Ecology Lesson 6: The Good, the Bad and the Tattletales

Title of Lesson: The Good, the Bad and the Tattletales: invasive species, indicator species and symbioses

Situation: 9^th grade Biology 1, 35 high school students of mixed gender

Time: 85 minute block schedule

Concept or conceptual understanding (listed as a sentence or 2):

Students will understand what makes an indicator species, how and why species become invasive and the basis of symbiotic relationships.

Real world connections (Relevancy):

In a changing world indicator species give early warning about ecosystem health and problems. Invasive species change the function of ecosystems, often threatening human developments and changing ecosystem services. Symbionts affect ecosystem functioning, and affect productivity in forestry and agriculture.

AZ standards: (include grade level and text):

AZ Strand 1, Concept 1: Formulate predictions, questions, or hypotheses based on observations. Evaluate appropriate resources. POs 1-4

AZ Strand 1, Concept 2: Design and conduct controlled investigations. POs 1-5

AZ Strand 1, Concept 3: Evaluate experimental design, analyze data to explain results and propose further investigations. POs 1, 2, 4, 6, 7

AZ Strand 1, Concept 4: Communicate results of investigations. POs 1-4

AZ  Strand 3, Concept 1:Describe the interactions between human populations, natural hazards, and the environment. POs 1, 3, 5

AZ Strand 3, Concept 2: Develop viable solutions to a need or a problem. POs 2, 5

AZ Strand 3, Concept 3. Analyze factors that affect human populations. POs 1-2

AZ Strand 4, Concept 3: Analyze the relationships among various organisms and their environment. POs 1, 2

Incorporation of inquiry:

Students will investigate traits that might make a plant invasive. In class students will work in groups to create a seed with good wind dispersal capabilities. They will collect data on wind dispersal, calculate averages, create appropriate graphs and draw conclusions about why their seed was successful or how it could be improved.  For homework students will create a model of a “weed of mass destruction” and write about the weed’s traits. Students will create hypotheses about how soil organisms will affect plant growth given what they know about bacterial symbionts and mycorrhizal fungi (experiment started earlier). They will record plant growth and make summary graphs.

Behavior objectives:

Objective 1: Students will be able to define and identify indicator species, the three types of symbiosis and give examples.

Objective 2: Students will design a wind dispersed seed, collect data and draw conclusions about the successes or failures of the seed.

Objective 3: Students will design a superior invasive plant species building on ideas of what weed species have in common.

Objective 4: Students will write a hypothesis about the effects of soil symbionts on plant growth, collect appropriate data from an experiment, create summary graphs and make conclusions from their results.

Prior knowledge necessary:

This lesson will build from materials covered in the previous 5 lessons. Students will need to understand the basic principles of ecology.

Identify possible student preconceptions:

Invasive species are “bad”.

Invasions can always be stopped.

All symbioses are beneficial.

Parasitism is not a symbiosis

Materials:

White boards and markers, lab notebooks, rulers, plant experiment, sunflower seeds, tissue paper, pipe cleaners, tape, glue, scissors, feathers. Supplementary materials: “weeds of mass destruction” handout, “gone with the wind handout”, worksheet for plant data collection, power point covering key concepts.

Safety:

Students will be use safe classroom standards. There is nothing inherently dangerous in these activities.

Lesson Description:

• Bellwork: Think of an example of an invasive species. Why do you think it was successful?
• Students will share their examples beginning our discussion and lesson.
• I will briefly lecture on invasive species. Students will be involved through discussion and open-ended questions.                                                                                  
• Students will be instructed be instructed in the invasive species homework and given the handout. They will use their imagination and knowledge of invasive species to create a “weed of mass destruction” by making a drawing and written description. Next class students will present their weeds and vote on the best weed for a prize.
• Students will be instructed on the “gone with the wind” lab. Students will work in groups to create a seed with good wind dispersal capabilities. We will test these through “wind” trials either with a fan or by dropping seeds from the balcony. They will collect data including the distance traveled and time to landing, calculate means and create graphs. A prize will be given to the top seed.
• I will briefly lecture on indicator species and symbioses using PowerPoint and discussion.
• Students will create hypotheses based on our previous plant experiment (plants grown in sterile or live soil) and measure plant height, number of leaves and flowers. Students will calculate means, make graphs and report their conclusions on worksheet.

Assessment:

Students will be assessed through oral and visual presentations, laboratory activities and write ups.

References:

• McDougal/Littell Biology 2008 by Stephen Nowicki
• http://www.weedinvasion.org/weeds/weed_home.php