We investigated the pollination of Habenaria tridactylites, an endemic orchid of the Canary Islands. The entirely green, widely open flowers have a long spur containing nectar. We carried out... Show moreWe investigated the pollination of Habenaria tridactylites, an endemic orchid of the Canary Islands. The entirely green, widely open flowers have a long spur containing nectar. We carried out fieldwork, a molecular clock analysis, herbarium surveys, identified pollinators by both morphology and DNA barcoding, and measured the length of floral spurs and insect tongues using a combination of traditional and innovative micro‐CT scanning methods to 1) determine the pollinator of this orchid and 2) investigate correlations between local mean spur length and age, altitude and longitude of the island. Habenaria tridactylites was found to be pollinated on Tenerife by both small and intermediate sized moth species with variable tongue lengths and mostly belonging to Geometridae and to a lesser extent Crambidae, Erebidae, Noctuidae and Tortricidae. Of the sixteen moth species identified, nine are endemic to the Canary Islands or Macaronesia. The different local populations of H. tridactylites on the islands of Gran Canaria, El Hierro, La Gomera, La Palma and Tenerife with different ages and distances from mainland Africa, did not show a significant correlation of mean spur length and altitude, but did show a significant and positive linear correlation with longitude and the geological age of the island. The latter is congruent with the evolutionary arms race theory first proposed by Darwin, suggesting that flowers gradually evolve longer spurs and pollinators longer tongues. Show less
Inghels, D.; Dullaert, W.; Aghezzaf, E.H.; Heijungs, R. 2019
Future global copper demand is expected to keep rising due to copper's indispensable role in modem technologies. Unfortunately, increasing copper extraction and decreasing ore grades intensify... Show moreFuture global copper demand is expected to keep rising due to copper's indispensable role in modem technologies. Unfortunately, increasing copper extraction and decreasing ore grades intensify energy use and generate higher environmental impact. A potential solution would be reaching a circular economy of copper, in which secondary production provides a large part of the demand. A necessary first step in this direction is to understand future copper demand. In this study, we estimated the copper demand until 2100 under different scenarios with regression and stock dynamics methods. For the stock dynamics method, a strong growth of copper demand is found in the scenarios with a high share of renewable energy, in which a much higher copper intensity for the electricity system and the transport sector is seen. The regression predicts a wider range of copper demand depending on the scenario. The regression method requires less data but lacks the ability to incorporate the expected decoupling of material use and GDP when the stock saturates, limiting its applicability for long-term estimations. Under all considered scenarios, the projected increase in demand for copper results in the exhaustion of the identified copper resources, unless high end-of-life recovery rates are achieved. These results highlight the urgency for a transition towards the circular economy of copper. Show less
Idle brownfields in urban settings are potential resources that could be put to productive use, meeting the goals of urban intensification, helping to curb urban sprawl on the periphery and... Show moreIdle brownfields in urban settings are potential resources that could be put to productive use, meeting the goals of urban intensification, helping to curb urban sprawl on the periphery and benefiting communities living around sites. Various decision support tools exist in order to evaluate redevelopment scenarios. Spatial decision support systems have recently been developed to aid in evaluating the implications of the physical attributes of redevelopment scenarios, with a limited focus on the proximity of essential amenities to the local community. The application of proximity analysis in this context supports stakeholders in determining which social amenities are furthest from the local community and the extent to which including such amenities on-site would benefit the local community. A geographic information system based proximity analysis approach is presented specifically for this purpose. The distribution of walking distances for local households is compared to scenarios in which specific social amenities are included on-site. The approach is demonstrated using an abandoned brownfield case study in the Flemish region of Belgium. The local community would benefit most from having a doctor and pharmacy on-site in terms reduced walking distance. The inclusion of other amenities on-site such as employment, schools, green space, meeting places and shops also shortens walking distances for the local community but to a limited extent in comparison to a doctor and a pharmacy. 'Walking distance' is an indicator that is easily understood by stakeholders and the approach lays the foundation for more detailed analyses that would include frequency of visits. Show less
Mendoza Beltran, M.A.; Prado, V.; Font Vivanco, D.; Henriksson, P.J.G.; Guinee, J.B.; Heijungs, R. 2018
