Transcript Ecology 1: Ecosystems - Miami Beach Senior High School

Ecology Unit
40% of the EOC
What is Ecology?
• Ecology is the scientific study of
interactions among organisms and
between the organisms and their
environments.
• An ecosystem is the sum of all the
living and nonliving things in an area
and the interactions among them.
Levels of Organization
• Page 64 - 65 in Textbook Copy all the
levels of organization Figure 3-1 and give
a specific example for each level
Levels of Organization
• Biosphere
– All areas of the earth from the
ocean depths to the atmosphere
that support life.
Ecological roles
• Autotrophs - Producer
• Capture energy and store it in the chemicals bonds of
glucose and other simple food molecules
• Heterotrophs - Consumer
• must eat other organisms for food;
• primary (mouse), secondary (fox), tertiary (bobcat)
**From page 71 in textbook Copy Figure 3-6
with an example of each type of animal.
HW 3.2 assessment pg 72 1-3
Food Chain
The path of food and energy from producer to consumer
to decomposer
Food Web
Food chains that interconnect through
multiple feeding relationships
Trophic Levels
• Each feeding level in an
ecosystem is a trophic level
• Energy pyramids show the
energy loss between trophic
levels in an ecosystem
• Only about 10% of energy
from each trophic level is
passed to the next level
• All of the living matter in a
habitat, trophic level or
ecosystem is its biomass
Video – Pole to Pole
• Answer the handout on the video –
do not forget about the trophic
pyramid and food web on back of
paper
How do nutrients cycle?
• Energy follows a ONE-WAY path
– Sun living organisms heat atmosphere
– The planet does not create or receive more of elements
when needed instead they cycle between the biotic (living)
and abiotic(nonliving) parts of the biosphere
• Matter CYCLES through living organisms endlessly
• Biogeochemical cycles
– Carbon and Oxygen
– Water
– Nitrogen
Carbon and Oxygen Cycle
Carbon/Oxygen Cycle
The continual transfer of carbon and oxygen
Between living and nonliving parts of the environment
Involves processes such as photosynthesis, cellular
Respiration, decomposition and combustion (burning
of fossil fuels)
Nitrogen Cycle
Nitrogen cycle – not on EOC
• Continual movement of nitrogen among
earths organisms, water, rocks, minerals and
atmosphere.
• Nitrogen fixation is a process in which certain
soil bacteria break down N2 and nitrogen
found in dead organic matter and convert it to
either nitrate or ammonia. These forms of
nitrogen are easily absorbed by plant roots.
• Denitrification – Bacteria convert nitrogen
compounds back to nitrogen compounds back
to nitrogen gas.
Water Cycle
Water Cycle
Also called the hydrologic cycle is the continuous
circulation of water among Earths organisms,
atmosphere
and surface
Evaporation – change of liquid to gas when heated
Transpiration – release of water through stomata
(openings
In a plants leaves.
Condensation – gas changes to liquid when it loses
thermal
energy
Precipitation – water that falls from atmosphere to
Earth as
Rain, snow, sleet or hail
In your notebooks
Using the Pictures given to you label the
water cycle and carbon cycle on separate
papers with all processes labeled and arrows
showing the direction of water, CO2 and O2
The role of Climate
• Weather- the day to day condition of
earths Atmosphere at a particular time
and place
• Climate – average, year after year
conditions of temperature and
precipitation in a particular region
Aquatic Ecosystems
• Many of the Earths organisms live in or
near water. Aquatic ecosystems are
defined by salinity, chemistry,
geography, depth, flow, light conditions
and water temperatures.
• Salinity is a measure of the amount of
salt in fresh water.
• Key factors that affect concentration of
animals are dissolved oxygen and water
temp. Cold water holds more Oxygen
Aquatic Ecosystems
• Estuaries – form where salty ocean
water mixes with freshwater from rivers
• Wetlands – water covers soil or is
present near the surface of the soil for at
least part of the year. Ex: bogs, swamps
and marshes.
Marine Ecosystems
• Defined by water with high salinity
• Divided into zones
• Intertidal zone – part of shore between
high tide mark and low tide mark.
Affected twice daily by tides
• Neritic zone- slopes down from
shoreline toward ocean floor
• Oceanic zone – extends from surface to
ocean floor
• Upwellings – movement of cool
nutrient rich waters from deep ocean
into shallower ocean areas.
• Hydrothermal Vents – crack in ocean
floor that emits hot mineral rich water
that are heated by magma
• Chemosynthesis – process by which
bacteria use chemicals for energy
Ocean Life
• Benthos – live on or near ocean bottom
• Plankton – organisms carried by ocean
currents
• Nekton –
free
swimming
organisms
Ecosystem Changes and
Succession
• Seasonal changes affect ecosystems
some animals migrate in response to
changes
• Migration – instinctive seasonal
movement of animals from one place to
another – usually for food, water or
mating
Ecological Disturbances
• Disturbance – event that leads to changes in the
composition of an ecosystem
• Succession – the natural process following a
disturbance in which one community of organisms
gradually replaces another
• Primary Succession – gradual development of a new
community from nothing
• Secondary succession – when a disturbance changes or
partially destroys an ecosystem without destroying its
soil. (abandoning farmland or leaving logged forest to
regrow)
• Pioneer species – first species to move into a devestated
area
• Climax community- fairly stable community that marks
the end of succession
Primary Succession
Population Dynamics
• All species have requirements for many
factors/conditions.
– Abiotic factors – non-living factors; ex.
temperature, precipitation, pH
– Biotic factors – other species; ex. prey
species, competing species
– Immigration – movement of organisms
into an area
– Emmigration – movement out of an area
Limiting Factors
• Anything in an environment that can
limit the size of a population is called a
limiting factor
Abiotic Factors
Biotic Factors
Sunlight
Pathogens
Soil (type, ph)
Predators and Prey
Water
Competiton
Natural disasters (earthquakes,
floods, hurricanes etc)
Symbiosis
Population Density
• Density dependent limiting factor –
depends on the size of the population –
• Population density – measure of the
number of organisms in a given area
• Density Independent Factors – Limit
the size of the population regardless of
size
• Carrying Capacity – The largest
population that an environment can
hold for a long period of time
What would the carrying
capacity of this fly
population be?
– The lesson of the Kaibab
Assignment
Biodiversity
• Biodiversity – refers to the number of different kinds
of organisms living on Earth or an ecosystem.
• Extinction – dying out of species
• Mass extinction – dying off of large numbers of
species in a short period of time
• Habitat place where an organism usually lives
• Habitat destruction – habitat is destroyed or changed
so that it can no longer support the species that had
lived there
• Invasive Species – an introduced species that harms
the environment into which it is introduced. Ex:
zebra mussels, pythons in everglades, lionfish
Humans Affect the Environment
• Renewable resources – Resources that
can be replaced at rates similar to the
rates in which they are used ex: forests,
freshwater
• Nonrenewable resources – used much
faster than can be replaced ex: fossil
fuels(oil, coal, natural gas)
• Air Pollution – release of harmful
substances substances or energy into
the air
• Particulates – small airborne particles of
•
•
•
•
dust, soot and other solids
Smog – visible haze that forms when smoke
and gases from burning fuels combines with
fog
Deforestation – removal of all tress in a forest
Ozone layer – Ozone layer in atmosphere
made up of 3 Oxygen atoms – absorbs much
of suns harmful rays
Water pollution – release of harmful
substances into bodies of water
The greenhouse effect
• Carbon Dioxide, methane, water vapor
and a few other atmospheric gases trap
heat energy of sunlight
Greenhouse
inside the earths
Sunlight Effect
atmosphere (just like
glass keeps a
greenhouse warm)
Some heat
escapes
into space
Greenhouse
gases trap
some heat
Atmosphere
Earth’s surface
Effects on Biodiversity
• Overfishing
• Desertification – transformation of
productive land into a desert
Conservation and Sustainable Practices
•
•
•
•
Reduce
Reuse
Recycle
Sustainable development – involves
using resources in ways that do not
destroy or deplete them for future
generations