Exam 2 (Chps 3-7) Flashcards
major abiotic cause of differences between ecosystems
climate
all life is composed of…
organic molecules
organic chemicals
C-C, C-H, C-O bonds
inorganic chemicals
neither C-C or C-H bonds
1st Law of Thermodynamics
takes energy to get energy
2nd Law of Thermodynamics
conversion always = some loss, so systems always need more
entropy
degree of disorder systems move only toward disorder
ecology
study of processes influencing distribution and abundance of organisms and their interaction with the environment multidisciplinary science
ecosystem
interacting biotic communities and abiotic environment in an area
species
share characteristics can interbreed
population
species in a certain area
landscapes
interacting ecosystems
biomes
large area that shares climate and vegetation
ecotone
transitional area between ecosystems
biosphere
earth
habitat
place
niche
all conditions and resources a species needs
conditions
environmental factors that vary in space and time
resources are…
consumed
survival curve parts
- optimum
- range of tolerance
- limits of tolerance
- zone of stress
synergistic effects, synergisms
two or more factors interacting in a way that causes an affect much greater than one would anticipate from the two acting seperately
4 spheres of Earth
- biosphere
- lithosphere
- atmosphere
- hydrosphere
energy forms
- kinetic
- potential
- chemical
1st Principle of Sustainability
sun
cell respiration
molecules broken down for energy (helped by enzymes)
Law of Conservation of Matter
in chemical reactions, atoms are neither created or destroyed
Carbon Cycle
air -> photosynthesis -> eaten/soil
Phosphorus Cycle
rock -> plants -> heterotrophs -> soil
Nitrogen Cycle
air -> plants -> consumers -> soil -> bacteria -> air
Sulfer Cycle
rock -> plants -> animals -> soil
population growth
change in population divided by the time over which that change occurs
community
populations of different species living together
growth rate
population change divided by time
J curve
shape of growth curve for pop. undergoing exponential growth
S curve
plotted logistic growth
exponential increase
growth produced when base population increases by a given percentage each year, characterized by doubling again and again. J shaped curved
logistic growth
pattern of growth that results in an S-shaped curve; population levels at carrying capacity (K)
critical number
minimum number needed to maintain a healthy viable population. Less = extinction
carrying capacity
K - max pop an ecosystem can support w/out being degraded or destroyed
biotic potential
reproductive capacity (opposite environmental resistance)
reproductive strategies
property of species balancing between reproduction and death (r vs. K)
recruitment
maturation and successful entry of young into an adult breeding population
environmental resistance
factors that cut back populations (opposite biotic potential)
top-down relationship
population control by predation
bottom-up relationship
population control by lack of resource(s)
ecosystem capital
goods and services provided by nature
commensalism
one benefits, one not affected
Maximum sustainable yield (MSY)
1/2 carrying capacity
resource partitioning
division of a resource and specialization in different parts of it
precautionary principle applied to fisheries
TAC is less than MSY
ecological succession
change in community, some species invading, others fading
introduced species implications and cost
- destroy habitat
- kill organisms
- cost money
standing crop biomass
biomass of primary producers
primary production
photosynthetic organism, creating new organic matter in ecosystems
primary succession
gradual establishment of climax ecosystem in unoccupied area
secondary succession
reestablishment, in stages, of ecosystem
climax ecosystem
last stage in succession, balance of biotic/abiotic
ecosystem resilience mechanisms
- nutrient release to soil
- regrowth by remnant roots and seeds
- invasion from neighboring ecosystems
- rapid restoration of energy and nutrients
- successional dynamics
biological wealth
commercial, scientific, aesthetic value of biota
natural goods
materials derived from the natural world
natural services
functions performed free by ecosystems (erosion control, etc.)
conservation
management of resource to ensure max benefits for the long run
preservation
ensure the continuity of ecosystems regardless of potential utility
consumptive use
harvesting natural resources for immediate needs
productive use
exploitation of ecosystem resources for economic gain
Total Allowable Catch (TAC)
yearly quota set for harvest of a species
tragedy of the commons
overuse/destruction of resource used by all
restoration ecology
restoring ecosystems to natural state
new forestry
Forest Service now prioritizes protecting ecological health and diversity, not just logging
wilderness
undeveloped, protected by Wilderness Act
national parks
National Park Service: scenic, ecological or historical importance, protection, public access
national wildlife refuges
U.S. Fish and Wildlife Service: maintained for protection of wildlife and provision of public access
Millennium Ecosystem Assessment
2 million species classified
8.7 million total (recent estimate)
intrinsic value
value for its own sake
instrumental value
value for benefiting others: cultivars, genetic bank, ecotourism, science, agriculture, medicine, etc.
responses to limits of change
- adapt
- migrate
- die
tropic categories
- producer (autotrophs)
- consumers (heterotrophs, primary secondary, higher)
- decomposers (detritus feeders)
Value of Ecosystem capital
$35 trillon/ yr
biodiversity
variety in species, genetics, ecosystems
causes of biodiveristy loss
- habitat destruction
- invasive species
- pollution
- population
- over-exploitation
current rate of extinction
100-1000x normal
Lacey Act
- forbids interstate commerce in illegally killed wildlife
- restricts injurious wildlife
- now includes plants
Endangered Species Act
protects species and habitats at risk of extinction
ESA Process
- Listing: agency or petition, based on best info, considers economic impact
- Habitat Identification: critical habitat must be designated
- Recovery Plans: to survive and thrive
International Union for Conservation of Nature
Red List: evaluates and creates a list of endangered species
CITES
169 nations that restrict trade of rare and vulnerable species
Convention on Biological Diversity
192 nations and EU
goals: conservation, sustainable use, sharing genetic resources
Critical Ecosystems Partnership Fund
grants to conservation NGOs
Why are ecosystems undervalued?
- free
- not noticed until gone or fouled
- no consensus on how to use sustainably
