from the article: Abstract Based on a review of recent literature, this paper addresses the question of how urban planners can steer urban environmental quality, given the fact that it is multidimensional in character, is assessed largely in subjective terms and varies across time. The paper explores three questions that are at the core of planning and designing cities: ‘quality of what?’, ‘quality for whom?’ and ‘quality at what time?’ and illustrates the dilemmas that urban planners face in answering these questions. The three questions provide a novel framework that offers urban planners perspectives for action in finding their way out of the dilemmas identified. Rather than further detailing the exact nature of urban quality, these perspectives call for an approach to urban planning that is integrated, participative and adaptive. ; ; sustainable urban development; trade-offs; quality dimensions
Worldwide, coral reefs are rapidly declining due to increased sea water temperatures and other environmental stresses (Figure 1). To counter the extinction of major coral reef building species on the island of Bonaire, the non-profit organization Reef Renewal Foundation Bonaire is restoring degraded reef sites using corals that are grown in local nurseries. In these nurseries, corals are propagated on artificial trees using fragmentation. After 6-8 months of growth in the nursery, the corals are transplanted to degraded reef sites around the island. Over the years more than 21.000 corals have been outplanted to reef restoration sites in this way. These corals show high survivorship under natural reef conditions but remain under threat by environmental disturbances, such as increased water temperatures, diseases, and competition with macroalgae. A promising intervention to increase reef persistence and resilience is to manipulate the coral-associated microbiome. At present, the composition of the microbiome in nursery-reared and outplanted corals on Bonaire is unknown. The aim of the current project is to identify and isolate naturally occurring beneficial bacteria that may stimulate the resilience of these corals. Our key objectives are: 1) to assess the presence of functionally beneficial bacteria in corals in nursery and restoration sites on Bonaire using metagenomic screening. 2) to design culture strategies to isolate these functionally beneficial bacteria. In the future, a selection of these beneficial bacteria can be applied to the corals to increase their resilience against environmental disturbances.
Many Caribbean reefs have shifted from coral-dominated to algal-dominated ecosystems. The high algae cover reduces coral recruitment, making the reef unable to recover from other disturbances and resulting in flatter reefs with lower biodiversity. One of the reasons for the proliferation of algae is a mass die-off of the herbivorous sea urchin Diadema antillarum in the early 1980s. Natural recovery of Diadema populations is slow to non-existent, making active restoration of this important grazer a top priority in Caribbean coral reef management, especially since Diadema densities were reduced by another mass mortality event in 2022. The marine park organizations of Saba and St. Eustatius want to restore Diadema populations by restocking cultured individuals. However, important knowledge gaps need to be addressed before large numbers of Diadema can be restocked on the reef. Current culture methods can only produce a limited number of competent larvae. In addition, only 8% of the settlers survive and after restocking, survival on the reef is low as well. In the RAAK PRO Diadema II project, the bottlenecks in Diadema culture will be addressed by comparing larval survival across multiple culture methods and investigating the relation between larval size and post-settlement survival. Growing-out juveniles at sea is likely to help prepare them for life in the wild, while restocking at an optimal size might also increase survival. Finally, a thorough restocking site selection based on high shelter availability and settlement rates will increase the long-term Diadema densities. The acquired knowledge and developed practices will be verified in a larger scale restocking experiment involving at least 5000 Diadema urchins. By restoring Diadema populations through restocking, macroalgae will be more intensively removed and corals will have a chance to settle and to survive, increasing the ability of the reef to cope with other stressors.
Woningcorporaties (woco’s) trachten een bijdrage te leveren aan een duurzaam gedreven, volledig circulaire economie in 2050. Daartoe voeren zij tools in zoals kennis over circulair bouwen of ketensamenwerking. Die verzameling tools wordt in dit onderzoek levenscyclusdenken genoemd. Het invoeren van levenscyclusdenken vraagt om een systemische verandering die complex is en transdisciplinair en praktische veranderingen op alle hiërarchische lagen binnen de woco. Daartoe is een dialoog nodig tussen die lagen, die momenteel ontbreekt. Dit leidt tot de onderzoeksvraag: Op welke wijze kan binnen de interne keten van woningcorporaties de dialoog worden gefaciliteerd over het structureel invoeren van levenscyclusdenken? Binnen het consortium van woningcorporaties (Wonion, Mitros), partners (HEMUBO, Van Wijk Vastgoedonderhoud) en experts (dr. ir. Ad Straub en Gijs van Mil) ontsluiten we een dialoog tussen projectleider, asset manager, directie en/of beleids- of strategiemedewerker en financiën over de gevolgen van levenscyclusdenken op de interne organisatie van woningcorporaties. Vervolgens wordt onderzocht of SNA als basis kan dienen voor een dialoogtool die in een groter onderzoek kan worden doorontwikkeld. De beoogde resultaten zijn: 1) Een leer- en bewustwordingsproces onder beroepsprofessionals uit verschillende hiërarchische lagen en afdelingen van woco’s door het openen van de dialoog over de betekenis van levenscyclusdenken in hun werkpraktijk; 2) Een visuele omschrijving (SNA) van de complexiteit van levenscyclusdenken bij woco’s; 3) Netwerkvorming en vraagarticulatie voor het opstarten van een groter project (bijv. RAAK-Publiek) waarin de bredere productieketen wordt meegenomen; 4) Een digitaal prototype (app) dat woco’s in staat stelt zelf een SNA te maken om de dialoog op gang te brengen. Naast doorwerking in onderzoek werkt het project direct door in de onderwijspraktijk van de HU-Master of Urban Area Development. De hierboven genoemde woningcorporaties zijn opdrachtgever voor masterstudenten. Het activiteitenplan is gekoppeld aan de looptijd van de cursus “Strategisch beheer”.
