City Branch Conceptual Design

Photo courtesy of OLIN/BCJ

Ben recently completed work on this OLIN/BCJ lead team to look at the what the City Branch in Philadelphia could become.  The plan is bold and in as much requires bold leadership from a variety of stakeholders, designers, and community members.

The City Branch is a SEPTA owned 2 mile long abandoned rail corridor that sits 30 feet below the surrounding cityscape.  It begins just east of where the Reading Viaduct transitions down to Broad Street.  It then passes under Broad Street and heads due West and disappears under Pennsylvania Ave, before jogging slightly and heading North.

Light and air wells under Pennsylvania Ave

The new below-grade park would extend from two points at the east end: the connection to the SEPTA Spur, where the rail viaduct dips under Broad Street (which is a bridge over the railway) and at Broad and Buttonwood in front of the School District Administration building. A key to the plan is the planned reconstruction of the Broad Street bridge, owned by PennDOT. The parking lot now in front of the School District building would be replaced with a multi-level public space leading to the park.1

Connection along the front of the  School District Building(Rotogravure building) originally designed by Albert Kahn

New connections are made throughout allowing for a steady, unimpeded flow to create a safe and vibrant space to move along and through.  Conceived as a series of connected program, adjacent buildings are provided an opportunity to connect to the park whether its retail or education.  The entire length is meant to function as a stormwater capture and treatment system.

Connection to Community College of Philadelphia

The draft of the Planning Commission’s Central District plan makes no mention of establishing a rail park and instead supports a Bus Rapid Transit line to take riders west to Fairmount Park.  This is viewed as an opportunity in that the width of the City Branch could allow for each to co-exist.

What is clear is that the current condition of the City Branch is such that it creates a drag on land use, property value, perception of safety, and overall health of the adjacent properties.  Why not imagine something better?  Well, we did.

Meadows: From Livestock Feed to Landscape Design Popculture

Gene and Ben in a hay field, Perrys Mills, NY

 Before the meadow experts draw their metaphorical knives, let me first say that I recognize that there are different types of meadows and that I am not an expert in any of them.  I know that there are perpetual meadows from alpine to coastal and everything in between that stand to discredit the title of this blog.  But it seems as though every presentation, every rendering, and every landscape design is clearly discussing what was heretofore known as a hay field.  Clients, unless it is truly a project where a perpetual meadow naturally occurs, or a research facility, or a hardcore Eco-wealthy tycoon, are not going to introduce the types of conditions required to maintain those meadows.  Thankfully it is quite rare that someone would set fire to a field of tall grasses.

Agricultural meadows are not rare on farms in upstate New York where I grew up. There, we just called it "hay" (although the family farm is itself truly becoming a thing of rarity).  If you were lucky and had the right field you got a second or third cut and you didn't leave it in the field to dry for "good winter color".  And, if it was long enough to cut, you cut it for feed.  The winter color near my house was severely stunted by a 6" haircut that was soon covered with snow that was then soon covered with a layer of dried or liquified manure.  The effects of this practice are hotly debated particularly this year in the Champlain Valley where the blue-green algae blooms threaten the life within Lake Champlain, not to mention the tourist and recreation associated with summer fun.

Those hay fields were not described in glowing language meant to sell a design concept.  It was a fact of life and a toilsome one at that.  I was too small to really be involved in the process and did what I could apart from not getting stepped on.  It was a lot of long hours cutting and bailing, loading and unloading, stacking and unstacking and finally feeding and cleaning manure. When it was time to "do hay" my father would climb from what we called the hay mow, an elevated barn attic where bailed hay is stored for the winter, looking as if he had been caught in a heavy rain.  A literal heavy rain, the man was exhausted.

I've described a simple process made romantic in my telling and somehow cheapened by master degree holding esthetes: a club in which I clearly hold a card.  I say that perhaps to assuage the dread that I may be morphing into a griping middle-aged man lost in the noble past.  Maybe I am.  Or maybe I can't help but acknowledge not only the hypocrisy inherent in the sale of a "meadow" as a design element, but that I am, even in my criticism, inherently and inextricably connected to that hypocrisy.  The day I, like so many others of my generation, left the rural homestead to pursue higher education I both forfeited my right to defend the farm life and the right judge others who, like me, are so entirely over educated that they need to rediscover that noble past.

So now we have urban chickens, urban farms, urban bees and urban meadows.  All of which I took for granted and all of which I now see in an entirely different way.  And somehow it irks me that my urban and suburban born friends are becoming enlightened to this fact.  Maybe its because what I wanted most was to have all the things they did growing up.  That I grew up in a way that was different and difficult and somehow that chip is slowly being tipped from my shoulder.

And I feel like I carry another secret: it's that is there is a reason why my generation left those farms.  It's hard.  Beekeeping is hard.  Doing hay is hard.  Putting up fence is hard. Catching cows when they get out is hard.  Keeping chickens alive is hard. The "evil" of  large scale industrial farming is not abstract and the people affected directly by it are real.  Like warriors or athletes it's a lifestyle that makes men and women strong in their youth and wears on them in old age.  Not everyone is cut out for that life and when I hear about concepts deployed by newly minted experts as a weekend warrior activity or a design aesthetic I am somehow on some level oddly offended.

So the dilemma I face isn't the acceptance of agricultural processes as pop-culture (something that has been done more or less since the advent of agriculture), it's that I haven't been able to let that chip fall.

Recreating an Ice Age

Photo courtesy of Inhabitat

From out in the south of Chersky in the Sakha Republic in northeastern Siberia a Russian geo-physicist by the name of Sergei Zimovis is attempting to recreate the last ice age across 160 sq km of Siberian “desert”, a project he calls the Pleistocene Park.  Permafrost has heretofore trapped hundreds of thousands of tons of methane below its surface.  As the industrial revolution, the automobile, and all of our other favorite carbon releasing baubles march on in more and more countries, the Earth's climate, as we all have heard is warming...check that..."changing".  This "change" is causing the permafrost to melt thus releasing methane like so many Taco Bell restaurant patrons.

Photo courtesy of Inhabitat

But wait, Zimovis disagrees.  His theory is that the herbivores grazing on that land kept it in its tundra-steppe, a cold, dry grassland state and that over hunting of these large animals, not climate change, led to their extinction.  He attributes the following ecological reasons for the warming of the land with regard to herbivore extinction:

1. Herbivores were no longer present to maintain the grassland ecology
2. "Grasses and their root systems stabilize the soil." 
3. "The albedo—or ability to reflect incoming sunlight skyward—of such ecosystems (grasslands) is high, so warming from solar radiation also is reduced"
4. "With lots of herbivores present, much of the wintertime snow would be trampled, exposing the ground to colder temperatures that prevent ice from melting."

According to Zimovis, all of this suggests that reconstructed grassland ecosystems, such as the ones we are working on in Pleistocene Park, "could prevent permafrost from thawing and thereby mitigate some negative consequences of climate warming.”

“The ecosystem that used to be here many years ago cooled the climate substantially. And the present-day situation – I mean climate warming and the melting of permafrost – is a separate problem which we are seriously engaged in. We came to realize that the revival of a rich ecosystem on a vast territory will considerably affect the climate and help us control the process of global warming. Scientists find hundreds of kilograms of mammoth-epoch bones on every hectare of northern Yakutia, which testifies to the bygone abundance of herbivores and a different landscape. Our objective is to find out why the situation varied so much after all.”


Zimovis has applied his theory to  Pleistocene Park  where he knocked down the trees and introduced grazing animals to feed on the grass.  Oddly enough, the research on the Park indicates that Zimovis may be correct. He has garnered attention from as far off as Princeton University.  He is looking to, with proper funding, scale up the research. 

Photo courtesy of Inhabitat

Read more: Geo-physicist Tries to Recreate an Ice Age Ecosystem in Siberia to Prevent the Release of 500 Billion Tons of CO2 | Inhabitat - Green Design Will Save the World 

MSNBC 

Nano Interventions: Fungi as Farmers, Plants as Mushroom Hunters- mycorrhizal evolution and its relationship to plants

This is the first part of a multi-part series that will discuss mycorrhizae and their importance to all living beings, specifically for landscape design and ecological restoration applications. This first discussion was written more than 10 years ago by me for an Evolutionary Biology class at Appalachian State University under the mentorship of Dr. Zack Murrell, but nonetheless introduces mycorrhizae as possibly the shepherd of phototrophs to land more than 350-450 million years ago.

Photo courtesy of www.mberg.com.auimagesmycorrhiza.png

A conditional “friendship” between plants and fungi (mycorrhizae) has received a lot of attention recently (note: this was written 10 years ago!) for its application in sustainable agriculture and habitat restoration, along with the fact that this relationship gives us an indirect view into the window of plant’s colonization of land. There is no debate that mycorrhizae benefit plants, however, there is some debate over how mycorrhizae evolved. The debate lies in whether fungal associations with plants evolved and are evolving simply in parallel to plants due to similar adaptive necessities such as similar environmental pressures or if mycorrhizae and plants coevolved with reciprocal gene-for-gene changes (Cairney 2000).

Introduction

Mycorrhizae literally translates to “fungus-root.” This mutualism between plant and fungus involves a fungus colonizing the cortical tissue of a plant's roots. The fungus benefits the plant host because it helps the plant indirectly absorb nutrients. For example, mycorrhizae can break down molecules into elemental forms that otherwise  are unusable by plants, such as phosphorus. In addition, mycorrhizae can benefit plants by providing protection from pathogens and also offer the plant assistance in retrieving water. In return, the fungus gets carbohydrates, a necessary compound for metabolism, from the plant which is produced through photosynthesis (Cairney 2000).

This mutualism with fungi was essential for phototrophs to come onto land and proliferate (Pirozynski and Malloch 1975). One other example of fungi as "farmers" and plants as "mushroom hunters" aside from mycorrhizae can be demonstrated in lichens (fungi and cyanobacteria or green algae associations), which can withstand harsh environments because of their symbiosis and maintain permanent relations (Hawksworth 1988). Similarly, mycorrhizae helped plants conquer the terrestrial environment and are responsible for not only the diversity of plants today, but also that of fauna, due to their dependence on plants (Simon et al. 1993).

White Pine seedlings grown in sterile conditions (left),
White Pine seedlings grown in forest soil with mychorrhizae.
 Photo courtesy of www.msu.educourseisb202

About 90% of extant land plants form symbioses with fungi (Cairney 2000). In phototrophs that have secondarily reverted back to the aquatic environment, their ability to form relationships with fungi is lost, providing more evidence that phototrophs evolved onto land with the aid of fungal associations (Pirozynski and Malloch 1988). Today, Atlantic white cedar fluctuate their levels of mycorrhizal "infection" during drought and flooding (Cantelmo and Ehrenfeld 1999), which indicate how plants regulate their fungal needs and also may be reminiscent of the first plant’s journey to land. Also, plants that do not form mycorrhizal relations are mostly in highly disturbed habitats or in wet or aquatic habitats where mineral resources are adequate and the diffusion of oxygen prohibits the growth of fungi (Fitter and Peat 1993). Even algae living in tidal zones form mycophycobiosis during low tides to cope with the desiccating stress (Kohlmeyer and Kohlmeyer 1979). Lastly, fossil evidence agrees with molecular data in that arbuscular mycorrhizae form a monopyletic group and arose around 353-462 million years ago, around the same time plants colonized land (Redecker et al 2000).

Arbuscular mycorrhizae.

Photo courtesy of terroirists.nettagmicrobiology

Types of Mycorrhizae


Arbuscular mycorrhizae (AM) are mychorrhizae that actually penetrate the plant's cortical tissue and are the most numerous type of mycorrhizae in present-day plants. However, AM consists of only 130 species (Morton 1990) and shows generality to plant hosts (Perry 1998). AM’s include fungi in the phylum Zygomycota, more specifically the order Glomales, and the plant hosts include most angiosperms, some gymnosperms, Pteridophytes and various lower plants (Smith and Read 1997). These AM associations occur mostly at mid-latitudes where phosphorus for plant consumption is limited (Read 1991). Fossil and molecular evidence significantly indicate that the ancestors of extant plants formed AM relationships (Cairn 2000) and today’s plants who do not have AM have lost their relationship with their ancestral host plant (Barker et al. 1998). Gehrig et al. (1996) have found a fungus endocytobiont, Geosiphon pyriforme, to be related to an ancestral form of Glomales, thus forming a monophyletic group, and is probably most like the Glomus fungi that first aided plants to adapt to land life. In addition, molecular clock analysis suggests that the phylogenetic radiation of ancient Glomales paralleled the colonization of land (Redecker et al 2000).

Ectomycorrhizae.
Photo courtesy of farm3.static.flickr.com

Another type of mychorrhizae, Ectomycorrhizae (ECM), form a sheath around the outside of the root of the plant and are only on woody trees and shrubs (Cairney 2000). ECM fungi permit their host to acquire phosphorus, nitrogen and organic material (Read 1991). ECM have a great importance in shaping the ecosystems of forests and involve fungi that belong to the phylums Basidiomycota, Ascomycota and Zygomycota (Cairney 2000). Interestingly, however, ECM extant plants can also form AM associations, depending on the soil conditions (Smith and Read 1997). In addition, some ECM capable plants only form AM associations at the seedling stage, providing even more evidence that all land plants that exist at the present evolved from an ancestral AM condition (Cairney 2000).

Ericoid mycorrhizae (ERM) occur in extremely nutrient poor soils and at high latitudes and altitudes (Read 1991). The fungi in this association have extensive coils of hyphae that cover the epidermal cells of the plant host and involve specifically Ericad plants (the Heather family) and Ascomycete fungi (Cairney 2000). ERM’s have good saprotrophic abilities permitting them to provide nitrogen and phosphorus and tolerate toxic cations that are in acidic soils (Smith and Read 1997).

Photo courtesy of the botany department at WVU

Conclusion


Coevolution is the reciprocal genetic change among a species or populations (Thompson 1999), while parallel evolution is the result of similar pressures acting on species and results in similar yet independent outcomes. Which evolutionary process acted on plants and fungi in mychorrizal associations? Currently evidence for pure coevolution is lacking (Cairney 2000). However, Juenger and Bergelson (1998) propose that the coevolution is more “diffuse” and at a “guild” level of selection. Cairney (2000) has looked at this very question in his paper, The Evolution of Mycorrhiza Systems. He believes that coevolution did occur, but he sees no evidence that gene-for-gene coevolution is occurring in extant species and that it is simply parallel evolution at the present day.

Despite the lack of direct evidence that coevolution is occurring today in mycorrhizae, I think that coevolution is indeed occurring today. If coevolution were a continuum, then I would suggest the exant fungal and plant species are to a lesser degree coevolving because I believe there is some gene-for-gene reciprocation. Mycorrhizal associations can help a plant survive and reproduce, excluding certain genomes that cannot fully exploit this symbiosis. Generalities occur in fungal associations because of common ancestral lineages and does not infer that parallel evolution is occurring. It is exhibited that in certain environmental conditions certain mycorrhizal associations take place, which could support parallel evolution. Perhaps it is not, since a basis for the two organisms to come together in symbiosis must have been established at some point to permit the relationship. I suggest that mycorrhizal associations are still coevolving, to a degree, in which genetic give and take must take place. It is important when creating fungal phylogenies of those that form mycorrhizae to include plant hosts and vice versa, for mycorrhizae associations were and are the essential associations for plants to survive. 


With the current prevalence and severity of habitat destruction and the overpopulation that permits limited resources, soil structure will never be perfect everywhere on Earth. However, for native plants and ecosystems to become or remain healthy and supporting, mycorrhizae are and will be the mechanism of survival for all life forms. In the future, man will foresee and artificially create these associations for habitat restoration and crop production and this application will be an important factor that will enable humans to feed one another and rebuild plundered ecosystems.

Barker, S.J. Tagu, D. Delp, G. 1998. Regulation of root and fungal morphogenesis in mycorrhizal symbioses. Plant Physiol. 116: 1201-1207

Cairney, J.W.G. 2000. “Evolution of mycorrhiza systems.” Natuwissenschaaften. 87:467-475

Cantelmo, A.J. and Ehrenfeld, J.G. 1999. Effects of microtopography on mycorrhizal infection in Atlantic white cedar pine. Mycorrhiza. 8: 175-180

Fitter, A.H. and Peat, H.J. The distribution of arbuscular mycorrhizas in the British flora. New Phytol. 125, 845-854     

Fitter, A.H. and Moyerson, B. 1996. Evolutionary trends in root-microbe symbioses. Phil Trans R Soc Lond B. 351:1367-1375

Gehrig, H. Schubler, A. Kluge, M. 1996. Geosiphon pyriforme, a fungus forming endocytobiosis with Nostoc, is an ancestral member of Glomales: evidence by SSU rRNA analysis. J Mol Evol. 43: 71-81

Hawksworth, D.I. 1988. Coevolution of fungi with algae and cyanobacteria in lichen symbioses. Coevolution of Fungi with Plants and Animals. Academic Press. 125-148

Heijden, M.G.A. van der. Boller T. Wiemken A. Sanders I.R. 1998. Different arbuscular mycorrhizal fungal species are potential determinants of plant community structure. Ecology. 79: 2082-2091.

Juenger, T. Bergelson, J.1998. Pairwise versus diffuse natural selection and the multiple herbivores of scarlet gilia, Ipomopsis aggregata. Evolution. 52: 1583-1592

Kohlmeyer, E. and Kohlmeyer J. 1979. Marine Mycology: the Higher Fungi, Academic Press

Morton, J.B. Benny, G.L. 1990. Revised classification of arbuscular mycorrhizal fungi. Mycotaxon. 37:471-492

Perry, David. 1998. A movable feast: the evolution of resource sharing in plant-fungus communities.Trends in Ecology and Evolution. Vol.13, issue 11: 432-434

Pirozynski, KA and Malloch, DW. 1975. The origin of land plants: a matter of mycotrophism. BioSystems. 6:153-164

Read, D.J. 1991. Mycorrhizas in ecosystems. Experientia. 47:376-309

Thompson, J.N. 1999 The evolution of species interactions. Science. 284:2116-2118

Redecker, D. Kodner, R. Graham, L.E. 2000. Glomalean fungi from the Ordovician. Science. 289: 1920-1921.

Simon et al. 1993. Origin and diversification of endomycorrhizal fungi and the coincidence with vascular plants. Nature 363: 67-69

Smith M.D. and Read D.J. 1997. Mycorrhizal symbiosis. Academic Press, London

Thompson, J.N. 1999. The evolution of species interactions. Science. 284: 2116-2118.

Macro Intervention: The Kraut Creek, Boone, NC

The Kraut Creek restoration project was initiated in 1995 as an integral part of a larger project pursued by Appalachian State University to replace its central energy plant, relocate its baseball stadium, realign Rivers Street, and to create a new entrance into their Campus (Hobbs, 2006).  There had been little to no research at that time done on stream restoration so this project represents an educated attempt to recreate a mountain stream in a high density downtown environment.



The creek was originally channelized in the mid 1960s resulting in frequent high velocity flooding.  The damage and repair costs associated with this condition encouraged the University to seek a long-term solution.  This solution involved a revolutionary idea at the time:  daylighting the stream.


As one of the pioneer attempts to balance art and science on a malfunctioning urban stream, this project looked to:  meander the stream to increase sinuosity to control velocity and to mimic the mountain stream context, carefully place wiers for function, visual effects, grade transition, and to create a step pool system.


Although in its infancy at the time, stream restoration, or daylighting as it was called then, was the lynch pin of this project.   A study was done of surrounding streams and a functional and esthetically pleasing stream was created.  Important features such as meander and step pools were incorporated.  The floodplain was sculpted to reduce velocity and spread the water flow.  When it wasn’t flooded, these areas form passive use and visually amenable experiences.


As a gateway to the University, this space links the downtown where many students reside to places where they attend classes.  It features two well used bus stops and tennis courts.  These amenities provide a desirable place to see and be seen and help to activate the park.  All of these nodes create a vibrant and well used park.  In addition, internal activity is created by a pedestrian loop trail.  Surrounding mountain stream morphology was analyzed and recreated with this design.  Native plants were also used to help recreate the sense of surrounding mountain  character.


As part of the gateway creation aesthetics and function meld to provide a balance between pedestrian circulation and recreation.  The quality of the aesthetic experience as well as the functionality of the floodplain design and trail layout help to create a picturesque mountain identity for Appalachian State.

The portion of this trout water stream to be restored represented the last section of the watershed.  The watershed itself had over 1/3 of its lower area urbanized with no stormwater controls in place.  This resulted in an increased frequency of high flash floods.  Designers had to contend with this as a design constraint in terms of the function of the stream but as a real threat during construction (Hobbs, 2006).  A major event did occur during construction, and the damage was significant.  Undeterred the project went through.

As noted this presented a challenge to designers that resulted in way was perhaps a restoration that was less successful from an ecological point of view.  Without the pool riffle sequence now utilized this stream does not provide the types of habitat necessary to support a complex stream food chain.  The meander was not created using hydrological calculations.  The calculations developed as well as new construction techniques reduce cost and provide tested long-term stability.  As it stands there are a few, what stream engineers call, nick points where there is some soil erosion.

Important lessons learned include recognizing and enhancing the existing activity nodes as well as the idea that new nodes can be created within a park setting (i.e. tennis court, trail, and bus stops).  Additionally, it is important to note that newer methods for stream design would have helped this stream function better and help to avoid some of the nick points Kraut Creek now has.  From a design standpoint many regard this as a shining example of an esthetically pleasing and successful urban stream restoration.

The Urban Hydrological Rationalization for Post Industrial Restoration

The traditional method of stream engineering in an urbanized area was to “remove large woody debris from the channel, straighten that channel, confine the stream in a new concrete channel, armor the banks with rip-rap, or enclose the stream in a pipe” (Brown, 2000). The aim was to move water as quickly and safely out of the immediate area to prevent “local urban flooding” (Brown, 2000). Due to this distorted form, urban streams ecologically malfunction and the wildlife that the stream and stream banks would normally support cannot survive (Brown, 2000). The physical effects of urbanization on natural water processes can be grouped into four categories: impervious surface cover (ISC), drainage density, temperature, and chemical and biological contamination (Paul, 2001).

“The most consistent and pervasive effect of urbanization is an increase in impervious surface cover within urban catchments, which alters the hydrology and geomorphology of streams” (Paul, 2001). When there is rainfall in areas with high ISC, water runs swiftly from roof tops and pavement with little to no absorption into the ground. This has two rather devastating effects both on the function of the stream and potentially to human settlement around those watercourses. Since the water runs more quickly, the time between the precipitation event to the “center of the runoff volume shortens within the urban catchments” (Paul, 2001). This results not only in more frequent flooding, but “floods that peak more rapidly” (Paul, 2001). In addition, since less water is absorbed into the ground, there is no water to provide baseflow discharge in the urban stream. The situation becomes one where there is little to no flow in what would normally have been an ephemeral stream followed by episodes of dangerously high flooding (Paul, 2001). Flooding in itself is as well a natural and much needed occurrence, however when the type and amplitude of flooding is not responsive to the climate, soil, and geology of the area, important amounts of land and vegetation can be lost from an area that normally would not have experienced those events.

It is important to address other water strategies in conjunction with stream restoration. There may be a question as to the detrimental impact of high density development or redevelopment of former industrial sites on the newly restored stream (Richards, 2000). If more ISC is introduced to an area using traditional grading and drainage plans there is no doubt that there will be a negative impact on the watershed (Richards, 2002). Lynn Richards, a policy analyst for the EPA sited two important studies conducted in 2000 that suggest that stormwater conservation redevelopment is more desirable condition compared with low density greenfield development or traditional redevelopment. The first is a study from Purdue University which “estimated that placing a hypothetical low-density development at the Chicago fringe area would produce 10 times more runoff than a mixed-uses development in the urban core” (Richards, 2000). The second, conducted at Jordan Cove, found that when “compared to conservation lot design, the large lot development produce 95% more runoff” (Richards, 2000). It only stands to reason that if there is a better and an often time cost effective (both in short and long term profit margins) means of constructing new, or retrofitting old neighborhoods it should be the preferable solution.

Brown, Kenneth. Urban Stream Restoration Practices: An Initial Assessment. Ellicott City, MD: US EPA, Office of Wetlands, Ocean, and Watersheds, 2000.

Paul, Michael J., and Judy L. Meyer. "Streams in Urban Landscape." Institute of Ecology, University of Georgia (2001): 333-356.

Richards, Lynn. Is Density Good for Water Quality? US EPA--OPEI APA Conference. 17 Apr. 2002. 19 Dec. 2005 <http://www.asu.edu/caed/ proceedings02/RICHARDS/richard1.htm>.