Showing posts with label green roof ecology. Show all posts
Showing posts with label green roof ecology. Show all posts

Thursday, January 20, 2011

Green Roof Cations, pH, Garbage Bags, Trace Minerals and Compost (All for Free)

Free Compost, Cations and pH tools
Not too glamorous yet very practical ( remember Louis Sullivan and functionalist architecture) collecting your neighbor's bagged up yard leaves can benefit your green roof and benefit your wallet.

Cation exchange capacity and pH are two important variables of a green roof.  Additionally, leaf compost can add valuable trace minerals needed by the rooftop plants.

Leaf compost typically contains twice the amount of trace minerals by weight as does horse manure.

And heavy duty garbage bags are expensive.  We used to pay about ten US dollars per box at our local home improvement store.  Now we have all the free heavy duty garbage bags we need.

Interestingly, leaves from different species of trees offer varying characteristics.  While ash leaves are relative neutral in pH, some maple species leaves are documented to possess a pH of around 4.5.

Research shows use of properly composted leaves greatly increases the cation exchange capacity of soils.  One of the important functions needed in green roof soil media is cation exchange capacity.

Save $10 per month on garbage bags
 Though varying opinions of organic compost value to green roofs exist throughout the industry, many believe organic material in the soil media is highly beneficial to green roof plants.

Remember, green roofs are individual ecosystems, intricate webs of life with complex interactions.

Flat roofs with poor drainage may or may not require lower organic content to prevent water saturation and facilitate drainage.

Sloped roofs may function appropriately with high organic content.

Collecting heavy duty garbage bags filled with fresh raked leaves (we avoid those lawns heavily treated with fertilizers and herbicides/pesticides - those lawns are easy to spot here in the US due to the small advertising signs the lawn companies stick in the lawn after a fertilizer application - and speaking of lawns and fertilizers - a short must-see video of the history of the American Lawn will have you rolling in your chair and scratching your head at the same time can be viewed here) is a positive step for the environment.

Other benefits include;
  • Free highly effective cation exchange capacity supplements from the leaf compost
  • Free organic matter from the leaf compost
  • Free trace minerals from the leaf compost
  • Free pH adjustment material from the leaf compost (this is especially important when using higher pH soil media or media high in calcium)
  • Free garbage bags
  • And a lesson to your children riding with you to scavenge that recycling is more important than pride. :)
Enjoy the photos of the free leaf compost we gathered last week and also the free heavy duty garbage bags and as always - Happy Green Roofing!

Kevin

Tuesday, December 14, 2010

Green Roof Fertilizer, Irrigation with Potable Water, Invasive Species and Mark Madoff

Mark Madoff's death is a tragedy no doubt, but no more so than any of the other countless lives lost to the end result of another  Ponzi Scheme - the use of Persistent Organic Pollutants (POPs) - and the associated denial of silent environmental and health impacts.

Having read the article posted by @psustentavel on Twitter - click here for the article about Persistent Organic Pollutants - the imagery of 'inorganic chemical 'fertilizers across countless green roofs,  the use of drinking water for irrigation - even backup irrigation - and the reckless abandon with which we use non-native species for landscapes, including those on rooftops, made me think - in our rush to install green roofs atop buildings, are we too creating a Ponzi Scheme someone else will have to pay for?

The value of green roofs is unquestionable.  There is solid scientific data to back up claimed benefits of habitat creation, carbon sequestration, oxygen production. greenhouse gas reduction, heat island effect tempering, cleaning of stormwater, integrated pest management and so much more.

Florida Extensive Green Roof Nature Irrigated

There is no doubt about the value properly designed and maintained green roofs can bring to the Urban Core.

Green roofs can be used to support Urban Permaculture - small scale, individualized rooftop farming operations providing food, fiber and medicine to city residents.

And many urban areas around the world are moving ahead with plans to increase urban agriculture.  Singapore, for example, produces 25% of the entire city's vegetable crop within the city limits. For a fascinating look at the importance of urban permaculture  read foodsecurity.org's white paper entitled Urban Agriculture and Community Food Security in the United States; Farming From the City Center to the Urban Fringe.


Rooftops are the new frontier of real estate in many urban areas.  Cities with limited available ground level real estate have acres of open rooftops.

Vegetated and green roofs are increasing in popularity, showing an impressive growth rate trend over the past decade.  According to Greenroofs.com, public awareness of and interest in green roofs is steadily growing.

Yet we must learn from the Madoff venture's collapse, the immense loss incurred by investors and also those innocent persons affected worldwide by careless and widespread use of persistent organic pollutants commonly associated with some inorganic fertilizers.

In our noble rush to restore volumetric green to the urban core we hopefully will recognize the potential environmental costs associated with mass production of green roofs.  The 'One Size Fits All' approach to green rooftops will not work for the worlds vastly different ecosystems.  Sadly and reminiscent of mega-agriculture's damaging past practices, we as an industry turn to potent chemicals to fertilize, control pests and then use much needed drinking water to either irrigate or serve as backup irrigation.

Independent and craftsman-like green roof design and construction could disappear.


As with the POPs causing health issues in Pakistan and other places, our indiscriminate use of hardy invasive species, potentially toxic chemical fertilizers, pesticides and herbicides on green roofs is a Ponzi Scheme our children too will pay for.


Importantly, we as an industry have already moved far in the direction of ecologically inappropriate and environmentally dangerous green roof design.  Florida's FDEP green roof in Pensacola, Florida possesses a large drip irrigation system, backed up with potable drinking water and planted with slow-release fertilizer compounds and soil amendments.


As in Ponzi Schemes, denial of reality is the basis of success.  Though the 'green' benefits of the FDEP green roof are often touted in the media - the fact that chemical fertilizers are applied and potentially damaging to Escambia Bay's ecosystem are hidden.


Yet FDEP is fully aware of the environmental problems resulting from POPs, fertilization and pesticide use on green roofs.  In the proposed, new State of Florida Stormwater Applicant's Handbook,   FDEP allows green roof credit for volume retention of stormwater only (no water quality credit),  and recognizes fertilizers and pesticides will be used on green roofs (why no water quality credit is given), an approach we must reject.  Moreover, FDEP is requiring the purchase and use of a 'pollution control media' made from ground up automobile tires under the green roof soil media to keep the fertilizer's nutrients on the roof. 

Over time and as water evaporates, added pesticides, herbicides and fertilizers will concentrate back into the surface waters and become an issue for our children.

In the rush to add volumetric green to the Urban Core, the Ponzi Scheme could easily go unnoticed.

Temper the hurry to install a green roof with the knowledge of a local native species botanist and a soils expert.  Rather than ordering large amounts of hothouse pampered plant material, find a local nursery with individual plants acclimated to the climate.

Green roofs can be crafted to add artistic, educational, ecological and ethnobotanical value.

But we must first reject the Ponzi Scheme that green roofs must be fertilized, irrigated with drinking water and doused in pesticides.

As always, email your questions here!

Happy Green Roofing...

Kevin