Will,

Good reading on reiterated trees.

You remember the big field pine at Kellogg? The Octopus white pine. It
has at least 8 huge reiterations from a short stubby main trunk. If I
remember right, I counted nine!  What would cause an open grown tree
to grow like this? I suspect it was broken off when very young. It is
the most reiterated tree I know of but I am sure you know of some
great hemlocks.

http://www.nativetreesociety.org/fieldtrips/north_carolina/kellogg_center.htm

James P.


On Mar 12, 4:36 pm, "Will Blozan" <[email protected]> wrote:
> Ed,
>
> Here is an excerpt from the Tsuga Search Project that should help:
>
> Wood distribution
>
> In total, this project sampled 3,340.1 m (10,955 ft) of eastern hemlock
> trunks (N=53) with a cumulative wood volume of 1,672.3 m3 (59,053 ft3)[1].
> The modeled trees did not always conform to a simplistic, single trunk form
> however, and required measuring some challenging structures (See
> Reiterations and bifurcations below). In all trees sampled, "conventional"
> main trunk wood composed anywhere from 63.7% to 100% of total tree volume.
> Bifurcations (forks of vertical leaders) accounted for a maximum of 36.3% of
> total wood volume, considerably more than a maximum of 10.05% for
> reiterations (limbs upturned into secondary trunks). Bifurcations were much
> larger; even though a total of 633.1 m (2,076.6 ft) of reiterations were
> measured, total bifurcation volume (42.9 m3; 1514.2 ft3) was 240% more with
> only two-thirds of the cumulative path length. Path lengths (length of all
> measured wood structures) of individual trees ranged from simply the length
> of the trunk to a maximum of 200.7 m (658.4 ft). See Appendix 4: Wood
> distribution of subject trees for more detail.
>
> Reiterations and bifurcations
>
> Reiterations are replicated trunks formed by the tree to exploit a light
> gap. Structure and growth of reiterations are markedly different from normal
> descendent or ascendant branches. Reiterations are included in trunk volume
> calculations as they are part of permanent, branch bearing structures of the
> tree. Their origin arises from the sprouting of normal branches and can be
> initiated by a light gap from the side or from crown damage above. The
> apically dominant portion of these structures are often much younger and
> model-conforming as in a young tree. The cross-section changes to a more
> oval shape as reaction wood is built up to support the added weight from
> increased growth and sap demands as the reiteration gains vigor. The
> buttressing allows a more permanent attachment than a conventional branch
> due to support on the lower portion being less likely to fail from injury to
> the upper surface. This also allows wounds with associated decay to persist
> and form a suitable substrate for vascular epiphytes (Sillett, Van Pelt
> 2007)
>
> Studies in redwood forests indicate that structural diversity in the canopy
> is strongly linked with aerial biological diversity. Reiterations generate
> niches not found anywhere else in the forest (Sillett, Van Pelt 2007). Our
> observations indicated moss mats, epiphytic plants and lichen gardens to be
> associated with these large structures. Large reiterations and breaks in the
> trunks were hosts to shade intolerant shrubs and wind disseminated trees
> such as Rubus and Betula. Complex, reiterated crowns could be refugia for
> those species lying in wait for a light gap or breach in the rhododendron.
>
> Of the thirty trees discussed in this project, eleven trees had large
> reiterations. Four of these were tall trees and seven were large trees (two
> trees are replicated). A total of thirty-seven reiterations were measured,
> ten of which grew on the Usis Hemlock, the most on a single tree in the
> project. Total reiterated trunk length measured on the Usis Hemlock totaled
> over 147.8 m (485 ft) for a tree total of 200.7 m (658.5 ft) of trunk.
> Likewise, the Cheoah Hemlock had a total of 185.6 m (608.7 ft) of measured
> trunk length in reiterations and bifurcations. These structures are likely
> to greatly increase the crown area of the tree, and bolster wood production.
>
> Reiterations on the subject trees (no repeated trees) totaled 14.7 m3 (518.8
> ft3) in volume, 527.0 m (1,728.6 ft) in cumulative length, and were found to
> compose anywhere from 0.5% to 10% of total tree volume, averaging 4.2% for
> all trees. Volume of individual reiterations reached a maximum of 1.78 m3
> (62.9 ft3) and a maximum structure length of 18.96 m (62.2 ft). On average,
> the reiterations were 31% larger and 12% longer on the large subject trees
> than on the tall subjects. Fusions between reiterations were documented in
> two trees, forming a strong interlocked crown with braced bifurcations that
> likely reduce mechanical failure of non-conventional crowns. "Transplanted"
> branches were noted in the Cheoah Hemlock. This occurs when a grafted branch
> severs its connection from its origin. This phenomenon is well documented in
> the coast redwoods of California, and is encountered in dense hemlock hedges
> as well. The Cheoah Hemlock and the Usis Hemlock both exhibited reiteration
> fusions; one of which started at 14.3 m (47 ft) and fused to another
> reiteration 9.7 m (31.9 ft) higher in the tree. The Cheoah Hemlock had a
> branch that crossed the inner canopy while grafting to three separate
> structures.
>
> Height of origin was noted for every measured reiteration. The lowest
> occurred at 12.59 m (41.3 ft) and the highest at 38.35 m (125.8 ft) above
> mid-slope. The highest recorded reiteration was over 25 cm (12 in) in
> diameter and was encountered in the Usis Hemlock. This tree also contained
> the highest cumulative and relative volume of reiterations; 4.36 m3 (154.3
> ft----------3) and 10.05% respectively. The most massive reiteration was
> found in the Cheoah Hemlock and scaled 1.78 m3 (62.9 ft3). This individual
> structure alone contained a path length of 34.33 m (112.6 ft) of measured
> trunks. A graphing of the origin heights below likely reveals a random
> height of origin as the events initiating the formation of a reiteration
> would likewise be random. Data gathered from a control population of
> non-superlative trees are needed for comparison.
>
> Of the thirty subject trees, three had large bifurcations that warranted
> frame mapping along the section(s) of trunk fusion. These massive, fused
> areas were up to 1.6 m (5.25 ft) across. Two other subject trees were
> bifurcated but did not exhibit reiterations. Of the subject trees, only the
> Cheoah Hemlock was both reiterated and bifurcated. This tree, supporting a
> bifurcation more than 83 feet long, was also nearly entirely cloaked in live
> crown from base to top. The longest and largest bifurcation occurred on the
> Yonaguska Hemlock; 28.75 m (94.3 ft) long and 5.37m3 (189.6 ft3)
> respectively. See example of a frame-mapped bifurcation fusion below:
>
> Frame mapping example from the Yonaguska Hemlock bifurcation fusion
>
> All the remaining trees in the project had a single trunk; one of which was
> broken at 31.74 m (104.1 ft). This tree (the Headless Giant) - as well as
> several others - had the vast majority of the crown originating on
> reiterations with very few non-reiterated branches. Several reiterations
> reiterated again (second order) with one fourth order reiteration noted in
> the Usis Hemlock. This immense tree had a fusion of two giant reiterations
> that supported a complex limb system supporting multiple reiterated sprouts
> - some originating from the same limb like a row of small trees extending
> upwards of ~12 m (~40 ft) from the trunk origin.
>
> Will F. Blozan
>
> President, Eastern Native Tree Society
>
> President, Appalachian Arborists, Inc.
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
>
> Behalf Of Edward Frank
> Sent: Wednesday, March 11, 2009 11:04 PM
> To: [email protected]
> Subject: [ENTS] Re: Another Big White Pine
>
> ENTS,
>
> I am wondering about these reiterations.  We have talked about it before,
>
> but everything is not clear in my mind.  A reitteration is what exactly?  It
>
> appears to be a secondary trunk formed ntially from an upturned limb...  How
>
> do they form and why?  What species of trees are know to have these
>
> reiterations?  I know this white pine, some of the hemlocks in the Tsuga
>
> Search project,  Many of the giant conifers from Bob Van Pelts book.  Are
>
> there examples of reiterations in trees that are not conifers?  Please
>
> enliughten me on the subject.
>
> Ed Frank
>
>   _____  
>
> [1] The cumulative volume total of all subjects in this study is just
> slightly more than the entire trunk volume of the largest known giant
> sequoia (Van Pelt 2001).
>
>
>
>  image003.gif
> 12KViewDownload
>
>  image004.gif
> 11KViewDownload
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