Transcript Document

HS415 Environmental Health
Seminar #2
Ecology & Life
(food webs)
Rules
Syllabus: Read it!
APA format: Google it.
Discussion: must respond to both questions
initial: by Sat midnight
min. 100 words
APA format & ref’s
peer: at least 2, 50 word min.
Must add to the discussion!
Word Count: I am not counting,
unless your post is short.
Rules, cont.
Please name your doc’s correctly.
 Ex: Name_HS415_projectname.doc

yes SShore_HS415_FinalProject.doc

no
FinalProject.doc
Rules, cont.
Late policy: nothing accepted late unless
Extenuating circumstances???
Try to Not get behind in class….
If you are having a problem,
let me know.
Grading: see the rubrics (syllabus)
Exams: Nit Picky!
(I did not write them)
Rules, cont.
I really hate to bring up this subject, but…
Plagiarism…will not be tolerated. The use of
Turnitin.com will be often.
I suggest you read the Academic Dishonesty Policy in the
Syllabus and in the Student Handbook,
& look in any Unit, Academic Tools
(next to the To-Do List)
Ecology
Ecology in Greek is “house or place to live”
 Study between organisms & their
environment
 Examining how organisms interact with
their environment

Organisms

Forms of Life which can be classified into
species
 5-100 million species, most are insects and
microorganisms
 About 1.8 million named
Wild & Domesticated Species

Wild
 A species that lives in
its natural
environment (where
it’s ancestors lived)
ex: coyote

Domestic
 A species that was
removed from its
natural environment
and placed in an
environment that
supports the needs and
wants of HUMANS
ex: dogs & cats
Some Words to Know

Populations

– Organisms that are part
– The place where a
of the same species and
live in the same area of
space

Genetic Diversity
– Each different
organism has a
different genetic makeup
Habitat
population lives. Each
one can very in size
and place.

Biological Community
– A population that
consists of a variety of
species that live in a
particular place.
One more Word

Ecosystem
– A community of different species interacting
with other species & their non-living
environment

Natural or Artificial
LIFE!

Living things are made up of one or more
cells containing DNA
 DNA is the instructions for making new
cells and amino acids, proteins
 Metabolism
– Chemical reaction that capture and transform
matter and energy from the environment to
supply the organism
More LIFE

Homeostasis
– Maintains optimal conditions despite changes
to the environment

Reproduction
– Asexual
 Single cell division (mitosis), or self fertilization
– Sexual
 Organisms exchange gametes (meiosis) and fertilize
the ova to create offspring.
Earth’s Life-Support Systems
Layers

Core (the actual center of the earth)
– Fe and Trace N
– Solid & Liquid

Mantle (between)
– Fe, Si, O, Mg
– Solid and Liquid


Responsible for continental drift
Crust
– Fossil Fuels
– Where we live
Spheres

Lithosphere
– Upper mantle and crust

Atmosphere
– Thin envelope of air around the lithosphere

Bio-Ecosphere
– Biotic and Abiotic Habitats
What is Needed to Sustain
Life?

One way flow of energy
– EX: Sunlight through feeding cycles, then into
environment and eventually back out as
infrared rays

Cycle of Matter and Nutrients
 Gravity
Cycles

Carbon
– CO2 from the atmosphere and earth’s water.


PHOTOSYNTHESIS
Phosphorus
– DNA transfers

Nitrogen
– Atmospheric N to the soil, helps with amino acids

Water
– Storage, evaporation, precipitation, runoff

Oxygen
The Sun

Photosynthesis

CO2 + H2O + sunlight  C6H12O6 + O2
Earth gets 1 billionth of the sun’s energy
 28% is reflected into space

(but what about the greenhouse gas effect)

.023% gets absorbed by plants
Ecosystem Concepts
Intro

Biomes
– Large Regions Characterized by features

Basic Zones
– Land
– Ecotone (transition)

Aquatic
Components of an Ecosystem
“tics”
– Biotic
– Abiotic
Living part of ecosystem
Non-living part of ecosystem

Examples
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ABIOTIC
Air
Water
Nutrients
Solar Energy
Precipitation
Wind
Altitude
Latitude
Frequency of Fire
Nature of Soil
Water Currents
Concentrations
Laws and Factors

Law of Tolerance
– The existence, abundance,
and distribution of a species
in an ecosystem are
determined by whether the
levels of one or more
physical or chemical factors
fall within the range
tolerated by that species

Limiting Factor
Principle
– Too much or too little
of any abiotic factor
can prevent growth of
a species
BIOTIC

Autotrophs-Producers
– Photosynthesis
– Chemosysthesis

Heterotrophs-Consumers
– Herbivores-Primary
– Carnivores-Secondary-Tertiary
– Scavengers eat already dead animals

Decomposers
– Break down dead organisms into nutrients
– Detritivors
– Bacteria
– Fungi
eat dead
GOAL OF ALL PRODUCERS
& CONSUMERS

Aerobic Respiration

C6H12O6 + O2  CO2 + H2O +ENERGY

In humans E= ATP (adenosine triphosphate)
(notice the CO2 ?)
Food Webs and Energy Flow
in Ecosystems
A few Definitions

Trophic Level
– Feeding level

Biomass
– Dry weight which is not counted with water
because water is not a source of energy
– Only small amounts of what is eaten is actually
converted into biomass
ENERGY

Some energy is lost from trophic level to trophic
level
 5-20% of energy is transferred from level to level
 The more trophic levels the greater cumulative
loss of flow (pyramid of energy flow)
– The energy flow triangle shows earth could support
more people if we ate grains instead of grazing animals
ENERGY (cont)

The energy loss is so large we can only support 45 trophic levels
 Gross Primary Productivity (GPP):
– The rate it takes ecosystems to convert solar energy into
chemical energy as biomass

Net Primary Productivity (NPP):
– It is what is left of the biomass after the organism has
used parts of it to stay alive, and reproduce
ENERGY (cont)

NPP is available to other organisms as food
(Net Primary Productivity)
 The earth’s total NPP is the upper limit
determining the planets carrying capacity for all
species!!!!!
 Most Productivity:
–
–
–
–
Estuaries
Swamps
Marshes
Tropical Rain Forest
ENERGY (cont)

Least Productive:
– Open Ocean
– Tundra
– Desert

59% of NPP from Land, 41% of NPP from Water
 Open ocean contributes a lot to NPP but
phytoplankton is not reasonably harvestable
 HUMANS waste 27% of potential NPP and 40%
of actual
Come
up with an example to fill in
the blocks of a food chain in two
different ecosytems.
Caring for the Environment
It is in our own best interests to look
after the world we live in.
 If a habitat is lost or damaged, it has
an effect on everything else, even if
we do not see or understand it
straight away.
 Remember - once something becomes
extinct, it’s gone forever!

THATS ALL
Now
it’s up to you…..
What
are YOU going to do to
help save our world and future
for our children?