BIODIVERSITY Flashcards
Define biodiversity.
-the existence of many species of plants and animals in a specific environment
-variety of life in an area
Define population.
number of individuals of the same species living in a certain place
Indication of high index of biodiversity and how it affects the survival of the ecosystem/community.
The community/ecosystem has many different species and they will be able to withstand environmental changes better compared to communities and ecosystems with low index of biodiversity.
How to measure biodiversity? Define each.
Species Richness and Species Evenness
Species Richness
-Qualitative
-Answers the question “How many different species can I see?”
Species Evenness
-Quantitative
-Answers the question “How much of each different species can I see?”
-Can further be measured by: percentage cover, species frequency, and population density
High biodiversity is based on __.
-species richness and evenness
-endemicity of species (one’s country’s organisms)
“Biodiversity” comes from the two words __ and ___, which means ____.
BIOS - LIFE
DIVERSITAS - VARIETY
“variety of life”
Explain the levels of biodiversity.
GENETIC, SPECIES, AND ECOSYSTEM
Genetic diversity - refers to the variation of genes due to the differences in nitrogenous sequences within a particular species.
Species diversity - variation of species as well as their abundance within the particular community/ecosystem.
Ecosystem diversity - variation of different communities and their association with their chemical and physical environment.
explain each of the ecosystem diversity biomes
Aquatic
-freshwater
-marine
Grasslands (differs in temperature and pre-dominant types of plants are shrubs)
-tropical (aka savannas - close to equator)
-temperate (up/down a few levels from the equator)
Forests
-tropical
-temperate
-boreal (aka taigas - Russia, Canada, Alaska)
Desert (judged based on the precipitation it receives annually)
-hot
-cold (the largest desert is Antarctica)
Tundra (Least Biodiverse Biomes as they are dry biomes covered in snow)
-arctic
-alpine
Define population density.
number of individual species per unit area
to measure:
number of individuals/size of area
factors affecting population density. (4)
birthrate
death rate
migration
limiting factors
examples of limiting factors
food
water
temperature
soil nutrients
living conditions
light
Define carrying capacity.
maximum population size an environment can support
Define endangered.
When the population of a species becomes so low that only a few remain, and will possibly go extinct.
As of 1991, which species are internationally recognized as threatened, and how many of each?
89 species of birds
44 species of mammals
8 species of reptiles
Define extinction.
disappearance of species when last of its members die
