Urban greening roundup

I have a bunch of urban planning, urban greening, landscape architecture and engineering journals in my RSS feed. Sometimes a lot of time goes by in between articles that I find interesting. But today an interesting cluster popped up, so here are a handful of highlights. The words below are my musings, not necessarily a summary of the papers. Click through if you are interested.

  • From Landscape and Urban Planning, Intensifying drought threatens the heat-regulating capacity of urban vegetation: Trees, parks, and soil cool cities through both shade and evapotranspiration. But for evapotranspiration to work and for the vegetation to persist long-term, there has to be water. There are going to be some areas where there is not enough water in an absolute sense, and others where there is enough water in a year-round water balance sense, but it is not stored during wet periods and provided to the vegetation during the dry periods in between the wet periods. Then there will be some lucky areas that are both hot and have plenty of water most of the time, although even there you may have an infrequent drought severe enough to kill vegetation without irrigation.
  • From Earth’s Future, Urban Landscape Irrigation and the Future of Sustainable Cities: Compared to agriculture, irrigation in urban areas is very ad hoc and not very scientific. Beyond that, and I don’t know whether this article gets into it, a lot of irrigation is done with drinking water. In an ideal world, you would capture every drop of rainfall and use it for something useful. You would deliver and use drinkable water in homes and businesses as efficiently as practical, and treat the resulting wastewater only to the state necessary to use it for irrigation. Then you would theoretically irrigate only at the rate of evaporation. All this requires a level of plumbing and real-time control implemented in a million decentralized locations with different owners/stakeholders and different types of land use. Maybe some sort of positronic brain could help, but it’s a heavy lift in the near-term.
  • From Urban Forestry and Urban Greening, Assessing patterns and gaps in recent urban nature and biodiversity planning across 25 European cities: The European Union has taken a heavy-handed regulatory approach as it tends to do, requiring urban areas to develop and submit “Urban Nature Plans” for approval. This appeals to me as a proponent of both planning and managing urban ecosystem service provision. I like the idea of weaving green infrastructure planning into the bigger picture of urban infrastructure planning, then tying public infrastructure funding to implementation of projects that are consistent with the plan, particularly in times when private-sector growth slows down and there is a consensus that government economic stimulus is needed. This is all rational, evidence-based, and non-partisan in my mind. I also recognize it is nowhere near politically viable in the near term in the United States or oh-so-practical developed Asia, let alone developing countries.
  • From Trends in Ecology and Evolution, The carbon cost of forest fragmentation: Size matters: In my fantasy world of rational policies and plans, we can start thinking both about total habitat and habitat connectivity within and across cities. Here is some evidence that connectivity has a multiplier effect on carbon sequestration that goes beyond just size. It makes sense, if vegetation around the edges of habitat tends to be more stressed and less productive. Of course, there is a longstanding debate about the relationship between productivity, and biodiversity or habitat quality. An algae bloom or a hillside covered in kudzu is pretty productive, for example, and the opposite of biodiverse.
  • From Ecological Engineering, Assessing the role of wildlife ecological corridors in restoring functional connectivity of road-fragmented habitats using a stochastic movement model and scenario simulation: There is a fair amount known about corridors and connectivity, although not so much in urban environments. (I don’t normally toot my own horn, but since this is really something I have looked into that many others have not, feel free to have a look at Chapter 6 in my dissertation. No pressure. Some day I would love to distill this into a concise seminal academic paper, but I don’t have the bandwidth or library access these days.) People are starting to use agent-based, stochastic simulation in addition to older approaches based mostly on static land use/land cover analysis, which I find interesting.

Leave a Reply

Your email address will not be published. Required fields are marked *