low thinning and crown thinning of varying intensities as ...lathrop leonard monica bueno seth...
TRANSCRIPT
Low Thinning and Crown
Thinning of Varying Intensities
as Restoration Tools at
Redwood National Park
Jason Teraoka – Redwood National Park
Phil van Mantgem – USGS
Chris Keyes – University of Montana
Acknowledgements
2007 Crew:
Charlie Escola
Eveline Wenk
Lathrop Leonard
Monica Bueno
Seth McIntyre
Elliot Brinkman
Faros Kahn
2008 Crew:
Jessica Engle
Justin Eurotas
Jesse Wilhite
2013 Crew:
Scott Powell
Graham Sivak
Forest Kirk
Brandon Piper
Amber Piper
Eamon Engber
Leonel Arguello
Stassia Samuels
Alison O'Dowd
Save-the-Redwoods-League Education Grant
NPS Mission
The National Park Service preserves
unimpaired the natural and cultural
resources and values of the national
park system for the enjoyment,
education, and inspiration of this and
future generations….
Two pervious attempts:
• First attempt: Late 70’s– Holter Ridge Project (1978)
– Moratorium on thinning 1979
• Second attempt: Early 90’s– Whiskey-40 Project (1995)
– Funding woes kill the program
– Increased public awareness
Forest Restoration ProgramForest Restoration Program
• Two projects prior to 2007
• Low thinning prescribed
- Large trees retained
- mimics self-thinning patterns
• Seems reasonable?
Aerial Seeding
National Geographic, July 1964
The A-972 Thinning Project (2007)
Test four treatments under a
single-entry thinning:
• Low Thinning vs. Crown Thinning
• 45% Retention vs. 80% Retention
Benchmarks:
• Restore more appropriate balance in overstory species composition
• Promote vigorous tree growth
• Initiate understory
Low Thinning
80% Retention
Low Thinning
45% Retention
Crown Thinning
80% Retention
Crown Thinning
45% Retention
Control
“L80”
“L45”
“C80”
“C45”
Contr
ol
Pre-Thin 2008 Immediate Post-Thin After 5-years
C45 L45 C80 L80
Contr
ol
C45 L45 C80 L80
Co
ntr
ol
C45 L45 C80 L80
Contr
ol
C45 L45 C80 L80
Contr
ol
C45 L45 C80 L80
Contr
ol
C45 L45 C80 L80
Tre
es/h
aB
asal
Are
a (m
2/
ha)
1500-
1000-
500-
60-
40-
20-
0-
0-
hemlock
redwood
Douglas-fir
Sitka spruce
alder
ANOVA/Tukey’s Post-Hoc
Trees of all Species
Douglas-fir redwood
ANOVA/Tukey’s Post-Hoc
Ba
sal A
rea
(m
2/
ha
)
Low Thinning - 80% RetentionPre-Thin 2008
Trees/ha = 1,758
Basal area = 68 m2/ha
Post-Thin
Trees/ha = 1,053
Basal area = 54 m2/ha
After 5-years
Trees/ha = 1,029
Basal area = 62 m2/ha
Low Thinning - 45% RetentionPre-Thin 2008
Trees/ha = 1,680
Basal area = 71 m2/ha
Post-Thin
Trees/ha = 417
Basal area = 32 m2/ha
After 5-years
Trees/ha = 395
Basal area = 39 m2/ha
Crown Thinning - 80% RetentionPre-Thin 2008
Trees/ha = 1,615
Basal area = 73 m2/ha
Post-Thin
Trees/ha = 1,266
Basal area = 58 m2/ha
After 5-years
Trees/ha = 1,103
Basal area = 66 m2/ha
Pre-Thin 2008
Trees/ha = 1,578
Basal area = 74 m2/ha
Post-Thin
Trees/ha = 494
Basal area = 33 m2/ha
After 5-years
Trees/ha = 460
Basal area = 40 m2/ha
Crown Thinning - 45% Retention
Summary• Doing anything was better than doing nothing
• Redwood and Douglas-fir responded well
• More relative growth in the higher severities
• If you're afraid of falling a lot of trees, cut fewer but larger trees
• Demonstrates the influence of thinning over a short period.
Further Analysis:
• Only five-year data!
• Much more analysis needs to be done on growth
• Understory development, overstory species composition
• Crown ratio, regeneration, overstory and understory cover, X,Y
coordinates
• 10-year measurement in 2018
