Rewilding Flashcards
Definition
The large scale restoration of ecosystems to the point where nature is allowed to take care of itself.
Focus on ecosystem processes with the aim to create a self-sustaining balanced ecosystem
Dave Foreman USA first coined the term
Foreman also founded the rewilding institute for continental restoration in Northern America – included reintroduction of apex predators e.g. reintroduction of Wolves to Yellowstone Park
rewilding three main methods:
translocation – species reintroduction
passive – leaving an area alone
pleistocene – reintroducing species with ancient history in the area
Debate questions
How far back do you go?
Was extinction caused by us directly?
Is it realistic?
3 C’s of intervention
Cores – identifying core regions in need of restoration
Corridors – to allow wildlife to move between regions to avoid the rewilding issue of deers starving in the netherlands after running out of foods
Carnivores – ensuring their presence to regulate the ecosystem
Methods of study
Habitat restoration
Species reintroduction
Improve habitat connectivity Create corridors for gene flow, migration etc.
Monitoring, adapting, managing –assess success and economic viability
Revert to sustainable landscape
Measuring rewilding success initially measured by:
-Ecological
- Social
-Economic – job creation/ job loss
Torres developed more specific approach
Ecological metrics:
Quantifiable measurements used to evaluate health, diversity, and functionality of ecosystems.
Eg. species richness/diversity, genetic diversity
Social metrics:
Quantitative measures assessing social impacts of rewilding initiatives on local human communities.
Eg. success of preserving cultural sites, local perception/attitude surveys
Economic metrics:
Quantifiable measures evaluating financial impacts of rewilding initiatives and associated economic benefits
Eg. ecotourism revenue, job creation/loss
thus giving indicators such as species richness baseline values
+ checking rewilding impact after 7 years to decide success level
Keystone species
A species that has a disproportionately large effect on the ecosystem relative to its abundance
Carnivores – trophic impact – more ethical issues with the introduction of these species, control prey density and distribution to restore self sustaining ecosystems
Herbivores – nutrient cycling, affecting fire risk, less/no trophic impact impact many ecosystem processes
Taxon substitution
Introducing a different species that fills the same niche of a species that has been lost due to extinction
Finding a species that is more economically viable
Finding less dangerous species that fill the same niche
Example: round island tortoise reintroduction
Where?
- 219 ha island off the coast of Mauritius
- humid upland forests, dry lowland forests and heathland
Why?
- To restore natural Mauritian biota after native giant tortoises went extinct
- To improve the landscape health for tourism and locals
- Create more dynamic forests
- Decrease non-native plants & Balance grassland communities
How?
- Aldabra giant tortoises
-Taxon substitution species introduced to the habitat
- Extensive research into risk assessment of introduction
- Initially kept in enclosures to monitor their impacts
- Released into the wider heathland and lowland forest environment
Success?
- Clusters of young palm plants increasingly dispersed due to tortoise seed dispersal - palm-rich lowland communities
- No impact seen on native endangered reptile species (eg. Telfair’s skinks)
- Decrease in cover of competitive non-native weeds
- Increase in species diversity in heathlands
Next?
- Action to be taken in regenerating soil-seed bank
- Increase number of shade sites -tortoises may overheat with increasing global temperatures
Evidence?
- Several studies examine Round Island rewilding efforts
- Reviews of ecosystem progression over time
General takeaway:
success, but additiona lefforts are needed to achieve goals
Summary:
Tortoises were present in the past so a similar species was recently introduced
Tortoises eat the invasive plants and distribute palm seeds
The tortoises required the introduction of shade stands to provide shelter for the tortoises in the rising climate
Example: Pleistocene park rewilding project in Russia restoring high productivity grazing ecosystems in the arctic
20km park founded by Serge Zimoff in 1996 with 2 primary aims: restoring a high quality grazing ecosystem in the arctic and mitigating climate change
1: Restore a high productivity grazing ecosystem in the arctic through reintroduction of key stone species
- Restoration of the mammoth steppe
^ Megafauna maintained steppe preventing tundra ecosystem formation thought to have been lost not due to climate change but overhunting so reintroduction could revert the tundra to grassland steppe
- Mitigation of climate change - slow the melting of the permafrost - by increasing nutrient cycling and ground compression
evidence suggests this is working although currently on a too small scale to be conclusive
Chernobyl: passive rewilding venture
Wild horses, gray wolf, lynx and bison population regeneration
Knepp: rewilding project UK
- Species introduced: Tamworth pigs (less dangerous than native boar)
- Exmoor ponies (replacing an extinct pony species)
- As well as white stalk and longhorn cattle
- Purple emperor butterfly population re-established and Songthrush population regeneration
- Amongst many others
Marine rewilding example: Arran Scotland
-Arran seabed trust set up in 1995 to fight the seabed trawling lift of 1984
-Lamlash Bay no take zone set up in 2008 ~3km – no swimming, fishing or boating
-284 km of coast now under protection from trawling
-restoring blue carbon stores and species diversity/ population size
success?
- Some species have increased by 400%
- Largest biodiversity recovery specifically in lobsters and scallops
- Seabed has been able to undergo succession, to recover ‘nursery’ habitats and ‘blue carbon’ habitats
