Trees in Paved Surfaces: Structural Stability vs Rootable Soil

Posted by Shane Carpani on Oct 15, 2015

http://blog.greenblue.com/

 

 

Soil structure is fundamental for the planting of trees, as well as the stability of roads, buildings, and other infrastructure. It refers to two things:

1. the arrangement of soil particles including silt, sand, and clay that aggregate together
2. the void pore spaces between these aggregate particles

In this article, we discuss why appropriate soil structure is critical to healthy tree establishment, and what landscape architects and other specifiers can do to ensure newly planted urban trees receive the conditions they need to thrive, so they can provide the many benefits that mature trees offer. 

Why We Need Soil Structure

Not every soil is conducive to the growth of trees and other plants, urban soils least of all. Tree growth and fertility are strongly influenced by soil structure, as it defines whether the tree will have rootable soil available and affects the movement of air, water, and other nutrients required for trees to flourish. 

Effectively the 'architecture of the soil', soil is usually the most critical element for the success or failure of urban trees. A well structured soil functions like a reservoir, enabling the tree to accept, store, and transmit water and nutrients, provide room in which roots can propagate, and allow the space required for life and the necessary biochemical exchanges for growth. 

Trees & Compacted Soil

Too often, trees are planted in cramped planting pits and poor subsoil, resulting in retarded growth, with roots tending to colonize the area immediately underneath paved surfaces, leading to structural pavement damage. 

Root colonization immediately underneath the paving stone roadway causing pavement damage 

There are different types of roots associated with tree establishment. Anchor roots function as a structural element to the tree and hold the tree in place in the soil. 

Fibrous roots (or feeder roots) are roots that intake nutrients, and typically grow in the top 6" of the soil. They can be directed lower to avoid damage to paved surfaces, if appropriate irrigation and aeration are ensuring the required nutrients are reaching lower levels. This "feeder zone" can extend between two and seven times the diameter of the canopy drip line. 

The feeder zone of any tree must be protected from compaction in order to ensure root establishment. 

"Resistance to root penetration due to soil compaction will affect
root establishment and the ultimate health of the tree"

Tree roots are opportunistic and seek out favorable growing conditions. Moisture and air trapped between impermeable pavements and compacted soil attracts nutrient-starved roots to grow into those areas. The resulting colonization of those roots causes subsequent pavement heave and infrastructure damage. 

These trees died prematurely due to unavailable rooting volume caused by soil compaction 

So how can urban trees be adequately provided for in their city settings, without compromising or damaging the structural integrity of paved surfaces? The answer is structural soil cells. 

How Soil Cells Work

As we discussed in last week's article, urban soil rarely provides the favorable environment trees need to grow and flourish. Hard compaction, lack of aeration, poor drainage, low nutrient levels, and the existence of pollutants in soil stunt root growth and make it nearly impossible for urban trees to thrive. Landscape architects, arborists, engineers, and other specifiers have the availability of strong soil support systems that, while conducive to root growth, also offer adequate support for roads and sidewalks. 

The concept behind soil cells was first developed by GreenBlue in 1992, when our UK branch installed the first tree pit using soil cells to provide uncompacted soil volume for root growth underneath a paved surround. 

Suitable for parking lots and sidewalks, soil cells prevent the topsoil in tree pits from becoming compacted by the pressure of surrounding hardscapes, amongst other things. They allow trees in urban settings to have large, healthy root systems, thriving in quality uncompacted soil.  

These modular units are assembled into a skeletal framework (or matrix) with over 90% void space to provide large volumes of soil within the tree pit for the healthy growth of roots - all while also supporting pavement loads. 

Designed to highly advanced engineering specifications in order to support heavy vertical and lateral loads, StrataCells bring tree root systems closer to the pavement surface. Engineers have calculated that with only 12" (300mm) of granular pavement depth, a StrataCell matrix can support maximum traffic loads, while providing over 94% of void space for root growth. 

With both vertical and lateral forces considered in the engineering make-up of tree pits, soil cell modules lock together, forming a monolithic framework with excellent modular strength. Highly secure connectors allow for modules to click together fast and simply, while it's enormous growth zone allows for plenteous root establishment. 

Structural Integrity of Soil Cells

GreenBlue soil cells are crush tested during manufacturing as part of our rigorous quality control standards. Whilst FEA (Finite Element Analysis) computer load testing was also conducted during the initial design stages to project the loading capacity laterally and vertically, physical laboratory tests were then used to clarify the cells actual loading capabilities. 

This physical load testing is part of an ongoing development and research program, and is the only true measure of structural integrity. GreenBlue soil cells are made using 100% recycled polypropylene, and have the highest structural integrity of any large soil cell. 

Fatigue Testing

As manufacturer of the world’s strongest soil cell, GreenBlue has subjected our soil cells to extraordinary laboratory tests, including fatigue testing. In one test, a university applied a load of 8.6 tonnes to a StrataCell® tower 10,000 times. The tower was then crushed to measure whether the ultimate load had been diminished by the cyclic loading. The high strength modules had lost no strength, verifying the design of this remarkable system. 

In closing, our streets do not have to be a battle between trees and pavement. They can coexist together, if specifiers and professionals consider the site conditions and provide an appropriate soil structure to suit both tree planting and infrastructure construction. 

Please consider sharing this article, and download our free eBook on the Soil Requirements of Urban Trees. 

Written by Shane Carpani

Shane Carpani is the Creative Director and Manager of Content Strategy at GreenBlue Infrastructure Solutions. Connect with Shane on LinkedIn or follow @ThinkGreenBlue on Twitter.

http://blog.greenblue.com/trees-in-paved-surfaces-structural-stability-vs-rootable-soil

 

 

 

 

More than 44,000 people came together to set the Guinness World Record for reforestation.

Curator: Parker Molloy

 

More than 44,000 people came together to set the Guinness World Record for single-day reforestation efforts.

 

A group in Ecuador set a world record over the weekend by planting nearly 650,000 trees in a single day.

 

Agence France-Presse reports that on May 16, 2015, nearly 45,000 people took part in the largest single-day reforestation project ever. In total, 647,250 trees (and more than 220 species of plants) were planted on roughly 5,000 acres of land, marking a new Guinness World Record. Woo!

 

Volunteers begin reforesting an area near Catequilla, Ecuador. Photo by Rodrigo Buendia/AFP/Getty Images.

 

Better than just a world record, these reforestation efforts will help Ecuador reach its own national target to conserve and restore more land than is deforested between 2008 and 2017.

Since 2008, the country's environment department notes, deforestation has been reduced by more than 50% of the historical rate, protecting 4.3% of the total land area (which comes out to the equivalent of something like 840 million trees, but who's really counting, anyway?).

 

A child plants one of more than 200 species of plants during Saturday's record-setting day. Photo by Rodrigo Buendia/AFP/Getty Images.

 

Reforestation helps offset the amount of carbon dioxide in the atmosphere through "carbon sequestration."

Essentially, there are two approaches to reducing the amount of carbon in our atmosphere: reducing the amount of emissions being produced (obviously) and sequestration, which deals with the carbon itself.

Trees naturally absorb carbon dioxide, pulling it from the atmosphere and using it for — you guessed it — fuel. Trees have some other benefits, too, like improved air, water, and wildlife, and some protection against erosion.

 

Photo by Rodrigo Buendia/AFP/Getty Images.

 

Trees are absolutely crucial to the fight against climate change.

While this seems pretty obvious, it's easy to forget. A great many things can affect climate change, from the things we eat to the cars we drive to the energy we use to power our homes. But the number of trees out there absorbing carbon are important factors, as well. Deforestation intensifies climate change, and reforestation and conservation efforts help push back.

 

Imagine how good things could be if every country had a day like this.

 

http://www.upworthy.com/more-than-44000-people-came-together-to-set-the-guinness-world-record-for-reforestation?c=ufb1

 

 

 

 

Saving trees: a story about going further

 

 

03/25/15 04:15 PM

Sponsor generated content

 

Can cloning halt climate change? It might sound like science fiction — but while it definitely involves science, arborist David Milarch believes it’s not fiction.

 

In fact, it is David’s life’s work as a former Ford employee and the founder of the Archangel Ancient Tree Archive. Driven by a singular goal — to reforest the world with ancient trees — David is just the kind of visionary Ford’s Go Further campaign celebrates.

 

A native of Copemish, Michigan, David comes from a long line of arborists. He founded the Archangel Ancient Tree Archive more than 20 years ago, firm in the belief that he could clone — and save — the largest living trees on earth. David says success could help reverse the effects of climate change.

 

“We found six champion trees, which are the measured largest of their species, and my sons Jared and Jake climbed them,” David says. “We took the tissue out of them, and we had nurseries in Oregon that said they would try and clone these trees for us.”

 

Remarkably, David’s plan worked. “Almost every step of the way, the experts told us this is impossible, it can’t be done. But here we sit,” he says, gesturing toward a greenhouse full of tree starts. “And it works.”

 

Archangel’s mission? Collect genetic material from ancient trees, some of which are nearly extinct. Propagate the material in a lab to grow new trees, while also compiling an archive of DNA for future study and use. Then plant trees where they can release oxygen — with the ambitious aim of putting the brakes on global warming.

 

Archangel arborists select trees with certain characteristics — longevity, hardiness, and resilience — that make them most beneficial to the environment. Many are two and three thousand years old. Some trees have particular biological skills: coast redwoods, for example, are champions at filtering carbon.

Others have historical value, like the giant sequoia trees Sierra Club founder John Muir brought from Yosemite to his home in California, or the beech trees famed landscape architect Frederick Law Olmsted planted in Central Park.

 

Collection isn’t easy. Climbers might scale halfway up a 300-foot tree to reach fertile material. Conversely, sometimes even stumps left after forest fires can yield productive tissue for cloning. In either case, the payoff is enormous: A thousand cuttings can produce as many as a million tree starts.

And at a time when as little as two percent of virgin forest remains in the U.S., David’s work to save ancient trees and repopulate barren stands of forest takes on new urgency.  

 

“What old growth forests do to clean the air and clean the water kept everything in balance and in check,” David says. “And in our infinite wisdom, what did we do? We cut down 98 percent of those forests.”

 

Determined to reverse the damage, Archangel Ancient Tree Archive has planted old growth forests in seven countries so far. From the ancient giants, David is finding new life to help the planet.

 

“If we can do what we’ve done here, and affect the world as we have, just think of what you could do,” David says. “One person can make a difference. A big difference.”

 

Link to video:  https://www.youtube.com/watch?feature=player_embedded&v=3qkEEjolpFU

 

From more information on this group--  https://www.ancienttreearchive.org/

 

http://www.msnbc.com/msnbc/saving-trees-story-about-going-further?cid=sm_fb_msnbc_ford

 

 

 

 

 

Where’s the best place to plant my tree?

From our Save-A-Tree, Plant-A-Tree Program:

 

When deciding the location to plant your tree here are a few things you need to consider:

 

1. The tree you received is currently too small to plant on your swale (area of right-of-way between sidewalk and street) so it should be planted on your private property. 
2. Know how big your tree will get.  Check the flyer you received or go to http://www.fortlauderdale.gov/saveatree/index.htm to find out. 
3. Plan for future growth.  Planting your tree in the right place will reduce maintenance and a number of problems for years to come.  These are recommended distances from your house, pool, underground utilities, sidewalks and other improvements:
   1. 8 feet for Small growing trees
   2. 15 feet for Medium growing trees
   3. 20 feet for Large growing trees 
   4. See the diagram below on placement around overhead utility lines.

 

 

4. Trees can save you money on your energy bill.  Trees should be placed on the south, west, and east sides of your house to provide the best shade. 
5. The tree you received needs full sun for best growth.  Don't place these trees in the shade of other trees. 
6. Call Before You Dig – What you can't see can hurt you, so before you reach for a shovel, reach for the phone. Did you know that a free call to Sunshine 811 will start the process of getting underground utility lines marked? Simply dial 811 at least two full business days before you plan to start digging and a representative will come out to your house or business and clearly mark the location of all underground utilities. This is a free service. You can also submit your request online at www.Sunshine811.com.
7. For more information:
   1. http://www.fortlauderdale.gov/saveatree/index.htm
   2. http://fyn.ifas.ufl.edu/FFL/right-plant-right-place.html
   3. http://www.arborday.org/trees/righttreeandplace/
   4. http://www.fpl.com/residential/trees/right_tree_right_place.shtml
   5. http://www.itreetools.org/design.php

 

 

 

 

The Best Technology for Fighting Climate Change? Trees

Between now and 2050, forests are one of our "most promising" geo-engineering tools.

 

Robinson Meyer

Feb 9 2015

 

 

When people talk about technologies that might offset climate change, they often evoke not-yet-invented marvels, like planes spraying chemicals into the atmosphere or enormous skyscrapers gulping carbon dioxide from the clouds.

But in a new report, Oxford University researchers say that our best hopes might not be so complex.

In fact, they are two things we already know how to do: plant trees and improve the soil.

Both techniques, said the report, are “no regrets.” They’ll help the atmosphere no matter what, they’re comparatively low-cost, and they carry little additional risk. Specifically, the two techniques it recommends are afforestation—planting trees where there were none before—and biochar—improving the soil by burying a layer of dense charcoal.

Between now and 2050, trees and charcoal are the “most promising” technologies out there, it said.

It also cautioned, however, that these so-called “Negative Emissions Technologies” or NETs should only be seen as a way to stave off the worst of climate change.

“NETs should not be seen as a deus ex machina that will ‘save the day,’” its authors wrote. NETs should instead be seen as one of several tools to meet the international goal of avoiding climate change greater than 2 degrees Celsius. Another crucial tool is reducing emissions.

It’s a solution that makes sense, as forest management is one of the oldest ways that humans have shaped their environment. Before the arrival of Europeans, Native communities in the Americas had been burning forest fires for millennia to support the growth of desirable plants like blueberries and to manage ecosystems. British communities have long practiced coppicing, a tree-cutting technique that keeps forests full of younger trees.

In other words, humanity has been “geoengineering” with trees for a very long time. The authors of the Oxford report add that afforestation will need global support in order to be successful.

“It is clear that attaining negative emissions is in no sense an easier option than reducing current emissions,” it says (emphasis mine). “To remove CO2 on a comparable scale to the rate it is being emitted inevitably requires effort and infrastructure on a comparable scale to global energy or agricultural systems.”

 

http://www.theatlantic.com/technology/archive/2015/02/the-best-technology-for-fighting-climate-change-trees/385304/

 

 

 

 

Finding the right tree for your space

Planting a tree can be fun and rewarding but you need to make sure you plant the right tree in the right place so that 10 to 15 years down the road the tree is not causing damage.  We are very lucky in South Florida that we have a wide range of tree species that grow in a multitude of sizes.  You should be able to find at least one tree species that will fit the space that you have.  Watch this blog over the next year for information on selecting the right tree for your planting space.  Here’s some basic information to consider when selecting a tree.  -- Gene

 

Tree Location – The Right Place

 

Growing space both above and below ground should be considered when selecting a tree to plant. Too often allowances are not made for the increased size of the tree when it matures. Some of the problems that can be avoided by selecting the proper tree for the available planting space are:

 

•Damage to houses through cracked foundations, leaves in gutters or abrasion of tree limbs hitting the house;

•Cracked pavement of sidewalks, driveways, porches and patios;

•Sewer lines or septic tanks clogged by roots;

•Dangerous screening by obscuring traffic signs, pedestrians or vehicles;

•Storm damage and electrical problems from trees or limbs affecting utility lines; and

•Blocking scenic views or windows.

 

One objective for planting trees in a residential setting is to provide shade to cool homes during the summer months. For morning shade, plant trees on the southeast exposure of the house. For afternoon shade, trees should be planted on the southwest exposure. Deciduous trees (those that lose leaves during the winter) allow the sun to warm the house during winter and shade it during the summer months. Evergreen trees planted on a northern exposure will screen or block cold winter winds.

 

Remember that trees will become larger with age. Your evaluation of the site before planting will allow you to choose the correct size of tree for the site, avoid crowding before it occurs and save time and money at some future date.

http://essmextension.tamu.edu/treecarekit/index.php/before-the-storm/planting-and-tree-maintenance/planting-the-right-tree-in-the-right-place/