There’s something about the bright, clear days of April that I will always associate with baseball. Some memories are still as clear as the day they happened: the smell of tanned leather, the ping of a bat, the grit of red dirt and dust, the excitement of the parade on opening day, a slushie from the concession stand after the game. The years I spent at the local little league fields were formative. I was never that good, but I enjoyed being out there. I played through my teen years and even umpired for a time.
The sport has evolved much since its inception, in everything from the dimensions of the field to rules outlawing certain pitches, the adoption of safety equipment, and the introduction of lightweight alloy and composite materials. One thing that has not changed, though, at least for the pros, is the use of wooden bats. For most of baseball’s history, bats have been made from ash, a hardwood renowned for its structural strength, forgiving flex, and large sweet spot. Iconic manufacturers Rawlings and Louisville Slugger have traditionally sourced their ash from the Allegheny hills of the twin tiers of southern New York and northern Pennsylvania, where rich soils produce fast-growing, high quality trees (the diamond-shaped bark seems to evoke knowledge of its ultimate destination). They prefer trees of about 14-16 inches diameter (40-50 years old), each of which yields about 60 bats. After initial cutting and shaving into rough cylinders called billets, they are shipped to the factory, where they are lathed, sanded, and varnished with production-line speed and precision into the final product.
Now as an ecologist, I’m aware that those spring days also bring about the waking up of hordes of insects from their winter slumber, sometimes with disastrous effects. In 2002, a small, iridescent green beetle called the emerald ash borer (Agrilus planipennis) (EAB) was discovered in Windsor, Ontario. Native to eastern Asia and Japan, it was likely introduced to North America via commercial shipping crates and has spread primarily through the moving of firewood or other wood products containing ash bark with larvae. Even the coldest weather has been insufficient to kill overwintering EAB in the upper Midwest, and its rate of spread remains between two and twelve miles per year. Climate change will continue to make the spread easier, as milder conditions allow for habitat expansion northward. In 2009, EAB was found in Cattaraugus County, New York and it has since been recorded in most other counties in the state.
The EAB lives off the bark of one genus of trees exclusively—ash (Fraxinus spp.). Adult females lay eggs in bark crevices or cracks and, after hatching, larvae burrow beneath, where they spend 1-2 years maturing and feeding on the vascular tissue of the tree. Extensive tunneling by larvae effectively girdles the tree, choking off the exchange of water and nutrients between the leaves and roots. Infested trees typically die quickly, in as little as 1-2 years, with peeling bark revealing a squiggly maze of chewed paths. The beetles emerge as adults through characteristic D-shaped exit holes and hang around briefly to feed on ash leaves and mate, perpetuating the cycle. So far, roughly 50 million ash trees in North America have been killed.
There are three species of ash in New York State. Green ash (Fraxinus pennsylvanica) and black ash (F. nigra) are trees of wetlands, found in swamps, river margins, and extensively along the lowlands of the Great Lakes coastal plain. White ash (F. americana) prefers drier upland settings that are not disturbed by pollution or soil compaction. Where native, EAB exists largely in ecological balance with its
hosts, which include Manchurian
(F. mandshurica) and Chinese (F. chinensis) ash. In North America, however, the species has no natural predators and trees are not adapted to warding off EAB, especially in such virulent numbers. North American ash are also generally lower in tannins (astringent, usually toxic compounds) than their Asian counterparts, making them more vulnerable to infestation by pests such as EAB.
Our native ash provide innumerable ecological functions to forest ecosystems. As a dominant canopy tree, they transport large amounts of water from the ground into the air, regulating flooding and water quality. Long-lived trees, ash can take 60 years to mature, capturing and storing immense amounts of carbon. Tadpoles feed on fallen ash leaves in ponds and pools and ash are the host plant for native butterflies and moths. In fact, studies have shown that dozens of native insects rely solely on ash for food or breeding, those insects in turn becoming prey for birds such as woodpeckers. The continued spread of EAB threatens these habitats and functions in New York State forests. For example, red maple, which is replacing dying ash across much of its range, has leaves much higher in tannins and less suitable for tadpoles, placing additional pressure on already threatened amphibian populations. In addition, the death and dieback of ash opens canopy gaps, providing light to opportunistic invasive understory shrubs such as honeysuckle, which can choke out native competitors. Last, changes in leaf litter composition can, over time, alter the nutrient makeup of soils, influencing water quality for wildlife across entire watersheds.
The importance of ash in New York is in more than just its forests, though. New York, of course, is the home of the Baseball Hall of Fame. As a child, my parents brought me and my brother to Cooperstown many times, soaking in the nostalgia and paraphernalia of all things baseball. We watched bats being made the old-fashioned way and bought our own to take home; we watched games played in full period clothing at Doubleday Field; and of course, we toured the hallowed Hall itself, paying our respects at that cathedral to the sporting gods. There’s a kind of solemn reverence to the tradition they carried on that is enshrined there, the shared heritage of everyone who has ever picked up a glove and ball.
Tourism to Cooperstown and central New York is significant, providing jobs and livelihoods for innumerable people in the region and beyond. As hiking and outdoor recreation continues to grow in popularity, the continued health of forests, especially in places like the Catskillls, Allegheny State Park, and the Adirondacks, should be seen as supplemental to that—a valuable economic and recreational asset. Protecting ash trees, then, not only protects the legacy and traditions of baseball and its birthplace, but also the continued viability and health of New York State.
The best way to protect those assets is to prevent the further spread of EAB, and we’ve taken a few swings at doing just that. First, early detection and rapid response (or EDRR) is a method of identifying and stamping out infestations as they occur, like ecological whack-a-mole. You may have seen those oddly-shaped purple boxes hanging from trees along roadsides or the thruway. They are traps hung in cooperation with the U.S. Department of Agriculture (USDA) and baited with a chemical that mimics a distressed tree, luring beetles to be either stuck on an adhesive pad or trapped inside. However, it turns out the traps are not very effective. They are meant to detect the leading edge of an invasion, but often they only find beetles when they have already been established in an area for quite some time. Strike one.
A second option is chemically treating trees to prevent infestation. Several insecticide solutions have become available, promising to kill or repel beetles for up to three years. Some can be injected into the vascular tissue near ground level, where it is transported throughout the tree, while others can be applied to the soil or foliage and absorbed indirectly. Typically, insecticides are used by private landowners treating large or high-value trees on their property or in urban areas, such as along residential streets, where ash trees provide shade and comfort and where loss would be a significant blow to the character and quality of those places. Treatment tends to work fairly well, but individually treating trees is expensive and time consuming and must be repeated every few years to remain effective. It is not practical for use on entire forests. Strike two.
The last resort has been biological control, finding a natural predator of EAB to control populations. Four species of parasitic wasps native to China have been approved by USDA to be released since 2007. While early indications are good (the wasps seem to be parasitizing EAB larvae and driving down populations), they seem to have limited effects. In Michigan, where this technique has been employed most widely, large numbers of ash trees still died and the wasps do not seem to have made much difference in curbing the spread of EAB. Strike three.
So unlike those spring days, the future for ash does not look bright. It may be simply a matter of time before the majority of ash trees in the northeast succumb to the beetle. In 2014, U.S. Forest Service entomologist Andrew Liebhold said that “Ninety-nine percent of the ashes in North America are probably going to die." In preparation for this eventuality, or perhaps simply following market trends, bat makers have begun to switch to other materials such as maple, birch, oak, and even bamboo. Maple is denser and stiffer, providing more power on impact, but has a smaller sweet spot and tends to shatter more easily. Even so, a majority of major leaguers now use maple.
Despite being called America’s pastime, baseball is a surprisingly cosmopolitan sport. It has been embraced everywhere from Japan to Latin America to Africa and has found a home in the Olympics and the World Baseball Classic. Every year, teams from around the world descend on the Little League World Series in Williamsport for their shot at glory. In that sense, though, baseball is a quintessentially American export. It represents the pursuit of a dream through ingenuity, hard work, dedication, and maybe a little luck. Coaches will tell you baseball is a metaphor for life, and they’re right. There are heroes and villains, powerhouses and underdogs, victory and heartbreak and destiny, all there in the game.
Now, the slow-motion death of ash across the U.S. mirrors that of baseball itself. With declining viewership and revenue, the future of the game is uncertain. Even prior to stumbling through this past season of Covid outbreaks and restrictions, there were cheating scandals, labor disputes, and steroids. Major League Baseball recently proposed rule changes to speed up the game and keep the interest of younger viewers and limited attention spans. Participation in Little League has decreased along with youth sports in general, and NCAA programs have begun to reach further into youth leagues to recruit and develop young talent. Those families are pressured into joining competitive travel teams, while other kids who don’t fit that mold feel like they don’t belong and are pushed out. There’s been talk of the end of the game, or at least its relevance in American life. What will become of it? What would it mean for something with such a storied history and cultural importance to fade away? Liebhold, discussing the decline of ash, went on to say, “The forests and the species that exist there, they’re part of America and what defines America. Without being too corny, they’re a symbol of what this country is.” The same goes for baseball.
For more: Research on fungal pathogens to fight EAB
Comentarios