Urbanisation through the process of habitat loss and fragmentation has caused drastic changes in ecosystem dynamics around the world. Many species can no longer survive in these urban areas; however there are those species that have been able to survive and in fact thrive in the newly created habitats. With increasing urbanisation it is important that animals are able to adjust to a life in close association with humans. One such group of organisms which has adjusted well to urbanisation is the suborder Megachiroptera (Chiroptera). Some species from this suborder have benefited from increased food and roost resources in certain urban areas. Exotic fruiting plants (introduced purposely and accidentally) as well as increased cultivated gardens have provided additional food sources in some urban environments, while man-made structures, and increased suitable vegetation, have provided additional roosting opportunities. Although these urban dwelling species live in close association with humans, very little is known of their ecology in urban areas. Wahlberg's epauletted fruit bat Epomophorus wahlbergi is one such species of which little is known of its suburban ecology despite its increased presence in many urban areas. This study on the ecology of E. wahlbergi was conducted from February to October 2011 in the urban environment of Pietermaritzburg, South Africa. The aim was to examine foraging movements and habitat use of E. wahlbergi in this urban environment. The objectives were to determine seasonal differences in foraging movements and home range sizes in this urban environment. In addition the roosting dynamics and roost characteristics of E. wahlbergi in this urban environment were determined. In late summer, it was found that individual E. wahlbergi movements ranged considerably, with some bats making extensive flights to different parts of town while others stayed in particular areas throughout; no bats were recorded to have left the urban environment. Some of the larger distances covered in a single night's movements were two and five km. In late summer roosting fidelity varied between individual bats; all the individual bats changed their roosts at least once during late summer. Some individuals had as many as three known daytime roost sites. There was a difference in home range size between the sexes; with females occupying a larger home range size than males. This variation in movement patterns of individual bats suggests that their social interactions, roost site preferences, or dietary preferences vary between individuals in late summer. A significant difference in home range size and habitat use by E. wahlbergi was found between winter and spring, with home range sizes being larger in winter. The increased home range sizes and habitat use in winter were a consequence of bats feeding on the fruits of the alien invasive Syringa (Melia azedarch) with few other trees in fruit. Consequently bats had to move greater distances for food in winter. In spring, fruit availability was greater and more varied including both indigenous and exotic fruits. Consequently in winter, the bats were more reliant on a few fruiting species to meet their dietary requirements than during spring. Bats changed their roosts regularly in summer, winter and spring. There was considerable variation in roost temperatures however roost temperatures were higher than ambient temperatures. Roosts in man-made structures were higher in temperature than those in natural vegetation. This study suggests the importance of temperature in the selection of daytime roosts, however other factors such as predator avoidance and proximity to food resources are also considered in selection of daytime roosts. Within the order Chiroptera, species from the suborder Microchiroptera have generally not been well represented in urban areas, it is important that the reasons for this be better understood. Further research is still required to better understand the ecology of urban dwelling species as well as to understand the reasons why many species are not able to adjust to urban environments. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Winnipeg is a spatially, culturally, psychologically and visually fragmented city, particularly due to the vehicular-oriented growth which has engendered segmented land-use, dismantled walkable networks and provoked disconnection between culture and nature as well as within nature itself. In particular, the displacement of daily life from the complex web of interrelationships in ecosystems, which are essentially the mechanisms supporting our existence, should be the primary concern of urban design. In order to resolve this critical issue, this practicum will isolate and examine a problematic site while deconstructing fragmentation into specific causes, namely pollution, habitat degradation, placelessness and lack of urban ecological education. Concluding that this condition is ultimately created by our own fragmented thinking, the production of pragmatic solutions which continually evoke further fragmentation, I present a series of solutions to these challenges in the form of a landscape architectural design proposal for the City of Winnipeg.

Swan Lake watershed, a sub-catchment of the salmonid bearing Colquitz Creek watershed located in the municipality of Saanich, on southern Vancouver Island, British Columbia, Canada, was studied to characterise the linkages between urbanisation and ecological health and resilience. Although rarely applied in watershed ecology, resilience (the ability to absorb disturbances without the loss of ecosystem identity) offers a useful construct in this case study to understand the effects of urban development over the past 150 years, and to outline some principles for integrated, watershed-scale management. Baseline landscape characteristics and processes of historical land-use were determined using paleoecology (pollen analysis) and historical records. Watershed health was assessed using: a Proper Functioning Condition assessment of riparian-wetland and stream channels; vegetation community mapping; vegetation plots; surface flow hydrology; and water quality analyses. Vegetation and lake hydrographs were compared with less disturbed reference ecosystems. Findings are discussed in terms of alternative stable state models and energy dissipation at the site and landscape scale. Analysis of the data revealed that over the past 150 years, forest clearing, agriculture, transportation infrastructure, and non-point source pollution have transformed the landscape and substantially altered the water and energy balance. Impervious surfaces and cleared land (covering 25% and 35% of the watershed, respectively) are inferred to have reduced latent heat dissipation of solar energy, an important landscape-scale process affecting resilience to climate change. Degraded stream channels represent reduced ecosystem services and lost social/economic value. The stream/lake hydrographs revealed a typical, urban flashy profile that exacerbates channel erosion and non-point source pollution, while excessive lake stage drawdown is also evident. Water quality is characterized by historic and ongoing excessive nutrient loading and associated cultural eutrophication, heavy metal pollution, and ecosystem “ageing” due to dissolved solids runoff. At the site level, invasive species, particularly reed canarygrass, dominate Swan Lake wetlands, whereas the pollen record shows abundant woody shrubs and associated species (some of which are now extirpated from the site) and an absence of grass; this helps to establish a rationale for vegetation management. Based on the findings of the above studies and according to a proposed conceptual model with assessment criteria in five categories (water, vegetation, energy, soil and nutrients), Swan Lake watershed has impaired ecological health and is not resilient to disturbances such as extreme climate/weather events. Future watershed management should therefore mimic the hydrological function and energy balance of the pre-development conditions.

Field research was carried out in the community of Notre Dame de Grace, an urban environment typical of the kind in which more and more older women will reside as Canada's population ages. Results of a questionnaire administered to 232 older urban dwellers demonstrate there are significant differences, especially with regard to fearfulness, in the ways in which elderly women who live alone, elderly women who do not live alone and elderly men know and use urban environments. Recommendations are made for changes to the planning process which would result in urban communities better suited to the needs of elderly women. / Anthony Gidden's structuration theory is applied as a framework for explaining why older women are more fearful than elderly men, and why older women alone are the most fearful group. Deficiencies in feminist and gerontological approaches are identified, and an argument is made for greater integration of these perspectives.

Thesis (doctoral)--Rijksuniversiteit te Groningen, 1999. / Includes bibliographical references (p. [339]-379) and index.

Typescript. Includes vita and abstract. Includes bibliographical references (leaves 107-115). Also available online.

Μια πόλη συνίσταται από τρία επίπεδα οργάνωσης: το φυσικό, το τεχνητό και το κοινωνικό περιβάλλον, τα οποία βρίσκονται σε συνεχή αλληλεπίδραση μεταξύ τους και αποτελούν τη βάση για την ανάπτυξή της. Η ισορροπία των τριών αυτών επιπέδων οργάνωσης διαταράσσεται ως αποτέλεσμα της έντονης αστικοποίησης, η οποία χαρακτηρίζει τα αστικά οικοσυστήματα και συνδέεται παγκοσμίως με την αλλαγή της χρήσης και του τρόπου κάλυψης της γης. Τα αστικά περιβάλλοντα πρέπει να διαχειρίζονται βάσει σχεδιασμού, ο οποίος θα λαμβάνει υπ‟ όψιν τα οικολογικά στοιχεία μιας περιοχής, όπως είναι για παράδειγμα η ξυλώδης χλωρίδα της. Η παρούσα διδακτορική διατριβή, η πρώτη στο είδος της για τον ελληνικό χώρο, στηρίζεται στη γνώση και στις αρχές της οικολογίας πόλεων και του αστικού σχεδιασμού. Έχει ως σκοπό να ερευνήσει την καλλιεργούμενη ξυλώδη χλωρίδα (δέντρα, θάμνους και ξυλώδη αναρριχώμενα) και την αυτοφυή εξάπλωσή της στην πόλη της Πάτρας και να εξετάσει εάν και με ποιο τρόπο οι τύποι αστικών βιοτόπων, δηλαδή φυσιογνωμικά ομοιόμορφες αστικές περιοχές με χαρακτηριστική δόμηση και ελεύθερους χώρους, μπορούν να χαρακτηρισθούν από τις καλλιεργούμενες ξυλώδεις συστάδες τους, καθώς και να διατυπώσει προτάσεις διαχείρισης για την ποιοτική αναβάθμισή τους. Για το σκοπό αυτό έγινε προσδιορισμός της ξυλώδους χλωρίδας της πόλης, χλωριδική, βιολογική και χωρολογική ανάλυση των taxa, καταγραφή της φαινολογίας τους και εκτίμηση της συχνότητας και σταθερότητάς τους, λαμβάνοντας υπ‟ όψιν τη σχέση μεταξύ της οικολογίας φυτών, του τύπου δόμησης και της χρήσης γης. Ως περιοχή έρευνας επιλέχθηκε η πόλη της Πάτρας, γιατί αφενός η καλλιεργούμενη χλωρίδα της δεν έχει μελετηθεί και αφετέρου παρουσιάζει τα χαρακτηριστικά μιας τυπικής ελληνικής μεγαλόπολης, κυρίως όσον αφορά στη δόμηση και στους ελεύθερους χώρους. Διακρίθηκαν 8 διαφορετικοί τύποι αστικών βιοτόπων, όπως Ολιγώροφες κατοικίες συνεχούς και ασυνεχούς δόμησης, Πολυώροφες κατοικίες συνεχούς και ασυνεχούς δόμησης, Ολιγώροφες και πολυώροφες κατοικίες πανταχόθεν ελεύθερης δόμησης, Βίλες, Εργατικές κατοικίες και Πάρκα. Στη συνέχεια επιλέχθηκαν 54 περιοχές μελέτης κατανεμημένες σε όλη την περιοχή έρευνας, συνολικής έκτασης 2.374,4 στρεμμάτων, έτσι ώστε να αντιπροσωπεύουν τα χαρακτηριστικά του εκάστοτε τύπου αστικού βιοτόπου και καταγράφηκαν σε αυτήν 218 taxa. Ο αριθμός αυτός των ξυλωδών taxa που εμφανίζεται στην περιοχή έρευνας, θεωρείται χαμηλός σε σύγκριση με άλλες πόλεις της κεντρικής Ευρώπης, όπου έχουν εκπονηθεί αντίστοιχες μελέτες. Αυτό αποδίδεται στην πυκνή δόμηση που χαρακτηρίζει τον πυρήνα της πόλης της Πάτρας, αλλά και γενικά στις λιγοστές επιφάνειες πρασίνου. Όσον αφορά στην καταγωγή των ξυλωδών taxa το ποσοστό των ξενικών και υβριδίων στην Πάτρα ανέρχεται σε 61,5% (125 taxa και 9 taxa αντίστοιχα) με τα ασιατικά και αμερικάνικα taxa να εμφανίζουν υψηλά ποσοστά (26,9% και 17,2% αντίστοιχα), ενώ των ιθαγενών σε 38,5% (84 taxa). Η κατανομή των βλαστητικών μορφών εντός της περιοχής έρευνας διαφέρει από εκείνη άλλων ευρωπαϊκών πόλεων. Έτσι, στην Πάτρα κυριαρχούν οι δενδρώδεις μορφές με ποσοστό 55,5% έναντι των θαμνωδών, ενώ σε πόλεις της κεντρικής Ευρώπης υπερτερούν οι θαμνώδεις μορφές. Όσον αφορά στην άνθηση, παρατηρείται μια παράταση στην περίοδο ανθοφορίας στο σύνολο των ξυλωδών ειδών. Το γεγονός αυτό αντανακλά την ανθρώπινη παρέμβαση στο φυσικό τοπίο και την προσπάθεια του ανθρώπου να εξασφαλίσει ανθοφορία όλο το χρόνο, αποτρέποντας παράλληλα τη δημιουργία μονότονων περιοχών. Τα φυλλοβόλα υπερτερούν με μικρό ποσοστό έναντι των αειθαλών. Αυτό οφείλεται στην παρουσία ενός σημαντικού ποσοστού φυλλοβόλων taxa, που ανήκουν στις δύο πλουσιότερες σε taxa οικογένειες, δηλαδή σε αυτές των Rosaceae και Leguminoseae. Όλα σχεδόν τα ξυλώδη taxa σχηματίζουν καρπούς, εκτός από ένα μικρό ποσοστό (5,2%). Το 40,8% των taxa στο σύνολο της ξυλώδους χλωρίδας φέρει σαρκώδεις καρπούς, οι οποίοι αποτελούν σημαντική πηγή τροφής για την ορνιθοπανίδα της περιοχής, αλλά και τρόπο εξάπλωσης των taxa μέσω των σπερμάτων τους. Το ποσοστό των καλλωπιστικών taxa στο σύνολο της χλωρίδας είναι σαφώς μεγαλύτερο από αυτό των ξυλωδών taxa με εδώδιμους καρπούς (76,8% και 22,6% αντίστοιχα), γεγονός που αντανακλά μια τάση προτίμησης των κατοίκων για καλλωπιστικά taxa και μάλιστα ξενικής καταγωγής, προβάλλοντας με αυτόν τον τρόπο την παρούσα οικονομική και κοινωνική τους κατάσταση. Όσον αφορά στη σχέση μεταξύ αριθμού ξυλωδών taxa και μεγέθους επιφάνειας δεν προκύπτει θετική συσχέτιση μεταξύ τους, σε αντίθεση με πόλεις της Κ. Ευρώπης, επειδή, σύμφωνα με τη θεωρία «small island effect», στις μικρές περιοχές μελέτης η επιφάνεια παύει να είναι ο καθοριστικός παράγοντας. Τaxa που να εμφανίζονται και στις 54 περιοχές μελέτης, δηλαδή με σταθερότητα 100%, δεν απαντούν. Όσα taxa εμφανίζονται με μεγάλη σταθερότητα, όπως τα Morus alba, Nerium oleander και Ailanthus altissima, είναι συγχρόνως και εκείνα με το μεγαλύτερο αριθμό ατόμων, γεγονός που υποδηλώνει ότι τα taxa αυτά ευνοήθηκαν από τη φύτευσή τους. Όσον αφορά στη σύνθεση των ειδών των τύπων αστικών βιοτόπων της Πάτρας υπάρχει μεγάλη ετερογένεια. Χαρακτηριστικό είναι ότι μερικά είδη εμφανίζουν πολύ μεγάλη σταθερότητα σε ορισμένους τύπους βιοτόπων, ενώ σε άλλους πολύ μικρή ή καθόλου. Το Acer pseudoplatanus αποδείχθηκε το χαρακτηριστικό είδος μόνο για τις πολυώροφες κατοικίες ασυνεχούς τύπου δόμησης. Από τα παραπάνω συμπεραίνεται ότι οι τύποι των αστικών βιοτόπων της Πάτρας μπορούν να διαφοροποιηθούν με βάση τον αριθμό, όχι όμως και με βάση τη σύνθεση των ξυλωδών ειδών που εμφανίζονται σ‟ αυτούς. Η αυτοφυόμενη ξυλώδης χλωρίδα της Πάτρας εμφανίζεται με ένα ποσοστό 17,9% επί της συνολικής ξυλώδους χλωρίδας και είναι συγκρίσιμη με αυτή που απαντά σε πόλεις της Κ. Ευρώπης, όπου έχουν γίνει αντίστοιχες μελέτες. Και εδώ παρατηρείται σαφής υπεροχή των ξενικών (53,8%) έναντι των ιθαγενών, αλλά και των δενδρωδών μορφών έναντι των θαμνωδών, όπως παρατηρήθηκε και στη συνολική χλωρίδα. Τα πιο σταθερά και συγχρόνως τα πιο πλούσια σε αριθμό ξενικά αυτοφυόμενα ξυλώδη taxa είναι τα Morus alba, Ailanthus altissima, Vitis vinifera ssp. vinifera και Hibiscus syriacus και από τα ιθαγενή το Ligustrum vulgare. Οι μελετηθέντες τύποι αστικών βιοτόπων παρουσιάζουν σχετική ομοιογένεια ως προς τον αριθμό των αυτοφυόμενων ξυλωδών taxa, γεγονός που παρατηρείται και σε πόλεις της Κ. Ευρώπης. Όσον αφορά στη σχέση μεταξύ αριθμού αυτοφυόμενων ξυλωδών taxa και μεγέθους επιφάνειας, δεν προκύπτει θετική συσχέτιση μεταξύ τους. Για να αξιολογηθεί η κατάσταση των τύπων αστικών βιοτόπων της Πάτρας, εκτιμήθηκε η αξία των παραγόντων εκείνων που ενισχύουν ή αποδυναμώνουν το χαρακτήρα τους. Τέτοιοι παράγοντες είναι κυρίως το μικροκλίμα/αέρας (θερμοκρασία, αερισμός, εκπομπές καυσαερίων) το έδαφος, το νερό, το φυσικό περιβάλλον (χώροι πρασίνου), η κυκλοφορία (πολύ αυξημένη – μικρή), ο θόρυβος (ηχορύπανση), οι κίνδυνοι για τη δημόσια υγεία (μικροκλίμα, εκπομπές καυσαερίων, κυκλοφορία, θόρυβος), οι χώροι αναψυχής, ο βαθμός εκμετάλλευσης (ενέργειας, επιφάνειας, κτισμάτων) καθώς και κοινωνικο-οικονομικοί παράγοντες (μείξη χρήσεων γης, π.χ. εργασία, κατοικία). Για τον καθένα από αυτούς τους παράγοντες καθορίστηκε μια 5-βάθμια κλίμακα αξιών. Μέσα από την εκτίμηση των αξιών των τύπων αστικών βιοτόπων προσδιορίσθηκαν τα πλεονεκτήματα, αλλά και τα προβλήματά τους. Την υψηλότερη οικολογική αξία την έχουν οι τύποι αστικών βιοτόπων που χαρακτηρίζονται από τον πανταχόθεν ελεύθερο τύπο δόμησης (Ολιγώροφες και πολυώροφες κατοικίες πανταχόθεν ελεύθερου τύπο δόμησης, Βίλες, Εργατικές Κατοικίες) και τα Πάρκα. Οι τύποι αστικών βιοτόπων που χαρακτηρίζονται από το συνεχή και τον ασυνεχή τύπο δόμησης εμφανίζονται μεν οικολογικά υποβαθμισμένοι, αλλά είναι κοινωνικοοικονομικά αναβαθμισμένοι. Γενικά όμως, όπου υπάρχει έντονη εκμετάλλευση του εδάφους υπάρχει και αυξημένη οικονομική δραστηριότητα, ενώ ταυτόχρονα υποβαθμίζεται η ποιότητα του φυσικού περιβάλλοντος. Οι τύποι αστικών βιοτόπων που χαρακτηρίζονται από έντονη εκμετάλλευση πρέπει να βελτιώσουν για παράδειγμα το μικροκλίμα, την ποιότητα του αέρα και του εδάφους τους. Η ξυλώδης χλωρίδα των πόλεων δεν είναι ο μοναδικός τρόπος βελτίωσης της ποιότητας των τύπων αστικών βιοτόπων, αλλά σίγουρα είναι ένας τρόπος θετικής παρέμβασης για την αναβάθμισή τους. Τα διαχειριστικά μέτρα που προτείνονται αφορούν στη βελτίωση του φυσικού, του τεχνητού και του κοινωνικού περιβάλλοντος. Περιλαμβάνουν προτάσεις διαχείρισης που στοχεύουν στην αποκατάσταση, βελτίωση και διατήρηση των παραγόντων εκείνων που επηρεάζουν την ποιότητα των τύπων αστικών βιοτόπων, με απώτερο σκοπό την υγιή και άνετη διαβίωση των κατοίκων της πόλης. / A city is formed by the interaction between natural, built and social environment. These three areas are fundamental for environmental development. Urbanization phenomenon around the world has been an important component of land use and land cover change and influences negatively the balance of those three areas. Management of urban environments must be based on urban planning, which takes into consideration the significant ecological components of an area, such as the woody plants. The present doctorate thesis, the first of its kind in Greece, is based on the knowledge and principles of the science of urban ecology and urban planning. The aim of the present study was to survey the woody species (trees, shrubs and woody climbers) of the city of Patras and to examine whether and in which way the urban structural units (defined as “areas with physiognomically homogenous character, which are marked in the built-up area by a characteristic formation of buildings and open spaces”) can be characterized by their planted woody stands. For that reason the spectra, combination, frequency and consistency of species were assessed, considering the relationships between plant ecology, biotope structure and land-use. The wider area of Patras‟ city was chosen as a study area, because there is a lack of knowledge on its cultivated flora and because it has the features of a typical Greek city concerning the formation of buildings and the open spaces. Eight urban structural units were identified within the city of Patras. These are Multi-storeyed attached housing, Multi–storeyed semi–detached housing, Low–rise attached housing (bungalows–two floors), Low–rise semi-detached housing (bungalows–two floors), Multi–storeyed and low–rise detached housing, Villas, Workers‟ housing, Parks (incl. squares and bocages). In total, 237,44 ha of urban land were studied thoroughly in the fifty-four study areas designated throughout the wider area of Patras city. 218 woody plants were recorded in the eight urban structural units studied. The number of woody species recorded in the study area of 237,44 ha is considered to be low when compared with that of central Europe, where similar studies have been undertaken. This low number is due to the very high building density found in the city centre and also to the limited number of green areas (e.g. parks). Concerning the origin of the woody species in the city of Patras non-native and hybrids dominate. The proportion accounts for 61,5% (125 taxa non-native and 9 taxa hybrids), of which the Asiatic (26,9%) and the American (17,2%) species are represented by high percentages in the woody flora of Patras. The native species represent the 38,5% (84 taxa) of the total woody flora. The life-form spectrum of the woody flora in the city of Patras differs from that recorded in other European cities. The proportion of trees (55,5%) is higher than that of shrubs in the city of Patras, whereas in central European cities shrubs dominate. The prolongation of the flowering period recorded in the study area reflects human attempt to assure blooming all year, so that monotony of the urban landscape can be avoided. The proportion of deciduous species is slightly higher than that of evergreen species. This is due to the presence of high proportions of deciduous species, which belong to the two richest in species families, to these of Rosaceae and Leguminoseae. Almost all woody species fruit, except from a small percentage (5,2%). A significant proportion (40,8%) of the total woody species form fleshy fruits, which are an important food source for the fauna of the study area, especially for birds. At the same time, the distribution of the woody species is assured. The proportion of cultivated woody plants (76,8%) is higher than that of woody plants forming edible fruits (22,6%). This fact reflects inhabitants‟ preference for ornamental plants non-native in origin, denoting social and financial standing. Statistical analysis proves the absence of a positive correlation between the species number and the size of the area. On the contrary, in central European cities the correlation is positive. This is explained by the „small island effect‟ theory, according to which, in small study areas the size of the area does not play the most important role, when species – area relationship is surveyed. Species appearing in all study areas, i.e. with 100% consistency, were not observed. Those species with high consistency, such as Morus alba, Nerium oleander and Ailanthus altissima, are also those with the highest frequency. This shows that these species benefited from them being planted. Floristic composition in the various urban structural units shows great heterogeneity as several species present high consistency in some structural units but low or zero consistency in others. Acer pseudoplatanus proved to be a characteristic species only within the urban structure of multi-storeyed semi-detached housing. Taking these findings into account, we conclude that the urban structural units of Patras can be differentiated based on the number of woody species recorded in each, but not on their floristic composition. Spontaneous diffusion could only be identified for 17,9% of the cultivated species. This proportion is comparable to that recorded in other central European cities, where similar studies have been undertaken. The proportion of non-native species (53,8%) is higher than that of native, and so is the proportion of trees in comparison to that of shrubs. Similar proportions have been also recorded for the total woody flora of the city of Patras. The most frequent non-native spontaneous woody species observed in Patras are Morus alba, Ailanthus altissima and Hibiscus syriacus. The commonest native spontaneous species in the city is Ligustrum vulgare. The urban structural units studied in Patras show relative homogeneity concerning the number of spontaneous woody species. This homogeneity is also observed in cities of central Europe. The correlation between the species number and the size of the area is negative. For the evaluation of the urban structural units in the city of Patras, the value of criteria that strengthen or weaken the character of the urban structural units was taken into consideration. Those criteria are mainly microclimate / wind (temperature, emissions), soil, water, natural environment (green spaces), traffic (heavy or not), noise (noise pollution), dangers for public health (quality of microclimate, emissions, traffic, noise pollution), degree of resources‟ exploitation (of energy, surface, buildings) as well as socio-economic criteria (land-use). For each of these criteria a 5 – degree scale of values was designated. This consideration of the values which affect the urban structural units enabled the definition of the advantages and the drawbacks of each urban structural unit. The urban structural units characterized by detached free building style (multi-storeyed and low-rise detached housing, villas, workers‟ housing) and parks are highly attractive and have high ecological properties. The urban structural units characterized by attached or semi-detached housing have low ecological properties but are socioeconomically benefited. Generally, high exploitation degree (of energy or soil) is related to social and economic integration. At the same time the quality of the natural environment is degraded. Urban structural units characterized by high exploitation in terms of soil, water and energy must upgrade not only their microclimatic conditions, but also the quality of air and soil. The contribution of the woody flora to the environmental development is significant. The management measures proposed, aim to upgrade the natural, built and social environment. They include management proposals that aim to the upgrade and conservation of specific parameters which affect the quality of the urban structural units. Such proposals could make a valuable contribution to the upgrade of the quality of city life.

Thesis (MS en S)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: An ever changing urban environment, limited economic opportunities and rising poverty, have brought into sharp relief the need for strategies that support the livelihoods of the poor. Urban areas are complex and dynamic systems. No town or city is immune from either external forces (globalisation) that dictate the need to adapt, or to internal pressures (the natural growth pattern of an urban population and rural-urban migration) that collectively can precipitate growth or decline. The formal sector cannot, in most instances, fulfil the need for secure, regular employment in the urban areas, which leads to increases in unemployment, gradual breakdown of basic services - visual evidence includes large squatter settlements in and around urban centres - and the not unlikely increase in food insecurity. There is no doubt that the future of urban centres is dependent on the effective absorption of the increasing number of urban dwellers into its environmental, economical and social structures, and public policy plays an important role in the success of this process. The important contribution of urban agriculture in bolstering food security of urban households raises critical planning issues. The spatial integration of our settlements is critical; it holds the potential to enhance economic efficiency and social development. Spatial strategies should be combined with economic and environmental programmes to form an integrated approach towards development. Urban agriculture could possibly catalyse broader developmental processes such as local economic development, whereby disadvantaged communities could potentially secure the benefits of employment and increase food security. The provision of opportunities for urban agriculture not only makes it possible to meet the food needs of the urban poor, but to also ensure sustainable human settlements. / AFRIKAANSE OPSOMMING: In die lig van 'n dinamiese stedelike omgewing, beperkte ekonomiese geleenthede en toenemende armoede, beklemtoon die nood aan strategieë wat die arm stedelike gemeenskap bevoordeel. Stedelike gebiede is ingewikkelde en dinamiese sisteme. Geen dorp of stad is vrygeskeld van eksterne invloede (globalisasie), óf van interne invloede (die natuurlike groeipatroon in 'n stedelike gebied en migrasie van platteland na stede) wat kollektief groei of verval van stede kan aanhits. Die formele sektor kan in die meeste gevalle nie aan die behoefte van vaste werksaanstelling in stedelike gebiede voldoen nie. Dit lei tot 'n toename in werkloosheid en die geleidelike afbreek in fundamentele basiese dienste - ooglopende bewys hiervan sluit die groot plakkerskampe in en om stedelike sentrums - en die nie onwaarskynlike toename in voedseltekorte. Daar is geen twyfel dat die toekoms van stedelike sentrums afhanklik is van die absorpsie van toenemende stedelinge in hul omgewings-, ekonomiese- en sosiale strukture, en openbare beleid speel 'n kardinale rol in die suksesvolle verloop van hierdie proses. Die belang van die bydrae van stedelike landbou tot die rugsteuning van versekering van voedselsekuriteit in stedelike huishoudings kompliseer beplanning geweldig. Die ruimtelike integtrasie van ons nedersettings is belangrik; dit het die potensiaal om ekonomiese vaardigheid en sosiale ontwikkeling te verbeter. Strategieë om ruimte te optimaliseer behoort gekombineer te word met ekonomiese- en omgewingsprogramme, om sodoende geïntigreerde benaderings tot ontwikkeling te vorm. Stedelike landbou kan moontlik n katalisator vir verreikende ontwikkelingsprosesse soos plaaslike ekonomiese ontwikkeling wees, waar minder-bevoorregte gemeenskappe werksversekering en -geleenthede het en daar ook voedsel-sekuriteit is. Die voorsiening van geleenthede vir stedelike landbou maak dit nie net moontlik om die behoefte aan voedsel van minder-bevoorregte stedelinge te bevredig nie, maar verseker ook langdurige, volhoubare stedelike nedersettings.

The world is faced with a population explosion, and cities are becoming ever larger. The world population will grow from its present 3500 million to more than 7 000 million by the year 2 000. The majority of cities are thus faced with the problem of housing vast numbers of people living in single family dwellings forming low density urban sprawl. Conditions are no different in South Africa where the present white population of about four million is expected to grow to between six and seven million by the year 2000. The present housing requirement (1970-75) for Whites, based on low and high population projections, is 32 732 and 40 150 houses respectively. From 1995-2000 the figures will have risen to 42 742 and 65 580 respectively. At that rate sprawl here will reach alarming proportions unless it can be curtailed by higher density housing. As the population trend does not seem likely to be reversed the problem lies in how to provide housing for an escalating population but at the same time to reduce urban sprawl and provide satisfactory living conditions.

A fragmentação de habitats em muitos casos limita o potencial de dispersão das espécies. Por esta razão, muitas iniciativas visando à conservação de espécies em paisagens fragmentadas envolvem o delineamento de corredores ecológicos entre manchas de hábitat. Neste trabalho, foi modelado um sistema de corredores entre manchas de mata remanescentes no mosaico urbano-rural de uma grande cidade no sul do Brasil (Porto Alegre, RS), tendo como organismo focal o primata Alouatta clamitans (bugio-ruivo) que está ameaçado de extinção. Nossos objetivos específicos são (a) demonstrar a importância dá conectividade para a presença das populações de bugio-ruivo nos fragmentos florestais em Porto Alegre; (b) detectar os fragmentos mais importantes para manter a conectividade funcional potencial da espécie; (c) desenhar um sistema de corredores potenciais, considerando a capacidade de dispersão do bugio-ruivo em diferentes tipos de manchas de paisagem e (d) propor um método para avaliação da qualidade de corredores, levando em consideração a variação do atrito à dispersão ao longo do traçado dos corredores e a existência de pontos críticos de vulnerabilidade ao longo dos corredores. A vulnerabilidade foi avaliada em função da paisagem vizinha a cada corredor, entendendo-se como vulnerabilidade a probabilidade de futura modificação ou interrupção do corredor devido a mudanças na paisagem vizinha. Foi verificada a existência da relação da conectividade funcional com a presença da espécie nos fragmentos florestais através do índice Integral index of connectivity - IIC. Através da porcentagem de importância do mesmo índice (dIIC) para cada fragmento arbóreo, identificou-se o morro São Pedro como mais importante para a manutenção da conectividade da paisagem. Além do morro São Pedro foram selecionados os fragmentos arbóreos maiores que 10 ha para a modelar corredores utilizando o algoritmo do caminho de menor custo. Utilizou-se dois parâmetros: grau de antropização que avalia o potencial de persistência dos corredores e o atrito que simula a resistência dos habitats ao deslocamento da espécie. Esses parâmetros foram utilizados nas análises de fracionamento para quantificar o número de interrupções no corredor e a qualidade do habitat interno. Os resultados da análise de fracionamento e a extensão foram usados na classificação de qualidade de cada corredor. Foram gerados 136 corredores com extensão entre 4 m e 4128 m, Observou-se que corredores com mais de 1000 m tendem a ser potencialmente mais fracionados. Setenta e três corredores mantiveram-se contínuos segundo o potencial de persistência. A análise da qualidade do habitat revelou que 120 corredores foram fracionados. A área total de habitat efetivo (classe arbórea/arbustiva) para o deslocamento foi reduzida em 41%. A análise de qualidade global revelou que 32% dos corredores são bons, 51% são medianos e 16,2% são ruins. O potencial de persistência revelou-se um método promissor de avaliar o potencial de alteração que o entorno tem em relação ao corredor. A análise de qualidade de habitat mostrou-se eficiente para identificar os corredores lineares de hábitat ou íntegros. O método pode auxiliar na tomada de decisão do custo-beneficio para investir em gestão e manejo de corredores lineares multi-habitat. / Habitat fragmentation limits possibility of species dispersai. Many initiatives aim at species conservation in fragmented landscapes involve the delineation of ecological corridors among habitat patches. Here, we modeled a corridor system among remnant forest fragments in the urban-rural mosaic of a large city in southern Brazil (Porto Alegre, RS), using the endangered primate Alouatta clamitans (brown-howler-monkey) as a focal species. Our specific aims were (a) to demonstrate the importance of connectivity for the presence of the brown-howler monkey in forest fragments; (b) to identify the most important fragments for maintenance of potential functional connectivity for the species; (c) to draw a potential corridor system, considering the species dispersai capacity in different habitat patches; and (d) to propose a new method of corridor quality evaluation, considering friction variation to disperse along corridors and the existence of vulnerable criticai points for the persistence of corridors. Vulnerability was evaluated in terms of neighboring landscape of each corridor (context), being defined as the probability of future corridor modification or interruption due to changes in the neighboring landscape. We examined the existence of a positive relation between functional connectivity and the species presence in forest fragments using the Probability of Connectivity index (dIPC). We identified the São Pedro hill as the most important area for the maintenance of landscape connectivity based on the dIPC. In addition to São Pedro hill, we selected the forest fragmentes larger than 10 hectares to model corridors using the least-cost distance algorithm. To assess vulnerability, we used two parameters: the antropization degree, which is a proxy for potential of corridor persistence, and the friction degree, which is a proxy for habitat resistance to the species dispersal. These parameters were used to examine the fractioning of corridors, that is, to quantify the number of actual or potential interruptions in corridor trajectory and its inner habitat quality. The results of the fractioning analyses and the corridor extension were used as attributes for ranking ali corridors in terms of quality. We generated 136 corridors with an extension between 4 m and 4128 m. Corridors with more than 1000 m tended to be potentially more fractioned, while seventy three corridors were kept uninterrupted according to persistence potential. Habitat quality analysis revealed that 120 corridors were fractioned. Total area of effective habitat (arboreal/shrubby class) to movements was reduced in 41%. The global quality analysis revealed that 32% of corridors are good, 51% are median and 16.2% are bad. Persistence potential appears to be a promising method to evaluate the potential for antropogenic modification imposed on corridors by their surrounding landscape. This method cari help in cost-benefit decision making for management of multi-habitat linear corridors.