For several years now, I have been aware of the Emerald Ash Borer, ("EAB") an invasive insect originally found in China. It has been making its way east from Michigan, where it was first noticed in roughly 2002, probably arriving in a used hardwood shipping crate coming from China to the United States via the Great Lakes shipping routes. It has probably killed over 100 million trees in the United States since it arrived. It is obviously present in the woods to which I play Lorax in western Pennsylvania.
My emotions about this vacillate wildly from frustration to anger to profound sadness. Entire species of trees, green, white, pumpkin -- every kind of ash tree -- are being eliminated from our forests. Over a hundred million trees in just a little over a decade. Just wiped out, leaving yet another hole in our eastern hardwood forest ecosystem.
The connection that the EAB has to baseball is that the vast majority of wooden bats are made from ash. Hillerich and Bradsby's Louisville Slugger brand, in particular, produces the most wooden bats in the United States (nearly 2 million a year), mostly from ash trees and, to a lesser extent, maples. It sources its ash trees from the northern tier of Pennsylvania. Louisville Slugger's EAB statement can be found here. Their statement is woefully outdated, and their supply of ash, while immediately ok, is in serious trouble.
It isn't the end of wood bats. Maple is unaffected by the Emerald Ash Borer (but just wait until the Asian Longhorned Beetle gets loose...), so the wood bat is not going to die out anytime soon. Still, the prospect of the effective end of ash bats in baseball is very nearly upon us. It is not a possibility or something that "might" happen -- it is a drop dead certainty.
Nothing can stop the Emerald Ash Borer. Not spraying, not quarantine, not salvage harvests to create "firewalls" in the forest. It flies, it has been carried from place to place by idiots who ignore the firewood quarantines, and it has otherwise moved along major arteries, such as the Pennsylvania Turnpike, spreading irresistibly eastward toward central and eastern Pennsylvania. It has made its way to central Pennsylvania from Michigan in 11 years. If it could have been stopped, it would have been stopped before when the extent of the infested areas was much smaller.
The battle and the war are lost. The ash tree as a species is a dead man walking. I am speculating that virtually every marketable ash tree in Pennsylvania will be dead or infested by the EAB in another 5 years. A mortality rate of 99% is probably generous. After that point, ash will effectively be extinct in Penn's Woods, other than a few specimen plantings that are preserved in yards by people like me who can treat their mature trees with systemic insecticides annually.
Pennsylvania's EAB management plan for communities is not exactly a lie, but it is as meaningless as Hitler's plans for the defense of Berlin in 1945. It will be relegated to the dustbin of eastern hardwood forest history, much like the incredibly important American Chestnut tree and the American Elm. And you thought the Phillies were screwed...
All that remains at this point is to salvage harvest forests, triage specific landscape trees based on individual cost-benefit decisions, and plan for forests where ash trees, with their distinctive "woven" bark patterns, seed clusters (perhaps visible now), excellent wood, and open branch structure are just eastern hardwood forest memories like Elms and the incredibly important and sorely missed American Chestnut. [If I had three wishes, my first wish would not be for world peace, personal health, or "more wishes" -- it would be for a robust, traditionally-formed blight and phytophthora resistant American Chestnut.]
Since many communities replaced their dead or dying elm trees with ash trees decades ago, many streets and housing developments (and maybe your yard) have ash trees. My suburban yard has three mature ones that we are currently treating. I will need to treat all of them forever. If you have one in Philadelphia or a "collar county" you ought to ask a reputable arborist to begin treating your ash tree. I suggest making that call today.
The EAB larvae is the killer. The eggs are planted on the external bark of the tree. When the larvae hatch, they burrow into the bark and live in the phloem and young sapwood. They eat this layer, creating "galleries" which sever the internal connections in the tree between the roots and the canopy. The external manifestations of the EAB are "D" shaped boreholes in the bark. Later, as the infesting larvae become abundant and attract woodpeckers, the woodpeckers chisel off outer layers of the bark. This does not harm the tree, but shows clearly that the tree is being killed from the inside out by the EAB. This unusual bark pattern is usually what people notice first, and by then, it is often too late. Crown dieback is generally occurring already, and all that remains is to turn your ash tree into firewood. It makes excellent firewood.
Here is a shot of galleries that are made under the bark. It is from a cut log I use as a stool, and the bark has been removed to show the twisting pathways eaten by the EAB larvae underneath the bark:
Louisville Slugger may stockpile ash for a while, but over the next 5 to 10 years, ash bats will be phased out. The wood is just not going to be there to make them anymore. What then?
Bats in the MLB are governed first by Rule 1.10:
(a) The bat shall be a smooth, round stick not more than 23/4 inches in diameter at the thickest part and not more than 42 inches in length. The bat shall be one piece of solid wood.
NOTE: No laminated or experimental bats shall be used in a professional game (either championship season or exhibition games) until the manufacturer has secured approval from the Rules Committee of his design and methods of manufacture.
(b) Cupped Bats. An indentation in the end of the bat up to one inch in depth is permitted and may be no wider than two inches and no less than one inch in diameter. The indentation must be curved with no foreign substance added.
(c) The bat handle, for not more than 18 inches from its end, may be covered or treated with any material or substance to improve the grip. Any such material or substance, which extends past the 18 inch limitation, shall cause the bat to be removed from the game.
NOTE: If the umpire discovers that the bat does not conform to (c) above until a time during or after which the bat has been used in play, it shall not be grounds for declaring the batter out, or ejected from the game.
(d) No colored bat may be used in a professional game unless approved by the Rules Committee."
The key here is that there is no specific rule about what type of wood may be used. Composite or laminate bats are generally prohibited, which is probably a good idea, since that prevents some of the worst "arm's race" aspects from dominating baseball, rather than hitter's talents.
Ash bats have been preferred because their grain tends to compress and then release, along with the bats themselves flexing slightly. These material properties provide "spring" which helps batters using ash bats to hit balls harder. Less flexible or "springy" woods like hickory or oak are too "dead" to work well as bats. The weakness of ash is that its grains of wood function as something of a naturally-laminated piece of wood. Over time, the grains separate, and the bat comes apart non-catastrophically (flaking) or simply deadens from internal, non-catastrophic fracturing. The bats also fail by shattering, especially when the thin handles are made from wood with a grain that cuts somewhat across the handle. More on this later.
Maple is an alternative that gained popularity as a wood of choice used by Barry Bonds. Maple is harder and finer-grained. When maple first came into recent prominence, there was a lot of talk about it shattering more often or more dangerously, and bans were discussed. An excellent discussion of this issue is here, along with a non-technical discussion of kiln-drying, wood density, and wood grain. In essence, regulations about bat density (associated with moisture content and brittleness) and straightness of grain (associated with wood strength) were able to largely solve what was perceived as a pandemic of broken bats, including the horrific Tyler Colvin injury in 2010. Here is a an excellent summary of the proposed rules, discussion about wood grain, and how bats fail.
If the links above were "tl; dr" (begging the question of how you got to this point) then here is the short version: A key component of a strong baseball bat is wood that is nice and straight that lines up with the bat, from end to end, especially in the weakest part -- the handle. If the grain is offset in comparison to the bat's length-wise axis, it creates points of weakness. If the grain of the handle especially is not straight, the bat can separate along the grain of the wood, effectively "delaminating."
Most broken bats do not actually break across the grain. The strength of wood fiber is very high, and batted ball stresses are nearly incapable of breaking a bat of intact wood across the grain. Imagine trying to throw a ball through a baseball bat, and you get the idea. Not. Happening.
Most broken bats involve something jarring the wood so hard that the grains come apart. If you have ever split wood, you know that you hit a log with a wedge or maul so that you drive it into the grain to separate the log into halves. You don't go across the grain, like you are chopping down a tree. When most bats break, they are "split" in the same manner -- they are not "chopped" or "snapped" in half.
A significant problem with maple versus ash as a bat raw material is that the grain of maple has a meandering aspect to it. Maple grain can look like flowing water, whereas ash looks more like raked sand in a zen garden, with clearly-defined lines.
The type of maple used in bats is sugar maple. Norway maple, red maple, and typical "neighborhood" maples are soft woods that are wholly inappropriate for use as bats. Sugar maples have very hard wood, but again, the grain of the wood is not nearly as obvious or straight as ash. This leads to poor processing sometimes, including the manufacture of bat "blanks" that get lathed into bats where the handles are offset with respect to the wood grain. Ash is simply easier to make into a safer bat. There is also a much larger amount of institutional knowledge in processing ash for use in bats. Processes that work for ash may not work well for maple. Give the industry a decade or so making several million bats a year collectively, and they'll get better at it. There is already evidence of this.