Thacker Biology
Ecosystems and Human Impact Project
9/2016
Everything we use, the food we eat, the clothes we wear, the house we live in — are all essentially made of materials and energy drawn from environment—the earth's crust and surface, atmosphere or water. We never get something from nothing.
Environmental sustainability is meeting the needs of the present using resources from environment without compromising the ability of future generations to meet their needs.
Inecology, sustainability describes how biological systems remaindiverseand productive over
time, a necessary precondition forhuman well-being. Biodiversity boosts ecosystem
productivity where each species, no matter how small, all have animportant roleto play. For
example, a larger number of plant species means a greater variety of producers that can feed
many varieties of consumers, greater species diversity ensures natural sustainability for all life
forms, andhealthy ecosystems can better withstand and recover from a variety of disasters.
Today, the extent and nature of human interference in the various ecosystems are bringing about a change in ecosystem sustainability. Humans are driven by the need for excess in everything,and with that need comes the destruction of ecological balance.We have been using resources much faster than they can be replenished by ecosystems. And so, while we dominate this planet, we still need topreserve environment for future generations and all the life forms on earth.
Concepts for discussion:
Stability in an ecosystem is a balance between competing effects.Biodiversity refers to the collective variety of living organisms in an ecosystem. This structure is influenced by alterations in habitat, including but not limited to climatic changes, fire, flood, and invasion by organisms from another system. The more biodiversity in an ecosystem, the greater is its stability and resiliency. Unexpected disturbances caused by human intervention or the introduction of a new species, for example, may destabilize the often complex and delicate balance in an ecosystem. An ecosystem’s producers (plants and photosynthetic microorganisms) and decomposers (fungi and microorganisms) are primarily responsible for the productivity and recycling of organic matter, respectively. Conditions that threaten the stability of producer and decomposer populations in an ecosystem jeopardize the availability of energy and the capability of matter to recycle in the rest of the biological community.
Living things depend on nonliving things for life. At the organism level, living things depend on natural resources, and at the molecular level, they depend on chemical cycles. Water, carbon, nitrogen, phosphorus, and other elements are re-cycled back and forth between organisms and their environments. Water, carbon, and nitrogen are necessary for life to exist. These chemicals are incorporated into plants (producers) by photosynthesis and nitrogen fixation and used by animals (consumers) for food and protein synthesis. Chemical recycling occurs through respiration, the excretion of waste products and, of course, the death of organisms.
All organisms need an input of energy and nutrients to live. For animals, which are heterotrophs, this come from the food they eat. For plants, which are autotrophs, the source of energy is the sun — they produce their own food through photosynthesis — and their source of nutrients is the soil.
The feeding relationships between organisms form a food chain. Producers (plants or autotrophs) capture the sun’s energy and absorb nutrients from the soil to make their own food. Primary consumers (animals, heterotrophs, or herbivores) eat the plants and capture their energy and nutrients. Secondary consumers (animals, heterotrophs, or carnivores) eat the herbivores and capture their energy and nutrients. Tertiary (Third) and Quaternary (fourth) level consumers continue this chain by eating the lower level carnivores. Then finally decomposers breakdown waste and dead organism’s recycling the nutrients back into the ecosystem, so they are available for another generation of plants and animals.
When a consumer eats other organisms, only a small fraction of the energy taken is used for growth. About 50% of food is not digested or absorbed and is passed out as waste. About 40% of the energy of the food is lost as heat or used by the animal for cellular respiration, which makes energy for daily life. Only 10% of the food eaten is used for growth and is available as energy for the next tropic level in the food chain. This produces a pyramid of energy and a pyramid of numbers in an ecosystem. The greatest amount of energy and the largest population is the base of the pyramid with the producers. The least amount of energy and smallest population is at the top of the pyramid
.
Background : To begin: You will be working in a team of 2 persons. (you may choose to work by yourself if that is preferable to you)
You will have “work checks” each class period and are expected to have completed a certain portion of this project at the beginning of each class period.
You are going to choose an ecosystem in a specific location of the world to research. You will identify many different species that support this system from producers to top consumers. You will describe the interrelations between the species inhabiting the ecosystem and their physical environment as well as describing the roles of each. (Niche). You will then imagine an alteration in their environment, caused by human activities, and predict the impact that such a change would have on the organisms living in their ecosystem. You will then prepare an Environmental Impact Report (EIR) describing the status of the ecosystem after the disturbance.
Example disturbances are: man made flood, paving over the ecosystem to make a Wal-Mart parking lot, overfishing, deforestation, introduction of a foreign species, etc.). Finally, you will make suggestions of methods to mitigate the impact of the change.
Hints:
Look ahead. Consider the conditions associated with species endangerment while you plan your ecosystem.That way your EIR will be more interesting.
Procedure:
1. Your mission is to accuratelyresearch and document the various species in your ecosystem by completing the
student outline.
2.You are to design and artistically depict an ecosystem in a cleaver and unique way(poster, diorama, etc)that depicts the organisms in their proper trophic levels. On this you will also depict your Human Impact event in some way.
3. These are the required elements:
A. Location: Your ecosystem may be anywhere on earth!
B. Biological community: Research and choose organisms found in the ecosystem you selected. Remember that members within a trophic level should not feed on each other.
You are to identify :
1. Producers-----at least 4 organisms
2. Primary consumers--- at least 3 organisms These organisms eat what?______
3. Secondary Consumers---at least 2 organisms These organisms eat what?______
4. Tertiary Consumers----at least 1 organism These organisms eat what?______
5. Decomposers ---at least 2 organisms These organisms eat what?______
6. Scavengers-----at least 1 organism These organisms eat what?______
As you identify organisms and learn facts about them, please hand draw a colorful and accurate illustration of the organism onto your illustration page. You will cut out your illustrations and use these in your pictorial image of your ecosystem.
For each species in each Trophic Level be sure to include these criteria:
Tropic Level------what level is this?
Organism type-----1o, 2o, 3o, 4o, producer, consumer, decomposer, scavenger…pls. note if autotroph or heterotroph
Name of Organism----- common name
Habitat/Range-----where within your ecosystem does this organism exist?
Nutritional needs-----what type of soil, water, type of food does this organism eat….Should be something from the
tropic level below!
Reproductive Habits---how frequently does this reproduce, is reproduction seasonal? When?, Life span?
Niche----What role or roles does this organism play within the ecosystem
4. Now that you have created a food chain in your beautiful ecosystem, add a disturbance. Your disturbance must be man-made; intentional or unintentional, or a combination of these. Some of the examples are hunting/harvesting, land clearing, pesticides/herbicides, introduction of a foreign species, etc. Your illustration of the ecosystem will be BEFORE your disturbance. Please illustrate somewhere on your ecosystem illustration, your disturbance.
5. Identify the effects of the disturbance on the species in your ecosystem. Describe the sensitivity to the introduced environmental insult on the species in your ecosystem.
Use the list below to help you make the following declarations:
A. Extinct: Species which are completely decimated.
B. Endangered: Species which are in imminent danger of extinction.
C. Threatened: Species which are at significant risk of becoming endangered but are not in immediate danger of becoming extinct.
D. No expected change: Species with moderate to large populations, whose numbers are expected to remain stable.
E. Increased: Species whose populations increase. May be potential pests.
6. Prepare your EIR describing what happens to each species. The EIR should also state why you are making your predictions.Include ideas for mitigation (lessening) of the environmental impact.Be prepared to share your results with the rest of the class.
SAMPLE ECOSYSTEM: THE VALLEYAREA NEAR LAKE PERRIS, CA
Note: My sample contains one species per trophic level. Your ecosystem must have the proper numbers of different species per trophic level.
1st Trophic Level: PRIMARYPRODUCER:Coastal Sage Scrub
a. Habitat/range: near lake water, interspersed throughout valley floor
b. Nutrition: autotroph, needs low Nitrogen content, sun and minimal water, does better
with higherwater content so grows well near lake. Can take heat to 1000F and down to
freezing.
c. Reproductive habits: plant reproduces sexually by being pollinated by bees and other
insects and setting seed. More seeds germinate in wet years.
d. Ecosystem Connections (Niche): This shrub provides vegetation for insects, and some small
mammals to eat, pollination opportunities and shelter for small mammals and reptiles.
2nd Trophic Level: PRIMARY CONSUMER: Honey Bee
a. Habitat/range: flying insect: hives on land, food is flowers of Coastal Sage Scrub,
frequently dips into lake water and floats on water, found throughout North and South
America
b. Species Biomass: .0001 tons per unit area of the valley ecosystem
c. Nutrition: eats nectar and pollen of the Coastal Sage Scruband of other blooming
plants as well
d. Reproductive Habits: Queen bee lays eggs in winter.Fertilized eggs will hatch into
female worker bees, while unfertilized eggs will become drones or honey bee males that
produce her workers
e. Ecosystem Connections (Niche): Bees provide pollination for many species of plants and trees.
3rd Trophic Level: SECONDARY CONSUMER:Crappie Fish
a. Habitat/Range: shallow waters of Lake Perris, found in many fresh water lakes
world wide. It occupies open water with submerged timber or aquatic vegetation in
standing water bodies and slow-flowing back
b. Species Biomass: .01 tons per unit area of the valley lake ecosystem
c. Nutrition: eats Mead Bee when landed on lake, worms, other insects
d. Reproductive habits:Female crappie may spawn with several males and can produce
eggs several times during the spawning period. It usually lives 4 years; sometimes up to
8 years or more.
e. Ecosystem connections (Niche): As a predator, this fish controls populations of worms and
insects. As with all fish, eggs and young individuals are commonly eaten by many other
species.
4th Trophic Level: TERTIARY CONSUMER: Red Tail Hawk
a. Habitat/range: North America into Central America. Commonly found in California.
b. Species Biomass: .0001 tons per unit area of the valley ecosystem.
c. Nutrition:eats fish of all kinds, small mammals like rodents and rabbits and reptiles
and birds.
d. Reproductive habits: Mating happens in late winter or early spring, they are
monogamous, lays 2-3 bluish eggs in tree tops, both male and female lay on eggs for 35
days. Birds can live from 13-20 years.
e. Ecosystem connections (Niche): Red Tail Hawks keep populations of rodents down and their
nests provide shelter for other birds. They are not attacked but their eggs are preferred
by owls.
All Trophic Levels: DECOMPOSER: Millipedes
a. Habitat/range: dry areas of the valley floor, away from the lake
b. Species Biomass:0.0001 tons per unit area of the valley ecosystem
c. Nutrition: eats dead, decaying organic matter including plants.
d. Reproductive habits: Millipedes reproduce sexually and the female lays fertilized eggs
that hatch anywhere from couple weeks to 3 months. Millipedes can live up to 10 years
depending on species.
e. Ecosystem connection (Niche): Millipedes provide decomposition of organic waste and of plants
in their area and also are a source of food for birds, beetles, ants and spiders.