Unit 3 Flashcards
Global Extinction Rate is _____ times higher than it was prehistorically
10-10,000
2-200 species become
Extinct every day
Factors related to increase in loss of biodiversity? (6 major)
Habitat loss and degradation Invasive species Hunting, overfishing, poaching Sale of exotic species Pollution Climate change
_____% of Earth’s surface has been taken over by human activity
40-50%
Global Forest cover has been reduced by ____%
20-50%
____ of all wetlands lost in ____
Half—last century
Over ___% of all virgin forests in US have been cleared since 1620
90%
___% of Prairies cleared
98%
Human-related intrinsic value of BD
Utilitarian uses including the development of drugs for Human betterment (medications)
the world’s species have gone largely untapped–more to be gleaned for this purpose
Non-human related intrinsic value of BD
..
Species Richness
Number of species in an area
Relative Abundance
Relative numbers of species
Taxonomic diversity
taxonomic relationships among species
Greater biodiversity is found in _____ latitudes
Equatorial latitudes
In water, biodiversity follows a ____ curve as depth increases
Bell curve
Keystone species
Play pivotal role in structure and function of an
ecosystem
Interaction with other species effect health and
survival of these species
Process materials out of proportion to numbers
or biomass
Indicator Species
Early warning of damage to an ecosystem
Birds- tend to respond quickly to change
Decline in songbird population indicative of
habitat loss
Decline in trout species, amphibians indicative
of water pollution
Autotrophs
Capture energy from non-living environment
e.g., photosynthesis
Provide energy for heterotrophs
Heterotrophs
derive energy from complex organic compounds
1st Trophic Level
Producers (autotrophs)
2nd Trophic Level
Primary Consumers (Herbivores) (feed off producers)
3rd Trophic Level
Secondary Consumers feed on primary consumers
Most ecosystems can sustain ____s trophic levels (#)
4-6
Each trophic level assimilates ____% of energy available from previous level
10%
Decomposers
recycle nutrients and organic
material- Nutrient cycles, Carbon cycle
Parasites
Live in or on other individuals and cause harm
Succesion
The change of ecosystems over time
Pioneer Species
A species that colonizes an ecosystem or speeds succession along
Climax community
Most stable stage of an ecosystem
Secondary succession
follows a disturbance
