Forest Ecology - Quiz 1

Tree growth and biodiversity

Springwood (earlywood)

The faster growing, lighter colored part of the growth ring, formed early in the growing season.

Summerwood (latewood)

The darker, more dense part of the growth ring, formed late in the growing season.

Cambium

The living layer of the trunk that adds diameter; divided into xylem and phloem.

Xylem

Layer of the cambium that transports water and minerals from the roots to the leaves.

Phloem

Layer of the cambium that transports sugars produced in the leaves to the rest of the plant.

Photosynthesis

The process of converting light energy from the sun into usable energy using water and oxygen.

Snag

A dead, standing tree; a very important habitat requirement.

Timber Stand Improvement (TSI)

The removal of trees that are competing with preferred trees; thinning, girdling, crop tree release

Thinning

Strategically removing trees from a stand to make it less dense, allowing more desirable trees to grow.

Girdling

Removing a section of a tree's cambium layer around the entire tree to slowly kill the tree and create a snag.

Crop tree release

Removing competing trees from around more valuable crop trees to give them extra growing space.

Shade tolerance

The amount of shade a species can tolerate while still being able to germinate and reproduce. Different species have different levels of shade tolerance.

Biodiversity (broad)

The number of species in a given area.

3 types of biodiversity

Alpha, beta, gamma

Alpha biodiversity

Local-level, single habitat type

Beta biodiversity

Between alpha sites, movement across habitats

Gamma biodiversity

Largest scale, multiple alpha and beta connections

Example of alpha biodiversity

A single stand of trees

Example of beta biodiversity

Comparing multiple stands of trees

Example of gamma biodiversity

Southeast Ohio, Wayne national forest

What is used for measuring alpha biodiversity?

Simpson’s Index of Diversity

What is used for measuring beta biodiversity?

Bray-Curtis Dissimilarity Index

Genetic diversity

How genetically rich or poor a species is.

Habitat diversity

How many

Mutation

The natural process when genes change across generations.

Natural selection

Variation in individuals can lead to different reproductive success

Geographic Isolation

Populations of a species colonize different areas, adapt and evolve differently, causing speciation.

Genetic drift

Random genetic changes in a population due to chance, not adaptation.

Island

An isolated stand made up of different species than the surrounding.

Leading cause of invasive species today

Travel/commerce

Species richness

How many different species are recorded in an area.

Abundance

The number of individuals in a species.

Evenness

Comparing the number of individuals in each species.