Week 6: Communities

Question 1

Metapopulation

Answer 1

A group of spatially separated populations of the same species which interact at some level.

Question 2

Patch

Answer 2

An area of habitat differing from its surroundings, often the smallest ecologically distinct landscape feature in a landscape mapping and classification system.

Question 3

Disturbance

Answer 3

A temporary change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements.

Question 4

Gap

Answer 4

The species or ecosystem occurs in the protected area system, occurrence is either of inadequate ecological condition, or the protected area(s) fail to address species’’ movements or specific ecological conditions needed for long-term survival or ecosystem functioning.

Question 5

Founder-controlled community

Answer 5

Species are approximately equivalent in their ability to invade gaps and can hold the gaps against all comers
during their lifetime.

Question 7

Dominance-controlled community

Answer 7

Some species are competitively superior to others, and an initial colonizer of a patch cannot necessarily maintain its presence there.

Question 8

Community Succession

Answer 8

Disturbances that open up gaps lead to reasonably predictable sequences of species, because different species have different strategies for exploiting resources.

Question 9

Climax stage

Answer 9

When the most efficient competitors oust their neighbours.

Question 10

Primary Succession

Answer 10

If an opened-up gap has not previously been influenced by a community,

Question 11

Secondary Succession

Answer 11

Where the species of an area has been partially or completely removed but seeds and spores remain,

Question 12

Chronosequence

Answer 12

A set of ecological sites that share similar attributes but represent different ages.

Question 13

Food web

Answer 13

Consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem.

Question 14

Trophic level

Answer 14

The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain.

Question 15

Direct effect

Answer 15

Deal with the direct impact of one individual on another when not mediated or transmitted through a third individual.

Question 16

Indirect effect

Answer 16

The impact of one organism or species on another, mediated or transmitted by a third

Question 18

Trophic Cascade

Answer 18

Occurs when a predator reduces the abundance of its prey, and this cascades down to the trophic level below, such that the prey’s own resources (typically plants or phytoplankton) increase in abundance.

Question 19

Top-down control

Answer 19

Directional regulation within an ecosystem, where species occupying higher trophic levels exert controlling influences on species at the next lower trophic level

Question 20

Bottom-up control

Answer 20

Competition between primary producers for limiting nutrients determines the state of higher trophic levels

Question 22

What is road salt?

Answer 22

Sodium (Na) & Chloride (Cl)

Question 23

The effects of road salt on Surface water

Answer 23

Elevated levels of chloride
salts

Question 24

Impacts of road salts on Surface Water

Answer 24

1. Toxic to certain fish species & invertebrates
2. Prevent vertical mixing - depletion of oxygen
3. Release of heavy metals from sediment

Question 25

Effects of road salt on Ground water

Answer 25

Elevated levels of Sodium & Chloride

Question 26

Impacts of road salts on Ground water

Answer 26

1. Increase salinity of drinking water
2. Increase salinity of base-flow to surface
   water

Question 27

Effects of road salts on Vegetation

Answer 27

Elevated levels of
Sodium and Chloride in soils, aerial exposure

Question 28

Impacts of road salts on Vegetation

Answer 28

1. Invasion of salt-tolerant species
2. Reductions in flowering and fruiting
3. Growth reductions & root injuries

Question 29

Effects of road salt on Soil

Answer 29

Increased soil salinity

Question 30

Impacts of road salt on Soil

Answer 30

1. Deterioration of soil structure
2. Loss of soil stability
3. Decreased soil permeability

Question 31

Effects of road salts on Wildlife

Answer 31

Behavioural changes

Question 32

Impacts of road salts on Wildlife

Answer 32

1. Increase in traffic-related deaths
2. Food shortages due to reduction in plant
   growth
3. Salt toxicosis from eating salt on road

Question 33

Road Salt alternatives

Answer 33

Sand & Beet juice

Question 34

Electric conductivity

Answer 34

A measure of how well
electricity can move through a
substance (i.e. water)

Question 35

Chlorides

Answer 35

Inorganic elements dissolved in water increase EC (dissociated ions carry an electrical current)

Question 36

Turbidity

Answer 36

Measures clarity/murkiness of the water sample

Question 37

Impacts of Turbudity on water quality

Answer 37

Increases water temps,
nutrient and chemical
transport

Question 38

3 main strategies for cold survival

Answer 38

1. Seasonal Migration
2. Torpor & Hibernation
3. Resistance

Question 39

Winter Food

Answer 39

1. Berries
2. Nuts
3. Seeds
4. Browsing

Question 40

Snow as an Insulator

Answer 40

a). Snow has low thermal
conductivity (TC)

b). Space between snow
granules traps heat (Light fluffy snow = low TC, Heavy dense snow = high TC)

c). Small mammals tunnel under snow when temperature decreases