Ecological footprint of societies part 1

Question 1

define ecological footprint

Answer 1

the strength of the direct and indirect impacts that an organism has on the larger ecological system it is part of

Question 2

ecological footprint - direct impacts

Answer 2

via direct trophic interactions for our focal societies

Question 3

ecological footprint - indirect impacts

Answer 3

via indirect trophic interactions, community structuring interactions

Question 4

ecological footprint: indirect impacts - community structuring interactions

Answer 4

• competition
• ecosystem engineering
• associated cascading ecosystem-level processes

Question 5

define ecosystem

Answer 5

• Ecological scale at which we see the exchange of common elements among organisms and the environment
• biological communities plus the physical environment in which they live.

Question 6

ecosystem - unique process

Answer 6

energy flux and nutrient cycling

Question 7

define ecosystem level processes

Answer 7

the intersection of biotic processes among all species in a region and the abiotic processes that surround them

Question 8

ecosystem level processes - abiotic processes include what?

Answer 8

• water cycle and nutrient cycling
• which can be reciprocally shaped by biotic interactions.

Question 9

Why is biodiversity important?

Answer 9

• Species are rarely ecologically interchangeable — they have different niches.
• Niches determine ecological function, and ultimately ecosystem function.

Question 10

why is biodiversity important - maintenance of biodiversity is critical for what?

Answer 10

critical for the maintenance of ecosystem function.

Question 11

The _____________________________________, because of the complex indirect effects of a species trophic interactions.

Answer 11

impact of the presence (or loss) of any one species is hard to predict

Question 12

biodiversity of social animals - social mammals

Answer 12

All form parent-offspring social units for some period of time, but only a small percentage live in more complex societies

Question 13

biodiversity of social animals - social insects

Answer 13

Social insects are a major component of the biodiversity of many terrestrial ecosystems.

Question 14

Why is abundance important?

Answer 14

• Natural patterns of abundance underpin stable food-web interactions.
• common species must remain common for ecosystem function (along with biodiversity)

Question 15

why is abundance important - what can an unstable abundance lead to

Answer 15

it can lead to trophic cascades that change the ecosystem, and “ecological meltdown” as a worst case scenario.

Question 16

why is abundance important - Termite abundance and activity experiment

Answer 16

• Large-scale manipulative experiment of termite abundance in Borneo rain-forest system
• control plots vs. termite “suppression”

Question 17

termite abundance and activity experiment - what are the results

Answer 17

Positive ecosystem-level effects of termite abundance and social foraging activity

Question 18

termite abundance and activity experiment - what are the positive ecosystem-level effects

Answer 18

• accelerated litter decomposition
• elevated soil moisture
• greater soil nutrient heterogeneity
• higher seedling survival rates

Question 19

define keystone predators

Answer 19

• A predator species that has substantial, disproportionately strong effects on community or ecosystem
• via direct or indirect interactions, despite often being at low abundance.

Question 20

Top-down trophic cascades are common, but ____________________________________

Answer 20

vary considerably in ecosystem-level impacts.

Question 21

keystone predators - Top-down trophic cascades initiated by keystone predators

Answer 21

can have massive ecosystem-level consequences.

Question 22

How do we study large ecosystem impacts of top predators?

Answer 22

• Manipulative experiments are not logistically or ethically possible in many cases
• Reintroduction conservation is better

Question 23

explain reintroduction conservation efforts

Answer 23

they provide an opportunity for experimental studies of the cascading effects of the reinsertion of a top predator in disturbed food-webs.

Question 24

reintroduction conservation - example

Answer 24

Grey wolves in Yellowstone National park

Question 25

Yellowstone prior to Grey Wolf introduction

Answer 25

Explosive growth of the elk population (primary consumers) after the local extinction of the Grey Wolf

Question 26

Yellowstone prior to Grey Wolf introduction - result of elk population growth

Answer 26

• loss of vegetation cover
• loss of vegetation cover then impacted water runoff and water cycle within ecosystem.

Question 27

Yellowstone after wolf reintroduction

Answer 27

• Elk population has been more than halved
• Elk herbivory rates have been reduced dramatically
• New higher altitude behavioral patterns in the elk, to avoid wolf social hunting.

Question 28

impactful top-predators must be what?

Answer 28

• they are numerically rare
• but ecologically impactful top-predators must be retained for persistent ecosystem function