Friday, September 28, 2012

Tree Tubes - Dozens of Uses

In 23 years of working with tree tubes I have never really sat down and listed all of the ways in which they are used.  I'm going to try to remedy that here in this post.

1) Hardwood reforestation

2) Windbreak & shelterbelt plantings

3) Riparian zone restoration plantings

4) Wildlife habitat (food plot) plantings

5) Mitigation banking

6) Orchard establishment

7) Mine reclamation

8) Ecological restoration

9) Urban & landscape plantings

10) Timber stand improvement

12) Nursery production

 I know, I said "dozens" of applications for tree tubes, but only listed an even dozen.  Here's the thing:  within each of these dozen applications are dozens more specific uses.  For example, orchard establishment encompasses everything from planting pistachios in the sun-baked San Joaquin Valley of California, to planting a field of anti-oxidant rich Aronia berry in Missouri (speaking of which, switching the common name away from "chokeberry" was probably a good marketing move on someone's part!), to a back yard orchard of heirloom apples in New York... and everything in between.

So in upcoming posts I'll take one of these categories and look at the history of tree tube use for that application, cover some case studies, and offer some tips for success.

Come back soon!

Tuesday, September 11, 2012

Tree Tube Chronology: B.V. and A.V.

Outstanding stem caliper growth in 2nd year oak planted as 
an 18 inch seedling in a 4ft Tubex Combitube Plus Tree Tube.
 I divide the history of Tree Tubes in the USA into two distinct eras:  Before Venting (B.V.) and After Venting (A.V.).  Venting - the seemingly simple act of punching holes in the solid walls of the tree tubes - is the single most important advancement in the development of tree tubes.
By 1989 treeshelters were widely used and accepted in the UK.  The largest and best maker of treeshelters was Tubex, Ltd.  Tubex Treeshelters were introduced to the USA in 1989 by a small company based in St. Paul, Minnesota.

At that time all tree tubes were unvented - solid translucent corrugated tubes.  It was thought at the time that the rapid growth of tree seedlings inside the tree tubes was due to the creation of a "greenhouse effect," and the goal was to create an air-tight growth chamber.

I was there at the beginning.  I was the first employee - fresh out of forestry school - of that first company that introduced Tubex Treeshelters to the USA.  By and large the results in the field with those unvented tubes were good - excellent survival rates, rapid height growth, and of course "not getting eaten by deer" generally beats the heck out of "getting eaten by deer."

But we also started to get some troubling reports of problems from the field - and not coincidentally those problems were more serious the farther you got away from areas with climates most similar to the UK.  Those unvented tubes performed well in the Chesapeake Watershed region, and in coastal California and the Pacific Northwest.

However, get the farther north or south you went, the more frequent and serious the complaints.  These complaints fell into three categories:

1) Winter injury.  In northern climates seedlings in tree tubes simply didn't harden off properly for winter, and often suffered die back due to cold weather.

2) Spindly stems.  Seedlings in tree tubes exhibited rapid height growth, but the trees had very thin stems relative to the height of the trees.

3) Fungal problems, notably in the south, and probably due to excess moisture in the tree tubes.
So by this point - and we're talking about the mid 1990s - the potential of tree tubes to increase survival, shield valuable seedlings from deer browse and accelerate height growth was clear to all.  However, it was equally clear that in many cases, and especially the more extreme the climate, the upside of using tree tubes was largely counteracted by the side effects: winter injury, thin stemmed growth, and fungal diseases.
Enter some good ol' Yankee ingenuity!  Every software package ever introduced has had 'bugs' that needed to be ironed out with subsequent updates.  The first effort at 'de-bugging' tree tubes was a partial recognition that air flow in the tubes can be good; growers in northern climates were advised to elevate their tree tubes in early autumn to allow the trees inside the harden off for winter, and then lower the tubes back to the ground after the first hard frost.
This advice worked as far as it went; elevating the tubes did greatly reduce the incidence of winter injury.  It also exposed the base of each seedling to rodent damage at a time of year when rodents are hungrily feeding in preparation for winter.
Then some enterprising landowners applied something that we tree tube peddlers sorely lacked:  Common sense.
Landowners started drilling holes in the tubes, and then calling to tell us how well their trees were growing.  And we tree tube peddlers did what most 'experts' do:  We ignored them.  In was only when research done in far away France confirmed - and scientifically explained (more about this below) - the benefits of venting that we finally took notice... and slapped ourselves on the forehead with a loud "d'oh!"

The performance of vented versus unvented tree tubes is night and day.  Venting didn't just solve the side effects of those early tubes.  It unleashed the full potential of tree tubes to massively increase total biomass growth.

The French researchers figured out that in solid tubes carbon dioxide often becomes a limiting factor - the seedling uses all of the CO2 in the tube then grows very little until the CO2 level recharges. In vented tubes the CO2 level is constantly recharged, and never is a limiting factor.

In addition properly vented tubes (such as the Tubex Combitube Plus) allow dappled sunlight to strike the leaves, and allow a puff of air to gently shake the leaves.  In both cases this triggers growth responses in the tree similar to if the tree was growing in full sun in an open field (namely thicker stem caliper growth and better root development) - except that the seedling still enjoys complete deer browse protection and a massive reduction in moisture stress a compared to its un-tubed comrades.
Even though unvented tubes performed well in areas with mild or maritime climates, it is important to understand that there is no climate in which an unvented tube outperforms a vented tube.

So you can see why I divide the history of tree tubes in American into B.V. and A.V:

Before Venting:
Complete deer browse protection
Increased survival
Rapid height growth
* Winter injury in cold climates
* Thin-stemmed growth in all climates
* Fungal diseases in hot/humid climates

After Venting:
Complete deer browse protection
Increased survival
Increased total biomass growth - height, stem caliper and roots
No more winter injury
No more fungal disease issue
In summary, tree tubes as they were developed in the UK were a great idea, but it took some French research and bunch of landowners with cordless drills and common sense, to unleash their full potential!

Tuesday, September 4, 2012

This is what tree tubes can do!

Click to enlarge

The facts on this tree are astounding.  This is a hybrid oak from Mossy Oak Nativ Nurseries.
It was planted as a 18 inch seedling in late fall 2011.  In other words, this is it's first growing season in the ground, and it's been less than two years since the acorn that produced it dropped from the mama tree.

It emerged from the green tree tube early this summer.  That green tree tube is 4 feet tall - so if the tree had stopped growing and decided to call it quits for the season at that point, the rate of growth would still have been impressive bordering on amazing.

But as you can see, it didn't stop - it was just getting started!  Deer started browsing the tip after it emerged from the 4 foot Tree Tube, so the grower added a 2 foot tall "tree tube extender" to provide another 2ft of deer browse protection.

Within a month the tree had emerged from the top of the tree tube extender, meaning it was by then 6 feet tall and had grown 4.5 feet this season.  And it still wasn't done.

Since then this tree - this supposedly slow growing oak tree - has grown another 2.5 feet, putting its height at about 8.5 feet. For those of you keeping score at home, that's 7 feet of growth in a single growing season, starting as an 18 inch seedling.

Top-notch growing stock and state-of-the-art growing practices are the basis of results like this.  But after seeing this you can't tell me that tree tubes aren't one of the most important developments in tree planting to come along, well, ever.

Let's start at the very beginning...

... a very good place to start!

And let this be the official beginning of a campaign for Mr. Graham Tuley to be awarded a Nobel Prize.  I'm serious.  Tree tubes are the single most important invention in tree establishment, and given the monumental importance of successful tree establishment and reforestation it's not a stretch to say that tree protectors are one of the most important inventions of the last century.  The iPod plays music.  Tree tubes heal the planet.

Treeshelters - as they were known in their early days - were developed by Mr. Tuley in 1979.  Tuley was a forester with the UK Forestry Commission.

Frustrated by continued failures in hardwood establishment - primarily English oak (or, as the British call it, common oak) and sessile oak - due to increasing levels of deer and rabbit browse, Tuley struck upon the idea of forming translucent plastic tubes around each seedling.  The idea was essentially to provide "safe passage" past the worst of the deer browse, while still giving the seedlings plenty of sunlight for growth.

The potential benefits in terms of animal browse were immediately obvious.  The wire or plastic mesh guards in use at the time had many failings; they were cumbersome to apply, and shoots often grew through the mesh to either get browsed by deer or later become girdled by the mesh itself.

Known in those early years as Tuley Tubes these solid translucent plastic tubes would clearly provide complete protection from animal browse until the seedling grew out the top.  The question was, how well would the trees grow inside the tubes?  The answer turned out to be:  Really, really well.  In Tuley's own words:

"(Tree) Shelters are 1.2 m tall plastic tubes which protect trees from animal damage and improve growth by creating a ‘greenhouse effect’ round each tree. After 3 years the mean height growth of sessile oak transplants in shelters was 142 cm compared with 45 cm in a mesh guard and 27 cm for unprotected trees and the average stem volume was 118, 37 and 19 cm3 respectively."

I think it's safe to say that Mr. Tuley was on to something big.

And after three decades of refinement - in design, protection methods, and guidelines for proper use - tree tubes have become and indispensable tool for successful reforestation worldwide.

There are so many heroes behind the treeshelter story.  And I'll keep telling them. Stay tuned!