Tag Archives: urban ecology

Philadelphia’s new rail park

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This article on Philadelphia’s new rail park sounds kind of cool. Sure, we are copying an idea from New York with the typical one-decade lag, but it sounds like the designers have given some thought to ecology.

The Rail Park’s horticultural design is a “simple palette” with three main layers, he explained.

Hardy London plane trees — “the classic park tree” found along the outer lanes of the Ben Franklin Parkway and throughout the city — will dominate the upper layer. Multi-stem oaks and Kentucky coffee trees will fill in the medium layer, along with shorter redbuds and other flowering trees, American holly and Eastern red cedars. A birch grove will “play off the window boxes” that adorn a neighboring apartment building, like “a domestic landscape writ large,” Hanes said.

The lower level of plants will be more diverse, with arrangements of shrubs and perennials that include:

  • Bottlebrush buckeye
  • Oak leaf hydrangea and viburnums
  • Sedges, tall grasses and ground covers
  • Several varieties of fern
  • Sumac
  • Asters
  • Sage
  • Goldenrod
  • Milkweed
  • Alum root
  • Wild petunias
  • Wild indigo

I can vouch for this part of town being sorely in need of some wildness.

March 2018 in Review

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Most frightening stories:

Most hopeful stories:

  • One large sprawling city could be roughly the economic equivalent of several small high-density cities. This could potentially be good news for the planet if you choose in favor of the latter, and preserve the spaces in between as some combination of natural land and farm land.
  • The problems with free parking, and solutions to the problems, are well known. This could potentially be good news if anything were to be actually done about it. Self-parking cars could be really fantastic for cities.
  • The coal industry continues to collapse, and even the other fossil fuels are saying they are a bunch of whining losers. And yes, I consider this positive. I hope there aren’t too many old ladies whose pensions depend on coal at this point.

Most interesting stories, that were not particularly frightening or hopeful, or perhaps were a mixture of both:

Seek

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This is pretty cool – a phone app to help you identify backyard plants and animals.

Drawing from millions of wildlife observations on iNaturalist, Seek shows you lists of commonly-recorded insects, birds, plants, amphibians, and more in your area. Use our maps and charts to determine what you want to look for and snap a photo when you think you’ve found it. Our image recognition software lets you know if you got it right and, if it’s a match, adds it to your collection. The more your collection grows, the more badges you’ll earn!

See something that’s not on the list? You can still take a photo of it and Seek will add it to your collection if it’s recognized!

Silicon Valley executives and their chickens

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Tech company executives have a new hobby – keeping chickens.

Michel uses “Coop Tender,” a system that allows owners to control their coops via smartphone, dictating temperature, ventilation and lighting.

The system includes an automatic door and “predator motion detection” that turns on a security light and sends owners a text when danger lurks. Despite their relative privilege, even these chickens are circled by predators like hawks, coyotes, raccoons and bobcats.

February 2018 in Review

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Most frightening stories:

  • A general rule across many types of wildlife is that their range after urbanization decreases to between one-half and one-third of what it was before urbanization.
  • The Cuban sonic attacks are real. At least, the people who experienced them have real brain damage, even if we still don’t know what technology did the damage.
  • Cape Town will probably not be the last major city to run out of water.

Most hopeful stories:

Most interesting stories, that were not particularly frightening or hopeful, or perhaps were a mixture of both:

agent-based wildlife modeling in cities

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This is an agent-based model of wild boars coming from wild lands into a city. We don’t have wild boar issues where I live, but raccoons and deer occasionally show up. I’ve lived places where black bears show up unexpectedly in urban areas, and that can cause a stir.

Pigs in space: An agent-based model of wild boar (Sus scrofa) movement into cities

Last decades saw a dramatic increase in wildlife populations within urban areas. Policymakers seek to minimize human-wildlife conflicts resulting from overabundance of species, such as wild boars (Sus scrofa). To this end, there is a need to understand the drivers governing infiltration of wildlife into cities. In this paper we study the availability and distribution of food resources in urban areas as driver of wild boar movement patterns. Based on the optimal foraging theory, we utilize an agent-based simulation model to investigate the ever-growing infiltration of wild boars into some cities. We apply the model to an artificial city that mimics the landscape of the city of Haifa. Manipulating food availability and relative resistance costs of different land-covers we demonstrate that infiltration of boars depends on population size of wild boars and on the amount and spatial distribution of attractors (e.g., food). Model outputs for likely sets of parameters demonstrate good correspondence to the reports of boar observations within the city of Haifa, Israel, where the porosity of the urban fabric and the connectivity of open space patches provide a trail network that makes food throughout the city accessible at a relatively low search-cost. Our results indicate that land cover and food patterns determine critically boars’ foraging movement and infiltration into the city. The proposed modeling framework provides a tool to investigate wildlife management policies that aim at reducing people-wildlife conflicts in cities.

mapping urban vegetation on a fine scale

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This is an interesting paper about mapping urban vegetation on a fine scale based on photos.

Mapping vegetation functional types in urban areas with WorldView-2 imagery: Integrating object-based classification with phenology

Mapping urban vegetation is a prerequisite to accurately understanding landscape patterns and ecological services provided by urban vegetation. However, the uncertainties in fine-scale vegetation biodiversity mapping still exist in capturing vegetation functional types efficiently at fine scale. To facilitate the application of fine-scale vegetation spatial configuration used for urban landscape planning and ecosystem service valuation, we present an approach integrating object-based classification with vegetation phenology for fine-scale vegetation functional type mapping in compact city of Beijing, China. The phenological information derived from two WorldView-2 imagery scenes, acquired on 14 September 2012 and 26 November 2012, was used to aid in the classification of tree functional types and grass. Then we further compared the approach to that of using only one WorldView imagery. We found WorldView-2 imagery can be successfully applied to map functional types of urban vegetation with its high spatial resolution and relatively high spectral resolution. The application of the vegetation phenology into classification greatly improved the overall accuracy of classification from 82.3% to 91.1%. In particular, the accuracies of vegetation types was improved by from 10% to 13.26%. The approach integrating vegetation phenology with high-resolution remote sensed images provides an efficient tool to incorporate multi-temporal data into fine-scale urban classification.

habitat complexity doesn’t affect biodiversity?

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There’s theory, and then there is collecting actual evidence to support a theory, which tends to be messy. In this case, the theory is that more complex habitats should support more diversity. They didn’t at least in this study of insects and spiders in Sydney.

Habitat complexity does not affect arthropod community composition in roadside greenspaces

Urban greenspaces including remnant patches of vegetation, backyard gardens and public parks provide important habitat for wildlife conservation. Maintaining and enhancing the conservation value of these spaces requires both an understanding of the biodiversity they support, and the factors, including habitat traits, influencing species occurrence. Roadside greenspaces, including road verges and median strips are often overlooked in current greenspace biodiversity studies. We quantified arthropod community assemblages in roadside and public park greenspaces, and determined if habitat complexity was an important trait influencing species composition in these areas. Using pitfall traps, we sampled ground dwelling arthropods along five major roads in the greater Sydney Region and in public parks. Whilst roadside greenspaces (road verges and median strips) and public parks supported significantly different arthropod assemblages, habitat complexity had no impact on community assemblage and neither factor affected the assemblage of key arthropods taxa including ants, beetles and spiders. Additionally, in public parks but not road side greenspaces we found an effect of habitat complexity on arthropod abundance; arthropods were more abundant in high complexity park sites. Our results highlight the unique arthropod community assemblage supported by roadside greenspaces, and suggest management practices like increasing habitat complexity may be important in some but not all urban greenspace types.

why our institutions are failing to deliver optimal green infrastructure

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I think this article explains well why real green infrastructure is hard to achieve. Multiple goverhment agencies are responsible for bits and pieces of it, and even if they are acting efficiently within each of their limited missions, they are not coordinating to achieve goals efficiently as a whole. I see this plenty in my professional life dealing with water, parks and transportation agencies.

Lost in Transactions: Analysing the Institutional Arrangements Underpinning Urban Green Infrastructure

Urban development has altered surface-water hydrology of landscapes and created urban heat island effects. With climate change, increasing frequency of extreme heat events and in some areas, episodic drought and flooding, present new challenges for urban areas. Green infrastructure holds potential as a cost-effective means of providing microclimate cooling and stormwater diversion. Further, green open spaces when combined with the provision of equipment and facilities have the potential to promote physical and emotional well-being. However successful implementation may be predicated on co-ordinated efforts of multiple agencies. The Institutional Analysis and Development framework developed by Crawford and Ostrom is used in a case study to understand the institutional impediments, transaction costs and gaps in responsibility associated with the delivery of green infrastructure. Lessons learned are potentially transferable to other urban settings. Our analysis reveals areas of high transaction costs as well as a gap in the polycentric decision-making of agencies. The local government council is concerned with the well-being of its residents but has limited financial capacity. None of the agencies who deliver green infrastructure have responsibility for facilitating the indirect or preventative health benefits. Thus, a co-ordination problem among agencies can lead to suboptimal investments in green infrastructure.

 

January 2018 in Review

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Most frightening stories:

  • Larry Summers says we have a better than even chance of recession in the next three years. Sounds bad, but I wonder what that stat would look like for any randomly chosen three year period in modern history.
  • The United States is involved in at least seven wars: Afghanistan, Iraq, Syria, Yemen, Libya, Somalia, and Pakistan. Nuclear deterrence may not actually the work.
  • Cape Town, South Africa is in imminent danger of running out of water. Longer term, there are serious concerns about snowpack-dependent water supplies serving large urban populations in Asia and western North America.

Most hopeful stories:

Most interesting stories, that were not particularly frightening or hopeful, or perhaps were a mixture of both: