second qtr final

population problem creates enviro problem because…

-human population size

-rate of resource consumption

carrying capacity

max number of individuals of a species that an area can support indefinitely
non-human pop growth limiting factors

-resource availability

-competing species

-predators & disease

-habitat condition

human pop limitng factors

biophysical factors:

resource availability

-waste accumulation

social factors:

-education

-economic status

-ethnicity

 

 

ecology
study of interactions between organisms and their environment
ecosystem
community of organisms and its local nonliving environment in which matter cycles and energy flows
biome
an ecosystem with similar characteristics(18 total) (CA has 11) (8 near UCLA)
biodiversity

range of different types of organisms and biological species in a given area

-genetic diversity

-species diversity

-habitat diversity

mechanisms of evolution

-mutation

-natural selection

-geographic isolation

-genetic drift

 

mutations

errors that occur in DNA replication; ultimate source of genetic diversity

natural selection

genes that produce better fitness come to dominate the population=survival of the fittest

1st result=origin of new species

2nd result=origin of new species

geographic isolation

-evolution via natural selection produces different adaptions in different places

-isolated species become different and can no longer interbreed, thus becoming different species=geographic speciaton

genetic drift

random events, independent of ability to survive or reproduce (ex:stepping on ants or a natural disaster)

-this can substantially change small populations (hunted northern elephant seal)

species
a group of individuals capable of interbreeding
population
group of individuals that are interbreeding and are seperated from other such groups

measuring biodiversity

species richness=total number of species (through this you can determine what plants are native to the area and will grow there, thus recovering the area…S.Pau in Hawaii)

species evenness= relative abundance of species

species dominance=most abundant species

species interactions

1)mutualism(symbiosis)-both benefit(ex:bird&flower)

2)predation/parasitism-one benefits,one is harmed(ex:owl eating bird or tick)

3)competition-both harmed(ex:squirrels)

competetive exclusion principle
2 species really alike wont last because they cannot occupy the same niche. if there are enough differences(aka specializations) then they can survive together(aka coexist)=niche partitioning
Biodiversity Hotspots

the most endangered forests, contain a high level of endemism and are threatened from habitat loss(mostly in tropics)

endemic species

native, only found in one place

*thats why biodiversity hotspots are so important to protect because if that area is ruined then so is the endemic species, forever

ecological succession
process of ecosystem development
disturbances
an external impact on an ecosystem that casues a measurable change in the ecosystem(it initiates ecological succession)
primary succession

occurs on abiotic substance

-cooled lava

-glacial retreat

-newly exposed soil

secondary succession

reestablishment of an ecosystem on formerly occupied ground

ex:after a natural disaster or an abandoned farm…Mt St Helens

autosuccession
same type of species tends to show up (ex:chaparral, because every 20 yrs the area burns down)
species interaction

-facilitation

-interference

-life history differences(tolerance)

-chronic patchiness

 

facilitation
early species alter conditions or the availability of resources allowing later species to become established and grow
interference
early species change physical environment in ways that suppress the establishment, growth or survival of later species(ex: dense prairie grasses)
tolerance (life history differences)
a predictable sequence of species replacements results because different species have different strategies for exploiting resources(ex:different rates and methods of seed dispersal)
chronic patchiness
in very harsh environments, patches of different species persist for long periods of time and succession does not occur (CA desert)
primary production
production carried out by autotrophs(PHOTOSYNTHESIS)

primary producers

(aka autotrophs) produce energy-containing organic matter from inorganic substances
gross primary production

rate of synthesis of organic matter

(production of organic matter before use)

net primary production

gross primary production – respiration

*rate of appearance of new organic matter

secondary production
production by heterotrophs, depends on production of autotrophic organisms
secondary producers
(aka heterotrophs) cannot make their own organic compounds from inorganic ones and must feed on other living things
net secondary production
gross secondary production – respiration
Agroecosystems

creating a new ecosystem by clearing land for agriculture

-differs from natural ecosystems:

1)prevents succession(we mainly farm for early successional species)

2)crop plants grown in monoculture(decrease biodiversity)

3)neat rows with neighbors in contact

4)food webs are simplified

5)plowing has no counterpart in nature

6)biotechnology

sustainable harvesting policy
harvest just the growth each year, the population will then remain constant
why protect endangered species??

-utilitarian reasons

-ecological reasons

-aesthetic reasons

-moral reasons

-cultural reasons

utilitarian reasons
medicines(penicillin is made from mold)
ecological reasons

keystone species- a species that is essential for a habitat to survive(ex:sea otter or do-do bird germinating tree seeds through their feces)

-redundancy=stability(you have 4 species spreading seeds or some activity and then 3 species die out, well the activity no longer gets done)

 

aesthetic reasons

-art

-music

-biophilia: humans need nature(patients near windows heal faster)

moral reasons

-US Endangered Species Act

-doesnt every being have a right to survive??

cultural reasons
many indigenous cultures live off of nature and even specific species
endangered
any species which is in danger of extinction throughout all or a significant portion of its range
threatened
any species that is likely to become an endangered species within the forseeable future thoughout all or a significant portion of its range 
Threats to biodiversity in US

-habitat destruction(species richness relative to area, island biogeography, biodiversity hotspot)

-pollution

-overexploitation

-disease

How to Protect

-Emergency measures(increased enforcement of laws, captive propagation)

-maintain minimum viable populations(500-1000 breeding individuals at all time)

-maintain habitats of minimum viable area

-restore degraded habitats

-establish linkages between habitats

-obtain essential ecological info

-maintain legal protection

-CONTROL AND AVOID TRANSPORT OF NON-NATIVE SPECIES

indigenous
native to an area
endemic
native, only found in one place
non-native
presence due to introduction (aka exotic, alien, or non-indigenous)

naturalized

non-native, sustaining population
invasive species

non-native, able to colonize new areas(often lack natural copetitors, predators, parasites)

-ex:Guam brown tree snake killed off bird species in Guam

-Avian malaria in Hawaii killed off birds

-Zebra Mussell from Europe- probably came through ballast water of ships, they colonize all over surfaces (and in pipes) and eat ALOT of phytoplankton

impact of invasive species

-decimate native species populations

-decimate crop plants

-promote fire

-alter hydrologic conditions

-hinder utility services

solution to invasive species

EARLY DETECTION is key

-biological control (aka bringing in the invasive species predator) risky

sea level rise

-melting of glaciers and polar ice caps

-thermal expansion of water

(effects- rice fields in asia will flood, cities will lose land to ocean and coastal wetlands will go underwater)

Latitudinal & Longitudinal Seasonal Shifts

-sediment samples allow scientists to identify pollen richness of the past and create seasonal records

-study of 1700 species: avg movement of 6.1 km/decade

–issues with the moth larvae

-crops wont shift well to higher latitudes because there is typically less land & less fertile land

-epidemic potential:malaria, if temps rise, that means mosquitoes can survive in more areas and thus spread malaria in more areas

 

Reserve Design

UP: Size & Connectivity

DOWN: Habitat Fragmentation & Edge Effects

conservation easements

a voluntary, legally binding agreement that limits certain types of uses or prevents development from taking place on a piece of property now and in the future, while protecting the propery’s ecological or open-space values

-Nature Conservancy hold tons of land this way

-taxbreak

-protects land into the future

-maintain ownership

Protect Rainforests because:

;

biodiversity

water

keeps things cool(global warming)

medicine

forests prevent erosion(form of flood control)

salmon issue

-Harvest (aka overharvesting)

-Habitat Degradation (some fishing methods destroy habitats)

-Hatchery operations(dilute genetic diversity, outcompete wild fish by volume ; vector for disease)

-Hydroelectric (blades of turbine kill the fish or disassociate them, dams create still water)

wetlands

functions:

-flood control(absorbs rain and overflow)

-groundwater refreshing(nutrient refreshing)

-storm protection(New Orleans)

-migratory birds home

solution:

-protection

-restoration

-mitigation(cram score)

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