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robertogreco : trails   10

Mount Sutro - FoundSF
"Mount Sutro, a hill in San Francisco, is difficult to characterize. At 908 feet, it’s a very tall hill that comes close to being a small mountain. (Another 92 feet, and it would have that distinction.) Many hundreds of years ago it might have started life as a hybridized sand dune/chert rock outcropping: it sits to the south of the Great Sand Bank of the outer lands of the city where offshore gusts threw sand from west to east with impunity one hundred years ago. It has a lot of trees growing on it, so many that it’s called a forest, although properly speaking it’s more like a tree plantation. Most of the trees are from one species, Eucalyptus globulus, the Tasmanian blue gum eucalyptus. When Mount Sutro is viewed from a distance, it looks almost cartoonishly rounded, a great tree-laden lump rising in the center of the city. The ravines and slopes of Mount Sutro are filled with blue gum eucalyptus, Himalayan blackberry and English ivy. They are all non-native.

Craig Dawson, the executive director of Sutro Stewards, a habitat restoration organization, likes eucalyptus trees and prefers the native blackberry over its invasive cousin. “Native blackberries are sweeter,” he says. “Himalayan blackberries are really tart.” He is openly dismayed by the English ivy, Hedera helix, the villainous plant of the understory which prevents native plants from growing well or at all and kills eucalyptus trees. “The birds eat the berries,” he says, “and the seeds gets distributed everywhere. You can’t fight all this,” he says, gesturing at the glossy leaves of the ivy."



"The North Ridge Trail is steep. I huffed and puffed after Craig, while he continued to name plants as he went. We stopped before a tall tree. “Toyon,” said Craig. We looked at it in silence. Here was a tree, solid and growing confidently in its old home. Maybe it had always been here— a historic remnant of a once larger community. Or maybe the seed it sprang from had been scarified in the acidic confines of a bird’s digestive tract and shat out to land— miraculously— in the one place it could sprout. We didn’t plant hardly any of this, Craig had said. Overhead the ravens croaked and chattered. Craig looked up in amusement. “When the ivy is in fruit, you can’t hear yourself talk. They’re very loud,” he said. Seed bearers to blackberry and toyon alike, they proved one thing: Invasion depends on movement. All things that creepeth and crappeth add more weight to Mount Sutro’s unbalanced ecological system, top-heavy with homogeneity. The current ecological system in the reserve depends on movement in the sky and on the trail below: hikers, bikers and birds all help propagate the eucalyptus, ivy and blackberry. We walked out of the murky confines of the reserve and into the summit. I saw the first direct sunlight I’d seen since meeting Craig in the Parking lot.

Rotary Meadow sits on about two inches of topsoil. The dirt was removed during the construction of a Nike radar base in the 1950’s. In an email sent to me later, Craig elaborated: “Rotary Meadow is planted in a debris field of unconsolidated rubble atop solid chert. On the top there is a bare minimum of a couple of inches of gravel, rock chips, and 50 years of composting resulting from the broom, blackberry and weeds that called it home.” The summit plant community, fragrant with mugwort and artemisia, is scraping by. It’s the only place in the reserve that supports a coastal scrub community. It does so on just under two acres of land.

Two bush lupines sat alongside a San Francisco gum plant. The lupines, small and fragile looking, are the only source of food on Mount Sutro for the tiny and endangered Mission Blue butterfly. “They’re no bigger than your fingernail,” said Craig, extending his for comparison. The lupine is also the butterfly’s nursery. The butterfly sips nectar from the lupine and lays its eggs on the underside of the leaves. The eggs hatch in six to ten days and continue feeding and living on the plant as caterpillars. The caterpillars are protected from insect predators (mostly wasps), by ants. Lupines, butterflies, ants: this elegant triad illustrates the basic schematic of ecology: a relationship between locale, plant and animal that is historically congruent and interdependent. It’s simple and very easy to disrupt. On Mount Sutro, the relationship is struggling. Two elements are missing: the butterfly and the ant.

Prenolepsis imparis, the ant, is missing. The ant/nursemaid to the Mission Blue caterpillar feeds on honeydew, a substance secreted by the caterpillar. The ants defend this food source from other predators like wasps. But a 2008 study performed jointly by biologists from San Francisco State University and the California Academy of Science described a startling finding: the absence of any native ants— any ants at all— in the interior greenbelt of Mount Sutro, downhill of the summit. The ant, it was surmised, was missing so completely because of the absence of habitat. Like elk clover, ants need the sun. And like mice, ants also need bare patches of land to travel. The study concludes that dense understory plants and too much moisture discouraged the ants from making it to the summit, effectively removing one crucial element from the three-part production that results in a population of healthy lupines and adult Mission Blue butterflies. The understory rolling and tumbling in the depths below affects the summit ecology dramatically: People literally can’t see the ants because of the trees.

A look of consternation flitted across Craig’s face. “Look at that,” he said. I looked. Purple star thistle had sprouted in a recently cleared patch to our right. “Workmen brought that up here,” he said. He said nothing more: he didn’t need to. Purple star thistle is a “major problem” according to the California Invasive Plant Council plant; the sort of plant that people who manage urban forests and regional parks cite as an example of why herbicides must be used."



"For the general public, living on the margins of (or downstream from) urban forests, the use of glysophate and triclopyr seems not to be accepted at all. Tired of high-handed interventions into the earth’s ecological systems, they’re perhaps protesting not only an intentionally toxic process, but also the seemingly endless interference, or management, of meddlesome humans. When will the earth be left to itself? Craig looked at the star thistle disgustedly. We walked on.

We entered the south ridge, project area number one. The south ridge has been thinned not once but twice; first in the 1930’s when the Works Progress Administration employed local men to log the eucalyptus grove, (there was a mill on Seventh Avenue and Clarendon) and again in 1954 to make room for a new Nike Missile radar base. “These trees are 58 years old,” said Craig and they look it: epicormic shoots sprout weirdly from the sides of the trees, evidence of logging, military installations and the most common method of thinning, fire. There have been seven fires in the reserve since the late 1800’s. The largest, in 1899, burned 60 acres, practically the entirety of the reserve. Another fire in 1935 burned ten acres and took 400 firemen to extinguish. Mount Sutro, with its wet western perimeter and persistent fog, is not exempt from California’s fire ecology. In California, everything can burn."



"In the battle to understand and manage the future, one fire regime tends to gets pitted against another. Chaparral is dangerous, say the critics of the UCSF forest management plan. Grasslands are dry. Coastal scrub doesn’t harvest fog or moisten the soil as efficiently as eucalyptus trees do. Eucalyptus trees explode, counter indignant Californians weary of hearing their native plant communities maligned. They increase the fuel loads to dangerous levels. They hog water. They perpetuate a mistaken vision of beauty for California: one that lionizes imported trees, while the glory of California’s coastal scrub and chaparral gets denigrated as dangerously “dry” brush with little or no regard for the astonishing amount of biodiversity it promotes. But the words of Andy Hubbs resolve this argument: “Everything burns,” he said. Eucalypts, native chaparral, southern coastal scrub communities, and the type of maritime coastal scrub/chaparral plant community that once grew on the hills in San Francisco- all of it.

In California, everything burns.

As Craig and I walked through the south ridge, the change in ambient moisture was abrupt. Minutes before the air had been fairly dry. Now dripping water fell everywhere. We were in the fabled “cloud forest” of Mount Sutro, standing in fog so thick that there was nothing to be seen but tree after tree, shrouded in whitish-grey mist. “You should be able to see the Marin Headlands from here,” said Craig. I felt like a ghost standing there. There’s an odd lack of “place” on Mount Sutro, a landmark isolated from its cousin landmarks, the Marin Headlands, the sea, and the southern reaches of the San Miguel Hills. There is no context to widen the understanding of what you’re standing on, no chance to compare the hill with other hills, bluffs and beaches. There is no way to appreciate the contiguity of the coastal ridge that runs from Point Reyes down the peninsula. One is forced to consider only the spindly trees and the shrouding fog. We walked back to the parking lot. Craig pointed to a eucalyptus tree. “See that? That’s what a healthy euc looks like,” he said. I looked at it and saw what I’d been looking at my whole life, in paintings or in windbreaks that edge the 101 freeway: a magnificent tree with a truck the color of pale ivory and a crown of dark green leaves radiating horizontally from the branches. It was the very picture of edenic California, lovely, healthy and serene.

We love what we know. Perhaps California’s native plant landscape is not … [more]
mountsutro  sanfrancisco  history  classideas  blackberries  plants  trees  eucalyptus  elizabethcreely  trails  forestknolls  midtownterrace  clarendonheights  innersunset  nature  ivy  ravens  ecology  craigdawson 
december 2017 by robertogreco
Self-organized Trail Systems in Groups of Humans [.pdf]
"We have developed an experimental platform for studying the trail systems that spontaneously emerge when people are motivated to take advantage of the trails left by others. In this virtual environment, the participants’ task is to reachrandomly selected destinations while minimizing travel costs.The travel cost of every patch in the environment is inversely related to the number of times the patch was visited by others. The resulting trail systems are a compromise between people going to their destinations and going where many people have previously traveled. We compare the resultsfrom our group experimentsto the Active Walker model of pedestrian motion from biophysics. The Active Walker model accounted for deviations oftrailsfrom the beeline paths,the gradual merging of trails over time, and the influences of scale and configuration of destinations on trail systems, as well as correctly predicting the approximate spatial distribution of people’s steps. Two deviations of the model from empirically obtained results were corrected by (1) incorporating a distance metric sensitive to canonical horizontal and vertical axes, and (2) increasing the influence of a trail’s travel cost on an agent’s route as the agent approaches its destination."
via:matthewbattles  desirelines  2006  systems  complexity  patterns  self-organization  trails 
june 2013 by robertogreco
Max Tabackman Fenton
[The delightful copy from May 15, 2012.]

"Hello, I'm Max Fenton.

Knowingly or not, I've enlisted friends, peers, and strangers to unpack a puzzle that involves reading and writing on networks and screens.

You can follow along or participate by reading, clipping, grokking, assembling, questioning, and sharing—while making a path. You'll need electrons, a wish to explore, and an eye for how these pieces might fit together in novel shapes and forms.

My trails are charted through twitter, tumblr, pinboard, readmill, reading, and 2nd hand [flavors.me]."

[As shared on Twitter:

"Made my site a little more accurate [http://maxfenton.com] then read @pieratt's "Transparency" http://pieratt.tumblr.com/post/23108094947/transparency-in-the-evolution-of-technology — Yes."

http://twitter.com/maxfenton/status/202477843534454784 ]

[See also: http://twitter.com/rogre/status/202481485633159168 ]
stockandflow  flow  commonplacebooks  friends  peers  talktostrangers  strangers  networkedlearning  benpieratt  transparency  comments  peoplelikeme  howwethink  howwecreate  socialmedia  participation  pinboard  readmill  flavors.me  reading.am  tumblr  twitter  2012  sensemaking  meaningmaking  clipping  assembling  sharing  questioning  crumbtrails  conversation  howwelearn  howwework  cv  online  web  trails  wayfinding  pathfinding  maxfenton 
may 2012 by robertogreco
EveryTrail - GPS travel community, geotagging, geotagged photos, Google Maps, GPS tracks, waypoints, coordinates
"* Upload GPS data and photos to view your trips on Google Maps! * Map your pictures with our patent-pending geotagging technology * Find GPS maps with tracks, coordinates and geotagged photos * Share your trips with the EveryTrail community * View your t
gps  mapping  community  hiking  travel  maps  location  geography  geotagging  googlemaps  running  trails  tracking  onlinetoolkit 
june 2008 by robertogreco
Crosscut Seattle - Seattle's pedestrian attitude toward pedestrians
"What keeps us planted on the corner, waiting for that little light to tell us to "walk"? Frankly, we're a bunch of walking wussies, and if the city's going to call itself foot-friendly, it's time step up to the challenge."
cities  walking  pedestrians  traffic  planning  urban  seattle  washingtonstate  cascadia  us  transportation  trails  culture  society  jaywalking  via:cityofsound 
january 2008 by robertogreco
Crosscut Seattle - Seattle's pedestrian attitude toward pedestrians
"What keeps us planted on the corner, waiting for that little light to tell us to "walk"? Frankly, we're a bunch of walking wussies, and if the city's going to call itself foot-friendly, it's time step up to the challenge."
cities  walking  pedestrians  traffic  planning  urban  seattle  washingtonstate  cascadia  us  transportation  trails  culture  society  jaywalking  via:cityofsound 
january 2008 by robertogreco
recreating movement- introduction
"Recreating Movement is a computer program for analysing film sequences and has been developed within a diploma thesis."
animation  film  visualization  graphics  motion  digital  video  trails  infographics 
november 2007 by robertogreco
ShiftSpace | An Open Source layer above any webpage
"Having wandered for years in an owner-centric Cyberspace, where do we turn for online public spaces? ShiftSpace (.org) seeks to provide a new town-square built above the existing privatized hyper-mall of information that is the World Wide Web. We are bui
opensource  firefox  shiftspace  web  community  social  internet  gui  collaborative  semanticweb  sharing  gamechanging  activism  socialsoftware  tagging  trails  communication  interaction  interactive  metaweb  collaboration  experience  cooperation  annotation  website  comments  extensions  browser  archive  danphiffer  browsers 
november 2007 by robertogreco
Jan Chipchase - Future Perfect: I Know What You're (Collectively) Thinking
"the best way to predict the future may be to invent it, but the easiest way to predict the future is, simply to predict it. Or keep tabs on those who are inventing it."
future  search  patterns  trails  business  research  laboratories  markets  janchipchase  attention  mobile  memory  networking  connectivity  futurists  predictions  futurology  profiling  identity  innovation 
january 2007 by robertogreco

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