Obj. 3 ECOSYSTEMS: UNITS OF SUSTAINABILITY
I. What are Ecosystems?
A. Ecosystems are the______________ and_________________ (nonliving)
factors in a specified area that interact with one another.
1. Understanding the ___________________of the biotic and abiotic factors
in an ecosystem can help us to see why particular_________________
______________ may be a problem for human survival.
2. Example: The loss of ___________ in the stratosphere
_______________the quantity of UV radiation on the surface of the planet. In the
same way that humans experience sunburn from too much sun exposure, so do plants.
Excessive UV may damage or destroy plant protein and DNA, ______________the
plant.
B. Plants and animals _______________with their abiotic environment. Attempts
are made by the plant or animal to reduce or increase the_______________ of an
abiotic factor.
1. Aspens have a waxy coating on their bark to reduce the quantity of sunlight
______________________.
2. Desert plants have hair-like structures to _____________________ the
quantity of sunlight reaching the leaf surface.
3. Pine trees have needle-like leaves that reduce the quantity of heat
______________ during the winter.
Fig. 2.2 _______________________ are not isolated from one another. One ecosystem blends into the
next through a transitional region, an _______________, which contains many species common to the
two adjacent systems.
Fig. 2.3 An ecotone may create a unique habitat with _________________________ species not found
in either of the ecosystems bordering it.
II. The Structure of Ecosystems.
A. Feeding Relationships.
1. Trophic Categories.
a. _________________________create organic molecules proteins, lipids and
carbohydrates- by capturing light energy and combining the captured energy with
inorganic molecules.
·
Differentiate between ____________ and _______________.
·
Differentiate between _______________ and ________________.
Fig. 2.4 The producers in all major ecosystems are green plants.
b. Consumers feed on producers and would not exist without producers.
·
Primary consumers (________________________)
·
Secondary consumers (______________________)
·
Omnivores are both ________________and ________________________.
c. Detritus (debris) feeders and decomposers
·
Detritus feeders can be _____________ (feed directly on detritus) or
__________________(feed on those who eat detritus). Generally detritus feeders can
be described as those who _________________dead plants and animals, feces, etc.
·
Decomposers are __________________ detritus feeders.
Fig. 2.5 Water and the simple molecules found in air and in rocks and soils are___________________.
The complex molecules that make up plant and animal tissues are _____________________.
Fig. 2.9 What an organism feeds on is described as a ________________relationship. Trophic types
include ___________________and ______________________
2. Trophic Relationships:
a._______________ _________________: feeding pathways
·
Food chains are a description of who eats whom.
·
Predator-prey and host-parasite describe specific feeding relationships.
b._______________ _____________: complexes of feeding relationships.
c. Trophic Levels or Feeding Levels
·
All producers belong to the first trophic level.
·
All herbivores (primary consumers) are on the second trophic level.
·
All primary carnivores (secondary consumers) are on the third trophic
level.
Fig. 2.12 A food web refers to all the ________________(feeding) connections among species within a
community.
Fig. 2.12 This figure shows trophic relationships within a marine community.
3. Biomass and Biomass Pyramid
a. All organic matter can be defined as_________________.
b. All biomass can be arranged into a feeding relationship with the producers on
the first trophic level.
c. On average, _________ of the energy from one__________ level moves to the
next trophic level. (This is due partly to the First and Second Laws of
_________________________.) At each trophic level most of the organisms are not
___________________, portions of organisms consumed pass through the consumer __________________, and energy is released to the environment as ________
potential energy is converted to __________ potential energy.
d. Because so little energy can be transferred between ____________levels, it is
necessary that the first trophic level contain the____________ number of organisms,
and the subsequent trophic levels contain fewer and fewer organisms. Limitations on
the__________ of energy between trophic levels creates the________________
___________________.
e. If organisms (_____________) eat high on the biomass pyramid (trophic levels
3, 4, 5, etc.), then fewer organisms can be _________________than if organisms eat
lower on the biomass pyramid.
Fig. 2.13 This is a graphic representation of the biomass (total mass of organisms) at successive trophic
levels has the form of a pyramid.
Fig. 2.14 The movement of nutrients (blue arrows) and energy (red arrows) and both (brown arrows)
through the ecosystem.
B. Nonfeeding Relationships
1. Mutually Supportive Relationships:___________________.
2. Competitive Relationships
a. How are competitive relationships reduced?
·
_____________
·
________________: resource partitioning
b. What happens when competition is not reduced?
Competitive exclusion principle
c. _______________factors.
Fig. 2.17 Five species of North American warblers reduce the competition among themselves by feeding
at different levels and on different parts of the trees.
C. ______________ _____________A myriad of limiting factors define the viability
of life. Basic items include ______________, ____________, ____________,
_____________ _____________, and _________________. Only one limiting factor
need be out of its optimum range to cause ___________for an_________________.
1. Optimum Levels
a. Each ___________ necessary for survival has an ideal range.
2. Zones of Stress
a. Each factor has a range of ____________ that are above or below the ideal
but not outside the range allowing___________________.
3. Limits of Tolerance
a. Each factor has an upper and a lower _____________ beyond which the
organism cannot survive.
4. Range of Tolerance
a. Each factor has a range of values that includes the ____________of stress
and the optimum levels. These values do not include the upper or lower limits beyond
which the organism cannot survive.
D. Law of Limiting Factors - Quantities of any single factor above or below
optimum levels necessary for___________ __________, _________________, or
______________will limit____________, __________________or
_________________.
1. Synergistic effects: The interaction of two or more factors cause an effect
greater than the sum of effects produced when each factor acts alone.
Fig. 2.18 For every factor influencing growth, reproduction, and survival, there is an optimum level. Above
and below the optimum, there is increasing stress, until survival becomes impossible at the limits of
tolerance.
III.. Global Biomes
A. The Role of Climate
1. Climate versus Weather
a._________________ -the average temperature over time
b. _________________-the daily variations in temperature and
precipitation
2. _________________ and ___________________ combine to create the
world's biomes.
3. Describe how ___________________change as temperature and
precipitation change.
a. Vary temperature while precipitation is held constant (Moderate
rainfall: cold =_________ ____________, warmer =_________________)
b. Vary precipitation while temperature is held constant (Cold
temperature: little rain = _______________, more rain =___________ _________,
more rain =_____________/_____________).
Fig. 2.19 This map represents biomes of North America and South America.
Fig. 2.19 This map represents biomes of Africa, Europe and Asia.
B. _______________________and Other ________________Factors
1._______________ Intensity: south-facing versus north-facing hillside.
2. Soil Type
a. __________
b. _____________-containing salt
c. ___________, ____________, ______________
3. Topography
C. Biotic Factors
1.______________ of One Plant by Another
2. ____________________Produced by One Plant May
_________________Growth of Another Plant
3. Presence of_____________________ tasty plants are consumed first.
D. Physical Barriers
Fig. 2.20 ________________________ is generally the overriding factor determining the type of biome
that may be supported in a region. Given adequate moisture, an area will generally support a forest.
Temperature, however, determines the kind of forest.
Fig. 2.21 Decreasing temperatures that result in the biome shifts occur both with increasing
_______________ (distance from the equator) and increasing _______________________.
Fig. 2.22 Abiotic factors such as _____________, ____________, and type of ____________ create
different microclimates by influencing temperature and moisture in localized areas.
IV. Implications for Humans
A. Three Revolutions
1. Neolithic Revolution
a. Development of __________________
b. Required permanent or long term ______________ and specialized ______
c. Allowed for the initial increase in ___________ population reliable _____.
2. Industrial Revolution
a. Created the _________ world
b. Energized by fossil fuels (initially _____________)
c. Resulted in the concentration of ______________ products
d. Created even greater increase in human population size because of the
specialization of the ____________________and the replacement of
___________/______________ power with fossil fuels.
3. Environmental Revolution
a. Need to create sustainable human__________________
b. Need to create systems in which waste products are not concentrated
(_______________________), and wastes are resources.