Tree Mortality in the WFDP:2012-2013!
By: Zak M. Hale & Joey D. Shaughnessy
Advisor: Dr. Jim Lutz
Background!
"
Location - Thornton T. Munger Research Natural Area of the Gifford
Pinchot National Forest in near Carson, Washington"
Establishment - The plot was created in the summer of 2009 and 2010"
Size - The plot area is 25.6 square ha (320 m x 800 m)"
Forest type - Old-growth, Douglas-fir—western hemlock forest"
Vegetation - Currently there is 30,718 stems recorded and mapped on
the WFDP plot. Tree species composition is Abies amabilis (Pacific
silver fir), Pinus monticola (western white fir), Pseudotsuga menziesii
(Douglas-fir), Taxus brevifolia (pacific yew), and Tsuga heterophylla
(western hemlock).
Mortality Equations!
Survivorship (3 years) = {(1-4.1%) (1-1.3%) (1- 2.0%)}= 92.9%."
Mortality (3 Years) = 1- survivorship (3 years) = 1-0.929 = 0.07146 = 7.1%"
1 year mortality = 1- Cubed Root(3 year survivorship) = 1-30.0929 =
0.0244= 2.4%"
1 year survivorship = Cubed Root (3 year survivorship) = 0.9756 = 97.6%"
"
5 year survivorship = (1 year survivorship)5 = (0.9756)5 = 0.8838 = 88.4%"
5 year mortality = 1 - survivorship (5 years) = 1- 0.8838 = 0.1162 = 11.6%"
Expected Mortality Rate
Actual Mortality Rate
Expected vs Actual Mortality Rates of T.
brevifolia in the WFDP 2011-2013
*Taxus
brevifolia mortality was 273% higher
than expected
0.05
Objectives!
4.10%
"
Results
Above: Mechanical damage as a
factor associated with death (FAD)
leads to remeasuring heights with
the LASER
0.0375
1) Establish mortality rates within the Wind River Forest Dynamics Plot
for all species for 2013; "
2) Explore the pacific yew, Taxus brevifolia (TABR), and it’s higher than
expected mortality rate."
3) Explore the western white pine, Pinus monticola, (PIMO) as it
suffered a 33% mortality rate in the plot.
2.47%
0.025
0.0125
0
0.83%
1.20%
0.83%
0.83%
2011
2012
0.83%
2013
*T.
brevifolia had no involvement with insect
FADs"
"
2.00%
AVG
2011-2013
*One
third of Pinus monitcola in the plot
experienced mortality in 2013, the highest
rate of any one species"
Mortality Rate by Species
5 Year Mortality Projections of Taxus brevifolia
12%
0.4
11.62%
Methods!
Above: Beetle Galleries can be
a great indicator for FADS
involving insects
33.3%
9%
Fieldwork:!
*Field crews did research in the plot from August-September
2013"
*Completed ingrowth data for any shrub or tree ≥ 1 cm at
DBH"
*Report of any tree mortality or fallen tree with factors
associated with death (FAD)"
Analysis:!
*Mortality sheets were translated into computer spreadsheets"
*Various sheets, table, and charts were created using
species, size classes, and factors associated with death
5 Year Projection; based on our data
5 Year Projection; Hann and Hanus 2001
0.3
0.2
6%
Acknowledgements!
16.0%
12.5%
3%
4.25%
0.1
1.1% 1.8% 2.2%
0
ABAM ABGR ACCI
2.1%
4.1%
AMAL COCOC CONU HODI
2.3%
0.9% 1.5% 2.1% 0.8% 1.7%
PIMO PSME RHMA TABR TSHE VAOV VAPA
0%
Discussion!
Taxus brevifolia Hann and Hanus 5 year mortality rate model for T. brevifolia is 4.25%."
Projected 5-year mortality rate based on our annual average is 12.33%, nearly 3x the
expected rate!
Pinus monticola The white pine blister rust, Cronartium ribicola, epidemic in the early 1900’s was
responsible for 2 mortalities from the 6 live stems that were recorded in 2012. "
"
We would like to thank any and all
people and institutions that are
involved with the Big Plots,
especially the principal
investigators for making it all
happen.
References!
Hann, David W., and Mark L. Hanus. Oregon State University. Forest Research Library. Enhanced Mortality Equations for Trees in the Mixed Conifer Zone of Southwest
Oregon. 2001. Print.
Lutz JA, Larson AJ, Freund JA, Swanson ME, Bible KJ (2013) The Importance of Large-Diameter Trees to Forest Structural Heterogeneity. PLoS ONE 8(12): e82784. doi:
10.1371/journal.pone.0082784