Ranger Steve’s Nature Niche
By Ranger Steve Mueller
Cedar Springs removed Ash Trees that were killed by the exotic Emerald Ash Borer. Different species were used to replace killed trees. This is happening in cities, towns, and villages throughout Michigan and other areas. People’s yards have dying ash trees. The epidemic is not normal in a healthy functioning ecosystem.
So what is not healthy about the ecosystem in Cedar Springs and other affected regions? It is not a new story but it one that evades many people’s attention. Early European people unknowingly carried diseases that were not usually lethal to them but were devastating and killed most Native Americans. Native Americans had not developed immunities over a period of centuries and suddenly introduced diseases caused massive deaths among native peoples.
A fungal blight unknowingly brought to North America almost completely eliminated the American Chestnut trees from the Oak-Hickory-Chestnut dominated forest in eastern US. The chestnut had not evolved with the fungus and they had developed no defenses. The remaining eastern forest is now described as Oak-Hickory Forest. The American Chestnut was an important species in the economy of early America and would still be if it continued to thrive.
Elm trees were devastated by the exotic Dutch the Elm Disease. Again the species had not developed immunities. Each of those species has unique nature niche stories regarding their demise. A common factor that all share is human caused introduction of exotics resulted in the ecological and economic loss. Many native species depended on those species and when they died it cause death or reduction for many other additional species.
Last summer I noticed the Emerald Ash Borer had infected and killed trees on neighbors’ property. I knew for years it was matter of time of before our area would experience massive deaths. I was told an inoculation costing about $35 per tree could save the tree. Repeated treatment every couple years would be necessary. With well over a hundred large ash trees at Ody Brook it not a feasible option.
This past winter I noticed most of the large ash trees at Ody Brook were riddled by woodpeckers. They remove bark on the trunks to feast on emerald ash borer larvae. Unfortunately, the help from woodpeckers was too little too late. The adult borers are members of the flat-headed woodborer beetle family. Many native species of borers thrive here with checks and balances that prevent them from wiping out their food source. Not so for the exotic species.
The emerald beetles first appeared in the Detroit and it is thought they probably arrived in packing material. The population was noticed in 2002 and rapidly expanded killing tens of millions of dollars worth of ash trees in Michigan. They eliminated trees that provide food for hundreds of native insects, birds, and mammals. The adults emerge from under the bark in spring and feed on ash leaves where damage is minor and not noticeable. Females lay more than 100 eggs on the bark. Eggs hatch about two weeks later and borrow through the bark to feed on the phloem. Phloem is the layer that transports water, minerals, and food upward to branches. This is where deadly damage occurs.
The larvae in the phloem cause lethal damage and treetops show evidence of dying. Within a couple years, the trees die. Ash trees will sprout new shoots from roots and it will help prevent complete loss of the tree species. When the shoot sprouts get large enough, they too will be killed. Google Emerald Ash Borer for details about the insect’s life cycle and impact on our economy and nature niches.
Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at the firstname.lastname@example.org Ody Brook, 13010 Northland Dr, Cedar Springs, MI 49319-8433.