Lesson 2.2 Ecosystem Balance

Preface

Healthy ecosystems consist of a delicate balance between biotic and abiotic components. Diverse organisms share ecosystem services in a healthy ecosystem. Living organisms work in harmony to provide ecosystem services, such as food, nutrients, and shelter, to each other. Scientists use data collection, mathematical calculations, and modeling to understand the relationships between biodiversity and services exchanged in an ecosystem. Once relationships in an ecosystem are understood, scientists can begin to identify and solve problems.

Scientists use models to simplify relationships within ecosystems. Conceptual models provide a visual understanding of using diagrams and pictures. Mathematical models quantify relationships and predict outcomes that could occur in an environment, such as population growth.

Students begin the lesson by researching relationships between organisms in a freshwater ecosystem. Then students use a conceptual and mathematical model to measure the population growth of deer. They end the lesson using models with limiting factors affecting a deer population.

Concepts	Performance Objectives
Students will know and understand	Students will learn concepts by doing
1. Healthy ecosystems have a diverse number of species dependent upon each other.	· Explain the interdependent relationship of organisms in a pond. (Activity 2.2.1)
2. Complex relationships in an ecosystem are analyzed using models.	· Model population growth of deer in an ecosystem. (Activity 2.2.2)
3. The functionality of an ecosystem is dependent on limiting factors.	· Use species population, predation, and area to predict ecosystem productivity. (Activity 2.2.3)

National AFNR Common Career Technical Core Standards Alignment

Career Ready Practices

11. Use technology to enhance productivity.

· CRP.11.01: Research, select, and use new technologies, tools, and applications to maximize productivity in the workplace and community.

Agriculture, Food, and Natural Resources Career Cluster

4. Demonstrate stewardship of natural resources in AFNR activities.

· AG.4.2: Explain the environmental considerations of decision making in AFNR management.

6. Analyze the interaction among AFNR systems in the production, processing, and management of food, fiber, and fuel and the sustainable use of natural resources.

· AG.6.1: Explain foundational cycles and systems of AFNR.

· AG.6.2: Explain the interconnectedness of systems within AFNR.

Environmental Service Systems Pathway (AG-ENV)

1. Use analytical procedures and instruments to manage environmental service systems.

· AG-ENV 1.2: Analyze and interpret results of sample measurements.

Natural Resource Systems (AG-NR)

1. Plan and conduct natural resource management activities that apply logical, reasoned, and scientifically based solutions to natural resource issues and goals.

· AG-NR 1.3: Obtain and analyze data by monitoring natural resource status.

· AG-NR 1.5: Execute natural resource strategies and activities applying scientific knowledge from the study of ecology and wildlife.

2. Plan and Analyze interrelationships between natural resources and humans needed to manage natural resource systems.

· AG-NR 2.1: Examine natural resource topics using science concepts, processes, and research techniques.

· AG-NR 2.2: Examine biological and physical characteristics to identify and classify natural resources.

· AG-NR 2.3: Examine natural cycles and related phenomena to describe ecologic concepts and principles.

3. Develop plans to ensure sustainable production and processing of natural resources.

· AG-NR 3.1: Plan for the production, harvesting, processing, and/or use of natural resources in a responsible and sustainable manner.

Next Generation Science Standards Alignment

Disciplinary Core Ideas
Life Science
LS1: From Molecules to Organisms: Structures and Processes
LS1.C: Organization for Matter and Energy Flow in Organisms	· The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen. (HS-LS1-5) · As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.
LS2: Ecosystems: Interactions, Energy, and Dynamics
LS2.A: Interdependent Relationships in Ecosystems	· Ecosystems have carrying capacities, which are limits to the numbers of organisms and populations they can support. These limits result from such factors as the availability of living and nonliving resources and from such challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance (number of individuals) of species in any given ecosystem.
LS2.B: Cycles of Matter and Energy Transfer in Ecosystems	· Plants or algae form the lowest level of the food web. At each link upward in a food web, only a small fraction of the matter consumed at the lower level is transferred upward to produce growth and release energy in cellular respiration at the higher level. Given this inefficiency, there are generally fewer organisms at higher levels of a food web. Some matter reacts to release energy for life functions, some matter is stored in newly made structures, and much is discarded. The chemical elements that make up the molecules of organisms pass through food webs and into and out of the atmosphere and soil, and they are combined and recombined in different ways. At each link in an ecosystem, matter and energy are conserved.
LS2.C: Ecosystem Dynamics, Functioning, and Resilience	· A complex set of interactions within an ecosystem can keep its numbers and types of organisms relatively constant over long periods of time under stable conditions. If a modest biological or physical disturbance to an ecosystem occurs, it may return to its more or less original status (i.e., the ecosystem is resilient), as opposed to becoming a very different ecosystem. Extreme fluctuations in conditions or the size of any population, however, can challenge the functioning of ecosystems in terms of resources and habitat availability.
Science and Engineering Practices
Developing and Using Models	Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed world(s).
	· Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.
Planning and Carrying Out Investigations	Planning and carrying out investigations in 9-12 builds on K-8 experiences and progresses to include investigations that provide evidence for and test conceptual, mathematical, physical, and empirical models.
	· Manipulate variables and collect data about a complex model of a proposed process or system to identify failure points or improve performance relative to criteria for success or other variables.
Analyzing and Interpreting Data	Analyzing data in 9–12 builds on K–8 experiences and progresses to introducing more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data.
	· Analyze data using tools, technologies, and/or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims or determine an optimal design solution.
Using Mathematics and Computational Thinking	Mathematical and computational thinking in 9-12 builds on K-8 and experiences and  progresses to using algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms, and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.
	· Create and/or revise a computational model or simulation of a phenomenon, designed device, process, or system.
	· Use mathematical, computational, and/or algorithmic representations of phenomena or design solutions to describe and/or support claims and/or explanations.
	· Use simple limit cases to test mathematical expressions, computer programs, algorithms, or simulations of a process or system to see if a model “makes sense” by comparing the outcomes with what is known about the real world.
Crosscutting Concepts
Patterns		Observed patterns in nature guide organization and classification and prompt questions about relationships and causes underlying them.
		· Mathematical representations are needed to identify some patterns.
Cause and Effect: Mechanism and Prediction		Events have causes, sometimes simple, sometimes multifaceted. Deciphering causal relationships, and the mechanisms by which they are mediated, is a major activity of science and engineering.
		· Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.  · Cause and effect relationships can be suggested and predicted for complex natural and human designed systems by examining what is known about smaller scale mechanisms within the system. · Systems can be designed to cause a desired effect. · Changes in systems may have various causes that may not have equal effects.
Systems and System Models		A system is an organized group of related objects or components; models can be used for understanding and predicting the behavior of systems.
		· When investigating or describing a system, the boundaries and initial conditions of the system need to be defined, and their inputs and outputs analyzed and described using models. · Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales. · Models can be used to predict the behavior of a system, but these predictions have limited precision and reliability due to the assumptions and approximations inherent in models.
Stability and Change		For both designed and natural systems, conditions that affect stability and factors that control rates of change are critical elements to consider and understand.
		· Much of science deals with constructing explanations of how things change and how they remain stable. · Change and rates of change can be quantified and modeled over very short or very long periods of time.
Understandings about the Nature of Science
Scientific Investigations Use a Variety of Methods		· Science investigations use diverse methods and do not always use the same set of procedures to obtain data. · Scientific investigations use a variety of methods, tools, and techniques to revise and produce new knowledge.
Scientific Knowledge Assumes an Order and Consistency in Natural Systems		· Scientific knowledge is based on the assumption that natural laws operate today as they did in the past, and they will continue to do so in the future.
Science Addresses Questions About the Natural and Material World.		· Science knowledge indicates what can happen in natural systems—not what should happen. The latter involves ethics, values, and human decisions about the use of knowledge.

Common Core State Standards for High School Mathematics

Modeling standards are indicated by the star symbol (*) throughout other conceptual categories.
CCSS: Conceptual Category – Algebra
Reasoning with Equations and Inequalities	Understand solving equations as a process of reasoning and explain the reasoning.
	Solve equations and inequalities in one variable.
CCSS: Conceptual Category – Statistics and Probability
Interpreting Categorical and Quantitative Data	*Summarize, represent, and interpret data on a single count or measurement variable.
Making Inferences and Justifying Conclusions	*Understand and evaluate random processes underlying statistical experiments.
	*Make inferences and justify conclusions from sample surveys, experiments, and observational studies.

Common Core State Standards for English Language Arts

CCSS: English Language Arts Standards » Science & Technical Subjects » Grade 11-12
Key Ideas and Details	· RST.11-12.3 – Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text.
Craft and Structure	· RST.11-12.4 – Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 11-12 texts and topics.
Integration of Knowledge and Ideas	· RST.11-12.7 – Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem.
Range of Reading and Level of Text Complexity	· RST.11-12.10 – By the end of grade 12, read and comprehend science/technical texts in the grades 11-CCR text complexity band independently and proficiently.
CCSS: English Language Arts Standards » Writing » Grade 11-12
Production and Distribution of Writing	· WHST.11-12.4 – Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
Research to Build and Present Knowledge	· WHST.11-12.7 – Conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating understanding of the subject under investigation.
Range of Writing	· WHST.11-12.10 – Write routinely over extended time frames (time for reflection and revision) and shorter time frames (a single sitting or a day or two) for a range of discipline-specific tasks, purposes, and audiences.

Essential Questions

1. What is the relationship between biotic and abiotic components in an ecosystem?

2. Why is biodiversity important in a healthy ecosystem?

3. Which ecosystem services do producers and consumers provide in an ecosystem?

4. How is field data collected?

5. How are relationships in an ecosystem modeled?

6. How are mathematical models of an ecosystem used to predict populations?

7. How do organisms support each other and improve the productivity of an ecosystem?

8. What are the dynamics of a predator-prey relationship?

9. How do limiting factors impact the productivity of an ecosystem?

Key Terms

Birth rate	Carrying capacity	Conceptual model
Consumer	Death rate	Decomposer
Ecosystem functions	Ecosystem services	Food chain
Food web	Functional diversity	Interdependent
Limiting factor	Mathematical model	Model
Natural resources	Population	Primary consumer
Producer	Secondary consumer	Trophic level

Day-to-Day Plans

Time: 7 days

Refer to the Teacher Resources section for specific information on teaching this lesson, in particular Lesson 2.2 Teacher Notes, Lesson 2.2 Glossary, Lesson 2.2 Materials, and other support documents.

Day 1:

· Present Concepts, Performance Objectives, Essential Questions, and Key Terms to provide a lesson overview.

· Provide students with a copy of Activity 2.2.1 Interdependent Organisms.

· Students work in pairs to complete Part One of Activity 2.2.1 Interdependent Organisms.

Day 2:

· Students work in pairs to complete Activity 2.2.1 Interdependent Organisms.

Day 3 – 4:

· Facilitate a discussion of the reading using the questions found in Lesson 2.1 Teacher Notes.

· Provide students with a copy of Activity 2.2.2 Population Model.

· Provide students with electronic access to the Deer Herd model.

· Provide students with Stella® Online accounts or instruct students to make their own.

· Students work in pairs to complete Activity 2.2.2 Population Model.

Day 5 – 6:

· Provide students with a copy of Activity 2.2.3 Productivity Prediction.

· Provide students with electronic access to the Carrying Capacity and Lynx and Hare models.

· Students work in pairs to complete Activity 2.2.3 Productivity Prediction.

Day 7:

· Distribute Lesson 2.2 Check for Understanding.

· Students complete Lesson 2.2 Check for Understanding and submit for evaluation.

· Use Lesson 2.2 Check for Understanding Key to evaluate student assessments.

· Homework Reading: Students read Concept 3-3 through 3-5, pages 53–64, of Sustaining the Earth before starting Lesson 2.3 Ecosystem Problems.

Instructional Resources

Student Support Documents

Lesson 2.2 Glossary

Activity 2.2.1 Interdependent Organisms

Activity 2.2.2 Population Model

Activity 2.2.3 Productivity Prediction

Deer Herd Model

Carrying Capacity Model

Lynx and Hare Model

Teacher Resources

Lesson 2.2 Teacher Notes

Lesson 2.2 Materials

Lesson 2.2 Check for Understanding

Answer Keys and Assessment Rubrics

Lesson 2.2 Check for Understanding Answer Key

Reference Sources

Ecosystem Function. (n.d.). The seq ecosystem service framework. Retrieved from www.ecosystemservicesseq.com.au/index.html

Herren, R.V., & Donahue, R.L. (2000). Delmar’s agriscience dictionary with searchable CD-ROM. Albany, NY: Delmar.

Miller, G.T., and Spoolman, S.E. (2015). Sustaining the earth. Stamford, CT: Cengage Learning.

Richmond, B. (n.d.). Food chain. Lebanon, NH: ISEE systems.

SEPUP. (2005). Science and sustainability. Ronkonkoma, NY: Lab-Aids.

Shaffer, D., and Wallace, K. (2000). Deer population, a core learning goal activity for science and mathematics. Silver Spring, MD: Maryland Virtual High School.

This lesson provides conceptual and procedural knowledge required for participation in the following FFA activities and awards.

· Agricultural Proficiency

o Environmental Science and Natural Resources Management – Entrepreneurship/Placement

· The National FFA Agriscience Fairrecognizes students who gain real-world, hands-on experiences in agricultural enterprises.

· The Environmental and Natural Resources CDEprovides competing students with an opportunity to demonstrate knowledge in areas that affect our air, soil and water.

· Lesson Plan: Current Events

Skills and knowledge from this lesson support the development and implementation of service-learning projects that address local community needs related to environmental responsibility.

· Service-Learning and Living to Serve Grants

o Service-learning projects focused on environmental responsibility address local issues regarding air and water quality, energy and water efficiency, at-risk ecosystems and conservation to protect and sustain the natural systems upon which all life depends.

o Project ideas include identifying and removing invasive species throughout the community, restoring natural habitats, constructing green infrastructures, and monitoring and improving water and soil quality.

o Living to Serve Grants provide funding to FFA chapters to support service-learning and community service projects.

For more information, visit the National FFA Organization website.

Foundational SAE

All students in an agricultural education program are expected to have a Foundational SAE. Students completing the APP and extensions listed below will meet the Foundational SAE qualifications. Students should record APP and extensions in their Foundational SAE Log and place all documented evidence in the Foundational SAE Section of their Agriscience Notebook.

· Career Exploration and Planning: AgExplorer

· SAE Planning: students will plan out their SAEs.

· Environmental Service Systems SAE Idea Cards - PDF versions of SAE cards divided by career focus areas (similar to Agriculture Food and Natural Resource (AFNR) pathways). The purpose of the SAE Idea Cards is to assist students with developing ideas for SAEs. There are 360 SAE ideas in nine different focus areas that can be downloaded or used online.

For more information on the guiding principles for implementing SAE programs, visit the SAE for All: Evolving Essentials site.

Critical Thinking and Application Extensions

Application

1. Students record the limiting factors and species present in a lake through physical observations and internet research. Then they make a conceptual model showing the relationships between biotic and abiotic components.

2. Students review the reproductive characteristics of a local species and the limiting factors affecting the population. Then they develop a mathematical equation to predict the yearly populations of the species.