Chapter 4 Doing Environmental Science
Complete this teacher-graded assignment. Submit it to your teacher by the due date for full credit.
Total score: ____ of 15 points
- Study an ecosystem of your choice, such as a meadow, a patch of forest, a garden, or an area of wetland. Determine and list five major plant species and five major animal species in your ecosystem. You will need to use online field guides to help in your identifications. You can use the notes from your Chapter 3 ecosystem if you wish or you can make observations of another area. Write hypotheses about
- Which of these species could be an indicator species and
- Which of them could be a keystone species.
- Explain how you arrived at your hypotheses. Then design an experiment to test each of your hypotheses, assuming you would have unlimited means to carry them out. A well designed experiment includes background material, a question, hypothesis, procedure, materials/equipment, data to be collected (independent, dependent variables and control), analysis, and expected results and conclusions.
- Be sure that you have 2 experiments, clearly labeled.
Background Information
Indicator Species
Organisms that provide early warning of damage to a community or an ecosystem
(birds and butterflies and sometimes frogs).
Keystone species
Organisms that if removed from a habitat, it may collapse since it is so vital to
that ecological community and part of an environmental structure (Bee’s or
butterflies, etc.)
Table 1. Characteristics exhibited by the various types of focal species Keystone species Umbrella species Flagship species Composition indicator Condition indicator species species Exert a disproportionate Garners public support Provide an assessment Demonstrate fidelity to a Exhibit a specific niche or over a range of stress influence on community and affection particular set of habitats a defined range of structure relative to its ecological tolerances abundance or biomass Limited change in Substantially change the Requires large tracts of Differentiate between Demonstrate fidelity to relatively natural or community type or structure and/or natural and anthropogenic community or habitat habitat type unaltered habitat structure if removed composition of a stress community or habitat upon its removal Non-migratory Relevant to ecologically Migratory or Lower the number of Relatively independent of sample size species in a community significant change non-migratory upon its removal Prevent a single species Amenable to traditional Exhibit low inter-annual Independent of spatial Independent of sample management practices or decadal population scales from becoming the size (e.g. fisheries variation competitive dominant management) Specialists rather than Exhibit low temporal and Independent of spatial generalists scales spatial variability Compatible with national Do not thrive in disturbed Exhibit low temporal and and international or anthropogenic habitats spatial variability indicators Require large tracts of Compatible with national Cost effectively observed and international and censured relatively natural or indicators unaltered habitat
Background material
a question, hypothesis, procedure, materials/equipment, data to be collected (independent, dependent variables and control), analysis, and expected results and conclusions.
A controlled experiment could be performed similar to the one conducted by Robert Paine on the rocky shoreline of the Pacific coast of Washington State. He demonstrated the keystone role of the top-predator sea star Piaster orchaceus in an intertidal zone community. Paine removed these mussel-eating sea stars from one rocky shoreline community but not from an adjacent community, which served as the control group. Mussels took over and crowded out many other species in the community without the Piaster sea stars. This type of experiment could be performed in other areas, with different species, to assess the role that certain species have in an ecosystem and whether a species could be classified as a keystone species.
- Area being Studied/Observed – Home Garden – A terrestrial ecosystem
- Five major plant species and five major animal species in your ecosystem:
- plant species -
An indicator species. It means that I’m very sensitive to things that surround me. If there are any changes in my environment, like pollution or global warming, I am one of the first to be affected by it. These changes could make me sick, or even kill me.
Explain why birds are excellent indicator species. Birds are excellent biological indicator because they are found almost everywhere and are affected quickly by environmental changes such as loss or fragmentation of their habitats
A keystone species has the power to largely effect entire ecosystems simply by performing natural behaviors for survival.
Threats to biodiversity are as numerous and varied as the sum of problems that face the overall environment.
Scientists are more and more convinced that many of these disappearances are related to increased UV exposure (due to the thinning of the ozone layer) or seemingly slight changes in weather and precipitation patterns that affect the frogs' reproductive behavior.
Amphibians are considered by many scientists to be an indicator species for damage from ozone depletion or global climate change.