Additional Case Studies: Materials Contributed by Teachers | AMNH
Organism Species Population Community Ecosystem Biome Competition = the relationship between species that attempt to use the same limited. This section contains data analysis worksheets created by teachers. Since some rodent species are more efficient carriers of the virus, scientists thought that the . Keywords: Predator/Prey Relationships, Trophic Levels, Ecosystem Balance. They describe the adaptive, trophic, and symbiotic relationships between the and distribute the two worksheets: Imaginary Marine Ecosystem Instructions.
Not surprisingly, ecologists also have terms that describe where in the food chain a particular consumer operates. A primary consumer eats producers e. And it can go even further: A single individual animal can act as a different type of consumer depending on what it is eating. When a bear eats berries, for example, it is being a primary consumer, but when it eats a fish, it might be a secondary or a tertiary consumer, depending on what the fish ate!
All organisms play a part in the web of life and every living thing will die at some point.
This is where scavengers, detritivores which eat detritus or parts of dead thingsand decomposers come in. They all play a critical role that often goes unnoticed when observing the workings of an ecosystem.
They break down carcasses, body parts and waste products, returning to the ecosystem the nutrients and minerals stored in them. This interaction is critical for our health and health of the entire planet; without them we would be literally buried in dead stuff.
Crabs, insects, fungi and bacteria are examples of these important clean-up specialists. Another category of interactions between organisms has to do with close, usually long-term interaction between different types of organisms. These interactions are called symbiosis.
The impacts of symbiosis can be positive, negative, or neutral for the individuals involved. Organisms often provide resources or services to each other; the interaction is mutually beneficial.
For example, ants living in a tree may protect the tree from an organism that would like to make the tree its next meal, and at the same time the tree provides a safe home for the ants.
Symbiotic relationships are not always positive for both participants. Sometimes there are definite losers. The predator benefits and the prey is harmed lethally, but it is a short-term interaction. In parasitism, the parasite does not usually kill its host, but just feeds on it for a long time while it is living. The interaction is seemingly neutral for one of the organisms.
For example, a barnacle attached to a whale is able to travel thousands of miles collecting and filtering food from the moving water. But then again, maybe those little hitchhikers are actually creating a tiny amount of additional drag as the whale moves through the water and therefore the whale has to expend just a little bit of additional energy.
If so, that would be a negative impact for the whale. Often, further research reveals that what was originally thought to be neutral for one participant and therefore an example of commensalism, actually has a very subtle positive or negative impact, so the classification is no longer commensalism, but rather mutualism or parasitism. Is a bird nest on a tree limb commensalism, or is there some slight advantage or disadvantage for the tree in having the nest there?
It is possible to come up with plausible explanations either way; only detailed research could provide the necessary information to answer the question. Competition is an interesting example of interactions. Competition is also an interesting example because it is just as likely to be intraspecific as interspecific language alert: An intraspecific interaction occurs within a species e.
If the competition is long-term and occurs between two different species, it would be another example of symbiosis. In summary, there are many different kinds of interactions between organisms in an ecosystem and it is not unusual for any particular organism to wear many hats and play multiple roles at different times.
For example, we humans are consumers and predators when we hunt, kill, and eat other animals such as a fish or a deer, or when we eat chicken we have purchased at the grocery store or a restaurant. Factors that affect birth and death rates and therefore population growth can be dependent on or independent of population density the number individuals in an amount of space.
Levels of Organization in an Ecosystem
Density dependent factors lead to repeating cycles in population size. Principles of population ecology are used extensively in the management of wildlife.
Hunting seasons, catch limits, size restrictions, and quotas used for fish, seafood, and game are all ways in which governments of the world promote healthy and sustainable population sizes for these organisms. Learn how populations grow and are limited in this resource from Mr. Niche represents the sum total of all the ways it utilizes resources in its environment: If two species share the same or a similar niche, they will both compete for the same resources and the worst competitor will be driven to extinction in that area.
This is called competitive exclusion. Habitats that are more complex in food sources, prey refuges, soil substrates, etc. Energy Flow The beginning teacher describes and analyzes energy flow through various types of ecosystems. Ecosystems include autotrophs organisms, such as plants, that manufacture their own food from external sources of energy and heterotrophs consumers, such as animals, fungi and many protists.
Once energy enters an ecosystem, it is passed from one organism to another by ingestion as food or decomposition. Primary producers convert light energy or, rarely energy from chemosynthesis, into chemical bonds.
Investigating Ecosystems Worksheet
Consumers rely on producers for their energy sources. All food chains begin with producers, followed by primary consumers, secondary consumers and tertiary consumers. Energy Flow through Ecosystems Energy flow in marine and terrestrial ecosystems is discussed in this resource from The Habitable Planet.