Our native Eastern hemlock trees are under attack by a nasty little pest from Japan called the Hemlock Woolly Adelgid (HWA). This almost microscopic critter has piecing and sucking mouthparts that it pushes through the base of hemlock needles to suck nutrients out of the tree. This weakens the tree and could eventually lead to the tree’s death. It gets its name from the white, waxy material they secrete for protection (see photo at right). HWA has been found in Michigan previously in small, localized areas where it was effectively eradicated before it could get out of control. However, as of 2016, HWA was found in several locations along the West Michigan Shoreline, including right here in the Macatawa Watershed!
How did this critter get here? HWA is native to Japan, where it feeds on Asian hemlocks and some spruce species. These Japanese trees evolved with HWA and have natural defenses against it. Our native hemlocks do not. In the United States, HWA only affects hemlock trees and not spruce. HWA was discovered in the Pacific Northwest and California in the 1920s (accidentally introduced, perhaps on shipping materials), but Western hemlock trees showed resistance to HWA and sustain little damage. Eastern hemlocks, however, are very susceptible to the damage caused by HWA. It was first found attacking Eastern hemlock in Virginia in 1951 and has spread up and down the east coast. It is now present in at least 19 states. HWA likely made its way to Michigan on infested nursery stock that was shipped from the east coast.
So why do we care about hemlock trees? Hemlocks serve numerous roles in the environment including providing shade to cool our rivers and streams, soil stabilization in dune and riparian areas, interception and infiltration of stormwater, and critical winter wildlife habitat for many species including deer. They are also very attractive trees that have long been prized for their aesthetic value in the landscape. The good news is that HWA moves slowly and is treatable.
How can I help? We’re glad you asked! The West Michigan HWA Task Force developed a website, savemihemlocks.org, and are asking you to identify, report and take action. There are pictures that will help you learn how to identify hemlock trees and the signs of HWA. You will also find contact information for several local nature centers that can help you identify hemlock trees and HWA. Once you confirm HWA, you can submit a report online. Reporting is important to track the spread and plan for treatment. Reporting is the first step in taking action. Another action could be joining the task force, helping to spread the word about HWA and raise funds for treatment. Finally, if you have HWA on your property, contact a reputable tree service (see list on website) that is certified in pesticide application and have your trees evaluated for treatment.
The MACC works with local farmers to implement and fund a variety of best management practices, or BMPs as we often call them. We currently provide funds for transitioning to a reduced tillage system (e.g. no-till), cover crops, water and sediment control basins, and gypsum. When we describe what we do to the non-farming public we quite often see an eyebrow raise at the mention of gypsum. Most of us are familiar with gypsum in its role as drywall, but many of us are not aware of the benefits gypsum has to plants and its role in water quality protection.
Gypsum is a soluble source of calcium and sulfur, both essential nutrients for plant growth. It provides these important nutrients to the plant without altering the pH of the soil, as do other types of fertilizer. The gypsum we use in an agricultural setting comes primarily from two sources. Gypsum is created as a byproduct in coal fired power plants. When exhaust from burning coal is exposed to a saturated limestone slurry, the slurry “scrubs” sulfur from exhaust before it is released into the air. This slurry is then dried out and the resulting product is flue gas desulfurization gypsum or FGD gypsum. The other and most common source of gypsum is mined gypsum. This is gypsum that is taken directly out of the ground and crushed so that it can be uniformly spread onto fields.
Gypsum helps to improve water quality in several ways. Calcium works in the soil to improve soil structure through a process called flocculation. In this process, calcium binds to clay soil particles and brings them together into small clusters. These clusters open pore space in the soil allowing water to infiltrate more easily. They also keep the clay particles from eroding off the field and entering waterways. Calcium also binds to excess dissolved phosphorus particles and forms a solid substance. This solid will settle out of the water and collect in the soil rather than entering our streams, creeks and ultimately Lake Macatawa.
Several ongoing studies by The Ohio State in the Lake Erie watershed suggest that gypsum can reduce dissolved phosphorus in drain tile outlets by as much as 30% to 50%. A study in Indiana has found similar results showing a 50% reduction in dissolved phosphorus loss in a no-till farming system.
Gypsum is and will continue to play a big role in restoring the Macatawa Watershed. It is a valuable tool that shows great results in helping to improve water quality. It is not, however, a single solution to the issues affecting Lake Macatawa. Gypsum plays a part in a multi-faceted approach to improving water quality. Using gypsum along with other best management practices will have the greatest impact on improving Lake Macatawa’s water quality.
The MACC is continuing its effort to engage the watershed’s farmers in a conversation about best management practices (BMPs) and the health of our waters. The MACC’s current Great Lakes Restoration Initiative grant focuses efforts in the three highest priorities sub-watersheds: Peter’s Creek, Upper Macatawa, and North Branch, respectively. Current qualifying practices include, but are not limited to, gypsum application, planting of cover crops, water and sediment control basins, and transitioning from conventional tillage to a reduced tillage or no-till system.
Growers who are interested in cost share funding or have questions regarding BMP’s should contact Rob Vink at the MACC. Rob can be reached at 616-395-2688 or by email at email@example.com
The following was summarized from the Project Clarity January 2017 Dashboard prepared by the Outdoor Discovery Center Macatawa Greenway. The full dashboard can be viewed here.
Wetland and Streambank Restoration
Agricultural Best Management Practices
Value Added Projects
Gift and Grant Totals
|Gift Division||Total Pledges, Cash & In-kind||% of Goal ($11,976,000)|