Elevation Distribution of Vaccinium Myrtillus

in Spruce-Fir and Lodge Pole Forests.

By: Nicholas Condello Schwinger 7/ 17/2013

Introduction:

• Pinus Contorta (lodge pole pine) forests• Rocky undeveloped soils are acidic• Thin layer of litter .5-1cm• Thin layer of duff 1-3cm (often no duff present)• Absence of other conifer species• Very little undergrowth• Vaccinium shows small presence

Expect to see a reduction in all ground cover as we move from lodge pole into the spruce fir forests.

-Fewer species-Fewer individuals

Introduction:• Pieca Engelmannii (engelman spruce) Abies Lasiocarpa (sub-alpine fir)

forests• Soils are more developed but still acidic.• Litter layer 1-3cm.• Duff layer 6-14cm.• Spruce and fir trees are co-dominant.• Species diversity is still low.• Vaccinium dominates the forest floor in many areas.

Introduction:• There appears to be a strong correlation between the spruce

fir forests and vaccinium dominance on the forest floor.

• Vaccinium has little presence in the lodge pole forest.

• What causes this pattern of dominance vs. near absence?

• Key factors that may play a roll in vaccinium distribution.• Elevation• Soil profile• Other vegetation types• Canopy cover

Methods:• Sample spruce fir and lodge pole forests using the following

techniques.• In a 200m by 200m area 5 random locations were selected for

each forest type.• Site 1: N. side of Niwot Ridge At an elevation of 3,300m with a

slope of 5 degrees and a due North aspect.• Site 2 N. side of Niwot Ridge at an elevation of 2,950m with a

slope of 7 degrees and an aspect of N. 5 degrees E. • Samples taken at each location include:

• 1 nested plot• 2 Daubermeyer plots• 1 soil sample• Bitterlich basil area estimation • Observation of other vegetation

Results: This graph shows that compared to

other species vaccinium dominates a large % of the ground cover at site 1.

The number of individuals for vaccinium far exceeds any other

species for site 1

Results:• A chi squared analysis of vaccinium shows a strong correlation

between vaccinium and the spruce fir forest• P value <<0.001 • In contrast to the lodge pole forest which has very little

correlation with vaccinium.• There also appears to be a relationship between thickness of

duff and vaccinium presence as shown below.

P value=0.011 show a strong correlation between duff and vaccinium.

Results:• The strong relationship between thickness of duff and

vaccinium dominance is supported by (Frak and Ponge nd).• Vaccinium rhizomes exploit nutrients in duff• Vaccinium roots exploit nutrients from the rocky soil below

• A 2 factor analysis of variance between the two sites shows: • Number of individuals changes very little for other forbs.• % coverage changes very little.• Mosses are replaced by sedges.• High p values reveal no statistical significance.

• For the plants in the following graph the two sites show little difference.

Results:• Other species associated with vaccinium like arnica, senecio

don’t show the same reduction. • by removing the vaccinium figures we can better see the

relation ship between the two sites for other important species.

moss arnica senecio sedge0

0.2

0.4

0.6

0.8

1

1.2

1.4

Site 1Site 2

Species

Mean # of In-dividuals

Discussion:• Visually there appears to be fewer individuals and less

coverage for other forbs from site 1 to site 2. Data does not support this

-What can be done.• Collect more samples across different elevations.• Explore different sampling methods.

• Vaccinium• Exploitation of nutrients at different depths.• Flourishes in spruce fir forests.• Associated with duff and acidic soil.

Discussion:• What Did I See -Other members of the understory community are not affected by:• Lack of vaccinium• Change in tree species• Absence of duff

-A correlation between the amount of duff and the amount of vaccinium.• Site 1 thick duff, lots of vaccinium• Site 2 no duff, sparse vaccinium

Questions?

Additional notes:

• One of the most interesting relationships I observed was the relationship between vaccinium and the amount of duff present.

• Large duff layers seem to appear where vaccinium is most prevalent. More data is required to verify this.

• Lodge pole pine have considerably less duff possibly because they are one of the first species to take over after a disturbance.

• Disturbances namely fire and logging may lead to the erosion of top soil, making it hard for vaccinium to reestablish it self without organic nutrients (more data required).

• The root systems of lodge pole pines may utilize nutrients in the same soil horizons as vaccinium also making it hard for the shrub to reestablish it self.

• Where there is a large duff layer in lodge pole forests vaccinium appears to form beds. This would be interesting to look at more closely.

• Elevation or the presence of associated forbs does not seem to be a key factor for the presence of vaccinium. Rather forest type and and soil profile appear to be controlling factors.

• In spruce fir forests at lower elevations thriving communities of vaccinium were observed.• Acidity levels between the two forest types are negligible and does not seem to affect the

presence of vaccinium, it thrives in acidic soils.• Forest canopy (which was not measured) may play a roll in vaccinium presence.• High standard error and standard deviation shows that more data is required.• I expected to see a correlation between the reduction of vaccinium and associated forbs, however

with the given data there was no significant statistical difference.• Arnica and senecio show the same level of occurrence in both forest types. The soil profile does

not seem to affect their presence.

Appendix A:

Refrences:

Mead, D J and Cornforth, I S. Eds. 1995. The Influence of Tree Species on Forest Soils: Processes and Patterns.Aplet, Laven and Smith