Sustainability and change

Ecosystem stability?

The ability of an ecosystem to maintain its structure and function over time even when facing disturbances 

Resistance?

The ability of an ecosystem to remain unchanged despite distrubances

Resilience?

The ability of an ecosystem to recover quickly after disturbances

Give an example of ecosystem stability?

Daintree rain forest, its conditions have stayed warm despite climate change

What are 4 key requirements for ecosystem stability?

• Energy flow

• Nutrient cycles

• Genetic diversity

• Climate stability

What environmental changes influence an ecosystem?

• Temperature 

• Rainfall

• Humidity

Mesocosms?

A partially enclosed outdoor experiment that simulates natural conditions allowing manipulation of environmental factors

The value of a mesocosem?

• The provide control to manipulate variables

• They are easily replicable

• They are ethically sound

• They are accesibile to gain insight into ecological processes

What are limitations of mesocosms?

• They are over-simplified 

• They are only small-scale 

• They can’t influence organisms behavior or ecological processes 

• The conditions are artificial and don’t reflect a real environment 

Sustainability?

The process of using resource in a way that maintains their availability for future generations 

An ecosystem is sustainable if it is…….?

• Environmentally sustainable

• Socially sustainable

• Economically sustainable

Resource harvesting?

They extraction or collection of natural resources from ecosystems for human use

Sustainable harvesting?

When a resource is used at a rate that allow the population and ecosystem to regenerate naturally

What is an example of sustainable harvesting?

Atlantic cod fish nearly collapsed in the 1990s and hunting was reduced and limited in certain areas to bring up the population

When populations exceed this they cannot replenish fast enough?

Maximum sustainability yield - The large amount of resources that can be harvested without causing long-term population decline

Sustainable agriculture?

Farming practices that meet current food need without compromising future generations ability to produce food 

Factors that negatively impact sustainable agriculture?

• Soil degradation

• Deforestation

• Chemical overuse

• Overgrazing

• Water mismanagement

Soil erosion?

The removal of the topsoil layer by wind or water leading to reduced soil fertility

Leaching?

The loss of water soluble nutrients from the soil thorough percolating water

Eutrophication?

The process of nutrient enrichment in aquatic ecosystems leading to excessive plant and algae growth 

Causes of eutrophication?

Excess nutrients

Effects of eutrophication?

• Food web disruption causing loss of species

• Oxygen depletion killing fish

• Submerged plants die

Biomagnification?

The increase of toxic concentration at each succesive trophic level in a food chain 

How does biomagnification occur?

Toxins like methlymercurey and DDT enter ecosystems through human activity

Causes of Biomagnification?

Primary producers absorb these toxins then herbivores ingest them

Bioaccumulation?

The gradual accumulation of substances such as peptides in organism

What causes pollutants to magnify?

• They are easily stored in fat

• Organisms absorb them faster than they release them 

• They are persistent 

Impacts of biogmanification?

• Ecosystem disruption

• Human mercurey poisoning

Maacroplastics?

Large visibile items

Microplastics?

Fragments of plastic that measure between 5mm and 1um

What are the effects of microplastics?

They cause marine wildlife such as filler-feeders to ingest carbon compounds which can be toxic

What are the effects of macroplastics?

Cause marine wildlife to become entangles in ropes and bags they mistake for prey

Rewilding?

The process of restoring ecosystems to their natural state by reducing human interference and letting natural processes take over

Methods of rewilding?

• Spreading seeds that should be a part of the ecosystem

• Reestablishing connectivity

• Controlling invasive species

• Reintroducing apex predators and keystone species

Rewilding allows?

• Natural processes to recover

• Reintroduces species with key roles

• Restores habitats for species to migrate to

Example of rewilding?

• Hinewai reserve netherlands 1,250 hectares of farmland had been restored to native forests along with animals

• Alien species were also naturally destroyed

Tipping point?

A threshold where an increase in environmental pressures causes large rapid irreversible change in an ecosystem

Keystones species?

organisms that has a large impact on its ecosystem

Examples of keystone species

sea otter control sea urchin population