Unit 3 - AOS 1 - CH 4 - Threats & Managment strategies for biodiversity Flashcards
Habitat loss definition
“Reduction or destruction of natural habitats, ecosystems, or specific areas where organisms live and thrive (usually human activity)
Describe contiguous and fragmented habitat
CONTIGUOUS: larger size of habitat
FRAGMENTED: habitat that has been split into smaller areas
- Smaller populations = more susceptible to changes in enviro
Overexploitation definition
“The excessive or unsustainable use of natural resources, particularly living organisms such as plants and animals beyond their capacity to replenish or reproduce. “
Inbreeding due to small population size
“Breeding between individuals that are close genetic relatives”
Inbreeding depression:
- “Decline in population fitness occurs due to increased homozygosity”.
- Due to relatives have ^ same alleles = ^ chance of deleterious recessive alleles being expressed
- e.g., genetic disorders, infertility, decreased, fitness.
LOSS OF POLLINATORS, DISPERSAL AGENTS, HOST SPECIES OR SYMBIONTS.
Symbiotic relationships = “different species live together in intimate association, (May be critical for one or both organisms survival)”.
- Loss of interactions limit opportunities for mating, seed dispersal, colonization of new habitats or genetic exchange between population.
Bioaccumulation, Biomagnification of pollutants
Bioaccumulation:
“The build-up of persistent, non-biodegradable pollutants within an organisms when it takes in more of the substance than can be removed”.
Biomagnification:
“The increasing concentration of a pollutant along a food chain through diff trophic levels
- Can cause physiological disorders, reproduction issues, reduced fitness and death. -> decrease in biodiversity and population size.
- Trophic cascade: Biomagnification
Climate change
“Increasing global temps and extreme weather events”
- Alter temp & precipitation patterns = shifts in habitat ranges & fragmentation. = disrupts ecological interactions between species.
- Disrupt migration routes, breeding sites and food sources
Can exacerbate existing threats to biodiversity and risk of extinction.
Disease
Outbreaks = declines in pop size of susceptible species.
- Some species may be particularly vulnerable -> due to low genetic diversity, habitat loss or environmental stressors.
- Can be species specific (e.g. tasmanian devil facial tumour disease)
Introduced species
“Species that have been deliberately or accidentally introduced into a new region”
- Can outcompete native species for resources such as food, habitat & nesting sites.
- Can lack natural predators or competitors in their new environment = rapid ^ in pop size.
Conservation of biodiversity
“Range of strategies required to maintain & increase pop, build species resilience to environmental change”.
Protected areas
“Nature reserves are areas of aquatic/terrestrial ecosystems that have been protected in order to conserve biodiversity”
- Most government owned = protected by law but some private.
Benefits of protected areas as conservation
- Legal protection for endangered species
- Control of invasive species and human exploitation.
- Restoration of degraded habitat
edge effect
“Described the boundaries between habitats or ecosystems”
- if area is fragmented = more edges = more areas of disurbance.
Retaining remnant vegetation
“Fragmentation of habitat has resulted in small patches of remnant vegetation that need to be conserved and managed”
- Often small and isolated from other ecosystems.
Wild life corridors
“Network of corridors cna be used to connect remnant vegetation”
- Involves habitat regeneration, restoration or replacement.
Advantages and disadvantages of wildlife corridors
ADVANTAGES:
- Movement of animals between patches
- Providing habitat and avenues for possible recolonization
- Allowing for gene flow -> subpopulations to reduce impact of genetic drift & inbreeding.
DISADVANTAGES:
- Aiding spread -> diseases, weeds, pests
- Supressing genetic variation (genetic swamping) -> if genetic diversity of a subpopulation is swamped by that of the immigrants.
- Helps spread fire
- ^ cost
Translocation
“Movement of individuals to an area where their # are low”
- When plants or animals are translocated to an area that their species no longer inhabits = reintroduced.
Captive breeding & reintroduction programs.
- Re-introduced organisms may be collected from wild/plants grown in nursery/captive breeding programs.
To be successful: - Threats initially responsible for decline in species must be managed at site for translocation or reintroduction.
In Situ conservation & adv/dis
“Focuses on restoration of ecosystems & protection of pop within their natural habitat”
ADVANTAGES:
- Species left in protected areas have access to natural resources & nesting sites.
- Able to protect more species at once & with larger population
DISADVANTAGES:
- Difficulty controlling illegal exploitation, especially in remote areas (humans take things etc. )
- Habitats may need extensive conservation & pop’s may continue to decline during habitat restoration.
Ex-situ conservation
“Taking species out of natural environment to operate and restore habitat”
- Particularly useful when species is critically endangered.
- Conventional vehicles = zoos, botanical gardens
- e.g. captive breeding, seedbanks, gene banks.
Gene banks
For collection of specimens & genetic material
- Material is often frozen -> preserve genetic diversity of species.
Reduction and improved targeting of pesticides
Either reduce or improve targeting
- Pesticides -> travel high distances through enviro
- Improvements to agricultural crop management to reduce requirement for pesticide =- benefits for diversity of insect species.
List the conservations for biodiversity
- Protected areas
- Retaining remnant vegetation
- Wildlife corridors
- Translocation
- Captive breeding & reintroduction
- In-Situ conservation
- Ex-Situ conservation
- Gene banks
- Reduction and improved targeting of pesticides.
Habitat restoration
- Degraded ecosystems repaired via human intervention
- Goal = recreate previous ecosystem or create new ecosystem
Erosion control
Erosion: wearing or rock & soil caused by moving water, wind or ice.
- Important when renewing/regenerating degraded areas.
- Control measures - planting vegetation along areas that are susceptible to erosion.
Name the two ways to restore degraded ecosystems
- Habitat restoration
- Erosion control
