Bradford Bender, Patrick N McGovern 2018
Hybrid aspens can regenerate from root suckers after a harvest and re-establish the site without replanting. This capability provides an option to plant less initial trees (e.g. 35/acre) then cut them at about age 5-7 to fully stock the site, or inter-plant the aspens with a companion species (e.g. Larch) and harvest them at the same time at about 20 years. The catch to these processes is balancing the initial planting costs with the desired harvest age, deer damage and weed control. This two site (Escanaba MI, and Rhinelander, WI) 5 year demonstration study was established the week of November 12-18/2017. It is intended compare growth differences of tree tube and textile fabric tree protection systems on Fall planted 5’ 6” tall 1-0 rooted aspens and the DN34 (Eugenei) control clone. The premise is that the 1-0 trees are taller than the 3’ sleeves and 5’ tree tubes, will be exposed to full sunlight and may grow at the same rate as the non-sheltered trees. It is primarily based on the following hypothesis: “If using tree shelters with tree heights exceeding the shelter, then significant stem growth differences will not be observed.”
Tree shelters can be used to help protect young aspens from deer, rabbit, vole and herbicide impacts. The most common tree shelters are commonly referred to as “tree tubes”, are readily available and typically cost over several dollars for the tube and stakes. Another tree shelter process involves using folded and stapled woven textile fabric sleeves [1]. Estimated material cost per 10” x 3’ sleeve is about $.35 each.
Typically, tree tubes are used for aspens with young seedlings or cuttings which require overhead protection via the 5’ tree tubes. However, the textile sleeves must be used with taller, thicker “deer proof” plant material having stem diameters ideally .5 inches at DBH to withstand deer breaking the stems with their teeth. This study uses about 7-9’ tall 1-0 aspen stock cut back after planting to about 6.5’ from root to the cut tip. Basically, the tree tube system can use smaller, less expensive stock but requires more expensive tree shelter materials. The textile sleeves require larger, more expensive 1-0 “deer proof” stock with less expensive tree shelter materials. The labor differences should be investigated and consider any post planting maintenance.
A desirable tree shelter process should be inexpensive, easy to install in the field and not require any maintenance post planting. The tree tubes may require retrieving the tubes/stakes at a later date and textile sleeves may be outgrown while the trees are still vulnerable to deer rubbing. See Open4st for more aspen project details including “Multi-Stage Aspen Planting Strategies” [1].
Potential planting risk factors affecting implementation, growth and survival:
Residual leaves were still on the 1-0 nursery trees when they were lifted to begin to meet the November 2017 planting date. The leaves were manually stripped from the stems which could impact growth/survival with a Fall planting. See 2017 Open4st Tree Shelter Demo nursery photos.
The ground may be too frozen for Fall tree planting, necessitating rescheduling to plant in the Spring.
There may be first year differences by variety and testing error caused by some trees having larger, more favorable root to shoot ratios.
We have observed field planted aspens fail when they break the tree tube (see: TxE-2014) and textile sleeves fail when they prematurely pull away from the stem due to staple failure or short width sleeves (see 2B29 buck rub).
We have observed potential tree bark damage even with the stainless steel staples on some trees, perhaps in dryer, more stressful areas. In 2018, McGovern’s personal plantings used only 3 stainless steel staples per stem with additional steel staples between the fabric edges and stem for a tighter fit.
These Fall planted trees will be planted during the deer mating season. Trees planted on non-fenced sites could be exposed to more deer damage since they are simply small diameter 1-0 rooted whips that have not yet had a growing season in that location.
Compare growth differences between tree tube, textile fabric tree and control tree protection systems on two different sites. One fenced (Rhinelander) and one not fenced (WY).
Compare growth differences of six hybrid aspen varieties to the DN-34 control clone.
Compare figured split wood test properties for three aspens in a separate Rhinelander plot.
Compare total costs of both protection systems including materials, installation and potential post planting maintenance.
The tentative design consists of a 2 block planting (one block per site) with randomized single tree plots on 9’ x 9’ spacings, 7 varieties with 3 replications, 6 trees per variety (21 trees per block (site), a total of 42 trees without a border planting). This may not be a statistically valid design due to the limited number of trees and blocks replicated across the fenced and unfenced sites. A more desirable field trial might consist of using at least 3 blocks per site, increasing the number of trees from 42 to 63 trees per site and evenly deploying fenced and unfenced plots. Therefore this study is considered a “field demonstration”, not a field trial primarily due to lack of plant resources for this 2017 Fall planting. Perhaps this small study will generate interest for a more robust field trial.
Weyerhaeuser (WY) Escanaba, MI RDJ5 site
This site is not fenced and is exposed to deer.
It is described as the “Demo3” test site below.
Rhinelander, WI Experimental Forest. GPS location TBD.
This site is fenced.
It is described as the “Demo1” and Demo2 test sites below.
Pat McGovern lifted the test material from the McGovern Breeding Program (MBP) nursery on 11/07/2017. Most clones still had about 80% leaf retention. McGovern removed all leaves after lifting the trees.
The two site plantings was established between 11/12-18/2017.
Pat McGovern took chronologically dated photos of the entire project and post them to a shared an online Google Drive location.
The MBP trees are in the public domain and not subject to royalties (see: MBP Research and Deployment Strategies and open4st Disclaimer and Copyright).
MBP used WY’s TxE stock, tree tubes and the Weyerhaeuser’s RDJ5 site.
Each variety included 2 shelter treatments (1 tree tube and 1 textile sleeve test) per site and a control with no tree shelter. A total of 16 tree tubes and at least 29 sleeves will be required for the entire demonstration trial.
The stock consisted of 7’ to 9’ 1-0 stock grown from 8” dormant cuttings (4” x 4” x 30” spacings) at MBP’s nursery in Grand Rapids, MI (see 2016 Bell Nursery Summary).
Trees were planted on 9’x9’ foot centers to a depth of 12” to 14” via a 6” gas auger, shovel or tree spade dependent upon conditions.
The stock will be root pruned to about a 7” wide root system. The root to tip height pruned to 7’ then set into the hole, covered with 6” of residual soil, packed with a 1.5” 3 tined hoe handle and covered with the remaining soil. This firm planting is needed to prevent the growing stems from rocking in the hole. After planting all of the stems will be cut back to 5’ 3” total height.
The tree tube treatments will have 5’ tree tubes and PVC stakes installed.
The textile sleeves will be produced off site using steel staples and fastened to the stems with 3 stainless steel staples on one side and 3 plastic staples on the other side. (see: MBP Aspen Planting Strategies).
After planting each tree label will be positioned next to the tree.
Post planting details to be recorded include: variety names, row/column locations and stem tip caliper (“live_dbh_cm”) and later posted to the r4st database via the online view: v5_field_trial_tree_shelter_2017.
After planting, the tree shelters should be left alone to emulate a production system with no post planting shelter adjustments. Any non-natural damage from weed control maintenance could be considered IF it would be done in a production setting. Any tree mortality should be noted annually and a post-mortum analysis on the stem and roots performed to observed any issues. It may also be discussed if some tree sleeves should be pulled back to determine if there is any injury under the sleeves after the first growing season.
The trees will be measured on a recommended schedule (TBD).
The experiment will end after 5 years.
The Planting details are recorded in this online spreadsheet: 2017 Open4st Tree Shelter Demo Data
The average time spent and material costs to assemble and install the two shelter treatments are listed below. Field installation is about the same for each option so it is not included.
Woven Textile Sleeve Costs:
The textile sleeves cost $37.36 for a 3’ x 100’ roll of the Mutual WF200 woven textile fabric.
Each sleeve is 10” wide so the fabric cost is about $.31 per sleeve.
It took 14 minutes to cut and staple 10 sleeves, which is 1.4 minutes per sleeve, about 42 sleeves produced per hour.
Sleeve labor assembly costs at $10 per hour and 1.4 per minute would be about $.24 per sleeve.
Stainless steel staples cost $.006 each (insignificant).
Total estimated cost per assembled sleeve is $.31 + $.24 = $.55
Tree Tube Costs:
100 5’ “Protex® Pro/Gro Solid Tube Tree Protectors” tree tubes can be purchased and shipped for $2.82 each.
½” PVC pipe can be used to stake the tree tubes. Ten foot PVC pipe can be cut to 5’ lengths with a table saw. Ten pipes can be purchased at a lumber yard for $1.69 each. The 5’ cut price would be $.85 each.
Total estimated cost per tree tube assembly is $2.82 + $.85 = $3.67.
1) Clone 1bw6 ((P. canescens x AG) x Wind pollinated) see: family 1xBW. The leaves are intermediate like AG but have more lobed margins and the stem has less tomentose. Similar to the family 16xAB so I speculate that the male could be a nearby P. alba (e.g. 3xAA89, 4xAA89, 5xAA89). Rooted 100% (29/29) from 8" cuttings. A 2011 cross that has performed well in the nursery and field.
2) Clone 2B25 (P. canescens x AG) - Rooted 70% (7/10) in 2016 from 8" cuttings. An example of a F2 double hybrid clone that is vigorous in the nursery but has below average rooting. It will be interesting to compare its field rooting potential with 12" field grade cuttings.
3) Clone CAG204 (P. canescens x AG) - Rooted 75% (15/20) in 2016 from 8" cuttings. A Canadian female CAG clone with moderate growth, excellent flowering/seed bearing characteristics and used in many crosses. See: MBP Phase IV Breeding Matrix and CAG204 Photos.
4) Clone 14B7 (P. canescens x AG) - Rooted 100% (10/10) in 2016 from 8" cuttings, from the 14xB family. An example of a F2 double hybrid clone that is vigorous in the nursery but has good rooting. It will be interesting to compare this clone to other CAG clones like 2B25.
5) Family 25xR - (P. alba x P. grandidentata) - An F1 “AG” hybrid family. The female parent is from the 83xAA04 family. The male is the figured aspen bigtooth clone GG12 found near Grand Rapids, MI. I will select 3 clones (25R10, 25r4 and 25r20) with 2 trees each from the 20 25xR clones that were planted with the ortet and its 5 8" cuttings. Perhaps 80% of these clones rooted with at least 4 of the 5 cuttings. A 2016 single 3” cutting split wood test of these clones found that 17 were very difficult to split, perhaps indicating figured grain.
6) Family XT-Ta-7-05 - P. tremuloides x P. tremula (TxE) - This F1 TxE family is well documented and widely planted by the Weyerhaeuser (WY) for many years. It is propagated via seedlings in a robust plug containerized system. I consider this to be the current aspen control. See: WY site photos of this material: 17 year Michigan Milakokia River and 2016-RDJ5-Aspen-Larch, 2014-RDJ5-Aspen.
7) Clone DN34(Eugenei) - An old standby F1 control clone with good rooting and disease resistance capabilities.
8) Figured Split Wood/LAW Demonstration Trees - The “Demo2” plantings represent separate, miscellaneous demonstration tests that differ at each site. The Rhinelander site will have 3 figured wood clones hopefully representing low, medium and high figure and the Layered Aspen Whip (LAW) propagation process. These trees will likely be located apart from the above tree shelter planting and fitted with tree sleeves. The trees would be cut and tested to demonstrate the split wood test during the 2018 Rhinelander Conference. The initial figured wood test would involve splitting the stems with hand pruners but may also involve using a digital force gauge to measure the force required to pull apart the split stems. The LAW materials will be from the TxE XT-Ta-7-05 family and will include the TE15 clone. They could be lifted during the tour to show rooting patterns from previous year’s stem.
Below are the clones proposed for this test:
25R8 - Qty 2. Tested as a straight, easy to split clone in 2016. See 25R8.
AGRR1 - Qty 3. Confirmed to be a lightly figured AG clone. See: AGRR1.
25R5 - Qty 2. Tested as a figured, hard to split clone in 2016. See 25R5.
TE15 - Qty 3. Plant 3 of this 5 stem LAW clone. See: TE15.
2B29 - Qty 1. Tested as a medium to split clone in 2016. See: 2B29.
The “Demo2” trees below are intended for the WY site and will be fitted with tree tubes or sleeves if none are remaining from the initial test.
23ba10 - Qty1, Plant 1 at WY only.
8bg3 - Qty 1, Plant 1 at WY only.
TBD - pending measurement updates and conclusion after 5 years.
Fall 2018 Update: The 2017 Open4st Hybrid Aspen Tree Shelter Demonstration test was severely impacted by heavy stock losses due to early lifting of the Fall planted stock. The poor health of the trees and inadequate heat venting of the enclosed woven textile sleeves likely contributed to the severe sun scald issues on the South side of many stems. A new test should be investigated using Spring lifted "deer proof" stock and textile sleeves installed to allow improved ventilation. See: Multi-Stage Aspen Planting Strategies.
TBD - pending the test conclusion after 5 years.
I am grateful for the following contributions to this project:
The Weyerhaeuser Corporation’s donation of the tree tubes and their RDJ5 planting site.
The USFS Rhinelander planting site and Ron Zalesny’s assistance and technical support.
Brad Bender’s planting help and support.
McGovern P.N. (2017) Multi-Stage Aspen Planting Strategies. Retrieved from https://sites.google.com/site/open4st/faq/multi-stage-aspen-planting-strategies