Studying Arthropod Species Richness

Jeffrey A. Baker
Type Category
Instructional Materials
Activity , Article , Lesson/Lesson Plan
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



This article in the September 2016 issue of The American Biology Teacher describes an investigation designed to help students engage in three-dimensional learning as they explore the phenomenon of  biodiversity in two natural areas of different sizes. Using arthropods as a model group of organisms, the article describes how one class observed two unmowed natural areas on school grounds over time to measure the number of species. Students formulated their own hypotheses, designed their investigations, and assessed arthropod species diversity over time. The students analyzed their results using a variety of mathematical representations described below. The author relates that food webs, energy flow through ecosystems, and biodiversity were topics covered in class throughout the investigation. Relevant materials used in this investigation included studies of food webs from the Biology Corner ( and an online biodiversity calculator (

Intended Audience

Educational Level
  • High School
Access Restrictions

Available by subscription - The right to view and/or download material, often for a set period of time, by way of a financial agreement between rights holders and authorized users.

Performance Expectations

HS-LS2-2 Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.

Clarification Statement: Examples of mathematical representations include finding the average, determining trends, and using graphical comparisons of multiple sets of data.

Assessment Boundary: Assessment is limited to provided data.

This resource was not designed to build towards this performance expectation, but can be used to build towards it using the suggestions provided below.

Comments about Including the Performance Expectation
The author states that the primary goal of this investigation is to compare the arthropod biodiversity of two natural areas of different sizes. For this reason, and the fact that students use a variety of different mathematical expressions to analyze and represent their results, HS-LS2-2 is the best alignment for this activity, although other performance expectations are considered in the article. Teachers may want students to study the natural areas first and consider different factors that may influence the arthropod biodiversity in each area. Factors may include objects that cover the ground, plant diversity, dampness, temperature, wind, or any other biotic or abiotic factor the students notice. The article describes using bar graphs to compare species numbers, and pie charts to compare the percentages of each species. Teachers may want to ask students to consider how they want to express their results mathematically so that students have the opportunity to figure this out for themselves.

Science and Engineering Practices

This resource was not designed to build towards this science and engineering practice, but can be used to build towards it using the suggestions provided below.

Comments about Including the Science and Engineering Practice
The investigation strongly supports students developing and using mathematical representations as they investigate the phenomenon of biodiversity. As suggested earlier, teachers may want students to figure out ways to represent their data mathematically. When students think through their results and consider different ways to represent their data mathematically, their understanding of the phenomenon they are observing will deepen. Teachers may want to help students understand the math behind the biodiversity indexes used in the investigation. The article “Measuring Biodiversity with Probability” published in Mathematics Teacher (published by the National Council of Teachers of Mathematics)explains calculating biodiversity using the Simpson biodiversity index for high school students: The biodiversity calculator mentioned in the article ( is one of many such calculators available online. The URL for another online calculator is included in the instructional supports section below. However, if the Shannon and Simpson biodiversity indexes are too complex for students, other mathematical representations, such as bar graphs and pie charts, will also communicate understanding of species diversity and still allow students to practice using mathematical and computational thinking.

Disciplinary Core Ideas

This resource was not designed to build towards this disciplinary core idea, but can be used to build towards it using the suggestions provided below.

Comments about Including the Disciplinary Core Idea
Observations of the two study areas take place over time. The article suggests a daily 30-minute observational period each weekday for two weeks. This observational period provides students with opportunity to investigate how the numbers and types of arthropods change or remain stable over time. Teachers may want to extend this discussion of time scale with students to other longer ecologically relevant timescales. One question that teachers may want to ask their students is if the conditions within each ecosystem are stable or unstable. Students may want to consider their answer to this question as they evaluate their daily data. If a major weather event, such as heavy rain or high winds, occurs during the observational period, it may provide students with an additional opportunity to see how the arthropod populations respond to an unanticipated disturbance.

Crosscutting Concepts

This resource was not designed to build towards this crosscutting concept, but can be used to build towards it using the suggestions provided below.

Comments about Including the Crosscutting Concept
The investigation allows students the opportunity to compare two areas which are similar except for size. In the results of the investigation reported in the article, the students did not see any difference in the arthropod diversity between their two study areas. The author suggests that this result was encouraging to the students; it helped them to see that returning small areas to their natural state after human disturbance may have a positive impact on arthropod diversity. Teachers may also want to introduce the idea of different time scales. The study takes a relatively short period of time; encourage students to consider possible outcomes over much longer timescales.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This activity provides students with the opportunity to practice three-dimensional learning as they explore the phenomenon of biodiversity using the science and engineering practice of mathematical and computational thinking while studying two natural areas of different sizes. The two areas serve as models of different scale, and students draw comparisons of these two models as they create pie charts, bar graphs, and use biodiversity indexes.

  • Instructional Supports: This relevant and authentic resource engages students in meaningful observation of ecosystems within their own local area. The suggestion in the article is to use natural areas close to school. However, any familiar area within the students’ neighborhood or community may be used. The author recommends that teachers support students who are struggling to meet the expectations of the activity with lessons on food webs, ecosystem energy flow, and biodiversity using The Biology Corner ( for supporting materials. The author also mentions that the students represented in the article showed a higher interest level and deeper understanding of these concepts while simultaneously studying the arthropods on their own school grounds. Teachers may want to expand the lesson to include peer-review, sharing of ideas throughout the activity, and a presentation of their results at the end of the investigation. The author does suggest that this investigation could be extended for students with high interest to consider other factors besides size. No alternatives were offered for students who are English language learners. Two helpful resources to distinguish between species richness and species diversity may be found here: ; Additional online biodiversity calculator includes:

  • Monitoring Student Progress: This investigation does elicit direct, observable evidence of three-dimensional learning as students engage in observing the phenomenon of arthropod biodiversity. The development of a hypothesis, the design of the investigation, and the collection and analysis of data all provide opportunities for the teacher to monitor and evaluate student progress. However, no rubrics or formative assessments are provided. The investigation, as is, is grade-appropriate and accessible for most students.

  • Quality of Technological Interactivity: There are no technologically interactive components in the actual lesson. However, there is an online biodiversity calculator ( that does not have very clear instructions; to use the calculator, just enter one number in the provided box - the number of species (or kinds of organisms) the students observed under their cover board. After this number is entered, the next screen will provide a place to enter the data. From this point, the directions are clear.