Climate change will not leave the green lungs of our cities untouched
The Sustainable Cities Collective blog carries a post today about a German effort to identify the trees most likely to thrive in tomorrow's environment. Obviously, models show different conditions for different places. What trees will thrive in African cities, for example, where they often provide essential shade and shelter?
It is issues like this that are likely to be overlooked when we think about climate adaptation. Without people of vision like Klaus Körber, no one will pay attention to trees until theirs are dying, at which point it is a little too late to plan. Philips, the electronics conglomerate, has a competition underway for its "Livable Cities" award. One of the finalists, James Kitoya, proposes creating 45 ‘Shade Stands’ across Uganda’s capital, Kampala, to provide such shelter. (Sadly, it is running last in the voting).The streets of Bobo Dioulasso, Burkina Faso, are lined with shade trees. Photo courtesy of Guillaume and Pauline via Flickr, licensed under Creative Commons with some rights reserved (non-commercial use only, attribution required, no derivative works).
One thing that troubles me about the discussions of good tree species to use is that there doesn't appear to be any thought of invasiveness. For example, in the Sustainable Cities Collective article, Ailanthus is mentioned as a very "resistant" species. Is Ailanthus the tree of the future? Perhaps, but let's not make it a self-fulfilling prophecy just yet - it is highly invasive and corrosive to natural systems in North America (evidently less so in Europe). It undermines the resiliency of natural habitats by replacing a diverse system with monotypical stands (it is allelopathic). Nothing grows under it, it is almost impossible to eradicate, and it colonizes quickly (in Washington DC it is called the "ghetto palm" because vacant lots in the inner city quickly fill with the palm-like shoots of this rapidly growing tree species). So to plant Ailanthus is in a sense to opt for the "nuclear option". Not to say it isn't the right choice - but it is important to chose deliberately and carefully and to know what you're getting, because there's no turning back. What other features contribute to resilient cities that are being overlooked?
Amplify’d from sustainablecitiescollective.com
"Climate change will not leave the green lungs of our cities untouched. We already know that some species will not get along with the associated weather extremes in the long run, "said Klaus Körber of the Bavarian State Institute for Viticulture and Horticulture in Veitshöchheim, Germany.
With the predicted increase in extreme weather events the following aspects have to be considered more in the selection of trees:
• a firm fastening in the ground by a strong root system,
• the danger of wind damage and falling branches,
• the regeneration by shoots after storm damage and
• an extensive root system to prevent soil erosion.
Another important aspect: drought stressed plants are more susceptible to disease. "With the globalization of trade the infestation of plants with new diseases and pests is enormous. Previously robust, local species can be infected, too, "said Körber. According to the expert, it must be the goal, not always put on the same five or six main tree species, but to increase the diversity. "Only a broad base of suitable plant species and varieties reduces the risk that more new diseases and pests reduce the available range." With this claim there have been problems in the past by the debate on nature conservation and autochthony. Also exotic, recommended
species and varieties often weren’t available in the nurseries because there was little reliable demand from the municipalities. "For the city trees of the future, it will not be about which species have been growing here before, but what types thrive right under the changed conditions and work good as the green lungs of our cities in the long run," stressed Körber. "And for the nursery the change to new species on the one hand is a challenge, but on the other hand, it’s a great opportunity!"
Extremely resistant to the urban climate are trees such as Ginkgo, Gleditsia Tree-of-heaven (Ailanthus), Honey Berry (Celtis australis), Turkish Hazel (Corylus colurna) and Sophora. "But from past experience one shouldn’t not put too much on such exotica,” Körber stated. “First, in their homeland a number of diseases and pests exists that could follow their hosts. Second, there are significant differences between cultivars with respect to the resistance, too. Third, the growth form in some cases doesn’t meet the requirements of a street tree." Generally, the proportion of a certain tree species in a city should never be too high.
Contingency
More than half of humanity lives in cities now, and that ratio could rise to three-quarters by the end of the century. As a student of human and ecological resilience, it makes sense that I pay close attention to the urban environment. One of the sites I visit regularly is the Infranet Lab. It has posted what must be my favorite post of the year so far, "Infrastructural Opportunism, A Manifesto". You could view this as an architect or planner's take on resilience. I'm not sure that I understand scalar indifference and will have to work on it, but this is food for thought. I recommend a visit to Infranet Lab if you are looking for fresh perspectives on the urban environment. Oh, and I found a new job title (#2). Except that I'm still an apprentice.
Amplify’d from infranetlab.org
Arthur Jensen, played by Ned Beatty, in the 1976 film Network said: You have meddled with the primal forces of nature, Mr. Beale, and I won’t have it, is that clear?! You think you have merely stopped a business deal — that is not the case! The Arabs have taken billions of dollars out of this country, and now they must put it back. It is ebb and flow, tidal gravity, it is ecological balance! You are an old man who thinks in terms of nations and peoples. There are no nations! There are no peoples! There are no Russians. There are no Arabs! There are no third worlds! There is no West! There is only one holistic system of systems, one vast and immane, interwoven, interacting, multi-variate, multi-national dominion of dollars! petro-dollars, electro-dollars, multi-dollars!, Reichmarks, rubles, rin, pounds and shekels! It is the international system of currency that determines the totality of life on this planet! That is the natural order of things today! That is the atomic, subatomic and galactic structure of things today! And you have meddled with the primal forces of nature, and you will atone!
Buckminster Fuller, labeled a dilettante and a dabbler in his age, was instead the forerunner of a new breed of designer / thinker that we like to call the expert generalist. Long live the new expert generalists!
After a multi-day traffic jam in Hetaocun, China, Andrew Jacobs of the New York Times wrote: Stranded drivers chain-smoked, stomped their feet against the chill and cursed the government for failing to come to their rescue. As the night wore on, fuel lines froze and cellphone batteries died. The residents of Hetaocun, however, saw the unmoving necklace of taillights from their mountain village and got entrepreneurial. They roused children from their beds, loaded boxes of instant noodles into baskets and began hawking their staples to a captive clientele. The 500 percent markup did not appear to dent sales.
Donald Rumsfeld’s infamous 2002 speech yielded a term that now has its own Wikipedia entry: unknown unknowns. He said: [T]here are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don’t know we don’t know.
Daniel Plainview, played by Daniel Day-Lewis in the 2007 film There Will be Blood says: Drainage! Drainage, Eli, you boy. Drained dry. I’m so sorry. Here, if you have a milkshake, and I have a milkshake, and I have a straw. There it is, that’s a straw, you see? You watching?. And my straw reaches acroooooooss the room, and starts to drink your milkshake… I… drink… your… milkshake!
The Medusa Bag was conceived in 1988 to meet the anticipated requirement for large scale water imports to California as well as to Israel, Jordan and Palestine. Others at the time were looking into tanker conversions and pipelines, but no practical economic embodiment of these ideas was found. The bags size and shape have been optimized and the first prototype bag will be built using industrial polyester fabric and special straps. A bag containing 0.5 gigaliters of water would be 465 meters long and 110 meters wide, while a 1.5 gigaliter bag would be 670 meters long and 160 meters wide.
Thilafushi Island in the Maldives has grown at the rate of a square metre a day, as more and more rubbish is dumped here. Mountains of rubbish – plastic, metal tins and rusty oil barrels – extend as far as the eye can see. Unlike the adjacent resort islands, the only visitors here are the Bangladeshi workers who wade through the sludge and brave the stench to burn the tonnes of refuse that arrive at the island every day. Spotting the potential to generate revenue from the mushrooming island, the government decided to lease part of it for industrial purposes. Additional terrain was created using white sand and now giant cement cones, oil drums and the skeletons of future boats can be seen dotted around. Metal compactors compress junk into blocks for sale to India. Each tonne sells for US$175. The island has grown to such proportions that it now has a café, a restaurant, two mosques, a barbershop, a clinic, a police station and rather unexpectedly, a makeshift zoo.
Mark Danielewski’s House of Leaves is a book about a book about a movie about a house. A series of surveying measurements initially reveal that the house is larger on the inside than on the outside. The discrepancy is less than an inch, but is a sign of things to come. One day a small, closet-sized room appears in the home, although the outside dimensions remain unchanged.
A thermokarst lake, also called a thaw lake, refers to a body of freshwater, usually shallow, that is formed in a depression by meltwater from thawing permafrost. This landscape operates by scalar indifference as pools appear and disappear under freeze and thaw.
The Russian chessplayer Savielly Tartakower said: Tactics is knowing what to do when there is something to do, strategy is knowing what to do when there is nothing to do.
