AOS 1 Unit 3 Flashcards
Biodiversity definition
Biodiversity definition: The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part of ; this includes diversity within species, between species and of ecosystems.
the different levels of biodiversity
- Genetic diversity
- Species diversity
- Ecosystem diversity
Genetic diversity
- The total genetic information contained in the genes of all species on earth
- As a result, the genetic makeup of an individual organism determines much of its apperance and what it does
- Genetic diversity refers to variation in genetic information between species as well as the variation between individuals of the same species
species diversity
- The variety of species on earth. Species diversity measures the number of different species and the number of different individuals within each species in a particular area of an ecosystem.
Ecosystem diversity
- The variety of habitats, natural communities and ecological processes in the biosphere
- Ecosystem diversity incorporates the wide range of ecosystems on earth, both terrestrial and aquatic.
Importance of genetic biodiversity
Genetic diversity is valuable because a species or population with a low level of genetic diversity only has a low capacity to adapt to changes in its environment
5 benifits of biodiveristy
- Ecosystem productivity
- Ecosystem resiliance
- Decomposition and soil fertility
- Pollination and soil disperal
- Climate regulation
Ecosystem productivity:
Diverse ecosystems are typically more productive because they encompass a broader range of species that fufill various ecological roles
Ecosystem resiliance:
Biodiverse ecosystems demonstrate greater resiliance to environmental changes and disruptions like climate change, disease and natural disaster.
Decomposition and soil fertility:
A diverse community of decomposers like bacteria, fungi, and inverterbrates breaks down organic matter, recycling nutrients and improving soil sturucture. This process is supporting plant growth and ecosystem health by enhancing soil fertility. Healthy soils act as carbon sinks, mitigate climate change, and protect water quality, highlighting the global importance of maintaning soil fertility.
Pollination and seed dispersal:
Biodiversity is vital for the pollination of crops, which directly affects the global food secuirty. Pollinator diversity: a variety of pollinators, including insects, birds, and bats, ensures, the pollinations of many plant species leading to succesful reproduction and maintenence of plant diversity. Seed disperal: Different animal species contribute to seed disperal, facilitating plant colonization and genetic diversity across the landscape.
Carbon sequestration:
Diverse ecosystems, like tropical rainforests and wetlands, are crucial for capturing carbon dioxide from the atmosphere, thereby playing a vital role in regulating the global climate.
Three main factors contribute to rarity of a species:
- Population size: The number of individuals within a local area
- Geographic range: The area where a species is found. Some species live in many places (widespread), while others are only found in a small area (restricted).
- Habitat specificity: How many different environments a species can live in. Some species can survive in many places (generalists), while others need very specific conditions (specialists).
The IUCN assesses species based on:
- Population size – how many individuals are left
- Rate of decline-
- Geographical range
- Threats
Four levels of biodiversity conservation:
- Genetic diversity – variety of genes within a species
- Population diversity- variety of populations within a species, including differences in their size, genetic makeup, and location
- Ecosystem diversity- variety of different ecosystems within a region or across the planet
Three factors contribute to rarity of a species
1) Population size -> Number of individuals within a local area
2) Geographic range-> The area where a species is found
3) Habitat specificity-> How many different environments a species can live in
Species richness
The number of different species present in a particular region. The species richness of an area doesn’t give a full picture of diversity.
Extinct (EX)
No reasonable doubt that the last individual has died.
Example: Eastern Hare Wallaby
Extinct in the wild (EW)
Known only to survive in captivity, cultivation or well outside its natural range.
Example: Pere Davids Deer
Least Concern (LC)
Population is stable enough that it is unlikely to face extinctions in the near future.
Near threatened (NT)
Close to qualifiying, or likely to qualifiy for a threatened category in the near future.
Example: Jaguar
Vulnerable (VU)
Facing a high risk of extinction in the wild. Due to population decline; habitat loss or other threats.
Example: Polar bear
Endangered (EN)
Facing a very high risk of extinction in the wild, due to severe population decline or habitat destruction.
Example: Tasmanian devil
Critically Endangered (CR)
Facing extremely high risk of extinction in the wild, with very few individuals left in the wild.
Example: Mountain pygmy possum
Ways of measuring biodiversity:
Richness: The number of unique life forms or groups of genetically or functionally related individuals
Evenness: The equatibility among life forms
Heterogenelty: The dissimilarity among life forms
Biodiversity Index: The number of species in an area divided by total number of individuals in that area.
Simpsons index of diversity
Quadrats: A tool where scienticts place a quadrat on the ground, count life within it, and repeat randomly.
Cultural services
- Research and education
- Recreation
- Cultural values
- Astethic values
Ecosystem services
- Provisioning service
- Regulating service
- Supporting service
- Cutural service
Supporting service
Ecosystems themselves could not be sustained without the underlying natural processes, such as nutrient cycling, that supports multiple aspects of an ecosystem.
Example: Nutrient cycling
Regulating service
A service that provides mechanisms to regulate an ecosystem and keep it in balance.
Example: Wetlands filter water naturally
Provisioning service
A service that provides resources such as clean water, food, fuel, fibre and medicines to individuals in the ecosystem
Benefits of biodiversity: Climate regulation
- Carbon sequestrian
- Temperature and water regulation
Two ways in which genetic diversity can be assesed in groups.
- DNA sequencing or molecule marker
- Morphological trait analysis
Human driven factors contibuted to extinction
- Hunting and bounty programs
- Habitat destruction
- Introduction of invasive species
- Negative public perception
Ecological and biological factors contributed to extinction
- Low genetic diversity
- Small population size
Lack of conservation awareness contribute to extinction
delayed protection efforts
Disease factos contributed to extinction
- Uknown epedemic
Reasons why a species should be preserved from extinction
1) Ecological importance
- Manitaining ecosystem stability
- Keystone species effect
2) Economic and human benefits
- Ecosystem services
- Medical discoveries
- Tourism and economy
Causes of species decline
Hunting and collecting
habitat destruction
Introduced exotic species
Pollution
Why is it important to protect native species
They maintain ecological balance, support food webs, and preserve genetic resources for future resilience.
Population diversity
Considers how populations of the same species vary across different environments and how they interact with their surroundings
Genetic swamping
Environmental disruption caused by human activities bring population of a spceis that once were geographically isolated into contact with one another.
Genetic drift
Occurs when the allele frquency in a population is determined by random events rather than natural selection. Genetic drift, some alleles may be elimianted from a population by chance, or come previously rare alleles become widspread.
Factors affecting genetic diversity in populations
- Muation and natural selection
- Genetic drift
- Inbreeding
- Extinction
- Genetic swamping
- Demographic variation
- Loss of organisms playing a key role
Vegetation structue
The vegetation sturcture of an area is determined by the type of vegetation present, the age of the plants, the environmental conditions.
Degree of endemism
A species is considered to be endemic if its native to the area only
Techniques for sampling mammals
- Indirect signs
- Spotlighting
- Direct observation
- Live trapping
- Capture-mark-recapture
Mass extinctions
- Orivician-sultian mass extinction
- Late Devonian extinction
- Permian- triassic extinction
- Jurassic extinction
- Cretacous- tertiary extinction
Environmental variation
Changes to the enviroment over short, emdium and long scale prouce a range of outcomes for spcies and ecosystems.
Medium-term change
- El nino
- Climatic phenomenona charchterized by the warming of sea surface temperature in central and eastern pacific ocean
- Leads to increased rainfall, and drought in other direction
Long term changes
Many species are endemic to different parts of the world due to the action of continetal drift.
Short-term changes
Fire, volcanic eruptions
Ways of measuring biodiversity: Random sampling
The study would be biased if quadrats were placed in the most onteresting areas or in the most accessible sites.
Ways of measuring biodiversity: Belt transect
A number of small quadrats joined together in a line.
Ways of measuring biodiversity: systematic sampling
Used when you are trying to observe the changes in enviornment over a given distance
Sampling edge effects
Sometimes a plant corsses the edge of a quadrant and a decision has to be made whether it should be counted or not.
Species diversity role in a succesful ecosystem
Higher species diversity enhances ecosystem productivity, stability and resiliance by ensuring that ecosystem functions, such as nutrient cycling and pollination, continue even if some species are lost.
Genetic diversity and its role in a successful ecosystem
Increases resiliance of populations by enabling spceis to adapt to changing environemntal conditions, resist diseases, and reduce the risk of extinction. thus ensuring ecosystem stability and funtionality.
Small population size
A small population is more vulnerable to genetic drift, inbreeding and loss of genetic diversity, which reduces its ability to adapt to environmental changes and survive threats such as disease, habitat loss or climate change.
Main threats to biodiversity
- Habitat loss
- Inbreeding
- Climate change
- Disease
- Introduction of invasive specie s
Inbreeding:
- When closely related individuals within a small population reproduce
- Reduces genetic diversity, increasing the likelihood of harmful genetic mutations and decreasing the populations ability to adapt to environmental changes
- Can lead to weaker offspring, lower survival rater, higher risk of extinction.
Inbreeding: How does it occur?
- Habitat destruction
- Overhunting or poaching
- Fragmentation
- Captive breeding programs
- Bottleneck effect: A sharp decline in population (die to natural disasters, disease, human impacts) leaves only a few surviving indviduals
Inbreeding: Examples of species affected
- Cheetahs= extremely low genetic diversity due to past population bottlenecks
- Tasmanian devils= Inbreeding has made susceptible to Devil Facial Tumor Disease (DFTD)
- Mountain gorillas= Small, isolated populations have limited genes
HIPPCO
Habitat destruction
Invasive species
Population growth
Pollution
Climate change
Over exploitation
Habitat loss:
Reduces the availability of resources that organisms need to survive. Causes population decline, and therefore loss of genetic diversity.
Types of habitat loss:
- Destroyed
- Fragmented
- Degraded
Habitat degraded
The reduction in habitat due to pollution, climate change, or human activities, making it less suitable for species.
Habitat destroyed causes
Deforestation, urban expansion, agriculture.
Habitat destroyed impact on biodiversity
Species are forced to relocate, adapt, or face extinction due to loss of food and shelter
Habitat destroyed examples
Rainforests cleared for palm oil plantations in Borneo.
Habitat fragmentation definition
Habitat fragmentation The breaking up of a habitat into smaller, isolated patches, making movement and genetic exchange difficult
Habitat fragmentation causes
Road construction, logging, land clearing.
Habitat fragmentation impact
Small populations become isolated, leading to reduced genetic diversity and increased extinction.
Habitat fragmentation example
Highways cutting through wildlife corridors in Australia.
Habitat degraded definition
The reduction in habitat due to pollution, climate change, or human activities, making it less suitable for species.
Habitat degraded causes
Pollution, invasive species, climate change, resource extraction.
Habitat degraded impact
Species struggle to survive as habitat conditions worsen, leading to population decline.
Habitat degraded example
Coral reef bleaching due to ocean warming and acidification.
Habitat loss- main causes
Main causes
- Deforestation- clearing forests for agriculture, logging, or urban expansion
- Land conversion- Wetlands, grasslands, and forests turned into farmland or infrastructure
- Climate change- Altering ecosystems (e.g coral bleaching)
- Pollution- contaminating soil, water, making it unsuitable for habitat.
Habitat loss impacts on biodiversity:
- Species displacement- Animals and plants lose their homes and food sources
- Reduced genetic diversity- isolated populations struggle to adapt
- Increased extinction risk- Many species cannot survive in altered environments
- Ecosystem imbalance- Loss of keystone species disrupts food webs
Examples: of habitat loss
Great barrier reef
- Orangutan’s in Borneo and Sumatra
Habitat loss: Pollution:
Why pollution matters in conservation:
Pollutants reduce species survival and reproduction, leading to biodiversity loss
- Persistent pollutants like pesticides (DDT), heavy metals and plastics have long-term effects on ecosystems
- Conservation efforts focus on reducing pollution sources, restoring ecosystems, and regulating harmful substances to protect biodiversity.
Introduced species:
- Non-native species that have been brought into an ecosystem either intentionally or accidentally
- Introduced species pose a major threat to a biodiversity, particularly when they become invasive and disrupt ecosystems.
Invasive species
Invading, becoming a threat
- Competition with native species-
-
Introduced species often outcompete native species for resources like food, habitat, and water, leading to population declines in native species
Predation on Native species-
Some introduced species prey on native animals that have an evolved natural defences against them, causing rapid population declines.
- Habitat alterations
- Some species change the structure or function of ecosystems, making it harder for native species to survive
- Example: Cane toads in Australia secrete toxins that harm native predators, disrupting food webs.
- Spread of disease-
Introduced species can carry new diseases or paristis that native speices are not resistant to, leading to biodiversity loss.
- Example: Chytrid fungus, spread by introduced amphibians, has devestated native frog populations worldwide.
- Hybridisation and genetic pollution-
Introduced speices can interbreed with native species, reducing genetic diversity and weakening local adaptations.
- Example: Farmed Atlantic salmon and other salmon
Diseases- impacts
- Reduced population size - Disease outbreaks can rapidly decrease population numbers, leading to local extinctions if species cannot recover
- Loss of genetic diversity: As populations decline, genetic diversity decreases, reducing the gene pool
- Spread by introduced species
- Disruptions of ecosystems- if a keystone species is affected by disease, it can alter food webs and ecosystem functions
- Example: The decline of pollinators due to disease impacts plant reproduction and food production.
- Increased vulnerability to other threats- Species suffering from diseases are more susceptible to predation, habitat loss and climate change, making survival even more difficult.
What is restoration in biodiversity?
Restoration= ways to help species adapt to environmental changes
what is protection in biodiversity?
= keep safe from harm, ways to help species survive and
Main conservation and restoration strategies:
- Protected areas
- Retaining remnant vegetation
- Wildlife corridors or zones
- Translocation of animals
- Captive breeding and reintroduction programs
- Gene banks for genetic material collection
- Reduction and improved targeting of pesticides
What is PROTECTED AREAS?
Land or marine areas that are legally protected to conserve ecosystems and species by restrickting human activitie like deforestation, fishing, and urban development
Why does PROTECTED AREAS MATTER?
Protects habitats, biodiversity, and ecosystem services, allowing species to thrive and recover from human impacts. Helps maintain genetic diversity and ecosystem stability.
Example of PROTECTED AREAS?
The great barrier reef marine park protects coral ecosystems from overfishing, pollution, and climate change effects, supporting marine biodiversity and tourism sustainability.
What is Retaining remnant vegetation?
Protecting patches of native vegetation that remain in cleared landscapes
why does retaining remnant vegetation matter?
Provides habitat for native speices, supports pollination, and maintains biodiversity
Example of retaining remnant vegetation?
Paddock trees and roadside vegetation help sustain wildlife in agriculture areas.
What is wildlife corridors or Zones?
Connecting fragmented habitats with green corridors or designated wildlife zones.
Why doe wildlife corridors or Zones matter?
Allows species movement, gene floe, and adaptation to environmental changes
Example of wildlife corridors or zones?
The great Eastern ranges initiative creates a continuous corridor for wildlife along Australias East coast.
What is translocation of animals?
Moving species from one location to another to boost population size or restore ecosystems
why does translocation of animals matter?
Helps repopulate areas where species have declined or gone locally extinct.
example of translocation of animals
Eastern barred bandicoots have been translocated to predator-free islands in Victoria.
what is captive breeding and reintroduction programs
Breeding endangered species in controlled environments for later release into the wild
why does captive breeding and reintroduction programs matter
Helps prevents extinction and increases genetic diversity in wild populations
example of captive breeding and reintroduction programs
Zoos Victoria Helmeted Honeyeater breeding program helps restore wild population
What is gene banks for genetic material collection
Storing seeds, tissue samples, or genetic material to preserve species for future conservation
why does gene banks for genetic material collction matter?
Helps restore species after population declines and supports genetic diversity.
Example of gene banks for genetic material and collection
The milennium Seed bank in the uk stores seeds from threatened plant species worldwide.
What is reduction and improved targeting of pesticids?
Using fewer and more targeted pesticides to reduce harm to non-target species
why does reduction and improved targeting of pesticides matter?
Protects pollinators, reduces water contamination, and prevents biodiversity loss.
Example of reduction and improved targeting of pesticides
Integrated Pest Mangagment (IPM) promotes natural predetors instead of excessive pesticice use.
