debarked. The barks of most of the nine species were known to be used as traditional medicine in the region. Debarking was concentrated on Warburgia ugandensis and Elaeodendron buchananii, which were also affected by cutting, and we analyzed them in detail. Debarking occurred primarily on larger stems of W. ugandensis and E. buchananii, and cutting more frequently involved smaller W. ugandensis stems. Debarking and cutting of E. buchananii was concentrated near the low-income housings adjacent to the forest. Patrolling nearly failed to protect either species from debarking and cutting. We discussed management options of the urban forest including reformed patrolling strategy and planting of useful species in degraded areas, and demonstrated how our approach could aid the management of informal and multiple uses of urban forest products.

Carbon storage and sequestration by trees in urban and community areas of the United States

Carbon storage and sequestration by urban trees in the United States was quantified to assess the magnitude and role of urban forests in relation to climate change. Urban tree field data from 28 cities and 6 states were used to determine the average carbon density per unit of tree cover. These data were applied to statewide urban tree cover measurements to determine total urban forest carbon storage and annual sequestration by state and nationally. Urban whole tree carbon storage densities average 7.69 kg C m−2 of tree cover and sequestration densities average 0.28 kg C m−2 of tree cover per year. Total tree carbon storage in U.S. urban areas (c. 2005) is estimated at 643 million tonnes ($50.5 billion value; 95% CI = 597 million and 690 million tonnes) and annual sequestration is estimated at 25.6 million tonnes ($2.0 billion value; 95% CI = 23.7 million to 27.4 million tonnes).

The role of urban forest in the protection of human environmental health in geographically-prone unpredictable hostile weather conditions

Few people know how many or what kind of treesare found in urban areas, or the effect these trees haveon a city’s environment and the health and well beingof its inhabitants. In order to understand the urbanforest structure and its function in environmentalimprovement 5 major landscape elements, i.e., buildingand hard pavement surface, water, road, urban forest,and general green land in the area (Brazel

Raising the profile of Canada's 9th forest region: Urban forests

A recent CIF Ottawa Valley section meeting in Carleton Place, Ontario was cause for reflection on the important role of urban forests. In spite of their well-known benefits, Canadian urban forests are under great pressure. However, recent developments in municipal planning and the creation of the Canadian Urban Forest Network show some progress — developments encouraged for the first time by the most recent National Forest Strategy. This contrasts to a historic denial by forestry organizations to include urban forests as part of "Canada's Forests" in spite of their economic and environmental significance. It also contrasts with urban forest programs initiated by the USDA Forest Service in the United States. For smaller communities like Carleton Place, urban forests are very important. They are being recognized by the community through its Official Plan, in operational guidelines and through an R.P.F.-led volunteer Urban Forest Advisory Committee. Key words: urban forests, strategic urban forest plans, Canadian Urban Forest Network, Urban Forest Advisory Committee

A Short History of Urban Forestry in Europe

In Europe, more attention is being given to the concept of urban forestry. However, it is applied more to forests under a strong urban influence than to urban greenspace at large. Urban forests especially differ from other forests in terms of the dominance of local actors in policy-making processes to determine which functions the forests should fulfill. As large parts of Europe have become urbanized, these forests are extremely important particularly as pressures on nearby recreation settings and on Europe's urban forests are high. In the context of a European study of urban forest policymaking, a tentative overview of urban forestry history is presented. In spite of existing cultural, socio-economic and political differences between countries and cities, some general developments can be described. Over time, more forests have become incorporated and planted in and near urban areas, with a growing number being opened to the public. Urban forest policy-making processes have become more complex, involving a larger number of people. The role of urban forests in the development of forestry practice and science deserves special mention.