Home Page

Bookmark and Share

Global Roundtable


  • A Study of Biodiversity in the World’s Cities

    0 Comment(s)
    Join our Conversation

    November 23, 2014

    Charlie Nilon

    What are the global patterns of biodiversity the world’s cities?  Are urban spaces biologically homogeneous and depauperate, or do they harbor significant native biodiversity?  These are the questions of a collaborative study of biodiversity in the world’s cities.

    For several years researchers and practitioners have thought that cities may be important in conserving biodiversity.  In 2011 a group of researchers started a project at the National Center for Ecological Analysis and Synthesis (NCEAS) to document patterns of biodiversity in the world’s cities.  Our project, “What Makes an Urban Biota ‘Urban’?” compiled data from previous studies of birds and plants and cities.  We focused on citywide studies of birds and of spontaneous (i.e., unmanaged or ‘wild’) vegetation because we wanted to identity patterns in cities that went beyond the relatively well documented flora and fauna of urban greenspaces and yards.  Our study only included data from published studies that were completed since 1990.  These resulted in a database of 147 cities with bird species lists for 54 cities and plant lists for 110.

    We wanted to know:

    1. Are cities becoming more homogenous in terms of biodiversity?  Several researchers have raised the issue of biotic homogenization resulting from design and planning practices that shape urban environments with standard species compositions and we wanted to know if cities are indeed becoming more similar to each other in plant and bird species composition.
    2. What are patterns of the proportions of native and non-native species of plants and birds in cities?  The biodiversity of native species is of global importance and we wanted to understand the relative importance of cities in this aspect of conservation.  That is…
    3. Are cities of conservation importance by harboring native spieces?  Are biogeographical (biogeographical realm, amount of remnant vegetation, latitude, elevation, mean temperature, rainfall) and cultural (urban extent, city establishment date) variables … Continue Reading
    4. Building Ecological Services: Restoring the Ecosystem Services of the Habitats We Are Replacing with Human Development

      1 Comment(s)
      Join our Conversation

      November 18, 2014

      Whitney Hopkins

      Every year, new scientific advances indicate life is more interwoven than we ever imagined. From recent reports that reveal the cascading effects of wolves’ reintroduction to Wyoming to current studies that track the dire impact of Washington dams on the decreasing nutrient loads in Montana forests, evidence builds of a tightly entwined biosphere. As we gain ecological understanding, the dream of engineering a new home from scratch seems more and more unrealistic. How could we construct a replacement to an interdependent system so complex that we don’t fully comprehend it?

      While our awareness increases of the services we gain from healthy and intact ecosystems, so does the call to preserve landscapes and repair those that have deteriorated or been completely lost. When the built environment expands, human development replaces the habitat that is performing life-sustaining services. Those services performed include water and air purification, climate regulation, carbon sequestration, waste decomposition, detoxification, and pest and disease control among many others. It becomes more and more apparent that our quality of life is tied to the health of the broader environment and that we need to prioritize habitats, all of which sustain the climate.

      As the population increases and we take up more area with the built environment, the remaining ecosystems are struggling to perform enough services to support us. Therefore, it has become our responsibility as practitioners who control the built environment to ensure our development contributes to ecological health by performing the same services of the habitat it replaced. We can do this in two primary ways, through ecological incorporation and biomimicry.

      Ecological incorporation

      Ecological incorporation is making space to include new habitats within our built environment. I have been struck by the recent innovation in this area as well as the development of traditional approaches. Designers and planners are increasingly devising … Continue Reading

    5. The Emerald Necklace: Metropolitan Greenspace Planning in Los Angeles and Beyond

      2 Comment(s)
      Join our Conversation

      November 9, 2014

      Will Allen


      Mike Houck
      Urban Greenspaces Institute

      In winter 2009, Houston Wilderness hosted an inaugural meeting of what would become the Metropolitan Greenspace Alliance.  Today the Alliance is a national coalition of coalitions working in ecologically, culturally, and economically diverse communities across the US. Alliance members represent Portland, Oregon; Seattle, the San Francisco Bay Area, Los Angeles, Houston, Chicago, Milwaukee, Cleveland, Nashville, St. Louis, Kansas City, Denver, and Baltimore.

      Over 80% of the population in the United States now lives within urban megaregions, and this trend of rising urbanization is similar in countries around the world. Amidst significant investments in “grey” infrastructure to support growing metropolitan regions, conserving nature is increasingly challenging. And, more often than not, the most significant challenge is protecting and restoring natural systems that provide clean air and water and other ecosystem services that nature provides us.

      Metropolitan regions that effectively incorporate greenspace and Green Infrastructure into their urban fabric share several things in common, often including ample parks and natural areas, both in quantity and equitable distribution; innovative stormwater management; climate adaptation strategies; public transportation and recreational trail networks; and sustainable food production and delivery systems. Whether it’s Vancouver, Reykjavík, Malmö, Portland, or any number of cities around the world that are “green” or in the process of “greening,” the collaboration among governments, nonprofits, scientists, natural resource agencies, and urban planners is essential to transform a place from grey to a green, living, interconnected network of systems that benefit humans and the unique urban ecosystem they inhabit.

      The following case study from Metropolitan Greenspace Alliance member Amigos de los Rios describes an almost century-long process of Los Angeles’ greening that should inspire other cities and metropolitan regions  toward a greener future. The struggles faced and overcome are not unique to Los Angeles. This … Continue Reading

    6. The Caterpillar and the Butterfly

      5 Comment(s)
      Join our Conversation

      October 28, 2014

      Lesley Lokko

      ‘There is nothing in a caterpillar that tells you it’s going to be a butterfly.’
              —Buckminster Fuller

      Architecture | Education | Landscape | Nature

      It’s been six months since Sweet by Nature was penned and released into the ether and in less than a week’s time, my students at the University of Johannesburg (whose work was featured in the article) will submit their Masters projects for external examination. In that time, I’ve not only come to understand better what it is I’m supposed to be teaching them, but also where the potential gaps in the overall structure of architectural education—particularly in Africa—may lie.

      One such gap has to do with ‘nature’ and specifically what we mean by ‘nature’ when we teach architecture. It may seem like an obvious point but education, even in the context of a semi-vocational/professional course like architecture, isn’t just about the delivery of an ‘approved’ curriculum, it’s also (perhaps more deeply) concerned with the transmission of values. In the context of Africa where the very idea of shared cultural values that transcend the specificities of place, language, history and even ‘race’ remains an elusive pipedream, the question of how we might teach an approach to ‘nature’ and by extension ‘landscape’ remains equally elusive.

      By and large, African schools of architecture follow curricula handed down/derived or adapted from one colonial context or another—British, French or Portuguese. South Africa’s eight schools have an added Dutch/Afrikaans layer of cultural complexity to contend with, but I believe it’s fair to argue that African schools have yet to attempt the profoundly complex translation of indigenous, pre-European built environment beliefs, rituals and ways of seeing into a functioning modern architectural curriculum. Given the explosive nature (no pun intended) of urbanisation, the question of how we define, explore, protect … Continue Reading

    7. Connective Tissue Matters in the Nature of Cities

      6 Comment(s)
      Join our Conversation

      October 20, 2014

      Mary Rowe

      The TNOC Roundtable for October 2014 focused on green corridors in cities to support nature, and the ‘natural’ ecology that resides in the city.  I am focused on the ecology of the city.  The aim of ecologists and scientists to strengthen the capacity of the city to connect nature within and across it, is the same instinct that those of us who focus on the physical shape and function of city have: to enable connectivity than enhances the overall function of the whole.

      I wrote in a previous post on this site about how cities are fundamentally natural—they are of a piece with nature, created by the interaction of people and place, and not artificial constructs, fated to  always-at-odds-with-the-natural.

      The contributors to the green corridor roundtable reinforced this for me.  They’re eager for ways to enable connection, build and exchange natural capital, explore how linear spaces and corridors can encourage biotic movement, dispersal, address the challenges of predators and invasive species, and encourage ‘biotic connectivity’.

      Look at how similar the challenges are for building the physical city for its human inhabitants, and how similarly people actually behave, with the other species with whom they share their urban home, in their use of it.  We face various kinds of predators: over-heated real estate markets fueled by speculation; growing mono-cultures of single land-uses; sprawling residential development that bulldozes down diversities of all kinds.

      The ways the physical city and its built environment can be created, in more authentic and organic ways, is a wonderful illustration of ‘biomimicry’: how human processes mimic natural ones.

      I first came across this term when its conceiver, author and natural scientist Janine Benyus, came to Toronto in 1997 to speak at a conference on cities convened to celebrate the work of Jane … Continue Reading

    8. Urban Protected Areas: Important for Urban People, Important for Nature Conservation Globally

      4 Comment(s)
      Join our Conversation

      October 8, 2014

      Ted Trzyna

      The international conservation movement traditionally has concentrated on protecting large, remote areas that have relatively intact natural ecosystems. It has given a lot less attention to urban places and urban people. About ten years ago, four of us long involved in IUCN, the International Union for Conservation of Nature, set out to correct this.

      IUCN is the global umbrella organization of nature conservation. Its 1,200 members in 172 countries include national governments as well as governmental agencies and nongovernmental organizations. IUCN advises UNESCO, the UN Convention on Biological Diversity, and other intergovernmental organizations, as well as governments, especially in developing countries. Although it has a staff of over 1,000, much of IUCN’s work is done by six commissions composed of professionals who volunteer or raise money to cover their time.

      The four of us were Jeff McNeely, longtime IUCN Chief Scientist and author of numerous scientific publications on nature conservation; Adrian Phillips, a former chair of the IUCN World Commission on Protected Areas and IUCN Program Director; the late John Davidson, co-founder of Britain’s pioneering Groundwork urban regeneration program; and me, a political scientist and former U.S. career diplomat and chair of the then IUCN Commission on Environmental Strategy and Planning.

      We decided to focus our attention on urban nature reserves, especially those fitting IUCN’s definition of “protected areas,” which is also used by the UN: “a clearly defined geographical space, recognised, dedicated, and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values.”

      The most important product of our efforts to date is a new IUCN book, Urban Protected Areas: Profiles and Best Practice Guidelines, by Ted Trzyna in collaboration with Joseph T. Edmiston, Glen Hyman, Jeffrey A. McNeely, Pedro da Cunha e Menezes, Brett Myrdal, and Adrian … Continue Reading