By Katherine Hollins, MNA Regional Stewardship Organizer – Eastern Lower Peninsula
MNA is fortunate to protect one of the top-ranked lakeplain wet-prairies in the state. This globally imperiled habitat is home to a beautiful diversity of plants, perhaps one of the most showy being the eastern prairie fringed orchid (PFO). MNA protects one of the largest populations of PFO and one of the few populations in the world that is considered long-term viable.
This beautiful, sweet-smelling orchid is a mysterious plant. It was once common in the state, but its population has declined to the point that it is now considered endangered by the state of Michigan and threatened by the federal government. This population decline is primarily due to habitat destruction. Many of the rich prairie soils were plowed into farm fields, and other areas were ditched or diked, altering the hydrology of the habitat that is so important to the plant. However, while we tend think of it as requiring extremely high quality habitats to survive, specimens have been found in roadside ditches and along the edges of mowed fields.
Historically, fluctuating lake levels helped support PFO habitat. High water pushes the orchid population inland, and prevents shrubs and trees from encroaching into the sunny prairie. When lake levels lower again, the orchid population moves back shoreward. Each year some plants are lost to too much or too little water and new ones are recruited where new suitable habitat is created. With land alterations, however, this ability to shift inland and shoreward according to the lake levels has been hindered.
Seasonal drought, lake level changes, and other factors influence the number of annually surviving plants, as well as the number of blooming plants. Individual PFO plants may not flower every year or may even go dormant when conditions are not favorable. In their PFO paper, Mike Penskar and Phyllis Higman say, “… the species is notorious for having large fluctuations in the number of flowering individuals from year to year.”
Because of this, we count the orchids each year so we can follow the general trends in the population. This year marked the 28th annual count and trumpets the highest level of volunteer involvement. Eighteen volunteers split into five groups to take on separate sections of the sanctuary.
We had beautiful weather: partly sunny with a slight breeze and very few mosquitoes. The sanctuary is crisscrossed with ditches from former farming on the property, and only one of us fell in! Our volunteers ranged from high school students to retirees. Several folks from other conservation organizations joined us, and a few volunteers even took off from work to participate!
Each team walked back and forth within their designated zone to mark GPS points and tally every adult blooming plant, just as has been done for the past 27 years. With this historic information, we are able to track the health of the population within the sanctuary and make sure our management efforts are succeeding. This year’s count showed 204 plants, down significantly from last year’s high of more than 400. Although this number seems low, it is still following a general trend up from previous numbers, and many believe that last year’s summer drought reduced the bloom level this year. We’ll count again next year to be sure we’re still heading in the right direction!
We work hard to protect this and other high-quality habitat, and we invite you to join us for some of our upcoming work days and events around the state. Keep up with all our events by checking out our online Events Calendar or emailing firstname.lastname@example.org with your area of interest.