Plant Competition

Today we will…

• Understand differences between intraspecific and interspecific competition

• Measure plant competition in Sanford Woodlot

• Apply our knowledge of correlations to understanding competition dynamics

Competition

Intraspecific (within species) Interspecific (between species)

CompetitionIntraspecific (within species) Interspecific (between species)

Competition

Direct Indirect• Effects of one species

impact another species indirectly

• Apparent Competition• Exploitative Competition

Animals: physical combatPlants: release of toxins

Apparent Competition (Indirect)

Abundance of one species increases likelihood of consumption of other species

Exploitative Competition (Indirect)

Individuals use same limiting resource (most common type of competition)

Why is it important to understand competition dynamics and outcomes?

What are the trade-offs between conducting

controlled, manipulative experiments and observational studies?

Today’s Activity: Measuring Competition

• Read over page 65

Today’s Activity: Measuring Competition

• We will measure:

– Intraspecific competition in beech trees

– Interspecific competition between beech trees and other trees (collectively)

Today’s Activity: Measuring Competition

• Methods: What will you do?

–Along transect, find focal beech tree, measure DBH

– From that tree measure DBH of nearest beech and nearest “other” tree

–Continue at every 6 meters (6 focal trees total)

Today’s Activity: Measuring Competition

• Each team needs

– One 30-meter tape

– Coursepack

– Writing utensils

Data Analysis & Results

• Calculate mean, standard deviation, and correlation coefficient using Excel sheet (ANGEL)

• Graph results

• Answer questions on page 66

• Class discussion of results

• Quiz