Tree Drop

Anglers Fund Tree Drop

The application of a "heavy lift" Sikorsky helicopter is the latest technique in providing large woody debris (LWD) to our trout streams. A small crew can now do in just a few days what ordinarily might take dozens of workers months to accomplish. While we have spent five years sponsoring a very efficient in-stream crew, building habitat on the Mainstream and the North Branch, this new technique of full tree placement is the wave of the future. The Anglers were able to match a DNR Inland Fisheries Grant that allowed almost two miles of the South Branch to receive eighty complete trees this past fall.

LWD promotes better trout survival. Full tree placement provides critical habitat for the fish and will provide nutrients to the stream as debris collects and is broken down. In many cases it also serves as a bank erosion control measure. The reduced abundance of larger brown trout observed over the past decade has occurred primarily because natural mortality rates have increased from past levels, according to Andy Nuhfer of the DNR Fisheries Research Division.

Forest Management Division pre-marked trees to create an opening for wildlife in a section of state land out of the river basin, but close to the site. Fisheries division then prepared the trees buy bulldozing them over, taking root wads and all. Cables are then attached to each tree allowing the helicopter to spend a minimal amount of time between drops. At a cost of $2,100 per hour for helicopter flying time it is important to limit the amount of air travel time between the drop site and the prepared trees.

Our fisheries biologist, Steve Sendek, had walked the river the day before. He anchored large helium filled balloons to serve as a placement guide for the helicopter. In many instances, the helicopter pilot was able to place the full trees, many weighing up to four thousand pounds, right on top of the balloons.

Placing whole trees into the stream would entail prohibitive man-hours by any other method and physical disruption of the bank could be severe, encouraging erosion. Historically, whole trees cluttered the rivers from natural causes. Turn of the century logging, and the more recent commercial canoe activity, has channeled much of the stream corridor.

The benefits are almost immediate. Deeper holding areas for trout now have massive amounts of cover, providing excellent habitat. As of this fall, stream flows were changing, creating deeper channels and runs as the trees, in many cases, caused flow diversions away from eroding banks. Seasonal movement of fish on the South Branch has been well documented and it is expected that this habitat will provide new homes for many trout that would normally migrate through.

The project was coordinated by the Huron Pines Resource Conservation & Development Area Council (RC & D), in partnership with DNR Fisheries Division and Forest Management Division with funding provided by the Anglers of the Au Sable, supporting a matching grant from the DNR.

The North Branch Property Owners Association is planning a major full tree drop in the fall of 2001. They would like to drop over 300 full trees. Approximately 20% of the trees will be placed between Lovells and Dam 4, another 40% between Dam 4 and Kelloggs Bridge, and the remaining 40% between Kelloggs Bridge and the Mainstream. Tax deductible contributions to support this effort can be made by sending a check to: Huron Pines RC & D, 501 Norway Street, Grayling MI 49738. Note on the check that the donation is for the North Branch River Habitat Restoration.

Efforts are also underway to secure Pitman-Robertson funds, in the amount of $150,000 per year for ten years. Much of this would be invested in the upper river watershed (full tree drop initiatives) where Consumers Energy settlement funds are not being used. (See Riverwatch, Fall 2000 article by Andrew Nuhfer, Au Sable River Watershed Habitat Restoration ). RWOL

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