ECOSYSTEM COMMUNITY STRUCTURE AND SPECIES INTERACTIONS

Question 1

Biodiversity

Answer 1

• The variety of life in the world, particular habitat or ecosystem

Question 2

Diversity (broadly)

Answer 2

• The “variety” of species in a community (i.e., more or less diverse)

Question 3

Species Richness

Answer 3

• The number of different species within the community

Question 4

Relative Abundance

Answer 4

• The proportion (%) of the community made up by a given species

Question 5

Species Evenness

Answer 5

• The distribution of individuals among species

Question 6

Dominance

Answer 6

• A term used to describe a community made up of primarily of one species

Question 7

Trophic Levels

Answer 7

• Different levels of groups of organisms that derive energy in a similar way

Question 8

Niche

Answer 8

• The role an organism plays in its environment, including the conditions it needs to survive and reproduce

Question 9

Guild

Answer 9

• A group of species exploit a common resource

Question 10

Functional Type

Answer 10

• A group of species with one of the following:
  1. Common response to the environment
  2. Common evolutionary history
  3. Common role within the community

Question 11

Fundamental Niche

Answer 11

• The range of environmental conditions in which a living organism can successfully survive and function due to adaptation

Question 12

Autotrophs (producers)

Answer 12

• Species that do not eat other biotic organisms, and instead convert abiotic resources into energy
  Plants are autotrophs: use CO2 and water to create energy

Question 13

Herbivores (consumers)

Answer 13

• An organism that feeds on autotrophs/producers (vegetarians)

Question 14

Carnivores (consumers)

Answer 14

• An organism that feeds on other consumers (either herbivores or other carnivores)

Question 15

Omnivores (consumers)

Answer 15

• An organism that feeds on both autotrophs and other consumers

Question 16

Competition

Answer 16

• The interaction between species that seek access to the same resource in their habitat
• Usually detrimental to both organisms

Question 17

Amensalism

Answer 17

• An association between organisms of two different species in which one is inhibited or destroyed and the other is unaffected
• Plant A might grow taller than Plant B
• Plant B will lose access to light
• Plant A benefits from the extra light, but hasn’t directly benefited from harming Plant B

Question 18

Predation

Answer 18

• A biological interaction where one organism, the predator, kills and eats another organism, the prey
• One organism benefits, one is harmed

Question 19

Parasitism

Answer 19

• Involves an organism (parasite) feeding on another (host) without killing it, but reducing its fitness
• One organism benefits, one is harmed

Question 20

Mutualism

Answer 20

• Association between organisms of two different species in which each benefits
• Both organisms benefit

Question 21

Commensalism

Answer 21

• One species provides a condition that is necessary for another without affecting its own well being
  One organism benefits, one is unaffected

Question 22

Vegetation Structure

Answer 22

• Is used for ecological classification (e.g. grassland, shrubland, forest)
  Vegetation structure reflects the interactions and spatial variability between abiotic and biotic factors
  1. Nutrients
  2. Moisture
  3. Competition for nutrients and moisture

Question 23

The Vertical Structure

Answer 23

• Influences the vertical gradient of light and provides a physical framework in which other biotic organisms live.
• The growth forms (height, width, size of leaves) of plants define the vertical structure of the forest

Question 24

Canopy

Answer 24

• The upper layer, consisting of treetops
• Receives the most light, and is the site of a large amount of photosynthesis

Question 25

Understory

Answer 25

- A mid-layer, consisting of stunted trees & saplings - Composition and density are dependent on the amount of light passing through the canopy

Question 26

Shrub Layer

Answer 26

- A mid-layer, consisting of shrubs - Composition and density are dependent on the amount of light passing through the canopy and understory

Question 27

Herb Layer

Answer 27

- A lower layer, consisting of grasses, ferns, wildflowers, etc. - Composition and density are dependent on the amount of light passing through the canopy, understory, and shrub layer

Question 28

Forest Floor / Ground Layer

Answer 28

- The lowest layer, consisting of mosses, lichens, and plant litter (e.g., leaves) - Composition and density are dependent on the amount of light passing through the canopy, understory, shrub layer, and herb layer