Interactions in public spaces : a study of Shared space impact on traffic safety, accessibility and attractiveness in public spaces

Inom stadsplanering har vi sett att kvaliteten i det offentliga rummet har minskat under det senaste århundradet. Under 1960-talet utvecklades det, exempelvis, i Sverige en modell för stadsplanering med hänsyn till trafiksäkerhet, SCAFT (Stadsbyggnad, Chalmers, Arbetsgruppen för trafiksäkerhet), som strävade efter separering av de olika trafikslagen. Trafikseparering av de olika trafikgrupperna medförde samtidigt separering av funktioner och sociala företeelser i det offentliga rummet. Det gjorde att städerna präglades av rum avsedda för transport och inte för social interaktion med vackra och inbjudande platser att vara på. En motsatt modell har däremot utvecklats i andra länder i Europa. I Nederländerna utvecklades en modell under 1960-talet vars syfte var att integrera människor och bilar på samma utrymme. Modellen heter idag Shared space och har spridit sig genom Europa under de senaste 20 åren. I Sverige började begreppet användas i början av 2000-talet. I denna uppsats behandlar jag konceptet Shared space, dess utveckling och hur det används i svenska städer idag. I uppsatsen analyserar jag gestaltningsmodellens påverkan på trafiksäkerhet, tillgänglighet och attraktivitet i det offentliga rummet. Målsättningen med detta arbete är att genom litteraturstudier och fallstudier av två utvalda platser i södra Sverige (Nya torg i Hörby och Storgatan i Eslöv) belysa användningen av metoder där människors förmåga, människors beteende och en plats utformning samspelar för att bidra till attraktiva stadsrum. Anledningen till ämnesvalet är förankrad i tidigare gestaltningsförslag där jag i någon form har använt mig av Shared space som koncept. Konceptet, tillsammans med andra gestaltningsidéer, har jag använt för att uppnå attraktiva rum där människor kan interagera med varandra, uppehålla och röra sig på ett säkert och trivsamt sätt.In urban planning, we have seen that the quality of the public space has decreased in the last century. In the 1960s, for example, was developed in Sweden a model for urban planning with regard to road safety, SCAFT (Urban planning, Chalmers, Working Group on Road Safety), which sought the separation of the various traffic groups. This separation led simultaneously to separate functions as well as social aspects in the public space; it also caused cities to be characterized by spaces intended for transportation instead of spaces for social interaction with beautiful and inviting places to be. In other European countries, however, have an opposite model of urban planning developed. In the 1960s, developed in the Netherlands a model that would integrate people and cars in the same space. The model is now called Shared space and has spread through Europe during the last 20 years. In Sweden, the term began to spread as a concept in the early 2000s. In this thesis I discuss the concept Shared Space, its development and how it is used in Swedish cities today. In this thesis I evaluate Shared space inpact on traffic safety, accessibility and attractiveness in the public space. The aim of this thesis is to illustrate, through literature and case studies of two selected sites in southern Sweden (Nya torg in Hörby and Storgatan in Eslöv), the use of methods where human ability, human behavior and the design of places interact to contribute to attractive urban spaces. The reason for the choice of topic is based on earlier design proposal which I in any form have been using Shared space as a concept. The concept, along with other design ideas I have used to achieve attractive places where people can interact with each other, reside and move in a safe and comfortable way

Session 17 Ecophysiology

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Iron nutrition dynamics - Differences between calcicole and calcifuge plants

One third of the earth´s soils is calcareous. Calcifuge plants are excluded from these soils, and one of the main causes is Fe deficiency, as Fe solubility in calcareous soil is very low. A lack of Fe lowers chlorophyll content, visible as yellowing of leaves, called chlorosis. It is demonstrated that the main cause of chlorosis in calcifuges is that a large part of the Fe in their leaf tissues is immobilized in a form that is not metabolically 'active', which is not the case in calcicole plants adapted to growth on such soils. The Fe fraction in leaves responsible for chlorophyll synthesis may be Fe2+ and can be extracted by synthetical chelators. 1,10-phenanthroline extractable Fe correlates well with degree of chlorosis. An additional cause of chlorosis in some calcifuges is a decreased Fe uptake by the root. Phosphorus concentration in the leaf tissue does not seem to have an influence on metabolically 'active' Fe, though phosphate addition to the soil may aggravate chlorosis. Studied were also other conditions of possible importance to calcicole-calcifuge behaviour, such as differences among plants in compartmentation of Fe between shoots, roots and the soil/root interface, as well as allocation of Fe and other plants nutrients to plant seeds. Iron immobilization in the tissue is ecologically important to the calcicole-calcifuge behaviour of plants, as it might decrease vitality in calcifuges and exclude them from calcareous soil

Chlorosis in wild plants: Is it a sign of iron deficiency?

Chlorosis in crops grown on calcareous soil is mainly due to iron (Fe) deficiency and can be alleviated by leaf application of soluble Fe2+ or diluted acids. Whether chlorosis in indigenous plants forced to grow on a calcareous soil is also caused by Fe deficiency has, however, not been demonstrated. Veronica officinalis, a widespread calcifuge plant in Central and Northern Europe, was cultivated in two experiments on acid and calcareous soils. As phosphorus (P) deficiency is one of the major causes of the inability of many calcifuges to grow on calcareous soil we added phosphate to half of the soils. Leaves in pots with the unfertilized and the P-fertilized soil, respectively, were either sprayed with FeSO4 solution or left unsprayed. Total Fe, P, and manganese (Mn) in leaves and roots and N remaining in the soil after the experiment were determined. In a second experiment, no P was added. Leaves were either sprayed with FeSO4 or with H2SO4 of the same pH as the FeSO4 solution. Degree of chlorosis and Fe content in leaves were determined

Use of 1,10-phenanthroline in estimating metabolically active iron in plants

If calcifuges are forced to grow on a calcareous soil, they usually develop chlorosis. However, total leaf iron (Fe) does not often correlate well with Fe deficiency symptoms. The extraction of 'active' Fe by 1 M HCl or Fe chelators, e.g., 1,10-phenanthroline, may reflect the relation between chlorosis and Fe-concentration in the leaves better than total Fe does. Extraction of 'active' Fe from leaves of wild plants by 1,10-phenanthroline, citric acid and HCl was compared. The 1,10-phenanthroline was chosen for further methodological studies. All samples were extracted at indoor light conditions and analyzed by AAS because dark incubation did not influence the oxidation state of Fe and non-specific light absorbance seemed to be high in colorimetric analysis. Washing of leaf material with H2O seemed to clean the leaf surfaces equally well as with 0.1 M HCl. Only fresh leaf material was extracted, as pretreatment (freezing or drying) changed the extractability of Fe. An extraction time of 16 h was adequate for the herbaceous plants tested but not for Carer pilulifera, where extracted Fe increased linearly with time. The age of the extractant solution may play a role because 1,10-phenanthroline had lost part of its chelation capacity after 6 weeks. The ratio of leaf weight:extractant volume did not influence the amount of Fe extracted, provided the same amount of chelator was supplied. The 1,10-phenanthroline did not interfere with the Fe determination by AAS, and HCl pH 3 as used for the preparation of the extractants had only a marginal influence on Fe extractability compared to 1,10-phenanthroline at pH 3. To get comparable results the extraction method should be standardized as much as possible. Samples can be stored in the refrigerator for several hours before adding the extractant and the extracts can be stored for a few days or frozen and measured on the same day, with the same instrument setting

Soluble inorganic tissue phosphorus and calcicole-calcifuge behaviour of plants

Background and aims Natural and semi-natural, non-fertilized calcareous soils are consistently low in soluble and easily exchangeable phosphate. An over-utilization, or possibly an immobilization, of inorganic P in the tissues of calcifuge plants may take place, if such plants are forced to grow on a calcareous soil, though this has not been experimentally demonstrated. The objectives of this study are, therefore, to elucidate if calcifuge plants, when forced to develop on a calcareous soil, not only have lower total P (Ptot) concentrations in their leaves than calcicole plants grown on such soil, but also a lower proportion of Not as water-soluble, inorganic phosphate. Such differences may be of importance in understanding the calcicole-calcifuge behaviour of plants. Materials and methods Plants of five calcicole and five calcifuge herbs and three calcicole and three calcifuge grasses were cultivated in a glasshouse on a moderately acid Cambisol and a calcareous Rendzic Leptosol using seeds of wild populations from southern Sweden. The calcifuges were: Corynephorus canescens, Deschampsia flexuosa, Holcus mollis, Digitalis purpurea, Lychnis viscaria, Rumex acetosella, Scleranthus annus and Silene rupestris. The calcicoles were: Melica ciliata, Phleum phleoides, Sesleria caerulea, Arabis hirsuta, Sanguisorba minor, Scabiosa columbaria, Silene uniflora ssp. petraea and Veronica spicata. Key results At harvest, calcifuges had much lower leaf tissue concentrations of Ptot and Pi than calcicoles when grown on the calcareous soil, and biomass production of the calcifuges was poor on this soil. Moreover, the calcifuge herbs had, on average, a lower proportion of their Ptot as Pi than had the calcicole herbs. The calcifuge herbs were also unable to avoid excessive uptake of Ca from the calcareous soil. The calcifuge grasses maintained a similar proportion of Ptot as Pi as the calcicole grasses, but their growth was still poor on the calcareous soil. Conclusions On calcareous soil, very little Pi in the tissues of calcifuge herbs is, at any time, available for use in various physiological functions. This is of importance to their photosynthesis, growth, competition and final survival on such soils

Immobilization of tissue iron on calcareous soil: differences between calcicole and calcifuge plants

Deficiency of P and sometimes of micronutrients; especially Fe, is of importance to the calcicole-calcifuge behaviour of plants. Calcifuge species are unable to solubilize these elements or keep them metabolically active in sufficient amounts on calcareous soils. To demonstrate if calcicole, calcifuge and 'soil indifferent' species differ in Fe nutrition dynamics, samples of such species were transplanted on a slightly acid silicate soil (pH BaCl2 ca 4.0) and on a calcareous soil (pH BaCl2 ca 7.2). Plants were grown in a computer-controlled greenhouse at a soil moisture content of 50-60% water holding capacity and with additional light (ca 160 mu E s(-1) m(-2), 12 h d(-1)) if ambient light was < 120 mu E s(-1) m(-2). The calcifuge species developed chlorosis when grown on the calcareous soil, whereas the other species did not. Calcareous-soil grown plants had less 1,10-phenanthroline extractable Fe in their leaf tissues than the silicate-grown plants whereas total leaf Fe showed more species specific properties. The ratio of 1;10-phenanthroline extractable to total Fe in the leaves was significantly lower in the calcifuges than in the calcicoles when grown on the calcareous soil. 'Soil indifferent' species did not differ much from the calcicoles. Root Fe, fractioned as DCB extractable 'plaque' on the root surface and Fe remaining in the root after DCB extraction, showed no distinct pattern of DCB-Fe related to the different categories, but remaining root Fe tended to be lower in the calcifuges compared to the two other categories. Leaf colour estimated by a colour scale correlated well with chlorophyll a + b content measured in the leaves of two calcifuges. Leaf P concentrations did not differ between the different categories but were more species dependent. We conclude that chlorosis in calcifuge species is related to an immobilization of Fe in physiologically less active forms in the tissue, if plants are forced to grow on a calcareous soil, whereas calcicole and 'soil indifferent' species are able to retain a much higher share of their leaf Fe in metabolically active form. This probably decreases the vitality and may exclude calcifuge plants from calcareous soil. We consider this property, previously almost unconsidered in an ecological context, as important to the calcifuge-calcicole behaviour of plants