Dendroecology of Piñon Trees At the Los Pinos

Mountains on the Sevilleta National Wildlife Refuge

By Jason Lopez

Dendroecology- Is the study of how age and growth of the trees reflects the underlining

ecological processes and conditions.

Why do trees produce annual rings?

• Limiting factors control the growth of the tree.– Water– Temperature– Competition and insect herbivory – Soil and geomorphological characteristics

Climate

Colorado Piñon• Colorado Piñon ( Pinus edulis )

Two-needle

• Piñon are conifer trees and produce dark annual rings.

• The oldest piñon tree discovered in Northeastern Utah is approximately 973 years.

Piñon Pine Distribution • Occurs 4,500 to 9,000 ft.

• Arizona, New Mexico, Nevada, Utah, and Colorado

Purpose

• To explore correlations between growth and age in piñon trees.

• See how the sites characteristics and geomorphology of the area might have influenced the trees growth.

Study Site• The Los Pinos Mountains are a poorly studied area,

and are dominated by Piñon-Juniper Woodlands

Field & Lab Equipment • Increment Borers• Field book• Clip board • Cleaning kit• GPS• Tape• Measuring tape• Drinking straws• Cleaning patches• Dissecting scope• Straws

Field Methods

• 5 Locations– North Facing Slope– South Facing Slope– East Facing Slope – 2 Ridges

• 2 cores were collected from 5 trees at each site.

Field Methods• Diameter root crown (DRC) of each tree was measured• Height at which core sample was taken was measured.• Crown, tree height and distance to nearest trees were

measured

Lab Methods• Seedlings were cut down and taken back to the

lab to analyze. – Seedlings were the same height as the core samples

• Cores were mounted and sanded down for analysis.

• Rings were counted on all cores.

Analytical Methods• Skeleton plots were created for each core.

Results

Results

Results

Results

Results

Results

Summary• No correlation between height and age.

• There is a strong correlation between diameter root crown (DRC) and age.

• There is a good correlation between volume and age.

• There were differences among slopes and geomorphological setting with respect to growth patterns

Discussion• There were indications that there were

differences among slopes with respect to growth patterns embedded in the general all-sites regression.

• However a larger sample size is need to confirm these patterns.

• The oldest tree found was 229 years old.

Further Research• Explore more of the soils and the site’s

landscape.

• Sample other parts of the Los Pinos mountain.

• Past climate

• Fire history.

Special Thanks ToJennifer Johnson

• Thanks for hiring me• Thanks for not firing me• Thanks for putting up with me• Thanks for making fun of me• Thanks for helping me with my project and

grammar• Thanks for not letting the other REUs kill me• AND JUST PLAIN THANKS FOR

EVERYTHING.

• The oldest tree found here was 229 years old

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