lodgepole pine cone density by: corey slinkard ebio 4100 spring semester 2012
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Lodgepole Pine Cone Density
By: Corey SlinkardEBIO 4100Spring Semester 2012
Outline
Hypothesis
About the Lodgepole Pine Location Importance Reproduction Cones
Methods
Results
Discussion
Citations
Hypothesis
Due to the strong westerly winds on Colorado’s Rocky Mountains, I hypothesize cone density on Lodgepole Pines will vary by hill slope direction, particularly on east-facing slopes in areas around MRS. Relates to winter ecology
because the LP has ~26 month
pollen-cone and seen-cone bud
Initiation… (Owens, 2006)
More on Lodgepole Pine
Location: Pinus contorta extends
from the Mackenzie district of the Yukon in Canada, to southern Colorado in the Rocky Mountains and northern Baja (Owens, 2006)
Lodge Pole pines are important because they account for about 7% of Rocky Mountain forests.
Distribution map:Pinus contorta subsp. contortaPinus contorta subsp. latifoliaPinus contorta subsp. murrayana
Lodgepole Importance
• Ecological
• Protective cover for watersheds
• Wildlife Habitat
•Aesthetic value for recreation
Economic Importance Valuable source of timber products One of the most extensively harvested trees in
west.
Points on Lodgepole Reproduction
Reproduction The cones are serotinous
“Serotinous cones do not open at maturity, but remain closed until the resin bond between cone scales is melted.” (Knapp and Anderson, 1980)
It is a fire adapted tree Lodgepole pines have fairly thin bark, which reduces their
defenses against fires. Tend to outcompete each other for resources, often
leaving many of them to dry up and die. These dead Lodgepoles then become a fuel source for a
future fire, increasing the heat needed for reproduction.
Cones
Opening the fire adapted cone Temperatures ranging from 40-69º C have been
reported as sufficient to open the cones. (104º-156ºF)
Seeds inside the cones DO NOT lose viability with age!
“Although direct sunlight can, in some circumstances, open the cones, fire normally releases the seeds to the favorable seedbeds.” (Knapp and Anderson, 1980)
Methods
Location: Surrounding areas of MRS
3.0m x 3.0m area
How much shade?
Count number of Lodgepole Pines
Direction hill slope faces South North East Flat
Approximate tree height
Count number of cones on each tree Total number Use binoculars
Results
East East North North South South Flat Flat0
10
20
30
40
50
60
70
80
90
Avg. number Cones vs. Slope-face
EastNorthSouthFlat
Slope-facing Direction
AverageNumberCones
Avg. cones East: 16.14North: 17.21South: 49.08*Flat: 15.38
*contained outlier
South-face slope? •What’s going on here?
Other Results
Seems to be no correlation between slope-face direction and cone density…
Light Moderate Extreme13
13.5
14
14.5
15
15.5
16
16.5
17
17.5
Shade vs. Average cones
Amount of Shade
Averagenumberof cones
• Relationship?
•”Lodgepoles are quick to occupy a site… full of sunlight”(Owens, 2006)
•Does contain outlier
Discussion
HYPOTHESIS FAILED?
Why? Cones only need to get to a certain
temperature to release seeds. If ground is on fire, wind direction might not make
a difference. Remember: cones remain closed until the resin
bond between cone scales is melted. (Knapp and Anderson, 1980)
Relationship between shade and cones? Maybe… Future projects.
Citations
A.K. Knapp and J.E. Anderson. “Effect of Heat on Germination of Seeds from Serotinous Lodgepole Pine Cones.” American Midland Naturalist , Vol. 104, No. 2 (Oct., 1980), pp. 370-372
Owens, J. "The Reproductive Biology of the Lodgepole Pine." Forest Genetics Council of British Columbia. (2006): 1-62. Print.
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