• What Are Invertebrates

Overview Understanding the relationships between biotic diversity and abiotic factors in an ecosystem can be a difficult task. Using soil invertebrates, students can identify both the number of species present in a soil sample and the number of individuals within a species.

With some simple math, a measure of biodiversity and effective number of species can be calculated. This information can be compared to soil pH, moisture, and temperature to develop an ecosystem model. Students construct a simple and inexpensive Berlese funnel to collect and identify soil invertebrates. Overview Understanding the relationships between biotic diversity and abiotic factors in an ecosystem can be a difficult task.

Using soil invertebrates, students can identify both the number of species present in a soil sample and the number of individuals within a species. With some simple math, a measure of biodiversity and effective number of species can be calculated. This information can be compared to soil pH, moisture, and temperature to develop an ecosystem model. Students construct a simple and inexpensive Berlese funnel to collect and identify soil invertebrates. Procedures Berlese Funnel Construction. Using scissors, cut the bottom off the jug. Tape around the edge of the cut end.

Place the milk jug spout in the mouth of the jar. The jug serves as the funnel. The jar is the collection chamber. Bend the mesh screen so that it fits securely into the milk jug and forms a stable platform for the soil sample. Do not let the screen fall below the handle. Assign each group of students a different area outside. Vary the amount of shade, moisture, and type of leaf litter.

What Are Invertebrates

Have students take pictures of their assigned area. Analysis & Discussion.

Calculate the percentage of soil moisture.% soil moisture = (water mass/final dry mass) × 100. Calculate invertebrate density. Density = total number of invertebrates/area (50 cm × 50 cm). Homelite 16 electric chainsaw manual. Calculate the Simpson Index of Diversity. D s = 1 – Σni(ni –1)/N(N – 1).

Compare group results and discuss differences in invertebrate samples, locations, biodiversity, and abiotic factors. Answers will vary.

What patterns can be established between biotic and abiotic factors? Temperature and moisture should affect the number and type of soil invertebrates.

How would the season of the year impact biotic and abiotic factors? As seasons change, temperature and precipitation amounts change.