Vertical Hazards… If You’re a Raindrop!

In a summer rain we often seek shelter under a tree.  Why? Because the tree and its canopy intercept the rain.  Often within woodlands, rain events can be completely masked from hikers below because the full canopy completely diverts all the rain.

One of the “new” benefits promoted for urban trees is the interception of rain.  In the urban forest, trees serve as storm water modifiers, reducing the runoff of rains into the city water system.  City planning offices calculate and enforce detention ponds for urban properties.   Many homeowners have rain water collectors for irrigation. Groves of trees can be more attractive than grassy detention ponds, will grow in value over time, and maybe more functional in managing rain water!   Others have rain gardens to detain flows off the roof and driveways (are you interested in creating your own rain garden?  In the Fort Wayne area, you might qualify for cash incentives!  Click HERE to learn more.).  Municipal areas would be more attractive with rain gardens, too.

The volume of water that is intercepted by a tree depends of the size and architecture of the individual tree. Just as in the woodlands in the summer, light rain events may never hit the ground. High percentages of precipitation can be “controlled” by biomass of an urban forest.

Honey Locust

Wet Side and Dry Side

Water Puddle

Click any of the pictures in the gallery to see a larger view.

This Honey Locust sits in Jeff’s front yard.  On an April, 2011, Monday, it was raining AGAIN (over 9” fell in the 6weeks of late April and May!).  In these pictures, you can see how the tree diverts the rainfall and creates a puddle at the base, allowing the water to be retained into the turf.  Runoff can further be “delayed” with tree bunkers or by retrofitting existing trees with Rootwell® (see our posts HERE and HERE), a low cost vertical channel product, which can direct gallons of rain water into the ground.

We are passionate about Urban Forestry here at Arborwise, LTD.  Give us a call and talk to us about your questions!

Viable Trees in Modern Spaces

Urban Forestry appears to be coming to a cross roads. It is not yet fully determinable and it surely is not pre-ordained. The decision points, however, are tangible; the pivot points are clear; the consequences will impact a generation of trees, arborists and the communities in which we live and work.

All decisions have consequences (both positive and negative), costs, benefits and penalties; some are purposeful, many are accidental, but all have their tangible outcomes. So too, Urban Forestry is defined and detailed by our outcomes and our ‘product’ (individual trees and the ‘community of trees’ inhabiting ‘our’ man-directed sites: city streets and parks, developed properties and individual homesteads).

Urban Forestry holds to a specific paradigm, a ‘belief system’, if you will: trees make sites better and more valuable. As proponents of this belief, as stewards of the investments, we speak and act: more trees are better than fewer trees. Big trees are more valuable to themselves, the eco-system they foster and for those around them (four-legged and two-legged). The community of big trees, i.e. canopy, is “the dream” and ultimate expression of successful urban forestry practice.

When a government or private entity cuts the horticulture budget due to reduced tax revenues and/or redirected political priorities, the results are easily projected: fewer trees planted, less arbor-care conducted. The Urban Forest, its content and character, is limited and depreciates. That is the tangible reality!

As 2012 begins, this “arbor philosophy” with its crash into political reality will be a thread with several levels of consideration and thought.  We look forward to the upcoming dialogue; leave your thoughts and comments below.

The Ultimate Vertical Hazard

This gallery contains 3 photos.

Please click on any of the gallery pictures above for more details! Trees are potential vertical hazards.  The risks associated with trees are multiplied by the structures and activities around them.  In late March, the red oak in Picture 1 … Continue reading →

Trash or Treasure?

Recently, I posted this message in one of my LinkedIn groups:

The ‘Tree of Heaven’ (a common nuisance tree in the urban setting) we so despise, is actually a ‘perfect’ urban tree . . . Nature says so- by millions of saplings and by the survival of so many un-nurtured large trees. Given the life expectancy of so many installed urban trees, it might be better for us to apply the term, “trash”, to the Rubrum Maples in parking lots and the Honey Locusts along streets.

As urban foresters, we specify, design, and plant counter-intuitively to Nature.  We choose to not just deviate, but to actually OPPOSE the natural process.  We impose our ‘order’ or our ‘sense of value’ onto a site.  We establish values on trees based upon an artificial ranking system- viable and defensible, perhaps, but not very functional. Many urban trees are planted, not based upon character or proposed outcomes but instead upon price at the nursery, or the availability in a particular size.  Is it any wonder, then, why the average urban forest tree lives only 7 years? 

Unlike people, Nature isn’t concerned about an individual specimen.  Instead, its processes have goals about biomass and natural selection.  The Mulberry tree and the “Tree of Heaven” fit into nature’s scheme- not as specimens, but as pioneers.  As these trees grow, they prepare the site for longer-living species. 

The truth is, in Nature, there are no ‘trash trees’, only purposeful succession. All plants share in the ‘creative genius’ and have a place.  What we choose to do in the urban forest isn’t necessarily wrong, but it is an artificial ecosystem created by people rather than by nature.  As urban foresters, perhaps we should take a cue from nature- maybe we should even be planting Trees of Heaven… and then come back in ten years and plant a Rubrum Maple.

Knowing Trees: From the Inside, Out

Continuing the thread in Issue 1, “Above the ground, the wood is both ‘descriptive’ of the species and ‘directive’ of its character and risks.”  Now it is time to give further consideration through example.

The Callery Pear, in all it cultivars, is a widely used urban tree.  This issue of the blog is not the place to discuss the merits and demerits this tree, other than to say that the marginal maintenance demands and the instant beauty of the Callery Pear in a lawn, coupled with the ‘low’ cost of this tree at the nursery makes it a natural choice for developers and urban planters. 

The ornamental pear holds within itself both positive and negative characteristics based in its genetic predisposition, both species- and cultivar-specific.  Again, at another time, the issue of the budding, flowering and leaf drop calendar will be discussed.

For pears in the USDA growth Zones of 4, 5, 6, the risks for structural failure are real, escalating over time and size. This is often the result of early ice/snow events, but the weather event is a mere inducement.  This mechanical failure is genetic!  The pear tree has a proclivity to acute angle branching and included bark crotches-  The gene pool, for most pears, predestines them to breakage.

There are pear cultivars which limit this risk and one can become a substantial sized tree in 25 years.  Given the urban tolerance of P. calleryana,  this has huge upside for golf courses and constrictive man-made sites. 

Knowing trees from the inside out can reduce costs over time and insure generational values in the urban forest.

Tree Template or Internal Directive?

In Issue 1, this axiom was recorded: 

 “Above the ground, the wood is both ‘descriptive’ of the species and ‘directive’ of its character and risks.”

 Nearly every facet of above ground wood is descriptive of the species and even,  in most cases, a ‘cultivar’ of that species.   Each wood component is descriptive of the species- from bark, conductive tissues and heartwood, to branch angles, bud radii and internode lengths.

 [A sidebar to all this are the many tree hybrids, both natural and man made. We now know that many species in the ‘White Oak’ tribe as well as the Rubrum and Silver Maples will hybridize naturally, producing interesting quandaries for inexperienced taxonomists.  Yet even here the wood characteristics codify the hybrid for what it is.]

 Designers and Site Managers often expect a tree to develop along a specific template of size and form.  This thinking is often based upon short term thinking, looking ahead only 10-20 years.  Unfortunately, some trees do die within that 20 year period (far short of their internal directive), but many trees live “generationally” (for fifty years or more).  During this time, their genetic stencil becomes fully evident:  Trees growing too tall (for the power lines and signs), growing too wide, (for the streets and buildings), hanging too low (for clearance), or producing too much ‘weak wood’ or co-dominate stems (and therefore storm debris and casualty risks).

 “Too tall, too wide, too low, too weak!”  This sounds like people-centered thinking, not the chromosomal directed, wood-established character guarantee, used to build each tree.  Rather than designing sites that attempt to sculpt a tree into a specific representation, isn’t it better to create a site that takes the natural design of a tree into prominent consideration?  I believe so.

Issue 1

One thing separates trees from all other plants:  it’s the wood!  More directly, the location and formation of the wood, both aerial and sub-surface, makes trees in general and specifically, in each species, unique.

It is the wood which produces the opportunities and risks for tree planting, tree longevity and tree risks on a cultured site or as assumed when a natural site is developed.

Above the ground, the wood is both “descriptive” of the species and “directive” of its character and risks.  Wood is tree engineering over time.  It is:

• the predetermination and the precipitation of a definite pattern to build the organism in three dimensions.  The genes map the shaping of the tree, the site drives its response to the site’s condition.
• it’s a real time response mechanism to the situations the trees find themselves under, for trees are responsive and reactive growers. 
• The wood is a recorder of history, both the organism and the site. Trees have a “body language” which can be read to tell its “story”.

A tree’s texture, form, vigor and life span will be altered by orientation, competition and site conditions and management (or mis-management).  Throughout its life, the tree will be the summation of its gene pool and the site’s impacts.

Whether a golf course, a suburban lawn, or an urban-scape, every tree will reflect its chromosomal template and its micro-environment imputes.