Does a photo purportedly comparing pinewood from the early 1970s to pinewood from the early 2020s accurately describe genetically modified structural lumber used in 2021 versus wood from the 1970s? No, that's not true: These claims were made without substantial evidence, and a representative of the American Wood Council told Lead Stories that they are "patently false."
These claims appeared in a Facebook post (archived here) published on August 13, 2021. Above the image of two pieces of unidentifiable and cut lumber, placed one on top of the other, the caption opened:
Today's FACEBOOK Lesson: Genetically modified, fast-tracked solutions to human problems are not always best. In the 1970s, forestry scientists began developing "genetically modified pine trees" which grew super fast to meet the demand for housing lumber. 50 years later, you can tell the difference between pinewood from the early 1970s and pinewood from the early 2020s (see picture).
This is what the Facebook post looked like on September 21, 2021:
(Source: Facebook screenshot taken on Tue Sep 21 23:26:16 2021 UTC)
It continued:
Notice the number of annual growth rings. Strength is found in nature's slow growth. The problems that arise from fast-tracked untested solutions are not immediately seen. Ceilings made with genetically modified pinewood are now buckling. Ceilings made with nature's slow-growth pinewood are not.
While there is a copy of a 1985 Journal of Forestry article about lumber quality attached to this post, it is taken out of context. The author of that article discussed juvenile wood being produced in the early stages of a tree's life, not what this post implies: tree ring density determines board strength. The post's claims offer no proof that the 2x4 on top in the image is "genetically modified pinewood," harvested in the early 2020s and the 2x4 on the bottom is pine harvested in the 1970s from a "natural" growing tree.
Lead Stories asked an expert at the Western Wood Preservers Institute (WWPI) to assess the validity of four claims within this post. Butch Bernhardt, a senior program manager at WWPI, responded via email on September 20, 2021, first, categorizing the overall post as inaccurate:
The post is inaccurate in claiming the piece of lumber on top is reflective of structural lumber today vs. the second piece from the past. That is simply not true. It misrepresents that structural lumber today comes from 'super fast' growing trees created by scientists, and it is worse than 'natural' growing trees. That is patently false.
Following are Bernhardt's comments, arranged by topic:
Genetically modified pine trees and the growth rate compared to other trees
Let's start with the term 'genetically modified.' What constitutes genetic modification? Is it selecting cones for seeds from an existing tree with preferred traits? If so, we as humans have been doing that for centuries. It if means going into the lab and altering the DNA of a tree, well that's something that has been done on a limited basis, not a commercial scale. There are many other ways to make trees grow faster that are far less complicated...
Climate has a significant impact on tree growth. Trees located in wet, warm climates grow faster than those in colder or drier locations. When you look at the growth rings, the space between rings is referred to as 'earlywood' or 'summerwood.' That's representative of a climate that promotes the growth of the tree i.e. spring or summer. The darker rings themselves are considered 'latewood' as they represent the wood that forms later in the season when the conditions are not as conducive for growth.
Forest management also plays a role in the speed of tree growth. You can promote faster growth by fertilizing the tree, controlling the spacing between trees, eliminating competing vegetation and other techniques. Such intensive management is expensive and there is questionable return on such an investment in terms of wood quality on a commercial scale, particularly for structural lumber.
Determining tree species and genetic alterations from a photo of stacked lumber
There's no way to tell by a photo whether a tree has been 'genetically modified.' In fact, you can't necessarily identify the species from a photo such as this. The photo is labeled as 'pinewood,' but there are hundreds of different pine species and all have different characteristics. To identify a species, in many cases you need to see the tree and bark.
The top piece in the photo could possibly be Radiata Pine, which is grown in South America and New Zealand under warmer climates and more intensive forest management. Radiata Pine is often converted into wood products for appearance applications, as opposed to structural products. It is very unlikely that the photos are representative of the same species and certainly the trees these came from grew in decidedly different climates as well as under different forest management practices.
The strength of the board based on the interspacing of the tree
Yes, the summerwood in a faster growing tree is weaker than the latewood. Summerwood is much more porous, which does impact the strength. Those characteristics are limited by structural lumber grading rules, which determines the strength of the piece. The number of growth rings and the slope of grain are controlling characteristics when lumber is graded for structural applications. Other characteristics, such as knots, wane and manufacturing imperfections, also impact the strength of a piece and are limited with specific structural grades.
Strength is also dependent on the species. For example, Douglas fir has much higher assigned strength values than Radiata Pine.
There are grades for appearance applications, where the controlling characteristics do not take into account their impact on strength.
Relative rate of deterioration of wood from "genetically modified" trees versus "natural" wood
Wood deteriorates when exposed to decay fungi and/or wood-eating insects. Decay fungi, the most common way wood deteriorates, needs four things to break down wood: food (the wood itself), oxygen, proper temperatures and moisture. It is difficult to control the first three when wood is used in service. Thus, moisture becomes a key to the future deterioration of the wood.
A case could be made that the more porous summerwood in a faster growing tree could absorb more when exposed to moisture. That, in turn, could lead to faster deterioration. However, the deciding factor is the moisture, not the wood itself.
