Ecological footprint of societies part 1 Flashcards
define ecological footprint
the strength of the direct and indirect impacts that an organism has on the larger ecological system it is part of
ecological footprint - direct impacts
via direct trophic interactions for our focal societies
ecological footprint - indirect impacts
via indirect trophic interactions, community structuring interactions
ecological footprint: indirect impacts - community structuring interactions
- competition
- ecosystem engineering
- associated cascading ecosystem-level processes
define ecosystem
- 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.
ecosystem - unique process
energy flux and nutrient cycling
define ecosystem level processes
the intersection of biotic processes among all species in a region and the abiotic processes that surround them
ecosystem level processes - abiotic processes include what?
- water cycle and nutrient cycling
- which can be reciprocally shaped by biotic interactions.
Why is biodiversity important?
- Species are rarely ecologically interchangeable — they have different niches.
- Niches determine ecological function, and ultimately ecosystem function.
why is biodiversity important - maintenance of biodiversity is critical for what?
critical for the maintenance of ecosystem function.
The _____________________________________, because of the complex indirect effects of a species trophic interactions.
impact of the presence (or loss) of any one species is hard to predict
biodiversity of social animals - social mammals
All form parent-offspring social units for some period of time, but only a small percentage live in more complex societies
biodiversity of social animals - social insects
Social insects are a major component of the biodiversity of many terrestrial ecosystems.
Why is abundance important?
- Natural patterns of abundance underpin stable food-web interactions.
- common species must remain common for ecosystem function (along with biodiversity)
why is abundance important - what can an unstable abundance lead to
it can lead to trophic cascades that change the ecosystem, and “ecological meltdown” as a worst case scenario.
why is abundance important - Termite abundance and activity experiment
- Large-scale manipulative experiment of termite abundance in Borneo rain-forest system
- control plots vs. termite “suppression”
termite abundance and activity experiment - what are the results
Positive ecosystem-level effects of termite abundance and social foraging activity
termite abundance and activity experiment - what are the positive ecosystem-level effects
- accelerated litter decomposition
- elevated soil moisture
- greater soil nutrient heterogeneity
- higher seedling survival rates
define keystone predators
- A predator species that has substantial, disproportionately strong effects on community or ecosystem
- via direct or indirect interactions, despite often being at low abundance.
Top-down trophic cascades are common, but ____________________________________
vary considerably in ecosystem-level impacts.
keystone predators - Top-down trophic cascades initiated by keystone predators
can have massive ecosystem-level consequences.
How do we study large ecosystem impacts of top predators?
- Manipulative experiments are not logistically or ethically possible in many cases
- Reintroduction conservation is better
explain reintroduction conservation efforts
they provide an opportunity for experimental studies of the cascading effects of the reinsertion of a top predator in disturbed food-webs.
reintroduction conservation - example
Grey wolves in Yellowstone National park
Yellowstone prior to Grey Wolf introduction
Explosive growth of the elk population (primary consumers) after the local extinction of the Grey Wolf
Yellowstone prior to Grey Wolf introduction - result of elk population growth
- loss of vegetation cover
- loss of vegetation cover then impacted water runoff and water cycle within ecosystem.
Yellowstone after wolf reintroduction
- 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.
impactful top-predators must be what?
- they are numerically rare
- but ecologically impactful top-predators must be retained for persistent ecosystem function
