Metolius Preserve Thinning

Introduction:  Last winter a major forest restoration project completed on the Metolius Preserve, a 1,200 acre FSC certified forest ownership recently purchased by the Deschutes Basin Land Trust.  IRM implemented an innovative regime on nearly 500 acres of young evenaged ponderosa pine.  Prescriptions were developed as part of a comprehensive forest stewardship plan completed for the trust in 2004 by IRM. 

 

Goals and Objectives:  The work is part of a long-term strategy to restore large tree and groupwise unevenage structure across the preserve, along with the understory bunchgrass communities and snag conditions that existed prior to major timber harvest and fire suppression.  To derive Desired Future Conditions (DFC), extensive analysis of reference era tree spatial patterns, density, composition, and size class structure was analyzed.  These conditions will benefit several focal management species including the white headed woodpecker, and other mature ponderosa pine dependant wildlife.

Before thinning and mastication.  Note heavy understory of grand/white fir.	After thinning treatment and before slash mastication with LightfootTM.	Thinned and slash treated with LightfootTM.

 

Methods/Activities:  The treatment reduced stand density in a non-uniform manner using a "mosaic thinning" approach, whereby the forest was thinned differently in small patches.  These patches were thinned to one of five treatments aimed at providing a range of tree growth rates, understory shade levels and patch structure.  Unthinned patches were retained to provide roost cover for owls and hiding and thermal cover for large ungulates, and to provide for small patch bark beetle mortality.  Small openings up to .5 acres in size were harvested across 5% of the area, to begin the process of re-establishing unevenage structure.

 

Treatments were completed with the most innovative and low impact equipment available.  A harvester/forwarder was used for tree harvest, processing, and yarding.  Operations were conducted over snow, minimizing soil impacts.  A rubber-tracked skid steer with a brush masticating head was used to reduce fuels generated during thinning while treating unwanted for regeneration and shrubs.

 

The project generated nearly 1 million board feet of timber from primarily small diameter ponderosa pine.  Follow-up treatments being implemented during the summer and fall of 2006 include prescribed burning, snag creation, and bunchgrass seeding.