Lecture 7 JD

Question 1

Anthropocene

Answer 1

the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment.

Question 2

Global Environmental Change

Answer 2

addresses large-scale chemical, biological, geological, and physical perturbations of the Earth’s surface, ocean, land surface, and hydrologic cycle with special attention to time scales of decades to centuries, to human-caused perturbations and their impacts on society.

Question 3

Biodiversity loss

Answer 3

reduction in abundance,
extirpation (local extinction), extinction

Question 4

Principal drivers:

Answer 4

1. Habitat loss
2. Overexploitation

Question 5

Habitat loss

Answer 5

the permanent conversion of former habitat to an area where that species can no longer exist (Convention on Biological Diversity)

Question 6

Habitat loss can occur through

Answer 6

habitat destruction, fragmentation and degradation

Question 7

Overexploitation

Answer 7

depletion of numbers through harvesting of individuals

Question 8

How does habitat loss and overexploitation impact biotic interactions?

Answer 8

By reducing species abundances and driving local extinctions, habitat loss can alter competitive interactions, predation, and mutualistic relationships between species

Question 9

Habitat loss is strongly linked with

Answer 9

declines in pollinators in Europe

Question 10

Overexploitation can lead to

Answer 10

trophic cascades

Question 11

Trophic cascade,

Answer 11

an ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling.

Question 12

Invasive alien species

Answer 12

An introduced species which becomes established in natural or semi-natural ecosystem or habitat, is an agent of change, and threatens native biological diversity

Question 13

Impacts of invasive species

Answer 13

Introduced species can have significant environmental (e.g. species extinctions), economic (e.g. cost of control) and human health impacts

Question 14

Why are some introduced species so successful? – the role of biotic interactions

Answer 14

Firstly, there must be suitable abiotic conditions

Question 15

Fundamental niche

Answer 15

is the physiologically optimal range of conditions where a species can survive,

Question 16

Realized niche

Answer 16

is where the species actually lives
(biotic interactions)

Question 17

Tolerance limits

Answer 17

Each environmental factors has both min and max levels beyond which a species cannot survive or is unable to reproduce

Question 18

Vacant niches due to degradation:

Answer 18

low diversity communities are more vulnerable to invasive species because vacant niches are present and the intensity of interspecific competition is reduced

Question 19

Example of vacant niche

Answer 19

Invasive Rhododendron ponticum in Killarney national Park

Question 20

Enemy release hypothesis:

Answer 20

invasive species, on introduction to a new region, experience a decrease in regulation by natural enemies, resulting in a rapid increase in distribution and abundance

Question 21

Japanese knotweed

Answer 21

(Fallopia japonica)

Question 22

Impact of weed

Answer 22

• Altershabitat,reduces diversity
• Winterdieback makes riparian areas vulnerable to erosion
• Can cause damage to property

Question 23

Invasive predators have caused

Answer 23

rapid declines in many native prey species across the globe. Predator invasion success may be attributed to prey naïveté, or the absence of anti- predator behavior between native and non-native species.

Question 24

Climate change can result in changes in

Answer 24

species phenology, sometimes causing trophic mismatches (interacting species change the timing of regularly repeated phases in their life cycles at different rates)

Question 25

Climate induced range shifts can result in

Answer 25

spatial mismatches in the distribution of interacting species (e.g. Bark beetles encounter naive hosts at their expanding range edge, increasing their population growth)

Question 26

Climate change will favor species

Answer 26

able to tolerate warmer and more variable climatic conditions, resulting in a relative increase in their performance (competitive dominance)

Question 27

Competitive interactions

Answer 27

are frequently altered by changes in the dominance of plant and animal species (climate change winners and losers)