Current Research

List of Ongoing Studies:  


StudyID Study Name Site Company Planting Year State County Species Study Size (acre)
CPT01 Critical Period Threshold Summit Starker Forest 2000 OR Benton DF, WH, WRC, GF 18.806
CPT02 Critical Period Threshold Sweet Home Cascade Timber Consulting 2001 OR Linn DF, WRC 9.403
CPT03 Critical Period Threshold South Bend AFM (Rayonier) 2013 WA Pacific DF, WH 10.578
CW101 Combining Weed Control Part I Belfair Rayonier 2009 WA Mason DF 11.019
CW102 Stock Type Blackies Corral Starker Forest 2009 OR Benton DF 0.992
CW103 Stock Type Hard Rock Starker Forest 2009 OR Lincoln DF 0.992
CW201 Combining Weed Control Part II Miltown Hill Lone Rock Timber Co 2012 OR Douglas DF 8.926
DPS01 Delayed Planting Boot Starker Forest 2008 OR Polk DF 1.983
DPS02 Delayed Planting Jackson Mast Lone Rock Timber Co 2008 OR Lane DF 3.526
ECR01 Evaluating Common Regimes Oakville WADNR 2006 WA Grays Harbor DF 3.526
HER01 Herb1 Summit Starker Forest 1993 OR Benton DF 3.526
HER02 Herb1 Marcola Weyerheauser 1993 OR Lane DF 3.526
CO101 Cosine I Bulgogi Rayonier 2017 OR Tillamook WH 7.934
CO201 Cosine II Mc-Dunn OSU 2017 OR Benton DF 2.645
CO202 Cosine II Boss Hog Cascade Timber Consulting 2017 OR Linn DF 2.645
CO102 Cosine I Whipple Hill Lone Rock Timber Co 2018 OR Douglas DF 8.926
CO203 Cosine II Burntwoods Starker Forest 2018 OR Lincoln DF 2.645
CO204 Cosine II Mountain Sun Rayonier 2019 WA Lewis DF 2.645
CO205 Cosine II 7B PIECES Roseburg FP 2019 OR Lane DF 2.645
CO103 Cosine I River Ranch Roseburg FP 2020 OR Lane DF ,WH 3.967
CO206 Cosine II River Ranch Roseburg FP 2020 OR Lane DF ,WH 2.645
CO207 Cosine II Camp 18 Greenwood Resources 2020 OR Clatstop WH 2.645


Critiacl Period Treshold (CPT)

The idea of the “Critical Period” is a key component of integrated weed management. The critical period refers to the portion of a crop’s lifecycle where weeds need to be controlled to avoid yield losses. This concept has been expanded to forest vegetation management with the objective of determining the timing and number of years of vegetation control necessary to optimize stand productivity.

The Critical Period Threshold studies utilizes a complete randomized block design containing eight different VM regimes. The VM regimes are shared across all the CPT study sites and represent different combinations and timings of post-planting herbicide spring release applications during the first five years of stand establishment. Each VM regime is coded by five letters with each of the letters representing one of the first five years after planting. Specifically, the treatments include OOOOO, TOOOO, TTOOO, TTTOO, TTTTO, TTTTT, OOTTT, and OTTTT with an “O” signifying no vegetation control during that growing season while a “T” indicates a treatment year


Combining Weed Control

Understanding the interactions and synergies between management practices and stock type can have important management implications. The Vegetation Management Research Cooperative (VMRC) installed the Combining Weed Control Study Part I (CW101) in 2009 to evaluate interactions between VM regime and Douglas-fir containerized stock size on seedling growth and survival. The study series was later expanded with the installation of Combining Weed Control Part II (CW201) in 2011 to apply the same concept to bareroot seedlings of varying sizes. Additionally, the VMRC installed two Stock Type study sites to test the effects of containerized Douglas-fir stock size on stand survival and productivity under conditions of operational vegetation control.


Delayed Planting

The delayed planting study series was established in 2008 to investigate different management options for units harvested during the late spring and summer. Some of the treatments were established during the first year and others delayed for a growing season. The objective of this design was to test whether it is better to treat a recently harvest stand immediately or wait one year to allow the vegetation community to develop before treatment. A secondary objective was to test if including Oust in the fall site preparation treatment had a longterm impact on vegetation cover and/or tree growth.


Evaluating Common Regimes

The Evaluating Common Regimes Study was designed to quantify the impact of six herbaceous vegetation control regimes on: 1) Douglas-fir seedling survival and growth, and 2) understory community dynamics. The Evaluating Common Regimes study contains six vegetation management treatments arranged in a randomized complete block design with four replications. 


CoSInE (COmpetition and Site INteractions Experiment)

The main objective is to develop a desicion support system with  focus on how site conditions and chemical vegetation management treatments interact to effect seedling survival and growth in PNW.  The study utilize a 2 x 2 x 2 factorial design, where factor 1 corresponds to fall site preparation, factor 2 corresponds to spring release during growing season 1, and factor 3 corresponds to spring release during growing season 2. 

The project aims to better understand the effects of vegetation management treatments on the soil and plant water relations of conifer plantations in the Pacific North West by analyzing conifer seedling and competing vegetation interactions during the first two years after planting. The study will include periodic assessments of biomass growth, water use and nutrient content of seedling and competing vegetation. Additional plant water potential and gas exchange will be carried out as well.