Long time risk assessment of soil water shortage in planting pits of young urban roadside trees in the city of Hamburg, Germany

Urban trees as main part of urban green infrastructure provide manifold ecosystem services and contribute to the wellbeing of humans. Unfortunately, urban trees, especially roadside trees, are severely challenged by both, political conflicts of interests in terms of city development and a variety of physically stressors. Contrary to the known benefits of urban green, its proportion in most cities is still decreasing. Furthermore, climate change exacerbates the already challenging preconditions.For northern Germany, climate change is predicted to shift temperature- and precipitation patterns. Simultaneously the frequency of &#8220;summer days&#8221; and &#8220;hot days&#8221; are likely to increase, leading to elevated risk of soil drying during the vegetation period.The city of Hamburg is home to almost 220.000 roadside trees. Especially trees planted nowadays are exposed to harsh roadside conditions. In the event of drought, young-trees compared to well-established trees, are not in touch with deep- or distant water reservoirs and the risk of vitality loss or death increases.Our research aims to characterize the soil hydrological conditions in the rooting zone of roadside young-trees during the first years after plantation. Further it aims to identify spatio-temporal dynamics of soil water response during phases of extreme meteorological drought. Our findings are based on a long-term soil water monitoring across the city of Hamburg, which was started in 2016. The monitoring covers 20 trees from 7 species, planted between 2007 and 2019 with large, medium and low soil sealing. Soil water tension and soil temperature were measured hourly with sensors in the root ball, in the tree pit filled with structural soil and the surrounding soil (16 sensors per site).Our data provides a broad characterization of soil water conditions for young-tree sites in urban areas, and show that water supply in years of moderate meteorological drought is not only extremely heterogeneous on large scales, but can also vary greatly on a small scale. The water tension in the root ball, which should provide the highest amount of water per unit, was highly variable and exceeded thresholds even in the first year after plantation and in almost every vegetation period across all sites. In years of high meteorological drought like in 2018, the soil water tensions exceeded the thresholds in almost all compartments, which leads to a risk of vitality losses and mortality.Our data show the need for adaption of general tree site concepts for future plantations. This unique dataset will be further completed with the aim to include future sites and plantation strategies e.g. the underground connection of planting pits, to increase the diversity of site characteristics and to develop reliable modelling and recommendations.

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Solar Irradiance Reduction Using Optimized Green Infrastructure in Arid Hot Regions: A Case Study in El-Nozha District, Cairo, Egypt

Sustainability ◽

10.3390/su13179617 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9617 ◽

Cited By ~ 1

Author(s):

Wesam M. Elbardisy ◽

Mohamed A. Salheen ◽

Mohammed Fahmy

Keyword(s):

Climate Change ◽

Urban Heat Island ◽

Green Infrastructure ◽

Solar Irradiance ◽

Urban Trees ◽

Heat Island ◽

Physiological Equivalent Temperature ◽

Urban Climatology ◽

Urban Heat ◽

The City

In the Middle East and North Africa (MENA) region, studies focused on the relationship between urban planning practice and climatology are still lacking, despite the fact that the latter has nearly three decades of literature in the region and the former has much more. However, such an unfounded relationship that would consider urban sustainability measures is a serious challenge, especially considering the effects of climate change. The Greater Cairo Region (GCR) has recently witnessed numerous serious urban vehicular network re-development, leaving the city less green and in need of strategically re-thinking the plan regarding, and the role of, green infrastructure. Therefore, this study focuses on approaches to the optimization of the urban green infrastructure, in order to reduce solar irradiance in the city and, thus, its effects on the urban climatology. This is carried out by studying one of the East Cairo neighborhoods, named El-Nozha district, as a representative case of the most impacted neighborhoods. In an attempt to quantify these effects, using parametric simulation, the Air Temperature (Ta), Mean Radiant Temperature (Tmrt), Relative Humidity (RH), and Physiological Equivalent Temperature (PET) parameters were calculated before and after introducing urban trees, acting as green infrastructure types that mitigate climate change and the Urban Heat Island (UHI) effect. Our results indicate that an optimized percentage, spacing, location, and arrangement of urban tree canopies can reduce the irradiance flux at the ground surface, having positive implications in terms of mitigating the urban heat island effect.

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OPTIONS FOR ASSESSING THE SUITABILITY OF URBAN ENVIRONMENTAL ACUPUNCTURE

10.32008/geolinks2021/b1/v3/01 ◽

2021 ◽

Author(s):

Barbara Vojvodíková ◽

Jiří Kupka ◽

Adéla Brázdová ◽

Radim Fojtík ◽

Iva Tichá

Keyword(s):

Climate Change ◽

Assessment Tool ◽

Mitigation Measures ◽

Small Scale ◽

Financial Sustainability ◽

Technical Solution ◽

The City

To increase their resilience to climate change, cities are looking to apply elements of urban environmental acupuncture. The essence of such measures is many smaller sites that is functioning as mitigation measures. Many of these small places then create a large overall effect. The advantage of these small-scale measures is that they can be in densely populated areas The assessment tool described in this paper is designed for city representatives and is an aid to assess the suitability of applying a particular measure based on the parameters described. The evaluation itself then helps to decide whether the solution is suitable for a particular site or whether any of the parameters need to be adjusted to make it suitable, or whether it would be appropriate to change the proposed solution. The intention of the evaluation is not to assess the technical solution but relies primarily on the location, long-term (especially financial) sustainability and acceptance by the citizens of the city. The paper presents an example of the application of the evaluation to four sites in city Liptovský Mikuláš, describing the results and identifying parameters that can be improved to ensure the urban environmental acupuncture is accepted by citizens and thus future-proofed.

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Sustainability Strategies and Projects of Turkish Municipalities

E-Planning and Collaboration ◽

10.4018/978-1-5225-5646-6.ch074 ◽

2018 ◽

pp. 1575-1592

Author(s):

Seda H. Bostancı

Keyword(s):

Climate Change ◽

Literature Review ◽

Environmental Sustainability ◽

Swot Analysis ◽

Small Scale ◽

Healthy City ◽

Sustainability Strategies ◽

The City ◽

City Models

Municipalities have variety of tools for improving environmental sustainability. The effects of climate change increase the renewable projects developed by municipalities and public private sectors. Turkish municipalities practiced the early steps of sustainability projects, some of which were small-scale projects. In addition, Turkish municipalities have gained experience in LA 21 Process since the late 1990s. Some of the city models for sustainability, such as CittaSlow and healthy city projects developed by Turkish Municipalities. The work in this chapter represents research about variety of issues for environment and sustainability in Turkish Municipalities. Visions, strategies and projects of these municipalities have been analysed to attain this goal. A literature review and SWOT analysis were used for the methodology to determine the Turkish municipalities' potential for sustainability.

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Small scale CO2 fluxes in a rainfed maize field under N fertilization

10.5194/egusphere-egu2020-18170 ◽

2020 ◽

Author(s):

Györgyi Gelybó ◽

Réka Deli ◽

Márton Dencső ◽

Bernadett Kósa ◽

Viktória Mateika ◽

...

Keyword(s):

Soil Respiration ◽

Soil Water ◽

Field Measurements ◽

Vegetation Period ◽

N Fertilization ◽

Small Scale ◽

Material Transport ◽

Sowing Time ◽

Area Index ◽

Maize Field

Carbon-dioxide (CO2) fluxes in the soil-plant-atmosphere system contain bidirectional material transport with organic and inorganic sources and sinks, and various pathways. Proportion of irrigated fields in the total area of Hungarian arable lands is low, and incase of a rainfed field water and CO2 fluxes are only driven by meteorological factors. In this study we focused on maize under different fertilization treatments to see the plot scale variability of CO2 fluxes and connected parameters.The site is a multifactorial sowing time-fertilizer-maize variety field experiment near Martonv&#225;s&#225;r. Two treatment plots were selected for the measurements with contrasting 60 kg N ha-1 and 180 kg N ha-1 fertilizer treatments and no other factors were considered in the present study. We performed synchronized observations of (i) CO2 fluxes: soil respiration (Rs; EGM-5 gas analyser + SRC-1 chamber, PPSystems); leaf scale photosynthesis (A; CIRAS-3 portable photosynthesis system, PPSystems)), (ii) soil temperature and soil water content, (iii) plant parameters: root growth (CI-600, CID-Bioscience), plant height, leaf area index (Accupar LP-80 ceptometer, Li-Cor). Data on the above parameters comprise several spatial replicates to explore spatial heterogeneity in case of a maize field managed in accordance with the typical Hungarian practice. The average applied N amount in the country is around 100-105 kg ha-1.Field measurements for CO2 fluxes and biotic and abiotic drivers were performed six times in the vegetation period to establish relationship among them. Data were analyzed to optimize the labour intensive protocol for this experimental setup. Photosynthesis varied within the vertical canopy as reflected by measurements on five leaves per plant. Soil respiration was more dependent temporally on soil water availability than on temperature.

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Using soil water isotopes to infer the influence of contrasting urban green space on ecohydrological partitioning

10.5194/hess-2020-425 ◽

2020 ◽

Author(s):

Lena-Marie Kuhlemann ◽

Doerthe Tetzlaff ◽

Aaron Smith ◽

Birgit Kleinschmit ◽

Chris Soulsby

Keyword(s):

Soil Water ◽

Green Space ◽

Urban Green Space ◽

Urban Trees ◽

Urban Vegetation ◽

Isotopic Tracers ◽

Drought Period ◽

Urban Green ◽

Water Demands ◽

Prolonged Drought

Abstract. Many urban areas are facing challenges in balancing domestic and industrial water demands while simultaneously maintaining the water supply for green infrastructure. Consequently, quantitative knowledge about ecohydrological partitioning in different types of urban green space is crucial for balancing sustainable water needs in cities during future challenges of increasing urbanization and climate warming. Using isotopic tracers in precipitation and soil water, along with conventional hydrometric measurements in a plot-scale study in Berlin, Germany, we investigated water partitioning under different generic types of urban vegetation (grassland, shrub and trees). This allowed assessment of effects on subsequent evapotranspiration, subsurface flow paths and storage during a prolonged drought period with episodic rainfall. Water losses under forest were slightly higher than grassland over the monitoring in the growing season of 2019. Despite higher soil evaporation losses under urban grassland, higher interception and transpiration likely contributed to slower turnover of soil water and older groundwater recharge under urban trees. Shrub vegetation seemed to be most resilient to prolonged drought periods, with lower evapotranspiration losses. Our results contribute to a better understanding of ecohydrological partitioning under mixed urban vegetation communities and an evidence base for better adaptive management of urban water and irrigation strategies to sustainably meet the water demands of urban green spaces.

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Sustainability Strategies and Projects of Turkish Municipalities

Practice, Progress, and Proficiency in Sustainability - Handbook of Research on Sustainable Development and Economics ◽

10.4018/978-1-4666-8433-1.ch004 ◽

2015 ◽

pp. 56-71 ◽

Cited By ~ 4

Author(s):

Seda H. Bostancı

Keyword(s):

Climate Change ◽

Literature Review ◽

Environmental Sustainability ◽

Swot Analysis ◽

Small Scale ◽

Healthy City ◽

Sustainability Strategies ◽

The City ◽

City Models

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Pigeonpea Yield and Water Use Efficiency: A Savior under Climate Change-Induced Water Stress

Agronomy ◽

10.3390/agronomy11010005 ◽

2020 ◽

Vol 11 (1) ◽

pp. 5

Author(s):

Misheck Musokwa ◽

Paramu Mafongoya

Keyword(s):

Climate Change ◽

Grain Yield ◽

Water Use Efficiency ◽

Soil Water ◽

Water Use ◽

Smallholder Farmers ◽

Block Design ◽

Soil Water Tension ◽

Use Efficiency ◽

Water Tension

Frequent droughts have threatened the crop yields and livelihoods of many smallholder farmers in South Africa. Pigeonpea can be grown by farmers to mitigate the impacts of droughts caused by climate change. An experiment was conducted at Fountainhill Farm from January 2016 to December 2017. The trial examined grain yield in addition to water use efficiency (WUE) of pigeonpea intercropped with maize versus sole pigeonpea and maize. A randomized complete block design, replicated three times, was used. Soil water tension was measured at 20, 50, and 120 cm within plots. The highest and lowest soil water tension was recorded at 20 m and 120 m respectively. Combined biomass and grain yield were significantly different: pigeonpea + maize (5513 kg ha−1) > pigeonpea (3368 kg ha−1) > maize (2425 kg ha−1). A similar trend was observed for WUE and land equivalent ratio (LER), where pigeonpea + maize outperformed all sole cropping systems. The inclusion of pigeonpea in a traditional mono-cropping system is recommended for smallholder farmers due to greater WUE, LER and other associated benefits such as food, feed and soil fertility amelioration, and it can reduce the effects of droughts induced by climate change.

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Peat depth as a control on moss water availability during drought

10.22541/au.160735596.64463109/v1 ◽

2020 ◽

Author(s):

Paul Moore ◽

Benjamin Didemus ◽

Alexander Furukawa ◽

James Waddington

Keyword(s):

Climate Change ◽

Water Content ◽

Soil Water ◽

Water Table ◽

Summer Drought ◽

Drought Period ◽

Near Surface ◽

Soil Water Tension ◽

Water Tension

Peatlands are globally important long-term sinks of carbon, however there is concern that enhanced moss moisture stress due to climate change mediated drought will reduce moss productivity making these ecosystems vulnerable to carbon loss and associated long-term degradation. Peatlands are resilient to summer drought moss stress because of negative ecohydrological feedbacks that generally maintain a wet peat surface, but where feedbacks may be contingent on peat depth. We tested this ‘survival of the deepest’ hypothesis by examining water table position, near-surface moisture content, and soil water tension in peatlands that differ in size, peat depth, and catchment area during a summer drought. All shallow sites lost their WT (i.e. the groundwater well was dry) for considerable time during the drought period. Near-surface soil water tension increased dramatically at shallow sites following water table loss, increasing ~5–7.5× greater at shallow sites compared to deep sites. During a mid-summer drought intensive field survey we found that 60%–67% of plots at shallow sites exceeded a 100 mb tension threshold used to infer moss water stress. Unlike the shallow sites, tension typically did not exceed this 100 mb threshold at the deep sites. Using species dependent water content - chlorophyll fluorescence thresholds and relations between volumetric water content and water table depth, Monte Carlo simulations suggest that moss had nearly twice the likelihood of being stressed at shallow sites (0.38 ± 0.24) compared to deep sites (0.22 ± 0.18). This study provides evidence that mosses in shallow peatland may be particularly vulnerable to warmer and drier climates in the future, but where species composition may play an important role. We argue that a critical ‘threshold’ peat depth specific for different hydrogeological and hydroclimatic regions can be used to assess what peatlands are especially vulnerable to climate change mediated drought.

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Thermal Comfort and Perceptions of The Ecosystem Services and Disservices of Urban Trees in Florence

Forests ◽

10.3390/f12101387 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1387

Author(s):

Andrew Francis Speak ◽

Fabio Salbitano

Keyword(s):

Ecosystem Services ◽

Thermal Comfort ◽

Urban Trees ◽

Climate Data ◽

Urban Green ◽

Urban Green Spaces ◽

Open Questions ◽

Wide Range ◽

Microclimate Conditions ◽

The City

Modern urban lifestyles have most likely generated a loss of awareness of the bio-cultural benefits derived from the presence of trees and forests in cities. The present study aimed at understanding the level of awareness and the ability to express significant relationships, both positive and negative, on ecosystem services and disservices by the citizens of a Mediterranean city where thermal comfort during the summer period can be particularly problematic. A questionnaire consisting of multiple-choice and open-ended questions was disseminated to citizens of Florence, Italy. The open questions allowed respondents space to describe what they perceive are the benefits and disbenefits of urban trees. Meanwhile, geospatial and climate data were processed in order to check the vegetation and microclimate conditions of the city areas where the 592 respondents live. The vast majority of respondents felt Florence is unbearably hot in summer with 93% agreeing the city needs more trees, and shaded places were perceived as the most important feature of urban green space. The results reveal many positive and negative associations to different species of trees and bring out a rich mosaic of perceptions towards urban green spaces and the features they contain. People are generally aware of a wide range of the benefits trees provide to communities and a good knowledge of the microclimate modification properties was revealed. Many of the popular public tree genera in the city, such as Tilia, Platanus and Pinus were favoured by residents however there was some overlap with trees that provoke negative experiences, and this information can be useful to city planners aiming to maximise ecosystem services and minimise ecosystem disservices.

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Young urban trees as important structures in the cultural heritage of cities – a case study from Prague

Environmental & Socio-economic Studies ◽

10.2478/environ-2019-0014 ◽

2019 ◽

Vol 7 (3) ◽

pp. 14-23 ◽

Cited By ~ 1

Author(s):

Ales Rudl ◽

Ivo Machar ◽

Lubos Uradnicek ◽

Ludek Praus ◽

Vilem Pechanec

Keyword(s):

Ecosystem Services ◽

Green Infrastructure ◽

Urban Areas ◽

Urban Trees ◽

Young Tree ◽

Urban Green ◽

Field Mapping ◽

Large Trees ◽

Urban Green Infrastructure

Abstract Urban trees generate numerous ecosystem services, and these are often closely associated with the species, age and size of trees as well as with their vitality. Generally, the focus of urban and regional planning is aimed at very large trees, because very large trees are considered to be key green structures in an urban green infrastructure. However, there is a significant knowledge gap related to the importance of young trees in cities, despite their value in urban green spaces, greenways, parks, gardens, urban forests, and as components of green roofs and green walls. This study is the result of field mapping young trees in the urban area of the famous European historical city of Prague. Field mapping revealed a total of 40 individual young trees, or young tree groups, with cultural value in the study area of Prague. The results of this empirical study indicate that young trees (not just very large and old trees) can be very important structures for the provision of cultural ecosystem services in cities, and that they can be viewed as living cultural symbols. This is a new aspect in the awareness of the environmental and social roles of urban trees. This case study from Prague suggests that (i) young trees in urban areas need more attention from researchers and (ii) should be incorporated into urban planning as an important component of urban green infrastructure.

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