Plant performance in living wall systems in the Scandinavian climate

The concept of green façades is not new (Koehler, 2008), but their reintroduction may offer benefits in the current urban design, which is increasingly focused on urban densification. The benefits of vertical greening include noise abatement (Van Renterghem et al., 2013), filtering of airborne dust and pollutants (Ottele et al., 2010 and Sternberg et al., 2010), and reduction of temperature close to the area of vertical greening (Onishi et al., 2010, Wong et al., 2010 and Perini et al., 2011a). The thermal aspects of vertical greening are, however, still under debate (Hunter et al., 2014). One particular type of green façade is living wall systems, which are vertical greening systems where plants are grown without the need for contact with the ground (Koehler, 2008, Francis and Lorimer, 2011 and Perini et al., 2011b). Living wall systems can be seen as an alternative way of introducing urban greening in dense urban areas in the same way as e.g. green roofs, which have shown to support a high arthropod diversity (Rumble and Gange, 2013 and Madre et al., 2013). Like plants on green roofs (Emilsson and Rolf, 2005 and Emilsson, 2008), plants in living wall systems must be able to cope with extreme conditions, such as high irradiation, considerable differences in temperature and possible water shortage. The main aim of this study was to determine whether it is possible to grow perennial plants in living wall systems in the Scandinavian climate and we hypothesized that perennial plants could survive in, and would be a viable option for, living wall systems in the Scandinavian climate

The Hammenhög biochar plant – residues and by-products to produce biochar and residential heating

In the small community of Hammenhög in Sweden, one of the largest biochar plants in Europe have been built as part of two projects supported by the Swedish government. Rest till Bäst is a Vinnova-funded project whose purpose is to develop solutions for managing organic residues (park- and garden waste, sludge, algae’s and seaweed) and create a valuable product (biochar), while minimizing environmental and climate impact and a carbon sink is established. The other project is a climate initiative, Klimatklivet, which supports activities that act to mitigate climate change. The pyrolysis plant consists of two clines, were one is constructed to be run at high temperatures in order to separate Cd and other metals in the process. This capacity makes pyrolysis of polluted materials like sludge, algae and garden wastes a viable alternative and tests are being run. The main feed-stock in the other cline is residues from seed production on site that is pelleted. The plant is expected to produce xx W and produce 6500 tons of biochar per year. The nearby community will get distant heating from the plant making it a carbon negative community. The biochar characteristics as well as the growth potential in different applications like raingardens, urban tree plantations, green roofs and green walls, are tested in the project. Please click Additional Files below to see the full abstract

Exploring the Integration Between Colour Theory and Biodiversity Values in the Design of Livning Walls

Designing green infrastructure in cities requires vegetation that has multiple outcomes and functions, particularly using plants that have both attractive visual or aesthetic features and high biodiversity values. Plantings that have high visual appeal are more highly valued by people and increase their feeling of wellbeing. Increasing biodiversity in cities is one of the major challenges facing urban planning and design. However, balancing biodiversity and aesthetic outcomes in urban planting design is complex, and to date there are few methods that can be used to guide plant selection. To address this knowledge gap, we investigated the use of a colour theory framework for planting arrangements to see if we could design vegetation that is highly aesthetic and has high biodiversity. We did this by configuring planting combinations for living walls in Malmö, Sweden, using principles based on Johannes Itten’s colour theories. The plant combinations on each wall were graphically arranged using (1) colour analysis of each plant and (2) design of the plant species into two colour schemes: light-dark colour concept and a complementary colour concept. For each species used in the compositions we created a biodiversity classification, based on its pollination value, “nativeness” and conservation value as a cultivar; and a plant visual quality classification, based on the performance from living walls studies. The graphical colour composition and interlinked biodiversity value were then compared to designs created with randomly selected plant species. The results showed that it is possible to design a living wall based on colour theory without compromising with biodiversity outcomes, namely species richness, pollination and the nativeness of the species. The results also indicate the potential application of this design approach to deliver greater aesthetic appreciation and enjoyment from plantings. While more work is needed, this study has shown that a theoretical colour framework can be a useful tool in designing green infrastructure to improve delivery of both cultural and regulatory ecosystem services

Biochar in urban applications

Urban use of Biochar is increasing but the effect on the plant growth is neither verified nor estimated. Biochar use in urban tree plantings and raingardens is becoming generic in some of the largest Sweden Cities. The objective behind using biochar in tree plantations have been that it is safer to establish in this substrate than in structural soils and the trees grow well. Carbon/macadam and structural soils are used below hardcover surfaces and sustain the load from traffic. In raingardens, which is a dry system, biochar increases the water-holding capacity and thereby secure the establishment and growth of the plants. Biochar is also purifying the storm-water reducing the pollution loads to recipients. New applications that have been tested is in green roofs, in living walls, in parks, street trees, courtyards and urban meadows. Survival and growth of the vegetation is determined and preliminary results show that biochar can be used in and benefit these vegetation systems. By expanding the use of biochar into urban vegetation, the CO2 mitigation potential is increasing Please click Additional Files below to see the full abstract

Alkaline habitat for vegetated roofs? Ecosystem dynamics in a vegetated roof with crushed concrete-based substrate

Using local and recycled materials is a sustainable way to establish a vegetated roof. In order to understand how the roof ecosystem functions and returns ecosystem services, it is important to study vegetation, soil organisms and runoff quality. We established a vegetated roof experiment based on a substrate containing lightweight crushed concrete, an alkaline side product from a concrete factory, mixed with compost. This five-year experiment in southern Finland tested how planting method (pre-grown vegetation mats vs. pot planting), compost content (20% vs. 40%, fresh volume), and substrate depth affect the cover and diversity of plants, the abundance of soil animals and the quality of runoff. Although the substrate had a high pH (7.3–11.8), many vascular plants were able to survive and establish viable populations. The planting method had a strong effect on plant diversity and the cover of individual species because the vegetation mats became dominated by the invasive, non-native Phedimus hybridus. Establishment with pot plants in turn provided bare ground that was colonised by spontaneous non-invasive species. This resulted in higher diversity, and a more even distribution of species. The amount of compost had only a weak impact on vegetation, whereas high pH generally reduced plant abundance and diversity. The concentrations of total phosphorus and total nitrogen in runoff were low as compared to values reported from many other vegetated roofs, were not affected by compost content and decreased over time. In summary, the high-pH substrate based on recycled materials is an environmentally responsible choice, suitable for a wide variety of plants, even rare and endangered species.Peer reviewe

Risk of root intrusion by tree and shrub species into sewer pipes in Swedish urban areas

Blockages in sewer pipes caused by roots are very common and several tree and shrub species are reported to be particularly likely to cause root intrusion. This study examined the relative ability of roots of different species to intrude into urban sewer pipes. Data on root-intruded pipes and the woody plants surrounding these pipes were collected from two Swedish cities, Malmö and Skövde. Plant material, location data and closed-circuit television (CCTV) inspections on root-intruded pipes with a total length of 33.7 km, containing 2180 different points of root intrusion, were examined. An inventory of 4107 woody plants was compiled. The results showed that broad-leaved trees dominated as a cause of root intrusion, but that conifers and a number of shrubs, e.g. the genera Ligustrum, Spiraea and Syringa, were also likely to have caused root intrusion. Malus floribunda Van Houtte was found to have the highest mean share of root intrusions per estimated number of pipe joints when all joints and all root intrusions within a 10 m radius from trees were calculated (0.694, maximum number of intrusions per joint 1.0), while Populus canadensis ‘Robusta’ Moench had the second highest, with 0.456 intrusions per estimated joint. However, other Malus and Populus species and cultivars had a much lower mean share of root intrusions. Most species seemed capable of causing root intrusion, and not only species of the genera Populus and Salix that were previously seen as the species most likely to cause damage to stormwater and sewer systems. There were differences in the frequency of joint intrusion by roots of different species, but the reasons for these differences were not identified and further research in the area is needed

Gröna tak för biologisk mångfald

Gröna tak kan utgöra livsmiljö för många växter och djur om man anlägger taken med detta syfte. I detta Movium Fakta presenteras erfarenheter och resultat från BiodiverCity samt andra relaterade projekt med målsättningen att bidra till ökad kunskap om den potential ett grönt tak kan ha för att främja den biologiska mångfalden

The social foundation of executive function

In this study, we propose that infant social cognition may ‘bootstrap' the successive development of domain‐general cognition in line with the cultural intelligence hypothesis. Using a longitudinal design, 6‐month‐old infants (N = 118) were assessed on two basic social cognitive tasks targeting the abilities to share attention with others and understanding other peoples' actions. At 10 months, we measured the quality of the child's social learning environment, indexed by parent's abilities to provide scaffolding behaviors during a problem‐solving task. Eight months later, the children were followed up with a cognitive test‐battery, including tasks of inhibitory control and working memory. Our results showed that better infant social action understanding interacted with better parental scaffolding skills in predicting simple inhibitory control in toddlerhood. This suggests that infants' who are better at understanding other's actions are also better equipped to make the most of existing social learning opportunities, which in turn may benefit future non‐social cognitive outcomes