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Ornamental grasses are often used in gardens to improve biodiversity and as additional aesthetical resources. However, their use in green roofs (GR) and living walls (LW) is not so widespread and it has not been studied extensively. The aim of this work is to assess the performance of seven grass species (Imperata cylindrica ‘Red Baron’, Acorus gramineus, Stipa tenuissima ‘Pony Fails’, Carex flagellifera ‘Bronzita’, Carex oshimensis ‘Evergold’, Uncinia rubra ‘Everflame’ and Miscanthus sinensis) for their use in GR and LW. The growth of the plants was evaluated (i.e. biomass production, dimensions), as well as their visual quality and survival. C. flagellifera and C. oshimensis showed coverage levels greater than 75% and good visual quality, while A. gramineus reached 55–60%. I. cylindrica and M. sinensis showed coverages slightly below 50% in the LW, however, both performed well in the GR, though with a lower visual quality. U. rubra did not develop well, reaching the lowest coverage (below 45%) but maintaining a high visual quality. S. tenuissima also attained low coverage in the LW and presented high mortality, especially in the GR. In LW, C. oshimensis stood out in flowering, while S. tenuissima showed the highest flowering rate in GR. The species should be selected considering their characteristics and performance in order to achieve a correct appearance and development. Interspecific interactions are especially important in LW, as species with upward growth should be placed above species with fallen leaves, not below.

Currently, the population spends most of the time in indoor environments, which makes Indoor Air Quality (IAQ) very important for health and comfort. As vegetation can act as a biofilter capturing air pollutants, this study aims to assess the effectiveness of a living wall module in the removal of the Total Volatile Organic Compounds (TVOCs) for IAQ improvement. An airtight glass chamber was used to release contaminants, monitoring the TVOCs both with the chamber empty (control) and with a small Fytotextile® living wall module planted with Nephrolepis exaltata L. A substantial reduction of TVOCs was observed when the living wall was inside the chamber. In few hours, TVOCs levels were reduced below the recommended limit (following Spanish regulations). More tests are recommended considering different plant species and other variables related to the IAQ.

This paper seeks to identify the most unfavourable areas of a city in terms of high temperatures and the absence of green infrastructure. An automatic methodology based on remote sensing and data analysis has been developed and applied in sixteen Spanish cities with different characteristics. Landsat-8 satellite images were selected for each city from the July-August period of 2019 and 2020 to calculate the spatial variation of land surface temperature (LST). The Normalized Difference Vegetation Index (NDVI) was used to determine the abundance of vegetation across the city. Based on the NDVI and LST maps created, a k-means unsupervised classification clustering was performed to automatically identify the different clusters according to how favourable these areas were in terms of temperature and presence of vegetation. A Disadvantaged Area Index (DAI), combining both variables, was developed to produce a map showing the most unfavourable areas for each city. Overall, the percentage of the area susceptible to improvement with more vegetation in the cities studied ranged from 13 % in Huesca to 64–65 % in Bilbao and Valencia. The influence of several factors, such as the presence of water bodies or large buildings, is discussed. Detecting unfavourable areas is a very interesting tool for defining future planning strategy for green spaces. This study was financed by the Spanish R & D Programme for projects addressing the challenges of the society (2018 call), in the framework of the State Plan of Scientific and Technical Research and Innovation 2017–2020, financed by the Spanish Ministry of Science, Innovation and Universities, grant number RTI2018095097-B-100.

Vertical greening systems for buildings are becoming common in many cities. There are different options in the market but some types of living walls require the use of inorganic substrates as plants are grown in a hydroponics culture. In this study, three different substrates (expanded clay, perlite and pumice) are tested in six living wall modules (two per substrate) with two lighting conditions. The substrates were physically and chemically characterized and both water consumption and plant development (green cover, flowering, biomass production and photosynthetic activity) were monitored in two different tests. The three substrates showed to be suitable for living walls and most of the differences observed were due to the lighting conditions. Among the three substrates assessed, pumice exhibited a slightly better performance in terms of green cover and biomass production.

Aquaponics is a developing technique that combines the simultaneous production of plants (hydroponics) and fish (aquaculture). With it, the use of resources (i.e., water, nutrients, land) is reduced whilst at the same time minimising residues’ discharge to the environment. Among its benefits, it allows the production of healthy vegetables and fish in reduced spaces by means of small-scale systems. In this work, three of them based on FAO models with different hydroponic subsystems (nutrient film technique -NFT-, floating raft, and vertical felt) are tested to produce lettuce (Lactuca sativa) and goldfish (Carassius auratus). Water parameters as well as the growth of plants and fishes were monitored in two different production cycles. The hydroponic subsystem that outperformed the best was the NFT, both in terms of crop production and water consumption. All systems showed similar results in fish production. Further research is needed to corroborate the outputs obtained when using other combinations of plants and fishes. Small-scale aquaponic systems are particularly interesting for self-production and even more so in urban environments with reduced available space.

The present study evaluated the role of having plants at home during the confinement period as a result of the COVID-19 pandemic that deprived people of freely visiting open green spaces. Preferences concerning the quantity of the desired vegetation as well as the ways in which the COVID-19 crisis affected the change of perceptions with regard to having plants at home were also evaluated. A questionnaire, which was filled by 4205 participants, provided an undistracted evaluation of the impact of indoor and outdoor plants on their emotional welfare considering behavioural, social, and demographic variables. The emotional state of the respondents was neutral and a significant proportion expressed positive emotions. Having indoor plants was correlated with more positive emotions, and confined inhabitants allocated more time for plant maintenance. By contrast, negative emotions prevailed in respondents who related to a positive COVID-19 case, which was more frequent in females and young participants living in small houses that received low levels of natural light and had few or no plants. A few indoor plants placed in strategic positions were also preferred compared with a high number of plants. By contrast, an increased amount of vegetation accompanied by living walls was preferred for outdoor settings. Living walls were considered as advantageous for increasing indoor vegetation, but they were also associated with technical and economical hurdles.

Irrigation plays a very important role in a Mediterranean garden. In spite of this, there are not many studies assessing irrigation water management of landscapes. Moreover, historic gardens represent a special challenge due to their unique characteristics. The aim of this work is the characterization and evaluation of water management in a historic garden. For that, the gardens of The Real Alcazar of Seville were used as a case study. They comprise a total of 20 gardens of different styles with a total area of nearly 7 ha. Landscape water requirements and irrigation volume applied were estimated and used in conjunction with other descriptive and financial variables to calculate 6 performance indicators. Only 20% of gardens showed adequate irrigation in the spring-autumn period, being 10% during summer. However, the two well-watered gardens represent 30% of the total irrigated area. Management, operation and maintenance costs are 0.63 €·m−2 representing 0.58 € per volume of irrigation water used (m−3). Results obtained support the need of improving irrigation management. For that, simple solutions such as installing metering devices, calculating actual water requirements or optimizing irrigation schedules can be implemented. Other more complex actions such as modifying the irrigation network or creating hydrozones might also be explored.

Vertical greening systems are becoming a new reality worldwide in urban areas in order to increase and enhance green spaces. Commercially there are many systems employing various materials which aim to enable an adequate development of the vegetal cover, ensuring long-term successful performance. Irrigation represents one of the main key factors, but there is a knowledge gap involving the performance of commercial systems in terms of water management. Felt-based systems present more difficulties due to the smaller water retention capacity, which is an important drawback, especially in warm climates. This work aims to improve an existing commercial system (Fytotextile) in order to optimise water retention and vegetation performance in harsh climate conditions. Therefore, three evolutions of the Fytotextile system were tested in terms of water retention capacity, drainage and vegetation performance. Fytotextiles 3 and 4 vastly improved the initial water retention capacity of the commercial system (2.9 and 5.8 times that of Fytotextile 1, respectively) but the former exhibited a lower volume of water drained and a slightly better behaviour of the plants.

Building-integrated vegetation systems, such as living walls (LW), are becoming common tools for improving the sustainability of cities as well as an aesthetic resource. When used indoors, LW usually require a lighting system to ensure both an adequate plant development and a correct appearance. In this study, six commercial LED lighting systems are tested in order to assess their suitability for the proper performance of LW. The LW monitored were composed of two plant species (Soleirolia soleirolii and Spathiphyllum wallisii) frequently used in indoor LW. All the lamps tested (Aster and Dahlia of Ignia Green, Logar CMH, CLH and Forum of Lledo) proved to be apt for their use to light LW (except for the case of CF-UT01 of Panda Grow), as they showed a favourable performance in terms of plant development, with few differences between them in biomass production and green cover. The tested Aster (Ignia Green) and Logar CMH (Lledo) lamp models were not efficient for long distances between the vegetation and the light source. Despite these results, as illumination is one of the factors that determines the indoor ambience, aesthetics and viewers’ preferences were also studied. According to the observers' perception, the Dahlia model (Ignia Green) was preferred by 54.4 % of the respondents, while the rest of the lamps were preferred less.

Urban development is causing environmental and social concerns that are compromising human welfare and the sustainability of cities. New urban greening concepts are being developed to mitigate these problems in a sustainable and natural way. Vertical greening systems can be defined as structures that allow vegetation to spread over a building facade or interior wall. These systems are becoming popular though they are still evolving and more knowledge on some of their particular impacts is required. In the last five years, the number of studies published in the scientific literature on this topic, especially involving living walls, has significantly increased. This scientific interest has corresponded with an increased and parallel attention by the general public. This work offers a broad description of the different systems and a comprehensive review of the particular benefits of these green infrastructures. Knowledge gaps and shortcomings have also been identified and discussed.

Different types of vertical greening systems (VGS) can be identified; these have different aesthetic and functional performances. Green facades, i.e., the extensive VGS, are based on climbing plants growing in the ground or in planter boxes. We can distinguish two large groups of living wall systems, i.e., the intensive VGS: cloth (or felt) and panels, made of galvanized steel, polyethylene, and recycled plastic. These systems are based on hydroponic culture or have substrates which allow planting shrubs, herbaceous, climbing plants, etc. This chapter also considers the correct selection of plant species, which, especially in the case of living walls, is very important for the design of successful installations.

Aquaponics is a farming technique that can be used in urban environments for the simultaneous production of plants (hydroponics) and fish (aquaculture). The fish consume the supplied feed and their waste is naturally converted to nitrate and other nutrients, which are then taken up by the plants, acting as a natural water filter. Regarding food safety, there is concern about nitrate accumulation in leafy vegetables produced using this technique. In this study, three different species are tested using a small-scale aquaponic system in order to determine if they are apt for consumption in terms of nitrate levels in their leaves. The nitrate contents observed (613, 2387.8 and 1425.4 mg kg−1 for romaine lettuce, Swiss chard and curly kale, respectively) are below the limits imposed by the European Commission in the existing regulations. They are also within the range of values obtained for the same vegetables cultivated in a conventional way.

Living walls (LW) are vertical greening systems that are becoming popular due to their multiple social and environmental benefits. When LW are installed indoors, a lightening system is often required to ensure an appropriate plant development. This work assesses the performance of three artificial lighting systems on six indoor LW [0.7 m (wide) × 0.7 m (high)] placed at two distances from the light source. The plant species selected for the tests were Soleirolia soleirolii and Spathiphyllum wallisii, which are frequently used in indoor LW. Three different lamps were used in the experiment: incandescent (IL), fluorescent (FL) and metal halide (MHL) lamps, all of them with an input electric power of ≈250 W. Differences in plant growth were only observed when the LW were close to the light source (about 1 m) but not at greater distances (≈1.5 m). IL had the poorest performance. Despite the lower photosynthetic photon flux density efficiency of FL compared with MHL, FL light enabled plants placed in the upper LW (closer to light source) reached similar size to those grown under MHL. Plant quality attributes were generally not affected by light type or the distance to light source. IL and FL generated higher total water losses (i.e. transpiration plus evaporation) than MHL on a LW basis. When expressed per unit of LW area covered by vegetation, FL and MHL reduced water consumption by 34% and 56%, respectively, as compared to IL. Overall, our results indicate that both FL and MHL outperform IL and have a similar ornamental performance, whereas MHL are more advantageous than FL in terms of water consumption and annual cost.

Vertical greening systems have increased in popularity during the last years due to their experienced added ecological and aesthetic value for current clients. The use of living walls is in line with a service sector focusing on environmental consciousness. Still, scientific evidence is lacking regarding the multiple benefits of LW. There is also a lingering fear of high installation and maintenance costs. Therefore, it is important to assess the intangible benefits that increase the value of living walls and, hence, of the place in which they are installed. The main objective of this work is the valuation of the returns obtained because of the publicity related to a living wall installed in the ‘Quironsalud Sagrado Corazon’ Hospital in Seville (Spain) and the assessment of the public’s perception towards it. The investment that the hospital would have made in order to obtain a similar media impact has been estimated. The living wall proved to be very profitable in terms of publicity as the installation costs were recovered six times over. Also, the attitude towards the presence of such a greening system in the premises was assessed. To do so, 555 questionnaires were handed out face-to-face to patients, visitors and workers present at the hospital. Most participants concurred that the living wall induced positive reactions and improved their psychological well-being. Therefore, they completely agreed with the investment made by the hospital on such a vertical greening system.

In this paper, a low-speed wind tunnel was used for experimental analysis of water volume retained, pressure drop, saturation efficiency and water consumption for three types of synthetic substrates used in active living walls: polyester (PR), polyurethane (PU) and polyamide–polypropylene (PA–PP) The substrates were of a similar thickness and were tested for different water and air flows. The water retained increases with higher water flow. The pressure drop increases with the presence of vegetation and when air speed and water flow is higher. Cooling efficiency is enhanced with vegetation and low air speed. Specific consumption of water is greater with vegetation at higher air speeds. Therefore, low air (between 0.25 and 0.5 m s −1 ) and water flows are recommended to ensure a homogeneous wetting of the substrate surface. PA–PP has the greatest pressure drop of the three, but also presents the best saturation efficiency, with an average water retention capacity and less specific consumption. PU offers the least resistance to air flow, with an intermediate efficiency level and high water consumption and water retention capacity. PR presents the worst saturation efficiency, a medium level of pressure drop and high water consumption.

Spain has undergone a period of uncontrolled urban expansion in a relatively short time-span, affecting people's quality of life in negative ways with significant impacts on the environment and land resources such as water and energy. Many new residential areas have low-density development, based on single-family houses with private gardens. These gardens are usually relatively small in size, but when considered as a whole, they make a substantial contribution to urban green spaces and have an important impact on the local environment. Although this includes a large variety of benefits, gardens demand a significant quantity of resources, including irrigation water, which is also important and should be taken into account. This paper analyzes features and management practices in domestic gardens, their relationships to garden design, and the attitudes of owners with regard to more sustainable alternatives. In addition, the main features of private gardens are examined. For this study, in-person interviews were conducted with homeowners who possess domestic gardens in the region of Aljarafe in southern Spain. The features of the gardens surveyed proved to be highly variable and related to several factors, such as the area of the gardens. Results seem to indicate that owners are reluctant to implement measures to lower water consumption in garden irrigation, apparently because of a lack of knowledge regarding more sustainable design alternatives. Homeowners who had prior knowledge of the principles of xeriscaping were significantly more open to applying these principles in practical ways.

Living walls are systems that allow the development of vegetation in a vertical surface attached to building facades or indoor walls. Traditionally, they have behaved as ‘passive’ bio-filters, but new approaches and technologies are moving towards their integration within the building's air conditioning and ventilation systems. In an Active Living Wall (ALW), air is forced to pass through the vegetated wall to take advantage of their evaporative cooling potential as well as the capacity of these biological systems to purify air. In the case of indoor ALWs, air is cooled, bio-filtered and humidified thus potentially reducing ventilation requirements. This work describes a prototypic indoor ALWs installed at the University of Seville (Spain). Preliminary results of its performance on indoor air conditions (temperature and humidity) are presented and discussed. Drops in temperature between 0.8 and 4.8 °C have been observed at different distances from the ALW. The cooling process was more efficient when the initial conditions of the room were drier and warmer.

Use of rooftops to produce locally grown vegetables is increasing. However, due to weight restrictions, shallow substrate depths, and potential harsh environmental conditions, optimizing production can be a challenge. Standard industry practices for ornamental extensive green roofs planted with succulents or other herbaceous perennials and grasses dictate that organic matter should be less than 20% of the original substrate mix. In rooftop agriculture, however, maximizing growth and yields are usually a primary objective and the amount of organic matter incorporated into these substrates are a major factor in this equation. In this study we quantified the optimal percentage of compost in a green roof substrate for optimizing growth and yields for cucumbers (Cucumis sativus) and peppers (Capsicum annuum). The study was conducted on raised green roof platforms over a period of 19 weeks and compared six substrates containing increasing amounts of a commercial compost produced from municipal yard waste (0, 20, 40, 60, 80, and 100%) mixed with a heat-expanded shale and sand base. These treatments were also compared to a typical garden plot at ground level. Plant performance evaluations such as plant growth, chlorophyll fluorescence (Fv/Fm) as an indicator of plant stress, and fruit yields were used as an indicator for optimal substrate mixtures. Generally, the addition of 60 or 80% compost resulted in the greatest plant growth and fruit yields, although compost influenced growth and yield of peppers to a greater degree than cucumbers. In addition, the ground garden plots performed poorly which emphasizes the point that growing vegetables on a rooftop can be advantage because substrates can be engineered to maximize plant health, although the same could be done with raised beds in a garden plot. (C) 2015 Elsevier GmbH. All rights reserved.

Living walls are becoming popular solutions to alleviate negative effects of urban development. They are vertical greening systems that allow vegetation to spread across a wall surface to cover a building facade or an interior wall. Because of their characteristics, irrigation becomes essential, but the infrastructure and management required differ from a regular irrigation system. This study aims to evaluate the influence of variables such as the type of substrate used, emitter flow rates, and drip line and emitter spacing on the system performance in terms of water losses and irrigation uniformity. The results show that the main differences are marked by the type of substrate used and the emitter flow rate. Higher flows are recommended when using recirculation systems, as more uniformity is achieved in spite of the higher runoff losses. In “run-to-waste” systems, the use of lower flows and short irrigation lengths (increasing the frequency) is advised. Some management recommendations such as irr...

This study investigates people's preconceptions of green roofs and their visual preference for different green roof design alternatives in relation to behavioral, social and demographical variables. The investigation was performed as a visual preference study using digital images created to represent eight different alternatives: gravel roof, extensive green roof with Sedums not in flower, extensive green roof with sedums in bloom, semi-intensive green roof with sedums and ornamental grasses, semi-intensive green roof with shrubs, intensive green roof planted with a lawn, intensive green roof with succulent and trees and intensive green roof with shrubs and trees. Using a Likert-type scale, 450 respondents were asked to indicate their preference for each digital image. Results indicated that respondents' sociodemographic characteristics and childhood environmental background influenced their preferences toward different green roof types. Results also showed that green roofs with a more careful design, greater variety of vegetation structure, and more variety of colors were preferred over alternatives.

The use of vertical greenery systems in buildings is becoming very popular as they provide several benefits. In this work, the influence of an indoor living wall on the temperature and humidity in a hall inside the School of Agricultural Engineering (University of Seville) was studied. Four different substrates, Geotextile, Epiweb, Xaxim and coconut fibre, were used to grow the plants in order to assess their performance. Several parameters such as temperature, humidity, plant growth or water consumption were monitored and analyzed during a 4-month period. The cooling effect of the living wall was proven, with an average reduction of 4°C over the room temperature though maximum decrements of 6°C have been observed in warmer conditions. Higher air humidity levels were experienced near the living wall, increasing the overall humidity in the room. All the substrates tested were suitable for plant growing and their behaviour was similar. Geotextile showed the best cooling capacity but higher water consumption, coconut fibre presented degradation problems and Epiweb performance was the poorest. Therefore, these systems have been proven to be very useful and interesting for warm indoor environments due to the cooling effect observed in addition to their bio-filtration capacity and the aesthetic component.

Problem-based learning (PBL) is widely regarded as a successful educational method. In Spain, most engineering degrees are still based mainly on old style lecture classes where a great deal of information is given to the students. This work assesses the introduction of a PBL strategy as a complement to traditional engineering education. The instructors’ and students’ attitudes towards its implementation are studied. A new approach has been proposed for the PBL strategy: instead of a single problem, a chain of problems was developed that could be solved in a collaborative environment. Results from the experience showed a high level of student acceptance. Response to the PBL initiative was found to be positive both for instructors and students, though lack of time, difficulties in evaluations and an increase in students’ and teachers’ workloads were the main disadvantages. Compared with traditional engineering curricula, the mixed traditional–PBL model appears to inspire a higher degree of involvement in study activities where on-line learning tools played an important role.