EVR2001 without module 4

scientific knowledge is gained by

gradual synthesis of info from experiments

steps of scientific research

1. make an observation
2. think of question
3. formulate hypothesis
4. develop testable predictions
5. gather data
6. develop general theories

mutualism

interaction between species that benefit both of them

obligate mutualism

they must be dependent on each other or else they will die

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ex. plant and mycorrhizal, corals and zooxanthellae

emergent properties

properties that become apparent resulted from various interactions and does not only belong to the individual alone

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groups behavioural that is different from individual behaviour ex. migration bird fly together to conserve energy

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complexity from simplicity

environmental science

interdisciplinary academic field that integrates physical and biological sciences

deforestation

Amazon

freshwater depletion

colorado river

effects of soil degration

fertile topsoil is lost to wind and water erosion

overharvesting effects

species extinction

habitat destruction

ecosystem services

ecosystem functions that benefits human

equation for sustainable development

I = P x A x T

impact = size of population x affluence x technological development

1st law of thermodynamics

law of conservation of energy

* energy can neither be created nor destroyed

2nd law of thermodynamics

law of entropy

* with each conversion, energy loses some ability to do useful work

entropy

how spread the energy content is

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entropy increases with each energy transformation

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energy of small system decreases at the expense of increasing entropy for outside of those systems

sunlight is most intense at

visible light

plate tectonics movement

crust is broken up into plates that very slowly drift across our planet

divergent boundaries

plates drafting apart forming mid-ocean ridges or rift valleys

convergent boundaries

plates colliding forming subduction or mountain uplift

transform boundaries

plates moving past each other

lava

exposed molten rock on planet’s surface

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when lava cools, igneous rock is formed

magma

lava that is still underground

earth internal heat melts and crystallize into

igneous rock

igneous rock goes through compaction & cementation to become

sedimentary rock

sedimentary rock goes through heat and pressure to become

metamorphic rock

igneous rock goes through heat and pressure to become

metamorphic rock

metamorphic rock melts and crystallize to become

igneous rock

metamorphic rock goes through heat and pressure to become

sedimentary rock

chemical weathering of limestone creates

caves and sinkholes

biogeochemical cycle

complete path a chemical takes through the atmosphere, hydrosphere, lithosphere, biosphere as it is converted from one form to others

nitrogen compounds are

essential for synthesis of proteins and DNA nucleic acids

N2 makes up

78% of earth’s atmosphere

nitrogen fixation

converting molecular nitrogen in the atmosphere to useful forms

physical fixation is

nitrogen fixation using lightning

biological fixation is

nitrogen fixation using specialized bacteria

nitrogen-fixing bacteria live mutualistically in

root nodules of legumes ex. clover, peas, peanuts, beans

denitrifying bacteria

convert nitrate back into atmospheric nitrogen

phosphorus is often the limiting factor for

plant growth

phosphorus is a part of

cell membrane structure

* important for regulating metabolism
* make up of the sugar-phosphate “backbone” of DNA molecules

excess phosphorus example

lake 226 eutrophication experiment

phosphorus cycle has

* no gaseous phase
* fast terrestrial subcycle
* fast aquatic subcycle
* slow geologic subcycle

florida is the main producer of

rock phosphate in the US

carbon is the most

essential building block of all life and basis of most complex molecules

photosynthesis

fixation of carbon into organic forms

2 important greenhouse gases

CO2

methane

carbon reservoirs

any location where carbon is stored ex. atmosphere, lithosphere, biosphere, hydrosphere

carbon fluxes

exchange of carbon between reservoirs ex. photosynthesis, respiration, decomposition, gaseous dissolution, combustion

nitrogen fixation impacted by humans

amount of nitrogen fixed by the industrial process exceeded natural N2-fixation

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mining rock phosphate is much more rapid than the natural weathering of phosphate-bearing rocks

ecosystem

combination of area’s biological community and nonliving environmental components with which they interact

organism

single living entity that seeks to propagate its genetic material

population

members of the same species inhabiting the same area of reproduction

community

all the populations of different species that inhabit an area

biomes

broad areas of earth that are home to similar types of ecosystems

examples of delineating ecosystems

* area of consisting multiple distinctive ecosystems
* ecosystems lacking clear boundaries at the surface of a fuzzy concept

ecotones

transition areas between adjacent ecosystems

can be abrupt & distinct or smooth & gradual

what does the pattern of closed communities look like

multiple distinct communities with minimal species overlap

what does the pattern of open communities look like

smooth and gradual transition between ecosystems

habitat fragmentation

when parts of habitats are destroyed, leaving behind smaller, unconnected areas

edge effects

changes in population or community structures that occur at the boundary of two or more habitats

* areas with small fragmentation exhibit pronounced edge effects

2 key drivers of building up large woody biomass characteristic of various forest

temperature

precipitation

what happen when there’s not enough rainfall for canopy forest

savanna/grassland

not enough rain for grasses

desert

3 key structure of ecosystems

structure

processes/functions

change

structure

what is there

how much is there

where is it/how is it arranged

processes

what does the thing there do

what does the thing there interact

what are the results of those interactions > energy flow and matter transfer

ecosystem processes example

ecosystem services

ecosystem change

ecosystem services mean

ecosystem function that directly or indirectly benefits humans

3 ways ecosystem change over time

disturbances

succession

evolutionary mechanism

ecosystem structure

physical and biological makeup of the ecosystem

habitat

place or set of environmental conditions in which a particular species lives

structure - eltonian niche

functional role of species in an environment, how it influences its environment

structure - hutchinsonian niche

combination of environmental conditions and interactions required for a species to exist in a particular environment

niche determinants are

environmental factors that determine where species live ex. climate, resource avail, interactions with other species, luck

generalists (niche determinants)

species with broad ecological niches ex. brown rat

specialists (niche determinants)

species with narrower niches ex. giant panda

shelfordian tolerance limits

lower and upper limits of a species distribution and abundance along an environmental gradient ex. temperature, moisture and resource avail

structural patterns

distribution of organisms within an ecosystem

* random
* uniform
* clustered

uniform distribution

the result of intraspecific competition ex. partitioning for limited resources

species interaction - competition

intraspecific

interspecific

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energy intensive > -ve consequences for an ongoing competition because there will be a more efficient competitor

competitive exclusion

elimination from a habitat of one of two different species with identical needs for resources

resource partitioning for intraspecific competition

species co-exist in habitat by utilizing different parts of a resource

ex. offspring dispersed to use different resources than adults (insects and amphibians)

resource partitioning for interspecific competition

utlizing resources at different times or only using specific parts of the resource

ex. small insect eating songbirds > hunt in different parts of trees

species interaction - predation

when hares are abundant, lynx are well fed and their number increases

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increased predation causes a crash in hare population, starving and killing lynx

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resulting low predation allows hare to bounce back, cycle restarts

predation - parasites

feed on organism but do not immediately kill it

* mosquitos feed on many hosts quickly
* tongue-eating louse try to become permanent guest

predation - parasitoids

eventually kill their host by consuming it and moving onto the next stage in their life cycle

food webs

depiction of feeding relationships within an ecosystem that consists of interconnected food chains

* incorporate all chains in ecosystem

symbiosis

prolonged, close interaction between species

mutualism

type of symbiosis in which both organism benefit from their association

commensalism

one species benefits while the other neither benefits nor is harmed

keystone species

species that exert a disproportionate influence on their environment relative to their population numbers or biomass

extirpation

to destroy completely

results in rapid degradation of the system, simplification of structure and elimination of functions

keystone species re usually

ecosystem engineer

bottleneck in trophic webs

when wolves are removed

aspen populations declined from increased elk population

when wolves are reintroduced

elk populations decreased, aspen population increased

what does sea otters do to sea urchins

exert direct population control

what does sea otters do to giant kelp

exert indirect population control

extirpation of sea otters triggers a trophic cascade that

reduces kelp density

trophic cascades are

indirect effects that propagate along food chains

7 ecosystem functions arising from ecological processes

* matter cycling
* gas exchange
* energy capture, storage and flow
* creation/alteration of habitats
* formation and stabalization of soil
* mitigation of natural variability
* resilience (ability to recover from disturbances)

photosynthesis

process through which photoautotrophs make their own food from water and atmospheric CO2 in the presence of sunlight