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~~*  The Singing Falls Stream Restoration Project  *~~


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~~*  Replacement of Vital Riparian Habitat Materials  *~~


Image Galleries: The story in picures of the acquisition and staging of logs and boulders for habitat restoration.
Logistics of Aquatic Habitat Restoration-Large Woody Debris Transport

Throughout ancient history large trees have fallen into streams and creeks to become long term instream structures that aid in creating a special type of habitat needed for the preservation of aquatic species.

We mustn't let the simplistic beauty undermine the importance of these instream structures. For a downed large wood tree sets up a multifaceted chain reaction in the riparian zone.

The first and immediate result of downed large wood is its impact on the physical geography of the stream and riparian zone itself. Generally speaking pools are always found around large wood. The dynamics of the hydraulics of the streams water as it flows past the wood is creates a scouring effect. As the water flows over, under and around the wood it focuses the energy of the water and forces aggregate materials out of the trees immediate vicinity and burrows into the stream bed.

Simultaneously the large instream object slows the stream flow enough to cause some of the aggregate materials from up stream that are being carried along by the velocity of the water to precipitate out of the water. Usually a short distance downstream of large instream objects one can see a gravel bar formed in the stream flow buffer zone created by the object. In many areas of this site we mention the need for this important material for nest building by salmon and other sea going fishes. Without it the eggs of the fish flow rapidly down stream to become food for other aquatic and fish species of the watershed. Even with good habitat this takes place to a degree in spawning areas for various reasons. But once the stream has its large woody and rock object removed they become of downcut gully; nothing more than an erosion ditch. Large wood and boulders inhibit the streams degradation.

Another facet of instream barriers on the physical geography is the process of creating stream complexity. Instead of the water roaring down and out of the stream, it is slowed and diverted around the objects. This in effect actually lengthens and widens the stream. This in turn creates a greater possibility for more pools (hence water storage for dry times of the year), more gravel storage and greater connectivity to the flood plane.

But there are other more subtle effects the wood has on the stream area. If enough large downed wood are in the riparian zone the wood acts as a mulch to slow evaporation from the ground. It also tends to keep the ground cooler in summer and warmer in the winter. The shade provided by the wood helps stream water temperatures to stay at levels less stressful for young fish.

Something else that I have observed is the shelter instream large wood provides for the young and mature fish alike. The greatest predator for fish are birds of various kinds. Large wood and the pools it creates are excellent covered water caves (refugia) for fish to hide in.

Many insects thrive on the ecological conditions set up by deteriorating wood. Fungi and small plant species that live on the wood becomes important sources of food and shelter for creatures further down the food chain. The biological activity surrounding downed wood is a valuable food source for fish or the living things the fish survive on.

It is well known that riparian zones are a good source of high quality wood. For that reason many of these near stream areas were logged in the past 150 years. There are very few streams in the United States that have large conifer or hard softwood trees remaining in their riparian zones. The shade and ecosystem support from this wood is all but gone in most places. For that reason most stream restoration projects require substantial funding to transport wood for habitat. This expense didn't even cross the minds of those who took the old growth large wood away to the lumber mills. It is for this reason that many Federal, State and Conservation groups have amassed funding to assist private land owners. The vast majority of the prime spawning habitat for salmon and other fish species is in the low flat areas chosen by most land owners for agricultural development. When the land was domesticated the large wood was usually one of the first things harvested. It helped pay for the land and its removal created space for pasture or cultivation.

To replace the wood that is missing from these areas is not always easy. There are certain engineering specifications that have to be met for the wood placement to be stable and effective for restoration purposes.

The Singing Falls habitat restoration project was very fortunate to have access to a substantial amount of old growth trees that have died and fallen over due to recent drought conditions in this area. Each tree removed from its place of origin was carefully chosen. Either it was a large hazard tree near a public roadway or it was contributing to catastrophic fire conditions due to fuel overload. Neither did we want to remove a valuable habitat resource from any given area. Special note was taken to provide standing dead wood or a reasonable amount of downed wood in the forest for ecological purposes. No use creating one environmental disaster to fix another one.

I have created a few image galleries that document the process of acquiring and transporting the large wood needed for the restoration project. It will give you a good picture of the scale of effort and time needed to move the project forward. I especially wanted to make my colleagues involved in stream restoration work green with envy. A large majority of the trees used in our project have the root wads attached to them. That makes them particularly desirable and valuable for restoration work. The root wads contribute substantially to the longevity of the wood and its ability to effectively influence instream conditions for habitat creation. View the project sites to see how they influence stream conditions. The galleries cover the harvesting and transportation of the logs and the process of staging them for distribution by helicopter or excavator. I hope you enjoy them.

Below is a table with hyperlinks to the image galleries. I've attempted to sort them in a logical sequence. Simply click on one of the thumbnail images to go to another page containing a larger version and perhaps some information relative to the image


Click on the links in the following table to access the information. All of them but the first one is off site.
image showing an excellent example of the wood needed for repair

Large Wood for Restoration Work


Stanley & Alexandra Petrowski
34620 Tiller Trail Hwy.
Tiller, Oregon 97484