AOS 1 Unit 3 Flashcards
(113 cards)
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