chapter 4 - mrs. moretz's science site · ecosystems 1) energy enters ecosystem as radiant...
TRANSCRIPT
Ecosystems
and Energy
Chapter 4
What is Ecology?
Ecology –
- eco - house; logi - study of
- study of the interactions among organisms and between
organisms (biotic) and their abiotic environment.
What is Ecology
Biotic - living part of the environment
Abiotic - nonliving or physical part of the environment
environment
bioticabioticECOLOGY
What is Ecology?
Levels of Biological
Organization
• Ecology focuses on levels
above the organismal level.
What is Ecology?
Population - same species living
at the same place at the same
time
Species - group of similar organisms whose members freely
interbreed with one a another in the wild to produce fertile
offspring
What is Ecology?
Community - Populations of different species living
together in the same place at the same time.
What is Ecology?
Ecosystem - community AND the physical
environment; includes all the interactions among
organisms and with their abiotic environment
CO2
What is Ecology?
Landscape –
region that includes
several ecosystems
What is Ecology?
Biosphere
the whole earth
interaction of land, water, and atmosphere
contains all living things
Atmosphere
gaseous envelope surrounding Earth
Hydrosphere
Earth’s supply of water
Lithosphere
soil and rock of Earth’s crust
Energy
• The ability to do work.
• Measured in kJ or kcal.
• Energy exists in many forms.
The Energy of Life
Potential vs. Kinetic Energy
PE = stored energy KE = energy of motion
Can change from one form to another
The Energy of Life
Thermodynamics –
The Energy of Life 1st Law of Thermodynamics –
energy can change forms, but is not created or destroyed
2nd Law of Thermodynamics –
amount of usable energy decreases as energy changes forms
“Entropy Rules!”
1st Law deals with quantity of energy,
2nd Law with quality of energy.
What do you think?
Quick Write
Use the following scientific terms to describe the
processes of photosynthesis and respiration:
Carbon dioxide
Oxygen
Water
Autotrophs
Heterotrophs
Solar energy
ATP
What is photosynthesis?
Photosynthesis, chemical equation
6 CO2 + 6 H2O + radiant energy
C6H12O6 + 6 O2
What is photosynthesis?
photo = light
synthesis = to put together
Purpose of Photosynthesis
Photosynthesis- turns energy into sugars
Energy Sugars
Photosynthesis
Process of Photosynthesis CO2 enters and O2 exits through stomata
stomata - small openings on the underside of leaves.
Process of
Photosynthesis
Water enters through
roots
Process of Photosynthesis
Light is captured by chlorophyll found in chloroplasts.
chlorophyll - light capturing pigment in chloroplast
Absorbs red and blue light from the sun.
Reflects green light.
Process of Photosynthesis
Process of Photosynthesis
Chloroplast
Organelle that contains chlorophyll.
Site of photosynthesis.
Cellular Respiration
Cellular Respiration:
C6H12O6 + 6 O2
6 CO2 + 6 H2O + energy (ATP)
Photosynthesis vs. Respiration
Photosynthesis- turns energy into sugars
Respiration- turns sugars into energy
Energy Sugars
Photosynthesis
Respiration
What do you think?
Why is it important for scientists to understand how
much photosynthesis is occurring in an ecosystem?
The Path of Energy Flow
Three options for energy use:
Growth, maintenance, reproduction energy is “lost” as
heat through respiration
Storage = biomass available for others to consume
Photosynthesis & Respiration
Gross Primary Productivity (GPP)
total amount of energy captured during photosynthesis
respiration uses some of that energy for life processes
Photosynthesis & Respiration
Net Primary
Productivity (NPP)
amount of energy
remaining in plant
tissues after respiration
only NPP is available to
consumers, and only
some of it is actually
used
Primary Productivity
Ecosystem Productivity
Net Primary
Productivity
Gross Primary
Productivity
Plant cellular
respiration=
Highly Productive Ecosystems
The Path of Energy Flow
Ecosystem Productivity
The Flow of Energy through
Ecosystems
1) Energy enters ecosystem as radiant energy.
2) Some of radiant energy is captured during photosynthesis.
3) Energy is stored in chemical bonds of glucose (chemical energy).
4) Animals get energy by consuming plants and their stored chemical energy.
5) ALL organisms respire to release energy from glucose.
6) Released energy becomes available to do work.
7) Energy escapes from organism as heat = unusable energy.
8) Heat energy radiates into space.
The Flow of Energy Through
Ecosystems
Producers, Consumers, and Decomposers
The Flow of Energy Through
Ecosystems
• Producers• a.k.a. - autotrophs
• Photosynthetic organisms
• Consumers• a.k.a. - heterotrophs
• Organisms who consume producers
• Decomposers• a.k.a. - saprotrophs
• Heterotrophs that break down dead organic material to get energy.
• Releases simple inorganic molecules that can be reused.
The Flow of Energy
through Ecosystems Types of Consumers:• Primary consumer (1o)
• eats producers• Herbivores = plant eaters
• Secondary consumer (2o) • eats 1os• Carnivores = meat eaters• Omnivores = plant and meat eaters
• Tertiary consumers (3o) • eats 2o
• Carnivores or omnivores
• Detritivores• Consume detritus - organic matter that includes carcasses, leaf litter, & feces.
• Helps break down waste products
The Path of Energy Flow
Food Chains – energy from food passes from 1 organism
to the next in a sequence
Trophic Level - each link in the food chain
Food Webs –
interconnected food
chains
The Path of Energy Flow
Case-in-Point: How Humans Have Affected the Antarctic
Food Web
Krill
Baleen whales
Squid Fishes
Toothed whalesSealsPenguins
What would happen if
you eliminated krill?
The Path of Energy Flow
Ecological Pyramids
Pyramid of Numbers Pyramid of Biomass
The Path of Energy Flow
Ecological Pyramids
Pyramid of Energy
The Path of Energy Flow
Desert: Primary producers
= 100 g / m2
Temperate forest: Primary
producers = 1,500 g / m2
Food webs very simple, very
few tertiary consumers
Food webs very complex,
more tertiary consumers,
some quaternary.
The Path of Energy Flow
Desert Biomass Pyramid
Primary producers = 100 g / m2
Primary consumers = 10 g / m2
Secondary consumers = 1.0 g / m2
Tertiary consumers = 0.1 g / m2
Tertiary consumers must range over large areas to obtain
enough energy to subsist.
13.5 kg coyote must
range ~12 ha to subsist
(30 acres).
The Path of Energy Flow Temperate Forest Biomass Pyramid
Primary producers = 1,500 g / m2
Primary consumers = 150 g / m2
Secondary consumers = 15 g / m2
Tertiary consumers = 1.5 g / m2
13.5 kg coyote only
needs ~1 ha to subsist
(2.5 acres).
Also, possibility of quaternary
consumers, like bears.
NOTE: just
relative
examples,
not accurate