THE CHANGES ON PINUS MONOPHYLLA DUE TO ELEVATION
Irving Granados
Department of Biiological Science
Saddleback College
Mission Viejo, CA 92692
There are distinctions amongst pinus monophylla between elevations of 6270
and 9270 ft. in the White Mts. of California. The pinyon pines can have
different respiration and photosynthetic rates at the elevations at which they
are growing. Pinyons grow in hot, dry location on slopes or flat land. It was
hypothesized that at a lower elevation the pinyon pinecones would be greater
in size because of the dry region than pinyon pinecones at a higher elevation
due to a more moisture condition. Twenty samples of pinyon pinecones
(n=20) were collected to measure the height, thickness of the scale and the
diameter of the pinyon pinecones at different elevation. The starting elevation
was 6270 ft. and every 500 ft. a new sample of pinyon pinecones were
collected. The average mean of the height measurement were statistically
different where at 6270 ft. were taller and started to get smaller as we went
higher in the mountain. (± SEM, N=20), (p=0, one-tailed ANOVA, Boneferroni
Correction). The mean of the scale thickness were statistically different where
the initial elevation was greater and the final elevation was smaller (± SEM,
N=20), (p=0, one-tailed ANOVA, Boneferroni Correction). The mean of the
diameter showed a statistically difference from a greater diameter to a
smaller size as the elevation increased (± SEM, N=20), (p=0, one-tailed
ANOVA, Boneferroni Correction). Possible explanations might be the type of
fertilization and soil nutrients concentration that allow the pinyon pine cones
to fully develop at lower elevations, whereas, in a higher elevation the
weather are more extreme for the pinyon pinecones to not fully developed to
its full size.
Introduction
Pinus monophylla is a semi-desert pine typical of the Great Basin but
extending southwards in to Baja California and southeastwards across Arizona into
New Mexico (Lanner, 1973). They are predominantly in drier regions and mountain
slopes. The intensity and duration of drought increase downslope, this factor
appears to offer at least a partial explanation of the differences in lower range limits.
The significance of this difference among the species to endure soil drought is
greatly magnified by the fact that the species of low altitude have the most rapid
rates of root penetration. Not only are they better able to endure soil drought, but
they are more likely to escape its influence (Daubenmire, 1943). They are also
moderately to strongly shade intolerant, and dependent on disturbance, particularly
fire, on productive sites for forest renewal.
The high elevation pines tolerate cold, arid sites with poor soils. (Tomback,
2010). Other related factors are the short growing season and low nutrients
available at high elevations. With increasing elevation, and increasing actual
evapotranspiration, the organic C, plant density, and the CO2 content of the soils
increased (Amundson, Chadwick, Sowers, 1989). Too high a concentration of CO2
causes a reduction of photosynthesis. The environment and phytosociological
characteristics of the pinyon woodland zone of the White Mountains of California
are described and contrasted with those of other southwestern representatives of
this vegetation type.
The pinyon woodland zone of the White Mts. is floristically allied to Nevada
and parts of Utah. The White Mt. zone is unique in the high upper elevation limit it
attains (9,500 ft) and in the low amount of average annual precipitation it receives
(8 to 12 inches)(Andre, Mooney and Wright, 1965). In contrast to other pines, the
surface tissue of pinyon cone scales (spermoderm) forms an irregular rim around
the cone scales recess, instead of forming a wing...which holds the seed within the
recess longer than it would otherwise remain in the cone (Lanner, Devender, 1988).
The purpose of this work was to examine the height, diameter, and thickness of the
scale variations from the pinyon pinecones from different elevation points from the
White Mountains of California. And examine if the elevations causes some sort of
variation amongst the pinyon pinecone factors.
Material and Method
Twenty pinyon pinecones were collected every five hundred feet at White
Mts. in California (n=140) starting from the elevation of 6270 ft. to the top of the
mountain at 9270 ft. on the 26 of November 2015. From each elevation twenty
pinyon pinecones were collected from different tree locations to have variation.
Each sample collection was place in a separate paper bag.
After each sample (n=20) were collected from the seven different elevations
of the mountain. Using a caliper device the measurements of the height, scale
thickness and diameter of the pinyon pinecones (n=140) were taken. The height
was measure with the c-clamp side of the caliper from bottom to the tip of the
pinecone. Then the thick edge of the scale was measure using the same side of the
caliper. And the diameter was measured from the bottom of the two longest sides of
the pinyon pinecones. All data were transferred to MS Excel (Microsoft Corporation,
Redmond, Washington) where all further statistical manipulation was performed
(n=140).
Results
The average thickness of the pinyon pinecones scales between the elevations
were statitiscally less in the elevations from 6770 ft to 9270 ft.; especially the
elevation of 9270ft compared to the elevation at 6270 ft. (p=0, one-tailed ANOVA,
Bonferroni Correction).
The average height of the pinyon pinecones between the elevations were
statitiscally less in the elevations from 6770 ft to 9270 ft. compared to the elevation
at 6270 ft. At the elevation of 6270 ft. the height were greater in size(p=0, one-tailed
ANOVA, Bonferroni Correction).
Average thickness of scale
(cm)
The average diameter of the pinyon pinecone between the elevations were
statitiscally less in the elevations from 6770 ft to 9270 ft. compared to the elevation
at 6270 ft. (p=0, one-tailed ANOVA, Bonferroni Correction).
1.8
1.6
1.4
1.2
1.
0.8
0.6
0.4
0.2
0.
*
*
6270
6770
7270
7770
8270
Elevation (ft.)
8770
9270
Average height of pinyon
pinecone (cm)
Figure 1. The different elevation and the average mean of the pinyon’s thickness of scale. The
average measurements of pinyon pinecones thickness of the scale were statistically less as the
elevation increased, especially at 9270 ft. compared to the elevation of 6270 ft. (p=0, one-tailed
ANOVA, Boneferroni Correction). Error bars are Mean ± SEM. ∗ =Statistically different from other
groups.
10.
*
8.
*
6.
4.
2.
0.
6270
6770
7270
7770
8270
Elevation (ft.)
8770
9270
Average diameter of the
pinyon pine cone (cm)
Figure 2. The different elevation and the average mean of the pinyon’s height. The average
measurements of pinyon pinecones height were statistically less as the elevation increased,
especially at 9270 ft. compared to the elevation of 6270 ft. (p=0, one-tailed ANOVA, Boneferroni
Correction). Error bars are Mean ± SEM. ∗ =Statistically different from other groups.
10.
*
8.
*
6.
4.
2.
0.
6270
6770
7270
7770
8270
Elevation (ft.)
8770
9270
Figure 3. The different elevation and the average mean of the pinyon’s diameter. The average
measurements of pinyon pinecones diameter were statistically less as the elevation increased,
especially at 9270 ft. compared to the elevation of 6270 ft. (p=0, one-tailed ANOVA, Boneferroni
Correction). Error bars are Mean ± SEM. ∗ =Statistically different from other groups.
Discussion
In this study, the data support the fact that pinyon pinecones were greater in size at a lower
elevation than at a higher elevation, thus reavealing a significant difference in height, thickness of the
scale and diameter amongst the elevation going up the mountain. At 6270 ft. the pinyon pinecones
were larger in size. Some factors was that temperature was higher and was more of a dryer
environment. Going up the mountain the amount of snow present was increasing and the size of the
pinyone pinecones were almost similar to each other from 6770 ft. to 8770ft. Once reaching the top
of the mountain at 9270 ft. the temperature was lower, and there was more snow present and the
size of the pinyon pinecones were a lot smaller than the other elevations.
Literature Cited
Amundson, R, Chadwick, O and J.M. Sowers. 1989. A comparison of soil climate and
biological activity along an elevation gradient in the eastern Mojave Desert.
Oecologia 80(3): pp. 395-400.
Andre, G, Mooney, and R. D. Wright. 1965. The Pinyon Woodland Zone in the White
Mountains of California. The American Midland Naturalist 73(1): pp. 225-239
Daubenmire, R.F. 1943.Soil Temperature Versus Drought as a Factor Determining
Lower Altitudinal Limits of Trees in the Rocky Mountains. Botanical Gazette 105(1):
pp. 1-13
Lanner, Ronald. 1973. Natural Hybridization between Pinus edulis and Pinus
monophylla in the Amerian Southwest. pp108-116
Lanner, Ronald and Thomas VanDevender. 1988. The recent history of pinyon pines
in the American Southwest. Ecology and biogeography of pinus pp171-180