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Above-ground carbon storage by urban trees in Leipzig, Germany: Analysis of patterns in a European city
Abstract
Many aspects of global change, including carbon dioxide emissions, have been attributed to urban areas. On the other hand, cities have been found to provide valuable ecosystem services such as carbon storage. The aim of this study is to estimate the above-ground carbon storage in trees in the central European city of Leipzig and produce spatially explicit carbon storage maps. We used stratified random sampling across 19 land cover classes using 190 sample plots to measure carbon storage. In addition, we derived canopy cover from color-infrared orthophotos using an object-oriented approach and Random Forest machine learning. Finally, we apply an error assessment method that includes sampling error, but also uncertainty stemming from allometric equations, and that so far has only been applied to rural forests. The total above ground carbon stock of Leipzig was estimated using both land cover and canopy cover, which was more laborious than just using land cover but reduced the standard error. Canopy cover was approximately 19% of the city area. Leipzig's above-ground carbon storage was estimated to be 316,000MgC at 11MgCha−1. The distribution of carbon storage across the city showed the highest values at intermediate urbanization levels. Carbon storage in the city of Leipzig was in the lower range compared to cities in Europe, Asia and the USA, and our results indicate that great care should be taken when transferring values between cities. We provide spatially explicit and detailed maps of above-ground storage that can contribute to ecosystem services assessments.
... Therefore, the selected ES are some of the most frequently assessed riverine ES, include regulating and cultural ES Environmental Management categories allowing for comparison, and are emphasized as being beneficial for well-being (Aylward et al. 2005;Hanna et al. 2018). All of the indicators have been welltested in other studies and are valued using empirical methods (Fagerholm et al. 2016;Larondelle et al. 2014;Rall et al. 2017;Sharp et al. 2016;Strohbach and Haase 2012;Yan et al. 2018). ...
... This study focused on the two most relevant pools, above-ground biomass, and soil carbon storage, for the ES assessment of the study area (EPA 2018;Paustian et al. 2006). The values used to quantify the aboveground carbon storage were obtained from an empirical study by Strohbach and Haase (2012). The aforementioned study was carried out in the city of Leipzig, Germany, which due to its similar latitudinal location and vegetation composition as our case study, serves as an ideal data source. ...
... The spatial values were mapped using kernel density analysis for the activity points. This is a technique that calculates the density of points around each output raster cell and it is based on the quadratic kernel function (Silverman 1986). It is a method widely used to visualize the spatial patterns of PPGIS based ecosystem service indicators (Brown and Fagerholm 2015). ...
Compared to technical infrastructure, nature-based solutions, NBS, strive to work with nature and to move beyond business-as-usual practices in order to address societal challenges such as flood risks. This research aims to spatially identify possible NBS areas and evaluate the areas capacity to provide selected ecosystem services, ES, for the Lahn river landscape in Germany. The research follows the functional landscape approach using hydromorphological landscape units, HLU, based on specific biophysical spatial criteria, such as slope, to then identify locations which may be considered suitable for NBS. The current ES delivery of these possible NBS areas is then evaluated. The three ES assessed are carbon storage, nutrient retention and recreation. We then undertake a geospatial comparison analysis to show the spatial relationships and patterns that emerge in regards to the ES configuration of the distinct NBS apt areas. Results show the HLU method serves to delineate and identify areas where NBS may exist or be implemented. The data depicts a distinct spatial pattern for each possible NBS space and complementary ES delivery. This explorative method is a useful spatial approach that can support NBS implementation and serve to investigate the multiple benefits NBS provide. The use of ecosystem services to compare and understand NBS is a viable prospect that must, however, be cautiously, locally and scientifically approached. Noticeable limitations regarding ES assessment remain, as available methods are often insufficiently inclusive of natural ecosystem processes and functions. Further research should assess a broader spectrum of NBS and their delivery of ES.
... The ecosystem services indicator shall be above-ground carbon storage/ha. The above-ground carbon storage quantification method will be linked to land use in t C/ha, as estimated by Strohbach and Haase [32] in a study on above-ground carbon storage in Leipzig (Germany). ...
... Again, sources of uncertainty in the assessment will be the different values in different climatic and geographical environments/conditions. 3.1.8. Regulating Services: Carbon Sequestration Table 3 presents the above-ground carbon storage per land cover to be considered, adapted from Strohbach and Haase [32], and a carbon storage index calculated, according to Equation (3). ...
This paper presents a new way of valuing ecosystem services based on the price of EU carbon dioxide emission allowances. Its main advantage is that it facilitates the monetisation of non-provisioning ecosystem services, which is the Achilles heel of current frameworks. The research approach is built on the notion that land rehabilitation and ecological restoration involve trade-offs between ecosystem services. A quantitative assessment (valuation) of these trade-offs is necessary to make sound decisions. However, using different valuation methods to estimate monetary values creates a non-comparability in the valuation process that is difficult to correct. To address this problem, in the first place, the propagation of imprecise preference statements in hierarchical weighting is proposed, avoiding the non-comparability caused by the different current approaches while reducing the effort of preference elicitation. In the second place, to achieve consistency, monetisation of all non-provisioning ecosystem services was carried on the above comparison and the monetary valuation of the attribute with the most direct and market-related valuation possible: carbon sequestration, using the EU Emissions Trading System. A former coal mining area exemplifies the valuation of ecosystem services provided by alternative ecological restoration scenarios. The aim is to estimate their contribution to human well-being, understand the incentives faced by decision makers to manage ecosystems in different ways and assess the values of alternative solutions. An exercise is then carried out to show that the price of EU carbon permits (as of December 2021) after the price escalation that coincides with phase 4 of the allocation of allowances under the EU Emissions Trading System can be estimated by prioritising biodiversity over other ecosystem services.
... In recent years, variation in ESs in urban-rural areas has attracted more research attention with the increasing degree of interaction between humans and nature (Gaglio et al. 2017;Haase et al. 2012). Studies have been conducted at different geographic scales, e.g., European urban-rural areas and Leipzig in eastern Germany Radford and James 2013), on different ES functions, e.g., food provisioning, climate regulation, pollination, and recreation (Nowak et al. 2013;Strohbach and Haase 2012), and on ES transfer and sensitivity (Lautenbach et al. 2011;Schwarz et al. 2011). ...
... The urban-rural gradient analysis method (UGAM) is useful in describing patterns and trends of urbanization, e.g., by comparing socioeconomic dimensions of biota in urban-rural areas and land cover structures (Hahs and McDonnell 2006;McDonnell and Hahs 2008;Zipperer et al. 2000). The method can be applied to analyze ES changes and trade-offs along an urban-rural gradient, based on assessments of ESs such as food, water, and energy supply , and carbon storage pollination, water regulation, and esthetic and recreation services (Radford and James 2013;Strohbach and Haase 2012). Such studies have shown that significant ES differences exist at the urban-rural gradient scale, but there is no typical model for gradients in different study areas (Larondelle and Haase 2013). ...
Urban agglomeration will be the main mode of future urbanization in China, greatly influencing social and economic development and ecosystem protection at the whole city cluster scale. It is important to analyze the impacts of large-scale, scattered land use and cover change (LUCC) consisting of one-pole-multi-point urbanization in city clusters on regional ecosystem services (ESs), so as to increase ecological security and maintain ES levels. Using the urban-rural gradient analysis method (UGAM), this study examined driver-response mechanisms of large-scale, scattered agglomeration urbanization on ESs along an urban-rural gradient and at a regional scale. This was done by simulating and analyzing tempo-spatial variations in ES characteristics along concentric ring gradients in the Central Yunnan City Cluster (CYCC) under its present urbanization path. The results showed that rapid urban sprawl is the main driver affecting the integral value of ESs in CYCC and that ES trade-offs (through LUCC caused by urbanization) between adjacent zones along the urban-rural gradient will particularly exacerbate the degradation of integral ES levels. Hence, CYCC should follow a sustainable, eco-friendly urbanization path and consider ecological principles and the impact of LUCC on regional ESs along the urban-rural gradient in top-level design and decision-making on urban planning and strategic land use management. Differentiated regional development policies should be formulated for each area, the urban-rural development pattern and layout optimized, the scale of construction land rationally controlled, and the overall efficiency of land use improved. Ecological buffers should be set up around areas with sharp and obvious changes in land use, to alleviate the negative impact of large-scale, decentralized city cluster urbanization on regional ESs.
... Above-ground development patterns in water shortage. The above-ground development of urban trees was tightly related to their physiological conditions and multiple ecosystem services 26,27 . Furthermore, tree species might adjust their above-ground patterns under various environmental challenges and stresses 28 . ...
Under rapid urbanization and agglomeration of population, cities are facing various environmental challenges. As urban forests play a crucial role in mitigating native environmental problems and providing ecosystem services, cities might enhance their urban forest construction through multiple approaches, of which the introduction of exotic tree species could be an effective way. Under the background of constructing a high-quality forest city, Guangzhou was considering introducing a series of exotic tree species to improve the local urban greening, among which Tilia cordata Mill. and Tilia tomentosa Moench became the potential objects. As Guangzhou was reported to experience higher temperatures with less precipitation and face drought events with increasing frequency and intensity, whether the two tree species could survive in the dry environment required to be investigated profoundly. Thus, we launched a drought-simulation experiment and measured their above- and below-ground growth in 2020. In addition, their ecosystem services were also simulated and evaluated for their future adaption. Furthermore, a congeneric native tree species Tilia miqueliana Maxim was also measured in the same experiment as a comparison. Our results showed that Tilia miqueliana exhibited moderate patterns of growth and advantages in evapotranspiration and cooling. Besides, its investment in root development at horizontal level could account for its special strategy against drought stress. Tilia tomentosa’s vigorous root growth could be the most positive behavior of coping with water deficit, which explained its maintenance of carbon fixation and implied a well adaption. Tilia cordata showed a complete decrease in above- and below-ground growth, especially for its fine root biomass. In addition, its ecosystem services were significantly reduced, reflecting a comprehensive failure when it faced a long-term scarcity of water. Therefore, it was necessary to supply sufficient water and under-ground space for their living in Guangzhou, especially for Tilia cordata. In the future, long-time observation of their growth under different stresses can be practical approaches to amplify their multiple ecosystem services.
... Urban afforestation has been largely encouraged in the last years as NCS to provide communities with a host of ecosystem services (Hiemstra et al., 2017;Hsieh et al., 2018;Marando et al., 2019;Nowak et al., 2018;Pataki et al., 2021) as well to increase climate change mitigation through atmospheric CO 2 sequestration and C-storage (Nowak and Crane, 2002;Raciti et al., 2012;Hutyra et al., 2011;Strohbach and Haase, 2012). This practice, currently considered one of the most important in the urban context, can contribute to achieve the goal of CO 2 emissions reduction of 40 % by 2030 (EU, 2020) through shadings effects, radiative forcing and energy demand reduction, and C-sink capacity from small to large scale (Escobedo et al., 2011, Stone, 2012Safford et al., 2013). ...
... The main methods currently used to estimate the impact of urban expansion on TCS are field sampling, image interpretation, and model simulations [6][7][8]. Model simulations are applied to estimate the impact of urban expansion on TCS owing to their advantages of low cost, speed, and predictability [9]. For example, Seto et al. [10] used a grid-based land the southwest and low elevation in the northeast, with elevations ranging from −210 to 1921 m, and mountains, hills, and plains are distributed sequentially. ...
Assessing the impacts and drivers of urban expansion on terrestrial carbon storage (TCS) is important for urban ecology and sustainability; however, a unified accounting standard for carbon intensity and research on the drivers and economic value of TCS changes are lacking. Here, urban expansion and TCS in the Yangtze River Delta were simulated based on Patch-generating Land Use Simulation and Integrated Valuation of Ecosystem Services and Trade-offs models; scenario simulation; Literature, Correction, Ratio, Verification carbon intensity measurement; and land use transfer matrix methods. The results showed that (1) from 2000 to 2020, urbanization and TCS loss accelerated, with 61.127% of TCS loss occurring in soil, and land conversion was prominent in riverine and coastal cities, mainly driven by the urban land occupation of cropland around suitable slopes, transportation arteries, and rivers. (2) From 2020 to 2030, urban land expansion and TCS loss varied under different scenarios; economic losses from the loss of the carbon sink value under cropland protection and ecological protection were USD 102.368 and 287.266 million lower, respectively, than under the baseline scenario. Even if urban expansion slows, the loss of TCS under global warming cannot be ignored. Considering the indirect impacts of urbanization, the failure to establish a regional development master plan based on ecosystem services may affect China’s carbon targets.
... Carbon dioxide (CO 2 ) is the major GHG contributing up to 76% of total GHG emissions (US EPA, 2016). The current level of CO 2 is 420 ppm, and it may increase to 685 ppm by 2050 (Stancil, 2021;The World Counts, 2022). Relentless deforestation, fossil fuel burning, urbanization, and other anthropogenic activities significantly contribute to the rising levels of CO 2 (Gandhi & Sundarapandian, 2017). ...
The forests are a key player in maintaining ecological balance on the earth. They not only conserve biodiversity, reduce soil erosion, and protect watersheds but also promote the above and below-ground ecosystem services. Forests are known as air cleaners on the planet and play a significant role in mitigating greenhouse gas (GHG) emissions into the atmosphere. As per programs launched in the Conference of Parties (COP) 26, there is a need to promote policies and programs to reduce the atmospheric carbon (C) through the forest ecosystem; it is because forests can capture the atmospheric CO2 for a long time and help to achieve the goals of net-zero emission CO2 on the earth. Therefore, there is an urgent need to know the advanced technological approaches for estimating C stock in forest ecosystems. Hence, the present article is aimed at providing a comprehensive protocol for the four C stock estimation approaches. An effort has also been made to compare these methods. This review suggests that tree allometry is the most common method used for the quantification of C stock, but this method has certain limitations. However, the review shows that accurate results can be produced by a combination of two or more methods. We have also analyzed the results of 42 research studies conducted for C stock assessment along with the factors determining the amount of C in different types of forests. The C stock in vegetation is affected by temporal and spatial variation, plantation age, land use, cropping pattern, management practices and elevation, etc. Nevertheless, the available results have a large degree of uncertainty mainly due to the limitations of the methods used. The review supports the conclusion that the uncertainty in C stock measurements can be addressed by the integration of the above-mentioned methods.
... Related ward-wise (micro-level) and zone-wise (meso-level) data used for the analysis, such as per capita open space, catchment area, served population, and vegetation cover, are given in Appendixes A-C. The open space map and catchment area map are in Appendix A for Area 1 (Figure A1), Appendix B for Area 2 ( Figure A2), and Appendix C for Area 3 ( Figure A3) Green spaces act as carbon sequesters [36,37]. Urban planning effort should be made to save these green areas which are also carbon reservoirs. ...
India’s urban population increase is creating pressure on the urban green open spaces. The overall city-level per capita open space is considered as a benchmark of the open space. The open space of Patna is 2.43 sq m per capita, but at the community level or ward level, there is a lacuna. So, there is a significant gap in open space distribution at the city level and the micro level, that is, ward or block level. An assessment was carried out on three parameters, i.e., quantity, accessibility, and quality. Open space, catchment area, and vegetation cover were used as independent variables, and population density and ward area as dependent variables, to understand the distribution at the ward level, that is, community level. Distribution was analyzed by Pearson correlation between the independent and dependent variables within three parameters. The open space distribution between three meso-level areas based on the growth pattern was analyzed with the help of linear regression and R-squared tests to compare the distribution between the areas. The result shows that Patna has poor distribution in the old and new areas. The developed areas in between have good distribution at the micro level and meso level. Patna has 2.3 sq m per capita as per the proposed open space plan and projected population of 2030, which is less than the standard 3.16 sq m/capita at the community level and 3.66 sq m/capita at the district level.
... A structured questionnaire was developed based on literature reviews for quantitative data collection. This study selected 16 ESs namely regulating ESs: global climate regulation (GCR) (Strohbach & Haase, 2012;Pataki et al., 2006), microclimate regulation (MR) (Xie et al., 2013;Gill et al., 2007), air filtration (AF) Grote et al., 2016;Jim & Chen, 2008;Nowak et al., 2006), water cycle regulation (WCR) (Armson et al., 2013), runoff reduction (RR) (Armson et al., 2013;Zhang et al., 2015), noise buffering (NB) (Aylor, 1972;Kragh, 1981), pests regulation (PR) (Costanza et al., 1997), erosion control (EC) (Costanza et al., 1997), and biodiversity conservation (BC) (Aronson et al., 2017;Fuller et al., 2007;Karuppannan et al., 2014); cultural ESs: spiritual values (SV) (Baur, 2018), aesthetic values (AV) (Gunnarsson et al., 2017), outdoor recreation (ON) (Costanza et al., 1997), ecotourism (EM) (Costanza et al., 1997) as well as education and research (ER) (Kibria et al. 2017); and supporting ES: habitat provision for wildlife (HW) (Blair, 1996;Blair & Launer Alan, 1997) (Supplementary Table 1). ...
Residents’ perceptions on ecosystem services (ESs) provided by urban green spaces (UGSs) are vital for developing sustainable cities. However, there has been limited research on this issue in Malaysia. The aim of this paper is to assess Malaysians’ perceptions on ESs provided UGSs and how their perceptions are influenced by different socio-demographic factors. We used a structured online questionnaire and obtained 645 responses on 16 ESs from regulatory, cultural, and supporting ES categories. Descriptive statistics and binary logistic regressions were used for data analysis. In general, city dwellers have high positive perceptions on ESs provided by UGSs. Their perceptions for global climate regulation, noise buffering, pest regulation, spiritual, and research and education services would likely to significantly increase as they grow older. Households with moderate income have significantly greater perceptions of microclimate regulation, air filtration and aesthetic services. Having non-tertiary level education would significantly lower their perceptions of global climate and microclimate regulation, spiritual, aesthetics, and recreational services. Tertiary educated residents with non-environmental degrees also showed similar associations. Infrequent visits to UGSs would likely to significantly reduce the perception of global climate regulation, noise buffering, runoff reduction, erosion control, spiritual, and aesthetics services. People living far (>5km) from the UGSs also have significantly lower perceptions of microclimate regulation, air filtration services. Suggestions are made to incorporate ESs related content in pre-university curriculum and establishing small parks in neighborhoods to improve knowledge and uses of UGSs. These findings would assist urban planners designing environmentally sound urban policies and thereby improving human wellbeing in the cities.
... While these pristine natural forests and dense shrublands may not be compared directly to the carbon storage potential of urban treescapes, some report almost as high stores of carbon from parks: up to 420 t ha -1 of above ground carbon in tropical Ghana (475 t C ha -1 roots included) (Nero et al., 2017) and up to 289 t ha -1 of above ground carbon in the cool temperate climate of Leicester, England (Davies et al., 2011) (Table 2). Residential trees in Florida are reported to store 63 t of above ground carbon per hectare, and in Leipzig, Germany, above ground carbon stored per hectare of tree cover in areas with multi-story houses is as high as 64 tonnes (Strohbach & Haase, 2012). Reported above and below ground sequestration rates of carbon average 61.2 t ha -1 over two decades in urban areas across the USA but over the same timeframe above ground carbon sequestration alone is as high as 137 t ha -1 in Seoul urban forest (Table 2) (Lee et al., 2019;Nowak et al., 2013). ...
Non-technical summary
As green spaces, lawns are often thought to capture carbon from the atmosphere. However, once mowing, fertlising and irrigation are taken into account, we show that they become carbon sources, at least in the long run. Converting unused urban and rural lawn and grassland to treescapes can make a substantial contribution to reducing greenhouse gas emissions and increasing carbon absorption from the atmosphere. However, it is imperative for governing bodies to put in place appropriate policies and incentives in order to achieve this.
Technical summary
Mown grass or lawn is a ubiquitous form of vegetation in human-dominated landscapes and it is often claimed to perform an ecosystem service by sequestering soil carbon. If lawn maintenance is included, however, we show that lawns become net carbon emitters. We estimate that globally, if one-third of mown grass in cities was returned to treescapes, 310–1630 million tonnes of carbon could be absorbed from the atmosphere, and up to 43 tonnes of carbon equivalent per hectare of emissions could be avoided over a two-decade time span. We therefore propose that local and central governments introduce policies to incentivise and/or regulate the conversion of underutilised grass into treescapes.
Social media summary
If unused lawns were planted with trees, a gigaton of carbon could be removed from the atmosphere over two decades.
... The soil carbon pool is the largest carbon pool in terrestrial ecosystems, and its carbon storage in temperate regions is three times more than that of plants. Therefore, increasing carbon storage in soil is an effective way to alleviate climate change [4,5]. Plants play an important role in soil carbon storage. ...
Planting plants to increase soil carbon input has been widely used to achieve carbon neutrality goals. Tartary buckwheat not only has good barren tolerance but is also rich in nutrients and very suitable for planting in barren areas. However, the effects of different genotypes of Tartary buckwheat roots and rhizosphere microorganisms on soil carbon input are still unclear. In this study, ozone sterilization was used to distinguish the sources of soil organic acids and C-transforming enzymes, and the contribution of root and rhizosphere microorganisms to soil carbon storage during the growth period of two genotypes of tartary buckwheat was studied separately to screen suitable varieties. Through the analysis of the experimental results, the conclusions are as follows: (1) The roots of Diqing tartary buckwheat have stronger carbon sequestration ability in a barren environment than Heifeng, and the microorganisms in Diqing tartary buckwheat soil will also increase soil carbon input. Therefore, Diqing tartary buckwheat is more suitable for carbon sequestration than Heifeng tartary buckwheat in barren soil areas. (2) In the absence of microorganisms, the rhizosphere soil of tartary buckwheat can regulate the storage of soil organic carbon by secreting extracellular enzymes and organic acids. (3) The structural equation model showed that to promote carbon sequestration, Heifeng tartary buckwheat needed to inhibit microbial action when planted in the barren area of Loess Plateau, while Diqing tartary buckwheat needed to use microbial-promoting agents. Adaptive strategies should focus more on cultivar selection to retain carbon in soil and to assure the tolerance of fineness in the future.
... Many scholars have carried out studies on the division of ecosystem areas and the prioritization of ecological protection areas in special natural zones (e.g., watersheds, wetlands, etc.) [61,62]. The ecological service effect of urban landscape pattern evolution has attracted more attention, especially the service value of urban ecological land [6,63]. The dominance, shape, and connectivity of the landscape affect environmental health risks and sustainable urban development. ...
The ecological restoration of territorial space emphasizes the synergy between ecology and social development. On this basis, we used landscape index analysis methods to explore the spatiotemporal evolution of landscape patterns in urban areas on a district scale. Then, we used multiple regression analysis to explore the driving factors behind this evolution. The results showed the following: (1) Landscape compositions have changed significantly. The growth rate of construction land in the main districts was about three times that in the urban area. (2) There were differences in the characteristics of landscape pattern evolution. Arable land is becoming more fragmented as construction land expands outward. The shapes of public green spaces, arable land, and woodlands tend to be simple and regular. The degree of both urban sprawl and agglomeration decreased in the urban area and the main districts. Meanwhile, landscape separation first decreased and then increased, and landscape diversity increased. (3) Population growth, industrial development, changes in industrial structure, and real estate development are the main driving factors of landscape pattern evolution. Based on this, this study puts forward some suggestions for landscape pattern optimization, which is significant for ecological restoration planning and promotion.
... US-based i-Tree Eco model was used for carbon sequestration studies in UK (Rogers et al., 2015). Canopy cover of urban forest in Leipzig city, Germany, has been used along with land cover to estimate above-ground carbon stock (Strohbach & Haase, 2012). Urban forest with a canopy cover of 19% of the city area was found to store 11 t C ha −1 in the above-ground biomass with highest values found at intermediate urbanization levels. ...
The role of urban forests in carbon capture and sequestration has been reviewed in a global context. An interpretive analysis was carried out using normalized difference vegetation index (NDVI) and allometric relationships in 5 cities of India, viz. Navi Mumbai, Nagpur, Bengaluru, Leh and Delhi, to evaluate the economic importance of urban green spaces in sequestrating carbon emissions and mitigating severe climatic impacts. NDVI maps were prepared using data from Landsat 7 and Landsat 8 satellite sensors. Bengaluru showed highest carbon sequestration (141.83 MT), and carbon sequestration in the city of Leh was comparatively very low (1.51 MT) as it is a cold desert with a very low urban forest cover. The valuation of urban green spaces in the selected cities was done by using market price method (MPM), value transfer method (VTM), and social cost of carbon method (SCC). The carbon sequestration valuation ranged from 55 to 5164 million$ for estimation using MPM and from 69.69 to 6537.15 million $ for SCC, whereas for VTM it ranged from 1575.06 to 147,736.94 million INR. The SCC approach used for valuation showed the highest cost of CO2 sequestered, while the MPM provided with the lowest value for all the five cities. Highest carbon sequestration and valuation values were observed in Bengaluru followed by Delhi. This study also points to the need of developing region-specific allometric relationships for better accuracy in quantifying carbon sequestration potential and associated economic value of urban forests.
... The use of species-specific equations available for some species, genus, families, and sites (species groups) have been suggested to be used (Nowak and Crane, 2002;Nowak, 1993;Strohbach and Haase, 2012). The biomass in Homegardens was estimated using the equation developed by (Kuyah et al., 2012a). ...
Scientific studies about the role of urban green spaces (UGSs) in biodiversity conservation and climate change mitigation are limited in developing countries. Therefore, the aim of this study was to assess the role of UGSs in biodiversity conservation and climate change mitigation. Using a systematic sampling method a total of 137 sample plots of various sizes were laid per cluster. The analysis of variance (ANOVA) was undertaken among clusters using the Honestly Significant Difference (HSD) test at a 5% level of significance. A total of 127 woody species belonging to 58 families and 99 genera were recorded. Of the total species, 7 (5.51%), 34 species (26.77%), and 86 (67.72%) were endemic, exotic, and indigenous to Ethiopia, respectively. The presence of threatened or endangered trees in Ethiopia, such as Hagenia abyssinica and Juniperus procera in the UGSs of Dessie, indicates that UGSs could be another potential site for biodiversity conservation. The overall mean carbon stock (ton ha − 1) and its total CO 2 equivalent of UGSs of Dessie are 745.17 ± 170.86 and 2734.79 ± 627.06, respectively. This indicated a significant potential of UGSs to mitigate a changing climate. A statistically significant difference (p < 0.05) was revealed for the carbon stock and diversity. The highest mean biomass carbon was recorded in the urban forests (1448.14 ± 736.32 tons C ha − 1) and the lowest in urban Homegarden (61.28 ± 0.231 ton C ha − 1). Correlation analysis revealed a weak positive relationship (r = 0.26) between biomass carbon stock and Shannon's index. It is concluded that UGSs have an important role in mitigating climate change through carbon sequestration and biodiversity conservation. Therefore, urban plans should consider the roles of urban green space at every stage of planning.
... While these pristine natural forests and dense shrublands may not be compared directly to the carbon storage potential of urban treescapes, some report almost as high stores of carbon from parks: up to 420 t ha -1 of above ground carbon in tropical Ghana (475 t C ha -1 roots included) (Nero et al., 2017) and up to 289 t ha -1 of above ground carbon in the cool temperate climate of Leicester, England (Davies et al., 2011) (Table 2). Residential trees in Florida are reported to store 63 t of above ground carbon per hectare, and in Leipzig, Germany, above ground carbon stored per hectare of tree cover in areas with multi-story houses is as high as 64 tonnes (Strohbach & Haase, 2012). ...
Non-technical summaryAs green spaces, lawns are often thought to capture carbon from the atmosphere. However, once mowing, fertlising, and irrigation are taken into account, we show that they become carbon sources, at least in the long run. Converting unused urban and rural lawn and grassland to treescapes can make a substantial contribution to reducing greenhouse gas emissions and increasing carbon absorption from the atmosphere. However, it is imperative for governing bodies to put in place appropriate policies and incentives in order to achieve this.Technical summaryMown grass or lawn is a ubiquitous form of vegetation in human dominated landscapes and it is often claimed to perform an ecosystem service by sequestering soil carbon. If lawn maintenance is included, however, we show that lawns become net carbon emitters. We estimate that globally, if one third of mown grass in cities was returned to treescapes, 310 to 1,630 million tonnes of carbon could be absorbed from the atmosphere, and up to 43 tonnes of carbon equivalent per hectare of emissions could be avoided over a two-decade time span. We therefore propose that local and central governments introduce policies to incentivise and/or regulate the conversion of underutilised grass into treescapes.
... In addition, new habitats are created, especially for birds (Strohbach et al., 2013). Furthermore, urban trees contribute to carbon fixation (Strohbach & Haase, 2012). ...
... Carbon storage and sequestration is one obvious benefit of green infrastructure. Many researches have quantified the amount of aboveground Carbon stored by green space in cities of the temperate climate zone (Davies et al., 2011;Hutyra et al., 2011;Wei et al., 2012;Strohbach and Haase, 2012;Schreyer et al., 2014;Ahmed et al., 2017) and in Nigeria (Eneji et al., 2014, Paul et al., 2019. The results indicate the role of tree density and size as two dominant factors determining the amount of aboveground carbon in urban green space (Davies et al., 2013;Kong et al., 2014). ...
Assessment of carbon credit potentials of trees in the Benue State Secretariat Makurdi was done using a non-destructive allometric model, consisting of Above ground Biomass (ABG), Below Ground Biomass (BGB) and Diameter at Breast Height (DBH) using the equation: AGB = Exp [1.627 + 1.393 * Ln(DBH)]. DBH(cm) was measured at approximately 1.3 meter above the ground level on each tree. BGB was determined as 20% of AGB (kg/tree).Furthermore, dry AGB and BGB were determined as 65% of AGB and BGB, respectively, while Total biomass (TB) was determined by the summation of dry AGB and dry BGB (kg/tree). A total of 150 trees (from 15 species and 10 families) were sampled in the study area with Khaya senegalensis (66) being the most abundant. Diversity indices-Importance value index and family value index-were also evaluated to ascertain species and family distribution. Khaya senegalensis (Meliaceae) had the highest IVI (488.9). The DBH class range (cm), 101-150 had the highest frequency followed by 51-100 and 151-200, and the least DBH classes were 0-50 and 201-250, implying trees of moderate height. DBH (cm) and AGB (kg) correlated positively (R 2 = 0.98, P= 0.000) in all the species sampled, hence AGB increased with increase in DBH. Furthermore, Gmelina aborea had the highest above ground biomass (10935.55), total biomass (8529.73), below ground biomass (2187.11), total sequestered carbon/tree (4264.86), sequestered carbon dioxide equivalent (kg) (15652.05), and sequestered carbon dioxide equivalent (tonnes/tree) (15.65), correspondingly. The study determined the total sequestered carbon (32.7 Tonnes) and sequestered carbon dioxide equivalent (120.23 tonnes/tree); thus, elucidating the potentials of these species and the urban park in carbon sequestration and climate change mitigation.
... Shevchenko O., Snizhko S., Samchuk E. (2012) & Haase D. (2011) on the example of Leipzig (Germany) investigated the impact of urban planning policy on the parameters of the urban climate. The article highlights the applied aspects of regulating the temperature of the city by green planting, the impact of spatial planning and landscaping of the city on the formation of heat islands etc. Green zones of Leipzig also have been studied by Strohbach, M. & Haase D. (2012). This article, in particular, highlights the aspects of carbon dioxide accumulation by trees in the urban environment, analyzes the relevant patterns in other cities in Europe and Asia. ...
The risks of abnormal temperatures and rainfall on urban ecosystems have been assessed. According to urban ecosystems study results, the scale of anthropogenic changes in the functioning of green zones, urban and suburban regional landscape parks is demonstrated. It has been established that negative changes in components’ state of landscape systems contribute to the effective manifestation of a number of adverse processes and phenomena (reduction of groundwater levels, intensification of droughts, soil erosion and deflation, their dehumidification, depletion of landscape and biotic diversity, etc.). The SWOT-analysis method demonstrated the positive role of green zones in the functioning of urban ecosystems and its negative effects on the complex green zones. At the basic stage of the study on the example of the Ternopil urban system the dynamics of the temperatures and precipitation during 60-year period has been demonstrated, the differences in the temperature indicators of the surfaces of different districts of the city have been clarified. It is established that industrial, residential neighborhoods, shopping centers, transport infrastructure experience the greatest temperature fluctuations. The morphology of the earth’s surface, the presence of depressions, significant angles of earth’s surface inclination, the ratio of green zones with built-up and covered with asphalt, pavement, concrete and road network systems and storm sewers, etc. is an important factor in the intensification of slope water runoff in urban systems. The vulnerability of Ternopil urban system to climate change has been analyzed. Temperature calculations of various city surfaces have been done. The features of moisture circulation on artificial and natural surfaces of urban system have been shown schematically. The flooding regular risk places of the lowered parts of the city territory have been revealed. The runoff coefficients and the combined runoff coefficient for different surfaces of the city have been calculated. Based on these data, the surface runoff volumes in case of heavy rain have been calculated. It has been proven that in the event of torrential rains, the existing rainwater drainage system will not cope with the volume of runoff, causing flooding and inundation of urban zones. A set of measures aimed at preventing flooding of buildings, communications and streets, increasing the rate of safe removal of surface runoff from places of its concentration in the urban system has been proposed.
... In recent years, the gradual increase in studies on the carbon stock estimation of different ecosystems at multiple scales has made it possible to visualize the results of regional ecosystem carbon stock projections. Strohbach et al. [12] used a stratified random sampling method to measure carbon stocks on 190 sample plots in 19 land cover categories to estimate the aboveground carbon stocks of trees in the central European city of Leipzig and mapped carbon stocks in space. With the development of information technology, model simulation-based carbon stock estimation methods have emerged. ...
Terrestrial carbon sequestration capacity is an important indicator of ecosystem service function, and the carbon storage value can reflect the climate regulation capacity of the regional ecological environment. The Zoigê alpine grassland is a representative area of the Qinghai-Tibet Plateau grassland ecosystem, with carbon sequestration types such as alpine grassland and marsh meadow and also an important water-conserving area in the upper reaches of the Yangtze River and the Yellow River. In this study, based on the land use/cover change pattern of the Zoigê alpine grassland region from 2000 to 2020, the carbon density coefficients corrected by the regional average annual precipitation and temperature factors were used to assess the carbon stocks of the Zoigê alpine grassland for three periods from 2000 to 2020 using the InVEST model. The results showed that the carbon stocks of the Zoigê alpine grassland region were 786.19 Tg, 780.02 Tg, and 775.22 Tg in 2000, 2010, and 2020, respectively, with a cumulative loss of 10.97 Tg and carbon densities of 183.70 t/ha, 182.26 t/ha, and 181.14 t/ha, showing a decreasing trend year by year. The carbon stock of the grassland ecosystem is the absolute contributor to the regional carbon stock, and the carbon stock accounts for 75.28% of the total carbon stock. The increase in the cultivated land area with a lower carbon density and the decrease in the grassland area with a higher carbon density are the main factors leading to the decrease in the carbon stock in the regional ecosystem of the Zoigê alpine grassland.
... The flora of urban areas usually consists of indigenous plants that are introduced from the surrounding natural and semi-natural habitats, and allochthonous plants that were introduced intentionally for the purpose of cultivation or came there by chance (Repić et al., 2013). Due to their unique role in ecosystems, urban forests and trees have been extensively studied in Malaysia (Sreetheran et al., 2006), Taiwan (Huang et al., 2009), and Germany (Strohbach and Haase, 2012). Goel & Singh (2006) collected important data on the diversity of dendroflora of the city of Delhi and identified suitable trees for expanding green areas. ...
The results of the research on the urban dendroflora of the Srebrenik minicipality are presented in this paper. The research was conducted in the period March-August 2020-2021. In the field of research, 100 taxa were identified, which were classified into 37 families and 64 genera. The family Rosaceae stands out with the largest number of taxa, followed by Pinaceae, Aceraceae, and Cupressaceae. The analysis of the presence of deciduous and evergreen elements shows that deciduous trees predominate in the dendroflora of Srebrenik in relation to evergreen taxa. In the dendroflora of Srebrenik, allochthonous taxa (50 taxa) are more represented than autochthonous taxa (48 taxa). According to the number of taxa, angiosperms dominate (84 taxa) compared to gymnosperms (16 taxa). Allochthonous dendroflora shows the largest representation of taxa of Eurasian origin, followed by taxa from Asia, North America, Europe, while all others are represented by less than 10 taxa. The results of research on the dendroflora of Srebrenik show a lack of park areas and urban greenery, so it is necessary to pay special attention to the arrangement of existing and the formation of new green areas.
... Urban afforestation has been largely encouraged in the last years as NCS to provide communities with a host of ecosystem services (Hiemstra et al., 2017;Hsieh et al., 2018;Marando et al., 2019;Nowak et al., 2018;Pataki et al., 2021) as well to increase climate change mitigation through atmospheric CO 2 sequestration and C-storage (Nowak and Crane, 2002;Raciti et al., 2012;Hutyra et al., 2011;Strohbach and Haase, 2012). This practice, currently considered one of the most important in the urban context, can contribute to achieve the goal of CO 2 emissions reduction of 40 % by 2030 (EU, 2020) through shadings effects, radiative forcing and energy demand reduction, and C-sink capacity from small to large scale (Escobedo et al., 2011, Stone, 2012Safford et al., 2013). ...
Urban afforestation is considered a promising nature-climate solution that may contribute to achieve climate neutrality by 2050, since it can increase C-storage and C-sequestration, whilst providing further multiple ecosystem services for citizens. However, the quantification of the CO2 sequestration capacity that may be provided by an urban forest as well as the capacity to impact the city-level C-balance and offset anthropogenic emissions is a complex issue. Methodological approaches, quantity and quality of information contained in urban tree database, and the level of detail of the planned urban forest can strongly influence the estimation of C-sequestration potential offered by urban forests. In this work, an integrated framework based on emission inventory, tree species/morphology and ecosystem modelling has been proposed for the city of Prato, Italy, a representative medium size European city to: i) evaluate the current C-sequestration capacity of urban trees; ii) upscale such capacity with different afforestation scenarios, iii) compare the sink capacity offered by ecosystems with current and projected anthropogenic emissions. Results indicated that the green areas within the Municipality of Prato can sequester 33.1 ktCO2 yr⁻¹ under actual conditions and 51.0 ktCO2 yr⁻¹ under the afforestation scenario which maximize the CO2 sequestration capacity, offsetting the 7.1 % and 11 % of the total emissions (465.8 ktCO2 yr⁻¹), respectively. This study proves that, in the various afforestation scenarios tested, the contribution of urban afforestation to the municipality carbon balance is negligible and that carbon neutrality can only be reached by the substantial decarbonization of emission sectors.
... Especially on warm summer days, the temperature below the canopy remains substantially lower than above exposed concrete surroundings, as the trees provide shading and a further cooling effect due to transpiration (Pace et al. 2020;Sanusi and Livesley 2020). Trees in urban areas also store significant amounts Communicated by Locosselli. of carbon-especially (old) trees in parks and cemeteries contribute to carbon storage (Kändler et al. 2011;Strohbach and Haase 2012;Richter et al. 2020). ...
Key Message
In an urban area, resistance and resilience of stem diameter growth differ substantially between tree species. Traffic emissions are reflected in wood nitrogen isotopes, but do not affect drought tolerance.
Abstract
With increasing drought and heat, the benefits of urban trees such as shading and cooling become more important. Yet, it is necessary to identify tree species able to withstand such extreme climatic conditions. We studied the resistance and resilience of stem diameter growth of five deciduous tree species in an urban area in Southwest Germany to three exceptional drought periods (2003, 2011 and 2015) for differences between and within species, especially considering the intensity of traffic emissions (NO x ). Analyses of the stable isotopic composition of carbon (δ ¹³ C) and oxygen (δ ¹⁸ O) as well as the intrinsic water-use efficiency (WUE i ) in the tree rings were carried out. Further, we investigated the stable isotopic composition of nitrogen in the wood (δ ¹⁵ N) to assess its potential as an indicator of NO x emissions from traffic. Stem diameter growth in all species was strongly limited by low water availability in spring, as was also reflected in elevated δ ¹³ C and δ ¹⁸ O values in Acer platanoides and Tilia cordata , which were particularly sensitive to drought. In contrast, growth of Platanus × hispanica and Quercus robur was less affected by drought, and resistance of Carpinus betulus ranged in between. Across species, δ ¹⁵ N was higher in trees located closer to roads and exposed to higher NO x traffic emissions. Unexpectedly, these conditions did not significantly affect drought resistance/resilience. Our study demonstrates the potential and interpretative challenges of coupled dendroecological and isotope analyses. It also indicates clear species-specific differences in drought tolerance and thus helps to identify suitable urban tree species.
... For 2012, an overall carbon storage of 1,656,655 t at 55 t/ha is calculated for the city of Leipzig, which has increased by 2018-1,699,414 t at 57 t/ha. These results are much higher than those calculated by Strohbach and Haase (2012) showing the value of 11 t C/ha for above-ground carbon storage only. Although, this study includes also below-ground carbon pools such a large difference cannot be explained. ...
To safeguard the well-being of urban dwellers, it is vital to restore, protect and enhance urban green infrastructures (uGI), their related ecosystem services (ES) and the associated benefits for a large number of inhabitants. This study maps and monitors land cover between 2012 and 2018 in the fast-growing German city of Leipzig to produce precise information using OBIA and very high-resolution digital orthophotos. Based on this, this research pinpoints spatially differentiated multiple ES. Research has revealed that essential ES, which comprise regulating, socio-cultural and cultural-aesthetic services, have a multifunctional impact on the human urban habitat. The study provides insight into each ES type by evaluating specific classes of objects within the urban environment in a spatially explicit way and at a very high scale of resolution. In doing so, it illustrates variations in the provision of ES and renders visible disparities in the accessibility to uGI in Leipzig. By analysing the number and stands of trees and their respective height development, the study confirms that intensive management is successfully rejuvenating the urban forest, but also that foliage in this forest is suffering from drought. The mapping procedure reveals a high spatial and temporal variation in the rates of carbon storage. This is also the case for the provision of recreation areas which has an impact on the equitable distribution of ES to Leipzig’s inhabitants. Residential areas with a relatively high uGI on the outskirts of the city actually register lower market rents and rent growth rates than in those districts which lie closer to the city centre and have a comparably lower uGI. Thus, market rents and uGI have become decoupled in the fast growing city. In order to ensure and maintain the well-being of all residents in a fair way, fast growing cities like Leipzig must make even greater efforts in urban planning.
... The inner city of Melbourne (Australia), with approximately 10,000 trees, is estimated to sequester one million tC/yr [58]. Canopy cover was approximately 19% of the urban area in Leipzig, Germany, where above-ground carbon storage was estimated to be 11 tC/ha/yr [59]. In 2002, the city of Tshwane, South Africa, developed a strategy to plant 115,200 indigenous street trees which were estimated to sequester 54,630 tC/yr [60]. ...
Trees in public urban green spaces provide a variety of ecosystem goods and services that are greatly appreciated by urban residents. A commonly used good, especially in Global South regions, is that of fuelwood for household energy needs. Yet the production potential of fuelwood from public urban green spaces has rarely been examined. This study quantifies the fuelwood production and allied carbon sequestration potential of 12 public urban green spaces in Bulawayo (Zimbabwe) stratified across neighborhoods of different housing densities. We estimated tree density in the green spaces by means of line transects, and annual production through estimates of the mean annual increment of a sample of marked trees. We found that Bulawayo’s public green spaces produce 1.9 t/ha/yr of fuelwood with a value of $340 to $490/ha/yr, and that production varied across spaces and housing density neighborhoods. This production is much lower than the documented demand but it is likely to be significant for fuelwood-dependent households. In contrast, the amount (1010 ± 160 kg/ha/yr) and value (US$4.04/ha/yr) of carbon sequestration were lower. Formal public green spaces produced more fuelwood as compared to informal green spaces and no difference was evident in tree growth rates between exotic and indigenous tree species. This is one of the first studies to show the value of the fuelwood production and carbon sequestration potential of public green spaces in the region and continent and requires that they are integrated into public urban green space policies, planning, and management in the city.
... The value for surface imperviousness increased by approximately 3% in dense urban areas based on studies of very compact cities such as Barcelona, Spain, or Vienna, Austria, where the soil sealing reached 90% in highdensity areas (Baró et al. 2016). For an approximation of the carbon pools and CO 2 mitigation capacity, we assume that the land use class of dense urban areas is similar to "continuous urban fabric", for which Strohbach and Haase (2012) found an average carbon storage of 4.2 tC/ha in the region of Leipzig, with a standard deviation of 2.1 tC/ha. The land use type "dense urban area" will most likely have fewer trees and, if so, smaller trees due to lack of sunlight, narrowness, and a poor soil state. ...
Cities that begin to regrow after a long period of decline and land abandonment are under pressure to provide comfortable housing conditions in preferred neighborhoods for their residents. On the other hand, these cities should preserve interim green spaces that result from decline because these spaces are a real treasure for densifying cities. Using the case of the city of Halle in post-socialist Eastern Germany, we explore four land use alternatives for neighborhood development close to what might happen: (1) urban densification, (2) spacious housing, (3) the green city, and (4) the edible city. We seek to discover opportunities for regrowth and sustainable land use development by applying the ecosystem services and green points frameworks to a set of land use transition rules. Land use change has been defined for strategic development areas according to the Master Plan and complementary visions of land change. The results of the study provide highly interesting insights into how both regrowth and greening can be enabled in densifying neighborhoods and what types of green are most effective in providing carbon storage and summer heat regulation. Moreover, gardens, as central elements of the edible city concept, were found to be flexible in implementation in very differently dynamic neighborhoods by providing multi-functional spaces for ecosystem services such as climate regulation, local food production, daily recreation, and nature experience. Results demonstrate that ecosystem services benefit flows increase only in districts where real estate pressure is low. In districts with growing population numbers, green spaces are reduced. This may result in increased injustice in green space availability seeing as we have modeled a recreational space per capita of < 9 m² in the Southern Suburb, whereas an increase to almost 70 m² was simulated in the shrinking, prefabricated Newtown. Most importantly, modeling the narratives of the Master Plan in a spatially explicit way demonstrates unused potential for greening in Halle. Thus, we conclude that urban planning should make regular use of such land use alternative to look for hidden combined visions of green and growth in a formerly shrinking city.
... The difference in total biomass may be due to variations in climatic and soil conditions. The carbon stock in our sites averaged 1,901 tonnes/ha, much higher than the carbon stock in the urban forests and plantations in Agartala, India [23] (45 tonnes/ha), Chennai, India [23] (43 tonnes/ha), the urban institutional area of Darmaga, Indonesia [24] (27 tonnes/ha), in Hangzhou, China [25] (30 tonnes/ha), and in the urban area of Leipzig, Germany [26] (5.9 tonnes/ha) ( Table 4). The carbon stock in an urban forest area of Muscat, Oman was reported to be 3,000 tonnes/ha [22], higher than that in our study. ...
Increasing number of urban settlements is a major contributor to global climate change and has resulted into rising sea level, increasing the frequency of floods and droughts and ultimately decreasing human well-being. Urban areas are likely to account for 68 per cent of the world’s population by 2050, which will result in extensive environmental degradation and ecological destruction. They are considered the major source of carbon emissions because anthropogenic activities such as the heating of domestic spaces and vehicular emissions are concentrated in urban areas. Tree populations in urban areas have a tremendous potential to mitigate emissions through carbon sequestration. However, only a few studies on the quantification of carbon stock in urban vegetation are so far available. There is therefore an urgent need to quantify the amount of sequestered carbon in urban tree cover for better monitoring and management of regional carbon stock. In the present study, we explore the potential of carbon dioxide sequestration in trees at a few sites in the heavily populated city of Varanasi. Our study shows that the carbon stock in both above-ground and below-ground biomass in different sites averaged 1901 metric tonnes of carbon per hectare, with carbon dioxide sequestration of 6977 tonnes per hectare. This indicates that urban tree plantations have a significant potential to sequester anthropogenic carbon locally at source and to stock it in their biomass for long periods of time. Some key recommendations regarding the expansion of urban green cover and the planting of fast-growing native species are offered, in order to enhance carbon dioxide sequestration.
... The perspective on urban areas is often shifted towards the negative effects that they have on ecosystems, from local to global scale, and in fact, many aspects of global change have their origins there ( Grimm et al., 2008;Strohbach and Haase, 2012). For example, a high proportion of the greenhouse gas like carbon dioxide is emitted from urban areas with most emissions being related to the activities of urban dwellers that require fossil fuel, industrial production, excessive traffic, heating, or cement production, but also to the disturbance and alteration of soils and vegetation through urbanization (Churkina, 2012;van Bueren et al., 2012;Zhou and Wang, 2018). ...
In recent decades, with the rapid growth of urbanization, the amount of carbon emission in urban areas has been globally accelerated. In this study, the carbon storage capacity of different small administrative regions (wards) of Khulna city has been estimated based on four major sinks types- trees, vegetations, soils, and water bodies. To estimate carbon storage capacity, the total coverage area of each of the sink’s types has been estimated by Sentinel-II satellite image data of 2019 through supervised image classification of remote sensing techniques. A comparison of more carbon-absorbing capacities between the wards has been assessed through GIS techniques as well. Results show that the north-west part of Khulna city has some extent of carbon sinks. However, the lower portion in the southern part is congested with built-up areas and has a huge lacking of carbon sinks. The obtained amount of carbon about 9306992 kg, 7733698 kg, 7328298 kg, and 6030692 kg have been absorbed through respective trees, vegetations, soils, and water bodies which is about 31%, 25%, 24%, and 20% of total absorption, respectively. The result shows that carbon absorption capacity is very high in ward no. 3 whereas ward no. 1, 2, 4, 6, 9, 14, 16, and 31 are high carbon-absorbing wards. Ward no 8, 13, 15, 17, 18 and 24 are moderate, ward no 5, 10, 12, 21, 22, 25, 26, 27, 28, 29 and 30 are lower and ward no 7, 11, 19, 20 and 23 are very lower carbon-absorbing wards of Khulna city. The findings of this study opt to provide valuable insights amongst significant stakeholders, i.e., local people, urban planners, policy-makers, and non-government organizations regarding the emission and absorption of carbon.
... The value for surface imperviousness increased by approximately 3% in dense urban areas based on studies of very compact cities such as Barcelona, Spain, or Vienna, Austria, where the soil sealing reached 90% in highdensity areas (Baró et al. 2016). For an approximation of the carbon pools and CO 2 mitigation capacity, we assume that the land use class of dense urban areas is similar to "continuous urban fabric", for which Strohbach and Haase (2012) found an average carbon storage of 4.2 tC/ha in the region of Leipzig, with a standard deviation of 2.1 tC/ha. The land use type "dense urban area" will most likely have fewer trees and, if so, smaller trees due to lack of sunlight, narrowness, and a poor soil state. ...
Cities that begin to regrow after a long period of decline and land abandonment are under pressure to provide comfortable housing conditions in preferred neighborhoods for their residents. On the other hand, these cities should preserve interim green spaces that result from decline because these spaces are a real treasure for densifying cities. Using the case of the city of Halle in post-socialist Eastern Germany, we explore four land use alternatives for neighborhood development close to what might happen: (1) urban densification, (2) spacious housing, (3) the green city, and (4) the edible city. We seek to discover opportunities for regrowth and sustainable land use development by applying the ecosystem services and green points frameworks to a set of land use transition rules. Land use change has been defined for strategic development areas according to the Master Plan and complementary visions of land change. The results of the study provide highly interesting insights into how both regrowth and greening can be enabled in densifying neighborhoods and what types of green are most effective in providing carbon storage and summer heat regulation. Moreover, gardens, as central elements of the edible city concept, were found to be flexible in implementation in very differently dynamic neighborhoods by providing multi-functional spaces for ecosystem services such as climate regulation, local food production, daily recreation, and nature experience. Results demonstrate that ecosystem services benefit flows increase only in districts where real estate pressure is low. In districts with growing population numbers, green spaces are reduced. This may result in increased injustice in green space availability seeing as we have modeled a recreational space per capita of < 9 m² in the Southern Suburb, whereas an increase to almost 70 m² was simulated in the shrinking, prefabricated Newtown. Most importantly, modeling the narratives of the Master Plan in a spatially explicit way demonstrates unused potential for greening in Halle. Thus, we conclude that urban planning should make regular use of such land use alternative to look for hidden combined visions of green and growth in a formerly shrinking city.
... In addition, other studies have also identified the average carbon storage per hectare of its urban green infrastructure in the city. In essence, 21,3 t/ha was estimated by Chen (2015) The contribution of NBS to urban resilience in stormwater management and control: a comprehensive resilience assessment framework 62 based on 35 key Chinese cities, of 33,3 t/ ha was estimated by Chaparro & Terrasdas (2009) for Barcelona, and 68,2 t/ha in Leipzig (Germany) was proposed by Strohbach & Haase (2012). ...
Nature-Based Solutions (NBS) are crucial to achieving the goals of the United Nations Agenda 2030 for sustainable development and other global agendas, such as the Paris Agreement on Climate Change. In the last decade, the NBS umbrella concept has become more relevant intending to contribute to urban resilience and to address the climate change challenges. NBS are living solutions inspired by nature that use or mimic natural processes intending to face several societal challenges, from the perspective of resource-efficient use and the promotion of economic and environmental benefits. Currently, cities are encouraged to understand and measure the NBS contribution to identify adequate strategies for enhancing resilience and prioritize investments accordingly.
The objective of the present thesis is to promote and enhance the NBS implementation in cities, focused on solutions for stormwater management and control. Based on the analysis of their contribution to urban resilience, the potential to meet environmental, social, and economic challenges and to adapt across diverse urban scales and contexts is demonstrated. In this sense, a Resilience Assessment Framework (RAF) to assess the NBS contribution to urban resilience was developed. This framework aims to assess the NBS contribution to urban resilience. Moreover, a Guidance for the RAF application in cities with different resilience maturity was developed, which involved the RAF validation by seven cities (from a national and international context), that participated voluntarily in this phase.
In this context, the developed RAF is comprehensive and multidimensional. It is driven by the definition of objectives, criteria, and metrics, according to the proposed structure for assessing the water supply and wastewater system service performance in the framework of the ISO 24500 standards of the International Organization for Standardization. For an oriented assessment of the criteria, qualitative and quantitative metrics were defined, considering data from different sources and complexity. Reference values were also identified and metrics’ classifications were defined. In this classification, each answer is associated with a resilience development level, intending to assess the NBS contribution to urban resilience on a normalized scale. To support the RAF application to cities with different resilience maturity (in terms of resilience and available information), three analysis degrees (essential, complementary, and comprehensive) and a set of metrics were proposed, which are pre-defined in the guidance for the RAF application. To support the selection of the analysis degree more adequate to any city, a structure to characterize the city’s profile was developed. This complementary profile also supports the interpretation of the RAF results, both at the city and at the level of specific NBS.
... The AGB (adult + sapling trees) of NZP was found higher than the value 26.9 Mg ha −1 , reported by Giannico et al. (2016); the major difference may be due to the approaching of LiDAR technique for the sampling of trees and tree species composition. The AGC value in the present study was found three times higher than the value (11 Mg-C ha −1 ) reported by Strohbach and Haase (2012) at Leipzig, Germany; it may be due to difference in species composition, structure, and tree canopy which leads to the variation in the values. The BGC of the present study was found lower than the reported values of North Ridge Forest (15.5 Mg-C ha −1 ) and Central Ridge Forest (11.5 Mg-C ha −1 ) of Delhi (Meena et al., 2019). ...
In a highly urbanized city like Delhi, the urban forest plays a vital role in climate change mitigation by capturing and storing carbon dioxide (CO2) from the atmosphere. Urban vegetation helps in increasing carbon sink and CO2 equivalent (CO2eq) and also provides other aesthetic and psychological environmental benefits. To understand how urban trees are vital for carbon sink, the present study aimed to quantify the carbon density and CO2eq in trees at National Zoological Park (NZP), New Delhi, a tropical semi-arid region of India. For this, we estimated tree biomass or dry matter content of 25 species with the help of allometric equations which are available in published literature and applicable for the tropical region. It was observed that the highest diameter at breast height (DBH) was contributed by Ficus sp. while the maximum density among adult tree species found in Albizia procera. The total mean dry matter content, C density, and CO2eq of NZP were 92.10 Mg ha−1, 43.61 Mg-C ha−1, and 168.83 Mg ha−1, respectively. The highest biomass, C density, and CO2eq obtained in the species of Ficus benghalensis followed by Ficus racemosa and Azadirachta indica. The data indicates that the trees having the capacity to store carbon are essential for the maintenance of a sustainable environment. Thus, the study suggests that there is a substantial scope to increase the carbon density and CO2eq in urban city through adopting various management strategies viz. afforestation and reforestation program on degraded and abandoned land to maintain a clean and sustainable environment.
... Due to limited resources for fieldwork data collection to measure carbon storage, carbon storage was estimated based on the percentage tree canopy cover and on the assessment carried out by Nowak et al. [73] using urban field data from 28 cities in the USA, where carbon storage averaged 7.69 kg C m − 2 (SE = 1.36). This method has also been applied for European cities by Baró et al., [9] whilst other studies have obtained similar results in European cities [93] . ...
Nature-based solutions have emerged as a concept for integrating ecosystem-based approaches whilst addressing multiple sustainable development goals. However, implementing nature-based solutions is inherently complex and requires consideration of a range of environmental and socio-economic conditions that may impact on their effectiveness. This research assesses ecosystem services within the Valletta urban agglomeration, Malta, and evaluates the implications arising from existing distributional patterns. Proxy-based indicators and expert knowledge were used to map and assess a set of 14 ecosystem services. Proximity and correlation analyses were used to assess distributional inequalities arising from differentiated availability of ecosystem types with high ecosystem service capacities for groups with different socio-economic characteristics. Data relating to schooling, employment, sickness, disability, and old age, were combined to identify areas of relative advantage and disadvantage. The highest ecosystem service capacities were in the urban fringes and the lowest in dense urban cores. Private gardens and urban trees had the highest regulating ecosystem service capacities per unit area. Contrastingly, public gardens had low effectiveness for regulating ecosystem services but the highest cultural ecosystem service capacities. Availability of urban green infrastructure and tree cover differ according to socio-economic advantage, and disadvantaged communities generally had reduced proximity to ecosystems with high ecosystem service capacities. Considering these findings, we argue that urban ecosystem service assessments can support greening strategies by identifying the most effective nature-based solutions that can play a redistributive role by addressing existing inequalities in green infrastructure and ecosystem services capacities distribution in cities.
Urban forests are highly heterogeneous; information about the combined effect of forest classification scale and algorithm selection on the estimation accuracy for urban forests remains unclear. In this study, we chose Chongming eco-island in the mega-city of Shanghai, a national experimental carbon neutral construction plot in China, as the study object. Remote sensing estimation models (simple regression models vs. machine learning models) of forest carbon density were constructed across different classification scales (all forests, different forest types, and dominant tree species) based on high-resolution aerial photographs and Sentinel-2A remote sensing images, and a large number of field surveys and optimal models were screened by ten-fold cross-validation. The results showed that (1) in early 2020, the total forest area and carbon storage of Chongming eco-island were 307.8 km2 and 573,123.6 t, respectively, among which the areal ratios and total carbon storage ratios of evergreen broad-leaved forest, deciduous broad-leaved forest, and warm coniferous forest were 51.4% and 53.3%, 33.5% and 32.8%, and 15.1% and 13.9%, respectively. (2) The average forest carbon density of Chongming eco-island was 18.6 t/ha, among which no differences were detected among the three forest types (i.e., 17.2–19.2 t/ha), opposite to what was observed among the dominant tree species (i.e., 14.6–23.7 t/ha). (3) Compared to simple regression models, machine learning models showed an improvement in accuracy performance across all three classification scales, with average rRMSE and rBias values decreasing by 29.4% and 53.1%, respectively; compared to the all-forests classification scale, the average rRMSE and rBias across the algorithms decreased by 25.0% and 45.2% at the forest-type classification scale and by 28.6% and 44.3% at the tree species classification scale, respectively. We concluded that refining the forest classification, combined with advanced prediction procedures, could improve the accuracy of carbon storage estimates for urban forests.
Urban parks are essential for offsetting high carbon emissions in cities, which are known to be high emitters. This study quantified carbon uptake and storage in Daejeon and Daegu, two major metropolitan cities in South Korea, and explored planting strategies to promote carbon offset services. Mean carbon uptake and storage per unit area in the study parks were 2.6 ± 0.1 t/ha/yr and 29.9 ± 1.7 t/ha, respectively. The urban park trees of a metropolitan city in South Korea were estimated to annually sequester and store 50 kt/yr and 572 kt of carbon, respectively. This carbon uptake equaled 1.5% of the total annual carbon emissions from residential energy consumption. The economic value of the carbon uptake was equivalent to $3.3 million/yr, which is 1.50% of the annual establishment budget of urban forests of the Korea Forest Service. Planting strategies included reducing unnecessary grass and pavement areas, the active planting of trees in the potential planting space, multilayered planting, and planting tree species with high growth rates. These results are expected to guide policies related to carbon credits, which have recently emerged as major concerns, and to provide useful information for quantifying carbon offset services in greenspace establishment projects.
The aboveground biomass (AGB) of trees plays an important role in the urban ecological environment. Unlike forest biomass estimation, the estimation of AGB of urban trees is greatly influenced by human activities and has strong spatial heterogeneity. In this study, taking Hengqin, China, as an example, we extract the tree area accurately and design a collaborative scheme of optical and lidar data. Finally, five evaluation models are used, including two deep learning models (deep belief network and stacked sparse autoencoder), two machine learning models (random forest and support vector regression), and a geographically weighted regression model. The experimental results show that the deep learning model is effective. The result of the stacked sparse autoen - coder, which is the best model, is that R ² = 0.768 and root mean square error = 18.17 mg/ha. The results show that our method can be applied to estimate the AGB of urban trees, which greatly influences urban ecological construction.
Green spaces play an important role in the well-being of society. Many research works have tried to establish green space's associations with air quality, reduced air pollution, controlled traffic noise, cooler temperature, and improved users' mental health. However, there are some contradictions in using the term 'Greenspace' and 'Green space' while formulating urban planning policies in India. The researchers have given an insight into these terminologies; still, there is some lacuna in applying these terminologies. This research work attempts to analyze the existing literature relating to this field and tries to figure out the interchangeability of these terms. For this objective, a literature review has been done. These terms have been observed to differ in meaning, attributes, characteristics, usability, and decision-making.
Greenhouse gas emissions cause serious global climate change, and it is urgent to curb CO2 emissions. As the last-guaranteed technology to reduce carbon emissions, carbon capture and storage (CCS) is emerging and has the potential to become an important choice to mitigate the greenhouse effect in the future. Forward-looking project deployment and accurate forecasting techniques occupy an indispensable position in CCS. Machine learning (ML), one of the fastest developing intelligent technology fields at present era, is considered as a substantial means to realize forecast demand relying on computer science and data statistics. This work provided a comprehensive review of ML applications in CCS, based on classical ML methods and mainstream research directions in CCS. The study shown that ML algorithms such as artificial neural network (ANN) and convolutional neural network (CNN) were widely used, mainly for predicting physical properties, evaluating mechanical stability, and monitoring CO2 plume migration and leakage during CO2 storage. Support vector machine (SVM) was generally combined with other ML methods for the prediction of petrophysical properties and sensitivity analysis of influencing factors. Deep learning (DL) algorithms, represented by generative adversarial network (GAN) and long short-term memory (LSTM), had shown good results in real-time monitoring of CO2 migration and leakage. Decision tree (DT) and random forest (RF) were mainly used to establish risk assessment and decision analysis framework, and estimate the success probability of CCS. This review summarized the applications of ML algorithms in CCS and presented the challenges and future prospects, from the geoscience perspective. The findings of this work can help for better understanding of the key role played by ML in CCS, as well as guiding the selection of ML algorithms and the development of new models in CCS research.
The implementation of the Sustainable Development Goals (SDGs) and the conservation and protection of nature are among the greatest challenges facing urban regions. There are few approaches so far that link the SDGs to natural diversity and related ecosystem services at the local level and track them in terms of increasing sustainable development at the local level. We want to close this gap by developing a set of indicators that capture ecosystem services in the sense of the SDGs and which are based on data that are freely available throughout Germany and Europe. Based on 10 SDGs and 35 SDG indicators, we are developing an ecosystem service and biodiversity-related indicator set for the evaluation of sustainable development in urban areas. We further show that it is possible to close many of the data gaps between SDGs and locally collected data mentioned in the literature and to translate the universal SDGs to the local level. Our example develops this set of indicators for the Bonn/Rhein-Sieg metropolitan area in North Rhine-Westphalia, Germany, which comprises both rural and densely populated settlements. This set of indicators can also help improve communication and plan sustainable development by increasing transparency in local sustainability, implementing a visible sustainability monitoring system, and strengthening the collaboration between local stakeholders.
In the dissertation, the carbon sequestration and the cooling effect of urban forest types (semi-natural forests, urban greening forests, and succession forests) are quantified, and the influence of phytodiversity on the provision of these ecosystem services is analyzed. The investigations were carried out in the heat and dry period of 2018/2019. Therefore, differences in the resilience of the urban forests against these climatic extremes can be seen in the results. Overall, the semi-natural forests on mesophilic sites were most effective in providing regulating services and were more resilient to the occurring heat and drought than the other forest types. In contrast, the highest phytodiversity was found in the succession forests. The forest structure essentially determines the regulating ecosystem services provision of urban forests. An influence of phytodiversity on the services could not be found.
Ecosystem services are essential for human well-being, but are currently facing many natural and anthropogenic threats. Modeling and mapping ecosystem services helps us mitigate, adapt to, and manage these pressures, but overall the field faces multiple major limitations. These include: 1) data availability, 2) understanding, estimation , and reporting of uncertainties, and 3) connecting socio-ecological aspects of ecosystem services. Recent technological advancements in machine learning coupled with rising availability of big data, offer an opportunity to overcome these challenges. We review studies utilizing machine learning and/or big data to overcome these limitations. We collect 56 papers that exemplify the current use of machine learning and big data to address the three identified gaps in the ecosystem service field. We find that although the use of these tools in ecosystem service research is relatively new, it is growing quickly. Big data can directly address data gaps, especially as new big data resources relevant to ecosystem service mapping become available (ex. social media data). Some properties of machine learning can also contribute to addressing data gaps in data sparse environments. Also, many machine learning algorithms can estimate and consider uncertainty, whereas big data can significantly increase sample size, reducing uncertainties in some situations. Some big data sources, like crowdsourced data, provide direct sources of social behaviors and preferences that relate to ecosystem service demand, thus allowing researchers to connect social and biophysical aspects of ecosystem services. Machine learning algorithms provide an effective and efficient tool for handling these large nonlinear socio-ecological datasets in tandem, giving researchers the ability to more realistically model and map ecosystem services without relying on oversimplified proxies or linear algorithms. Despite these opportunities, implementation is still lacking and limitations still hinder use.
Accurately mapping carbon stocks of urban trees is necessary for urban managers to design strategies to mitigate climate change. However, the aboveground carbon stocks of urban trees are usually underestimated by passive remote sensing data because of the signal saturation problem. The research is the first attempt to develop a framework to map aboveground carbon density of trees in urban areas by synergizing Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) LiDAR data with Gaofen-2 (GF-2) imagery. The framework consists of three key steps. First, we used a support vector machine classifier to classify GF-2 images and extracted urban tree regions. Second, we estimated the tree carbon density of ICESat-2 strips by developing a ICESat-2 photon feature-based aboveground carbon density estimation model. Third, we mapped the carbon density of urban trees by developing a synergistic model between ICESat-2 and GF-2 data based on an object-oriented method. We tested the approach for the areas within the fifth ring road of Beijing, China. The results showed that the 50th percentile height (PH50) of nighttime photons was a good predictor for estimating carbon density of urban trees, with a R² of 0.69 and a Root Mean Square Error (RMSE) of 2.81 kg C m⁻². Using the spectral features generated by GF-2 imagery, we could further extrapolate the carbon density estimated by ICESat-2 strip data to a full coverage of accurate mapping carbon density by urban trees, resulting in a R² of 0.64 and a RMSE of 2.32 kg C m⁻². The carbon stocks within the fifth ring road of Beijing were 8.28×108 kg in total, with the mean carbon density of 3.52 kg C m⁻². Such estimations were larger than that of previous study using passive remote sensing data only, suggesting the integration of spaceborne LiDAR and spectral data could greatly reduce the underestimation of carbon stocks of urban trees. Our approach can more accurately estimate carbon stocks of urban trees and has the potential to be applicable in other cities.
A large institutional campus with trees can be a potential solution for global warming and climate change. There were many international and national studies on Carbon stock of trees growing in university campus. However, such studies in North Eastern India are very meager. Considering the gap in the studies, the present study was conducted to estimate the total biomass and Carbon stock of trees growing in Cotton University, Guwahati, Assam, India. The study site was sub-divided into different plots, in each plot, random quadrats of 10 m × 10 m were laid for vegetation sampling of all the trees. Altogether 47 trees species from 45 genera and 24 families were recorded on the campus. The tree density (stem h−1), total above-ground biomass, total below-ground biomass, total biomass and total Carbon stock of all the trees growing in campus were 370 ha−1, 544.42 Mg h−1, 142.85 Mg h−1, 692.27 Mg h−1, and 346.14 Mg C ha−1 respectively. The present study revealed that Cotton University campus has good tree diversity and high Carbon stock potential. Higher educational institutions particularly in urban area maintaining good green cover chiefly with trees have the potential to conserve biodiversity and also to act as local Carbon sinks.
This report is the main outcome of Task 2.1 of work package 2 (WP2). Overall, this WP aims to analyze and compare the implementation of UF-NBS in selected cities and city regions in view of their impacts on urban ecosystems and societies, their cost effectiveness, and their replicability in distinct contents. In this context, Task 2.1 consisted of an exploratory analysis of all selected case studies, useful to provide the context for a comparative, in-depth analysis of ongoing cooperative efforts toward the enhancement of UF-NBS (T2.2) in the second phase of CLEARING HOUSE.
The report includes a wide Europe-wide perspective to UF-NBS potential in urban areas via a spatial quantitative analysis (Chapter 2), and five in depth case study analyses on the governance arrangements, planning approaches and socio-ecological situation of the CLEARING HOUSE urban areas (Chapters 3, 4, 5, 6, and 7).
The initial proposal for D2.1 was to conduct an exploratory analysis of not only the five case studies in Europe included in this report but also of five case studies in China; Beijing, the Hong Kong, Guangzhou, Shenzhen metropolis, Hangzhou, Huaibei and Xiamen. It became clear that a combination of data availability and obstacles presented by COVID-19 which prevented international travel and field work would make achieving this with the original timeframe impossible. Since D2.1 is an input to task 2.2 it was concluded that to avoid delay the exploratory analysis of the Chinese cities would be moved into task 2.2 (the in-depth analysis of the case study cities and city regions). A further advantage being to allow the case histories from D1.4 to be inputted directly into task 2.2 as well as the results from local co-design workshops.
Using the most recent available and comparable data provided by the Copernicus programme, a first assessment of mapping the UF-NBS potential in European urban areas is provided based on a selected set of indicators. The use of indicators which display respectively the availability of forest areas (forest share); the potential per-capita supply with forest areas and trees (forest area per resident); and the biophysical benchmark of canopy cover (tree cover density) was instrumental in showing the broad variety characterising European urban areas and in positioning the five case study localities. Analysing the relation between certain indicators allows a first but descriptive conclusion on influencing factors such as built-up structure or city size.
On the basis of the screening tool developed as part of Work Package 1, five case study analyses of five European localities were performed. These took the form of "locality profiles", each including elements of general context, information on the current state of UF-NBS in the locality, analysis of UF-NBS governance and finally an outlook on the strategic objectives for the locality, and on the existing challenges and barriers. The case studies were based on data collected through desk research, review of scientific and policy literature, and key informant interviews, and have also benefited from the discussion and exchange that took place during the project workshops (WP3).
The information presented in this report will populate the repository developed in WP1 with spatial and other information from the case study cities. It will feed into the development of the analytical framework to be used as a basis for the in-depth analysis of the case study cities and city regions. The findings from the exploratory analysis will be discussed in a workshop.
The challenges for sustainable cities to protect the environment, ensure economic growth, and maintain social justice have been widely recognized. Along with the digitization, availability of large datasets, Machine Learning (ML) and Artificial Intelligence (AI) are promising to revolutionize the way we analyze and plan urban areas, opening new opportunities for the sustainable city agenda. Especially urban spatial planning problems can benefit from ML approaches, leading to an increasing number of ML publications across different domains. What is missing is an overview of the most prominent domains in spatial urban ML along with a mapping of specific applied approaches. This paper aims to address this gap and guide researchers in the field of urban science and spatial data analysis to the most used methods and unexplored research gaps. We present a scoping review of ML studies that used geospatial data to analyze urban areas. Our review focuses on revealing the most prominent topics, data sources, ML methods and approaches to parameter selection. Furthermore, we determine the most prominent patterns and challenges in the use of ML. Through our analysis, we identify knowledge gaps in ML methods for spatial data science and data specifications to guide future research.
Human activities in cities, especially those burning fossil fuels, have increased atmospheric carbon dioxide (CO 2) concentrations. Urban trees play a crucial role in the biogeochemical cycle of carbon storage in cities. Many tons of carbon are annually stored by the structural components of trees in urban ecosystems. In the urban forest of San Juan city, Platanus hispanica is one of the most abundant species. The goal of this study is to estimate the amount of carbon stored by this species in its different structural components: trunks, primary, secondary and minor branches. We analysed samples collected from two areas in the city: the urban and suburban areas. We estimated dry matter for each structural component. Significant differences were found between the studied areas. Results indicated that P. hispanica accumulated 5,630 tons of carbon in the urban area and 4,700 tons of carbon in the suburban area. Around 20,662 tons and 17,249 tons of CO 2 , in the urban and suburban areas respectively, are annually seques-tered by this species from the atmosphere of San Juan city.
Urban agglomeration will be the main mode of future urbanization in China, greatly influencing social & economic development and ecosystem protection at the whole city cluster scale. It is important to analyze the impacts of large-scale, scattered land use and cover change (LUCC) consisting of one-pole-multi-point urbanization in city clusters on regional ecosystem services (ESs), so as to increase ecological security and maintain ESs levels. Using the urban-rural gradient analysis method (UGAM), this study examined driver-response mechanisms of large-scale, scattered agglomeration urbanization on ESs along an urban-rural gradient and at regional scale. This was done by simulating and analyzing tempo-spatial variations in ESs characteristics along concentric ring gradients in Central Yunnan City Cluster (CYCC) under its present urbanization path. The results showed that rapid urban sprawl is the main driver affecting the integral value of ESs in CYCC and that ESs trade-offs (through LUCC caused by urbanization) between adjacent zones along the urban-rural gradient will particularly exacerbate degradation of integral ESs levels. Hence, CYCC should follow a sustainable, eco-friendly urbanization path and should consider ecological principles and the impact of LUCC on regional ESs along the urban-rural gradient in top-level design and decision-making on urban planning and strategic land use management. Differentiated regional development policies should be formulated for each areas, the urban-rural development pattern and layout optimized, the scale of construction land rationally controlled, and the overall efficiency of land use improved. Ecological buffers should be set up around areas with sharp and obvious changes in land use, to alleviate the negative impact of large-scale, decentralized city cluster urbanization on regional ESs.
In 2005 Milan Municipality launched the “Adopt a green spot” model initiative, to restore and maintain scattered and marginal green areas, following a Payment for Ecosystem Services (PES) scheme. The PES scheme was designed in the form of two standardized typologies of voluntary agreements – sponsorship and collaboration - allowing flexibility in the commitment of involved private stakeholders, including condominiums, NGOs, and the business. 502 agreements, for a total surface of 265.398 m2, have been signed up to now. The paper analysis the design components of the PES scheme which determines its capacity to be replicated in different contexts involving a variety of stakeholders. The main elements enabling the success of the PES scheme are i) the flexibility of the voluntary agreements designed to meet the needs of various stakeholders; ii) the variety of green areas included in the initiative; iii) public recognition which makes it possible to attract firms iv) low transaction costs borne by the stakeholders. The financial resources committed, even if representing a small portion of the total social benefit generated, are sufficient to ensure an adequate requalification and maintenance of small green areas, often neglected because of scarcity of public financing. The replication capacity of this PES scheme makes it a model initiative. Given its characteristics and flexibility, it has been used for the definition of more than 500 agreements with different stakeholders, and for these reasons the policy design approach can be suitable for the replication in other urban contests.
Climate change adaptation is essential to mitigate risks, such as extreme weather events triggered by global warming and amplified in dense urban environments. Ecosystem-based adaptation measures, such as urban greening, are promoted in cities because of their flexibility and their positive side effects, such as human health benefits, ecological effects, climate mitigation and a range of social benefits. While individual co-benefits of greening measures are well studied, often in public green spaces, few studies quantify co-benefits comprehensively, leaving social benefits particularly understudied. In this study, we perform biophysical and socio-cultural assessments of co-benefits provided by semi-public, residential greening in four courtyards with varying green structures. We quantify effects on thermal comfort, biodiversity, carbon storage and social interaction. We further assess the importance of these co-benefits to people in the neighbourhood. Subsequently, we weight the results from the biophysical assessments with the socio-cultural values to evaluate how even small differences in green structures result in differences in the provision of co-benefits. Results show that, despite relatively small differences in green structures, the residential courtyards with a higher green volume clearly generate more co-benefits than the residential yards with less green, particularly for thermal comfort. Despite differences in the valuation of co-benefits in the neighbourhood, socio-cultural weights did not change the outcome of the comparative assessment. Our results highlight that a deliberate management strategy, possibly on neighbourhood-scale, could enhance co-benefits and contribute to a more sustainable urban development.
Trees sequester and store carbon in their tissue at differing rates and amounts based on such factors as tree size at maturity, life span, and growth rate. Concurrently, tree care practices release carbon back to the atmosphere based on fossil-fuel emissions from maintenance equipment (e.g., chain saws, trucks, chippers). Management choices such as tree locations for energy conservation and tree disposal methods after removal also affect the net carbon effect of the urban forest. Different species, decomposition, energy conservation, and maintenance scenarios were evaluated to determine how these factors influence the net carbon impact of urban forests and their management. If carbon (via fossil-fuel combustion) is used to maintain vegetation structure and health, urban forest ecosystems eventually will become net emitters of carbon unless secondary carbon reductions (e.g., energy conservation) or limiting decomposition via long-term carbon storage (e.g., wood products, landfills) can be accomplished to offset the maintenance carbon emissions. Management practices to maximize the net benefits of urban forests on atmospheric carbon dioxide are discussed.
Urban land in the United States currently occupies about 69 million acres with an estimated average crown cover of 28% and an estimated tree biomass of about 27 tons/acre. This structure suggests that the current total urban forest carbon storage in the United States is approximately 800 million tons with an estimated annual net carbon storage of around 6.5 million tons. Besides directly storing carbon, urban trees also reduce carbon dioxide (CO2) emissions by cooling ambient air and allowing residents to minimize annual heating and cooling. A method is provided for organizations to calculate the number of trees necessary to offset the CO2 emissions associated with the energy used in their office buildings. Tables are also provided to show how many trees an American could steward or plant to offset his or her per capita carbon emissions (2.3 tons/year). -from Authors
This paper presents the case study of an abandoned urban railyard in Berlin, the Schöneberger Südgelände. Originally a desolate freight railyard, then for over four decades an almost untouched novel urban wilderness, today it is one of the first official conservation areas in Germany in which urban-industrial nature is protected and made accessible to the public.The paper illustrates how different goals of biodiversity conservation and recreation have been united and how the conceptual and design principles have opened up access to the new wilderness.
Based on field data from 10 USA cities and national urban tree cover data, it is estimated that urban trees in the coterminous USA currently store 700 million tonnes of carbon ($14,300 million value) with a gross carbon sequestration rate of 22.8 million tC/yr ($460 million/year). Carbon storage within cities ranges from 1.2 million tC in New York, NY, to 19,300 tC in Jersey City, NJ. Regions with the greatest proportion of urban land are the Northeast (8.5%) and the southeast (7.1%). Urban forests in the north central, northeast, south central and southeast regions of the USA store and sequester the most carbon, with average carbon storage per hectare greatest in southeast, north central, northeast and Pacific northwest regions, respectively. The national average urban forest carbon storage density is 25.1 tC/ha, compared with 53.5 tC/ha in forest stands. These data can be used to help assess the actual and potential role of urban forests in reducing atmospheric carbon dioxide, a dominant greenhouse gas.
This is the urban century in which, for the first time, the majority of people live in towns and cities. Understanding how people influence, and are influenced by, the 'green' component of these environments is therefore of enormous significance. Providing an overview of the essentials of urban ecology, the book begins by covering the vital background concepts of the urbanisation process and the effect that it can have on ecosystem functions and services. Later sections are devoted to examining how species respond to urbanisation, the many facets of human-ecology interactions, and the issues surrounding urban planning and the provision of urban green spaces. Drawing on examples from urban settlements around the world, it highlights the progress to date in this burgeoning field, as well as the challenges that lie ahead.
While remote sensing has made enormous progress over recent years and a variety of sensors now deliver medium and high resolution data on an operational basis, a vast majority of applications still rely on basic image processing concepts developed in the early 70s: classification of single pixels in a multi-dimensional feature space. Although the techniques are well developed and sophisticated variations include soft classifiers, sub-pixel classifiers and spectral un-mixing techniques, it is argued that they do not make use of spatial concepts. Looking at high-resolution images it is very likely that a neighbouring pixel belongs to the same land cover class as the pixel under consideration. Algorithms in physics or mechanical engineering developed over the last twenty years successfully delineate objects based on context-information in an image on the basis of texture or fractal dimension. With the advent of high-resolution satellite imagery, the in- creasing use of airborne digital data and radar data the need for context-based algorithms and object-oriented image processing is increasing. Recently available commercial prod- ucts reflect this demand. In a case study, 'traditional' pixel based classification methods and context-based methods are compared. Experiences are encouraging and it is hy- pothesised that object-based image analysis will trigger new developments towards a full integration of GIS and remote sensing functions. If the resulting objects prove to be 'meaningful', subsequent application specific analysis can take the attributes of these objects into account. The meaning of object dimension is discussed with a special focus on applications for environmental monitoring.
The paper examines the causes, features and consequences of the vigorous dynamics of urban sprawl seen in recent years in eastern Germany. Firstly, regarding the theory of urban development, it demonstrates that this case of sprawl displays certain peculiarities—and so cannot be sufficiently understood by drawing on ‘western’ experience. Secondly, concerning the management of urban development, it is particularly striking that urban sprawl in eastern Germany has largely proved to be the product of specific legislative and political conditions. Changes in these conditions ought thus to significantly affect urban development. To help contain urban sprawl in the context under scrutiny, however, these changes need to be geared to the situation of urban stagnation and decline.
Accurate field data can be used to assess ecosystem services from trees and to improve urban forest management, yet little is known about the optimization of field data collection in the urban environment. Various field and Geographic Information System (GIS) tests were performed to help understand how time costs and precision of tree population estimates change with varying plot and sample sizes in urban areas using random sampling approaches. Using one-tenth acre (0.04 ha) plots, it is estimated that, on average, approximately three plots per day can be measured with plot data collected on several variables for all trees greater than 1 in (2.54 cm) in diameter along with general plot, ground cover, and shrub data. A field crew of two people can gather approximately 200 one-tenth acre (0.04 ha) plots during a 14 week summer field season depending on city traffic, city area, and tree cover conditions. These 200 plots typically yield approximately a 12% relative standard error on the total number of trees.
Trees, because they sequester atmospheric carbon through their growth process and conserve energy in urban areas, have been suggested as one means to combat increasing levels of atmospheric carbon. Analysis of the urban forest in Oakland, California (21% tree cover), reveals a tree carbon storage level of 11[center dot]0 metric tons/hectare. Trees in the area of the 1991 fire in Oakland stored approximately 14,500 metric tons of carbon, 10% of the total amount stored by Oakland's urban forest. National urban forest carbon storage in the United States (28% tree cover) is estimated at between 350 and 750 million metric tons. Establishment of 10 million urban trees annually over the next 10 years is estimated to sequester and offset the production of 363 million metric tons of carbon over the next 50 years-less than 1% of the estimated carbon emissions in the United States over the same time period. Advantages and limitations of managing urban trees to reduce atmospheric carbon are discussed. 36 refs., 2 figs., 3 tabs.
Urban green space is purported to offset greenhouse-gas (GHG) emissions, remove air and water pollutants, cool local climate, and improve public health. To use these services, municipalities have focused efforts on designing and implementing ecosystem-services-based "green infrastructure" in urban environments. In some cases the environmental benefits of this infrastructure have been well documented, but they are often unclear, unquantified, and/or outweighed by potential costs. Quantifying biogeochemical processes in urban green infrastructure can improve our understanding of urban ecosystem services and disservices (negative or unintended consequences) resulting from designed urban green spaces. Here we propose a framework to integrate biogeochemical processes into designing, implementing, and evaluating the net effectiveness of green infrastructure, and provide examples for GHG mitigation, stormwater runoff mitigation, and improvements in air quality and health.
It is often underestimated how much carbon is stored in the cities.
Here, we show that human settlements store at least as much carbon as
tropical forests per unit area. By the year 2000 carbon storage
attributed to human settlements of the conterminous US was 18 Pg of
carbon or 10% of its total land carbon storage. 65% of this carbon was
attributed to soil, 19% to vegetation, 11% to landfills, and 5% to
buildings. Given that human settlements harbor appreciable carbon pools,
we have an opportunity to contemplate how to store more carbon per unit
of emitted carbon in the places we live. To offset rising urban
emissions of carbon, regional and national governments should consider
how to protect or even to increase carbon storage of cities.
Urbanizing regions are major determinants of global and continental scale changes in carbon budgets through land transformation and modification of biogeochemical processes (Pataki et al. 2006). However, direct measurements of the effects of urbanization on carbon fluxes are extremely limited. In this paper we develop a strategy to quantify urban carbon signatures (spatial and temporal changes in fluxes) through measurements that can more effectively aid urban carbon scenario and predictive modeling. We start by articulating an integrated framework that identifies the mechanisms and interactions that link urban patterns to carbon fluxes along gradients of urbanization. Building on a synthesis of the current observational studies in major US metropolitan areas we develop formal hypotheses on how alternative development patterns produce different carbon signatures and how these signatures may in turn influence patterns of urbanization.
Urban areas are home to more than half of the world's people, responsible for >70% of anthropogenic release of carbon dioxide and 76% of wood used for industrial purposes. By 2050 the proportion of the urban population is expected to increase to 70% worldwide. Despite fast rates of change and potential value for mitigation of carbon dioxide emissions, the organic carbon storage in human settlements has not been well quantified. Here, we show that human settlements can store as much carbon per unit area (23–42 kg C m−2 urban areas and 7–16 kg C m−2exurban areas) as tropical forests, which have the highest carbon density of natural ecosystems (4–25 kg C m−2). By the year 2000 carbon storage attributed to human settlements of the conterminous United States was 18 Pg of carbon or 10% of its total land carbon storage. Sixty-four percent of this carbon was attributed to soil, 20% to vegetation, 11% to landfills, and 5% to buildings. To offset rising urban emissions of carbon, regional and national governments should consider how to protect or even to increase carbon storage of human-dominated landscapes. Rigorous studies addressing carbon budgets of human settlements and vulnerability of their carbon storage are needed.
Most of our global population and its CO2 emissions can be attributed to urban areas. The process of urbanization changes terrestrial carbon stocks and fluxes, which, in turn, impact ecosystem functions and atmospheric CO2 concentrations. Using the Seattle, WA, region as a case study, this paper explores the relationships between aboveground carbon stocks and land cover within an urbanizing area. The major objectives were to estimate aboveground live and dead terrestrial carbon stocks across multiple land cover classes and quantify the relationships between urban cover and vegetation across a gradient of urbanization. We established 154 sample plots in the Seattle region to assess carbon stocks as a function of distance from the urban core and land cover [urban (heavy, medium, and low), mixed forest, and conifer forest land covers]. The mean (and 95% CI) aboveground live biomass for the region was 89±22 Mg C ha−1 with an additional 11.8±4 Mg C ha−1 of coarse woody debris biomass. The average live biomass stored within forested and urban land covers was 140±40 and 18±14 Mg C ha−1, respectively, with a 57% mean vegetated canopy cover regionally. Both the total carbon stocks and mean vegetated canopy cover were surprisingly high, even within the heavily urbanized areas, well exceeding observations within other urbanizing areas and the average US forested carbon stocks. As urban land covers and populations continue to rapidly increase across the globe, these results highlight the importance of considering vegetation in urbanizing areas within the terrestrial carbon cycle.
Many studies have analyzed the benefits, costs, and carbon storage capacity associated with urban trees. These studies have
been limited by a lack of research on urban tree biomass, such that estimates of carbon storage in urban systems have relied
upon allometric relationships developed in traditional forests. As urbanization increases globally, it is becoming important
to more accurately evaluate carbon dynamics in these systems. Our goal was to understand the variability and range of potential
error associated with using allometric relationships developed outside of urban environments. We compared biomass predictions
from allometric relationships developed for urban trees in Fort Collins, Colorado to predictions from allometric equations
from traditional forests, at both the individual species level and entire communities. A few of the equations from the literature
predicted similar biomass to the urban-based predictions, but the range in variability for individual trees was over 300%.
This variability declined at increasingly coarse scales, reaching as low as 60% for a street tree community containing 11
tree species and 10, 551 trees. When comparing biomass estimates between cities that implement various allometric relationships,
we found that differences could be a function of variability rather than urban forest structure and function. Standardizing
the methodology and implementing averaged equations across cities could be one potential solution to reducing variability;
however, more accurate quantification of biomass and carbon storage in urban forests may depend on development of allometric
relationships specifically for urban trees.
If you wish to converse with me, define your terms.
—attributed to Voltaire, The Home Book of Quotations: Classical and Modern, Fourth edition (B. Stevenson, ed.), p. 428, Dodd, Mead and Co., New York, NY, 1944Though there is a growing appreciation of the importance of research on urban ecosystems, the question of what constitutes an urban ecosystem remains. Although a human-dominated ecosystem is sometimes considered to be an accurate description of an urban ecosystem, describing an ecosystem as human-dominated does not adequately take into account the history of development, sphere of influence, and potential impacts required in order to understand the true nature of an urban ecosystem. While recognizing that no single definition of urban is possible or even necessary, we explore the importance of attaching an interdisciplinary, quantitative, and considered description of an urban ecosystem such that projects and findings are easier to compare, repeat, and build upon. Natural science research about urban ecosystems, particularly in the field of ecology, often includes only a tacit assumption about what urban means. Following the lead of a more developed social science literature on urban issues, we make suggestions towards a consistent, quantitative description of urban that would take into account the dynamic and heterogeneous physical and social characteristics of an urban ecosystem. We provide case studies that illustrate how social and natural scientists might collaborate in research where a more clearly understood definition of urban would be desirable.
The quantification of urban–rural gradients using urbanization measures has become standard practice in many urban ecological
studies. Nonetheless, the choice of urbanization measures for a specific urban gradient still remains problematic. Increasing
numbers of papers stress the importance of comparative urban ecological research, in an attempt to contribute to an understanding
of the ecology ‘of’ cities. This implies that research in diverse urban areas globally should be comparable. This study follows
an approach to quantify the urban–rural gradient in Klerksdorp previously followed in Melbourne, Australia with the goal to
help elucidate the viability of creating a standard set of urbanization measures that is useful across continents. Satellite
imagery and spatial analysis were used to calculate the values of 12 urbanization measures across a 900km2 landscape grid. Principal components analysis is commonly used to identify smaller subsets of measures to quantify urban–rural
gradients. The results of this study indicate that factor analysis is more suitable than principal components analysis and
ideal in identifying these independent measures of urbanization. The factor analysis revealed that landscape structure and
demographic attributes are both essential characteristics of a city that needs to be accounted for in the choice of urbanization
measures. Additionally, we identified seven aspects influencing the direct comparison of cities, namely: scale of analysis,
spatial resolution, classification typology, accuracy of input data, specific measure equations, the type of statistical analysis
and the habitat context. These aspects must be taken into consideration and resolved before effective comparative gradient
research between cities can be achieved.
KeywordsUrbanization measures–Urban–rural gradient–Factor analysis–Principal components analysis–Landscape metrics–Demographic variables–Physical variables–Urban ecology–Comparative research
Ecosystem services are vital for humans in urban regions. However, urban development poses a great risk for the ability of
ecosystems to provide these services. In this paper we first address the most important ecosystem services in functional urban
regions in Finland. Well accessible and good quality recreational ecosystem services, for example, provided by urban nature,
are an important part of a high-quality living environment and important for public health. Vegetation of urban regions can
have a role in carbon dioxide sequestration and thus in climate change mitigation. For instance, estimates of carbon sinks
can be compared to total CO2 emissions of an urban region, and the municipality can aim at both increasing carbon sinks and decreasing CO2 emissions with proper land-use planning. Large and contiguous core nature areas, smaller green areas and ecological connections
between them are the essence of regional ecological networks and are essential for maintaining interconnected habitats for
species and thus biological diversity. Thus, both local and regional level ecological networks are vital for maintaining ecosystem
services in urban regions. The impacts of climate change coupled with land-use and land cover change will bring serious challenges
for maintaining ecosystem services in urban areas. Although not yet widely used in planning practices, the ecosystem services
approach can provide an opportunity for land-use planning to develop ecologically sustainable urban regions. Currently, information
on ecosystem services of urban regions is lacking and there is a need to improve the knowledge base for land-use planning.
KeywordsEcosystem services-Finland-Land-use planning-Recreation-Urban green areas-Urban region
There is general agreement that terrestrial systems in the Northern Hemisphere provide a significant sink for atmospheric CO2; however, estimates of the magnitude and distribution of this sink vary greatly. National forest inventories provide strong, measuretment-based constraints on the magnitude of net forest carbon uptake. We brought together forest sector C budgets for Canada, the United States, Europe, Russia, and China that were derived from forest inventory information, allometric relationships, and supplementary data sets and models. Together, these suggest that northern forests and woodlands provided a total sink for 0.6-0.7 Pg of C per year (1 Pg = 10(15) g) during the early 1990s, consisting of 0.21 Pg C/yr in living biomass, 0.08 Pg C/yrin forest products, 0.15 Pg C/yr in dead wood, and 0.13 Pg C/yr in the forest floor and soil organic matter. Estimates of changes in soil C pools have improved but remain the least certain terms of the budgets. Over 80% of the estimated sink occurred in one-third of the forest area, in temperate regions affected by fire suppression, agricultural abandonment, and plantation forestry. Growth in boreal regions was offset by fire and other disturbances that vary considerably from year to year. Comparison with atmospheric inversions suggests significant land C sinks may occur outside the forest sector.
It is well known that urbanisation has many deleterious ecological effects. These may be mitigated by good urban design but the first step in doing this is to quantify them. This paper describes four simple ecological performance indicators which quantify the effects of urbanisation on surface temperature, hydrology, carbon storage and sequestration, and biodiversity. They have been developed and customised from recent studies, are simple to use, and require a minimum of input information; the only major inputs needed are the percentages of the different surface covers.The indicators were tested by applying them to four urban areas of Merseyside, UK, of contrasting affluence. The results showed that the greatest influence on ecological performance was the percentage of greenspace, particularly of trees. The affluent areas had lower temperatures, less run-off, more stored carbon, and higher diversity, largely because they had more open area and woodland cover. These results suggest that the indicators could be a useful planning tool, facilitating the comparison of existing urban areas, and helping to predict the ecological impact of new developments. However, the indicators also suggest that compact cities with good regional performance will inevitably have poorer performance locally, because of a lack of greenspace. The performance indicators could determine the potential of possible means of amelioration such as the use of roof gardens or permeable paving.
We use data from two satellites and a terrestrial carbon model to quantify the impact of urbanization on the carbon cycle and food production in the US as a result of reduced net primary productivity (NPP). Our results show that urbanization is taking place on the most fertile lands and hence has a disproportionately large overall negative impact on NPP. Urban land transformation in the US has reduced the amount of carbon fixed through photosynthesis by 0.04 pg per year or 1.6% of the pre-urban input. The reduction is enough to offset the 1.8% gain made by the conversion of land to agricultural use, even though urbanization covers an area less than 3% of the land surface in the US and agricultural lands approach 29% of the total land area. At local and regional scales, urbanization increases NPP in resource-limited regions and through localized warming “urban heat” contributes to the extension of the growing season in cold regions. In terms of biologically available energy, the loss of NPP due to urbanization of agricultural lands alone is equivalent to the caloric requirement of 16.5 million people, or about 6% of the US population.
Given the optimal situation, error matrices should be provided whenever accuracy is assessed so that the users can compute and interpret these values for themselves.-from Authors
We present a classification procedure in order to delineate woody vegetation in an arid urban ecosystem using highresolution, true-color aerial photography. We adopted an object-oriented approach due to the physical nature of highresolution photography, in which the objects of interest
were typically composed of many pixels. The segmentation process was parameterized to isolate vegetation patches from shrubs to large trees. These objects were then spectrally analyzed for discrimination between woody vegetation and all other objects and a classification scheme developed.
Accuracy within subclasses was analyzed and indicated highest accuracy for large, dense vegetation. Error was caused by the following plant typologies: small vegetation, sparse canopy density, and gray vegetation. The outset of this procedure produces a binary matrix where the entire raster
set is classified highlighting the elements of the urban forest.
Ash (Fraxinus excelsior), birch (Betula pubescens and B. pendula), oak (Quercus petraea), sycamore (Acer pseudoplatanus) and lime (Tilia cordata) were felled at four localities in the English Lake District. The trees were growing on both siliceous and calcareous soils of variable depth. Correlations between loge tree dry weight and loge girth were higher (r = 0.9977-0.9871), than with loge height (r = 0· 9547-0.8147). Multiple regression analysis demonstrated that the inclusion of height only marginally improved the tree dry weight estimates. Regression equations, of the form loge y = a + b (loge x), where y = tree dry weight (trunk + branches) and x = tree girth at 1.3 m, were used to predict tree dry weight. The 95% confidence limits of the estimates were generally in the range of ± 10-15%, but in some examples as low as ± 2% and up to ± 20-30%, depending upon the sample number and variance of the particular regression. The regression equations for species from different sites exhibited small but significant differences as tested by analysis of variance. Equations derived from trees of all species provided acceptable estimates, but the most valid predictions of tree dry weight are obtained from species samples felled in the area for which estimates are required. Correlations between stem and branch categories and girth (in loge terms) were lower than for total tree weight and girth.
Urban trees can favorably affect factors underlying global warming by storing carbon and by reducing energy needs for cooling and heating buildings. To estimate carbon stored in roots and above-ground portions of trees, data was collected consisting of whole tree sampling of Amelanchier, Malus, Pyrus, and Syringa cultivars. Roots were excavated using an Air-Spade™. Regression analysis resulted in two equations for predicting total carbon storage based on height and diameter of trees up to 20 cm dbh: Y = 0.05836 (dbh2) for root carbon storage, and Y = 0.0305 (dbh2 × h)0.9499 for above-ground carbon storage, explaining 97% and 96% of the variation, respectively. Average carbon stored in roots of various cultivars ranged from 0.3 to 1.0 kg for smaller trees, those 3.8 to 6.4 cm dbh, to more than 10.4 kg for trees 14.0 cm to 19.7 cm dbh. Average total carbon stored by cultivars ranged from 1.7 to 3.6 kg for trees less than 6.4 cm dbh to 54.5 kg for trees larger than 14.0 cm. The data from these equations apply mainly to trees in nurseries and recently transplanted trees. Comparisons showed that above-ground estimates from previous studies using a sampling technique overestimated values obtained from actual above-ground weights.
There is increasing concern about the predicted negative effects of the future doubling of carbon dioxide on the earth. This concern has evoked interest in the potential for urban greenspace to help reduce the levels of atmospheric carbon. This study quantifies greenspace-related carbon storage and annual carbon fluxes for urban residential landscapes. For detailed quantification, the scale of this study was limited to two residential blocks in northwest Chicago which had a significant difference in vegetation cover. Differences between the two blocks in the size of greenspace area and vegetation cover resulted in considerable differences in total carbon storage and annual carbon uptake. Total carbon storage in greenspace was about26·15 kg/m2of greenspace in study block 1, and 23·20 kg/m2of greenspace in block 2. Of the total, soil carbon accounted for approximately 78·7% in block 1 and 88·7% in block 2. Trees and shrubs in block 1 and block 2 accounted for 20·8% and 10·6%, respectively. The carbon storage in grass and other herbaceous plants was approximately 0·5–0·7% in both blocks. Total net annual carbon input to the study blocks by all the greenspace components was in the region of 0·49 kg/m2of greenspace in block 1 and 0·32 kg/m2of greenspace in block 2. The principal net carbon release from greenspaces of the two residential landscapes was from grass maintenance. Greenspace planning and management strategies were explored to minimize carbon release and maximize carbon uptake.
Urban shrinkage affects many cities across the world, especially former industrial areas. One of the most dramatic areas of population decline has been in eastern Germany since the fall of the Berlin Wall. In 1999, the City of Leipzig started a program to revitalize its declining neighborhoods. Taking over the development of private brownfields and waiving property taxes in return for a promise of regular maintenance in a program called interim use, the city has vastly increased public greenspace in these neighborhoods. Despite regional acclaim and imitation, the strategy has thus far lacked a comprehensive evaluation: How successful has the interim use strategy been? This study approaches that question in the context of the city's sustainability goals and public use and perception of the sites, thereby providing insights for planners into the efficacy of this planning tool for neighborhood revitalization. Our sustainability assessment of the interim use sites uses a triangular integrated evaluation method combining indicator-integrated surveys and questionnaires with expert interviews. The results show that interim use sites scored higher overall than their closest counterparts, recently demolished brownfields. They also have a much greater usage rate. However, most people using the sites do not recognize the sites as being a result of city intervention, and many complain about the lack of site maintenance and benches. We conclude that public acceptance and support for interim use can be strengthened with more seating, punitive measures for property owners and increased communication about the strategy and its potential as a planning tool.