GEI Exam 1 Flashcards
Environment
external physical and biological conditions in which an organism lives
sustainability
meeting the needs of the present while ensuring the future generations will have the same or better quality of life
What are the impacts humans have had on the environment?
-higher rates of extinction
-higher rates of fossil fuel extraction
-ecosystem impacts like pollution and altered river courses
Why have humans had such large impacts?
-mechanization of industry and ag, along with inequalities in resource consumption
-exponential human growth
-unnatural materials (CFCs, PCB, and plastics)
ecological footprint (EF)
a measure of per capita consumption, tells us how much land is needed to support human activities. indicates sustainability of lifestyles
EF of average American
0.02 sq mi
frontier ethic
assumes unlimited supply of resources
sustainability ethic
acknowledges limit of resources and encourages conservation
Tragedy of the Commons
describes what happens when unlimited self-interest depletes a shared resource
- common pasture used by all herdsman
- one brings extra cattle to make extra money
- land is overgrazed, pasture is useless
NIMBY principle
“not in my backyard”: communities want to enjoy benefits of waste disposal or power supply, but don’t want environmental impacts
e.g. Yucca Mountain
energy
ability to do work
photosynthesis
6CO2 + 6H2O + solar energy -> C6H12O+ energy
metabolism
chemical reactions that take place inside an organism’s cells
global significance of photosynthesis
- transform light energy to chem energy
- create oxygen
- converts CO2 into sugars
Atmosphere composition
21% Oxygen 78% Nitrogen
population
all individuals of the same species in a certain area
community
all populations in a certain area
ecosystem
all communities plus abiotic parts of environment
biosphere
all ecosystems
categories of ecosystems
-marine
-freshwater
-terrestrial
ocean surface area
75% of Earth’s
What contributes 40% of oxygen production?
marine phytoplankton
freshwater surface area
1.8%
terrestrial groups
biomes: tropical rainforests, deserts, etc.
autotroph
produce own food
photoautotrophs
gets energy from sunlight
chemoautotrophs
liver near deep sea hydrothermal vents, get energy from chem. compounds
heterotroph
obtains energy by consuming other organisms
food chain
sequence of organisms at different trophic levels that nutrients and energy pass through
biomagnification
increasing concentration of toxic substances in organisms at successive trophic levels (accumulates in fat reserves)
-DDT from fish to bald eagles
biogeochemical carbon cycle
movement of carbon through land, water, and air (stored for long periods in carbon reservoirs)
eutrophication
excess N and P from fertilizer runoff and sewage that results in excess algae and plant growth, which leads to their decay and death to take up all the oxygen
hypoxic
lack of oxygen in water that kills fish
population ecology
studies the interactions between populations and environment
population size
total number of individuals (N)
population density
number of individuals living in a specific area
exponential growth model
N grows without limits
G = r * N
G
population growth rate
r
per capita rate of increase (how much each individual contributes to population)
shape of exponential growth
J-shape
logistic growth model
includes limits to population size that become more effective as population size increases
G= r * N * (1-N/K)
shape of logistic growth
S-shape
K
carrying capacity
K-selected
species adapted to stable environments
fewer offspring with more care
r-selected
species adapted to unstable environments
large numbers of offspring and low parental care
limiting factors of population
density-dependent
density-independent
density-dependent limiting factor
predation, inter- intraspecific competition, accumulation of waste, diseases
density-independent limiting factor
weather extremes, natural disasters, pollution
