Chapter 56 Flashcards
Genetic Divesrity
Rage of diff inherited traits within a species
Can comprise variation of a population or between population
Species diversity
Variety of specie sin an ecosystem or across the biosphere
Biophilia
Connection to nature and all o flife
What percentage of medicine if from plants
25%
What happens when species is lost
Unique genes and some code for enormously useful proteins is lost
Main threats to biodiversity
Habitat loss
introduced species
overharvesting
Global Change
Main reason for habitat loss
Agriculture, urban development, forestry, mining and pollution
Overhavesting problems
Large animals can’t reproduce due to low reproduction rates
Commercially important fish have been decimated by overfishing
Global Change, first concern
Alters fabric of Earth’s ecosystems
First concern was acid precipitation
Cause of acid percipitation
Burning of wood/fossil fuels release oxide of sulfer and nitrogen into the air: comes back down in form of sulfuric and nitric acids
Ecosystem services
A function performed by an ecosystem that directly or indirectly benefits humans
Introduced species
Invasive, non native, or exotic species moved by humans intentionally/accidentally from species native location to new geography region
extinctional vortex
A downward population spiral in which inbreed and genetic drift combine to cause small population to shrink and, unless the spiral is reversed, become extinct.
Small populations problems
Vulnerable to habitat loss, introduced species over harvesting.
Also emphasize extinction processes that bc pop. sizes have been greatly reduced
Genetic drift
A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next. Effects of genetic drift are most pronounced in small populations
Equation for estimated population size
N_e = (4N_fN_m)/(N_f + N_m)
N_e is the estimated population size
N_f is the number of females
N_m is the number of males
Minimum viable populatio
Smallest population size at which a species is able to sustain its numbers and survive
Effective population size
Estimate of size of a population based on the numbers of females and males that successfully breed; generally smaller than the total population
landscape
area containing several different ecosystems linked by exchanges of energy, materials, and organisms
Declining population approach
Focus on threatened/endangered pop.
Emphasize environmental factors that cause decline
Biodiversity is heavily influced by…
Physical features (structure)
Movement corridor
Narrow strip or series of small clumps of habitat connecting otherwise isolated patches
-Promote dispersal, prevent inbreeding
-But disease
What % of land is set aside by gov.
7%
Biodiversity hotspot
Relatively small area with numerous endemic species (not found anywhere else in the world) and a large number of endangered and threatened species
Endemic species
Species found in only one place
Problems with reserves
-Prevented disturbances
-Not sure to have many small or few large
Zoned Reserves
Extensive region that includes areas relatively undisturebed by humans surrounded by areas that have been changed by human activity and are used for economic gain
Urban ecology
Examines organisms and their environments in urban settings
Trying to balance needs of people and other species
Urban springs
Rise and fall quick
More likely to have nutrients and contaminants
4 types of environmental change
Nutrient enrichment, toxin accumulation, climate change, and ozone depletion
Biological magnification
Harmful substances become increasingly concentrated in successively higher trophic levels of food webs
Climate change
Significant global warming and changing patterns of precipitation due to increased CO2 levels, bc of burning fossil fuels
Sustainable development
Economic development that meets the needs of people today without limiting the ability of future generations to meet their needs.
Critical load
Amount of added nutrients, usually nitrogen or phosphorus, that can be absorbed by plants without damaging the ecosystem’s integrity
Excess nutrient is passed to water making it unsafe to drink
Eutrophication
Too much nutrients
Chlorinated hydrocarbons
Disrupt endocrine systems
DDT
WW2, affected birds reproduction, can also be used to control mosquitoes spreading malaria
Greenhouse effect
Insulation of heat
CFC
Puts hole in ozone layer
Used in refrigeration
Largest organization of ecologists
America - Sustainable Biosphere initiative
