Previous STCV works

Krebs, M. 2003 . Effects of understory vegetation on the photosynthesis and leaf water potential of young Douglas-fir trees on two contrasting sites in northwestern Montana. (Thesis) University of Montana, Missoula MT.

Keller, K. 2005. Applying the Prediction of Four-Year Height Growth of Douglas-fir and Ponderosa pine Saplings to an Existing Growth Simulator. (Thesis) University of Montana, Missoula MT.

Salas, C., A. Stage, and A. Robinson. 2008. Modeling Effects of Overstory Density and Competing Vegetation on Tree Height Growth. Forest Science 54(1)107:122

McHugh, R. 2009. Effects of Overstory Retention and Understory Vegetation on Small Tree Height Growth in the Inland Northwest. (Thesis) University of Montana, Missoula MT.

Large tree overstory plot (DBH ≥ 10.5”)

Area = 0.46 acre

Medium tree overstory plot (DBH > 3.5”)

Area = 0.26 acre

Small tree plot (x6) Area = 0.007 acre

Plot center

Vegetation transect (x6) Length = 31 ft

1m² or 4m² quad (x6)

Not drawn to scale

Tagged tree height measurement

Height measured to culmination of previous year’s growth (highest whorl)

Installation locations

Installation measurement schedules

Installation characteristics

Name Est Habitat type Grow cycles PIPO Saplings

Empry Mountain (EM) 2000 PSME 2 183 659

Grouse Creek (GC) 1999 ABGR 3 80 277

Kiefer Cabin (KC) 2001 PSME 2 97 1,438

Loon Lake (LL) 1999 PSME 3 211 3,458

Overstory conditions

Understory conditions by treatment

Tagged tree initial heights

Growth rates by initial height

Growth rates by CCF

Growth rates by US cover

Growth rates by US cover

FVS small tree height growth model

Intercept

1. Location

2. Habitat type*

3. Aspect & Slope

4. Species*

Slope

1. Initial height*

2. CCF*

3. BAL*

* Denotes species specific coefficients

FVS slope / aspect model term

Summary

Findings

Initial height and OS competition important

US competition effects slight, use habitat type as surrogate

FVS IE users be wary growing small PIPO under sparse OS conditions

Next steps...

Examine tree specific measures of US competition

More installations

Other species