By Ranger Steve Mueller
Benefits of the American chestnut tree were important for building United States society but a disease, unknowingly imported across the ocean, has mostly eliminated benefits. This happened to elm trees when Dutch elm disease was imported. Recently this occurred when the Emerald Ash Borer beetle was imported in 2002. Our livelihoods, economy, and landscape ecosystem functions are dependent on preventing exotic species from becoming established in native nature niches.
The rapidly growing chestnut was highly valued as a durable wood. Important uses included tool handles, furniture, doors, plywood, poles, fencing, railroad tires, and tannin. It had little shrinkage, minimal warping and good gluing qualities. The tree provided fruit that was roasted and sold in markets.
American chestnut trees (Castanea dentata) were a co-dominant species in the oak-hickory-chestnut forest that extended from Maine to Alabama and from the Atlantic Ocean to Michigan. Now the forest is referred to as oak-hickory. Southeast Michigan was the western range limit for the chestnut. Individuals at the edge of their range are considered ecologically important because they seem to offer more hope for adaptive genetic change. Fringe individuals might be better able to survive in new and changing environments. Their DNA might provide what is necessary to help the species survive in a changing world provided the living conditions do not change too rapidly.
Introducing new diseases that a species has never experienced is often devastating. It is a major reason Native American populations died when diseases like small pox were introduced by Europeans to America. Disease introduction to the American chestnut caused it to disappear from most of the landscape and ceased its function as an important ecological contributor in the eastern deciduous forest.
Fortunately, there were individuals that survived for some reason in outlying areas of the species range. The reason for survival has not been clearly determined. One factor could be fringe range individuals might have genetically variability that helps survival. Natural abundance ended in southeast Michigan but individuals lived farther west and north in Michigan. I have seen American chestnuts in Saginaw, Grand Traverse, and Kent Counties as well as many other counties. It is especially considered a rare sighting to find a large chestnut because few survive the disease to reach large size.
A fungus blight (Endothia parasitica) introduced from eastern Asia in the early 1900’s arrived in imported exotic chestnut tree species and devastated the ecosystem. The blight affected countless species beside humans that used the American chestnut trees for survival. We worry about diseases like Ebola and a variety of diseases that might challenge human survival. Diseases that challenge the survival of chestnuts, elms, and ashes also have great ecological significance on biodiversity. Other species like Purple Loosestrife, Garlic Mustard, and Phragmites crowd native species and eliminate them from healthy nature niche communities.
Ody Brook Nature Sanctuary is home to a large reproducing American chestnut that has a diameter of three feet. Hope continues that a disease resistant variety might be able to help the species reclaim its place the Eastern Deciduous Forest.
Help species survive by planting native species to help them and associated animals thrive where you live. Remove invasive exotic species. Encourage landscape nurseries to avoid selling species that crowd out native species when they escape the garden or yard. There are non-native species suitable for the garden and yard that are not invasive. Invasive species are harmful to society’s economy, livelihood, and functional ecosystems. Nurseries sell products to make a profit and choose stock that customers purchase. You determine the biodiversity we pass on the future generations by what you purchase and plant and whether your yard is maintained to encourage native species.
Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at firstname.lastname@example.org – Ody Brook Nature Sanctuary, 13010 Northland Dr. Cedar Springs, MI 49319 or call 616-696-1753.