ESSCOSMOS/2009:FieldSampling

Under Construction

Overview

In this activity, we will study the organisms and environment along a gradient from the edge of a marsh to the top of the hill.

Objectives

• Evaluate small scale gradients in biological and environmental conditions along a transect.
• Create graphical summaries of the findings
• Enter data into class database [link to google doc]

Background

The UCI Arboretum map of UCI Arboretum

Materials

• GPS device
• TDR probe for measuring soil moisture
• Thermometer for measuring soil temperature
• Map of garden and surrounding area with 10 x 10 m aligned to one corner of garden (add link to pdf here)
• Portable scale for measuring plant and insect biomass
• Meter stick
• Soil corer

Methods

Class will be divided into five groups of four, and each group will be asked to survey a 100m transect at 20m intervals.

At each 20m interval, record the latitude, longitude, soil moisture, and soil temperature. Sample plants and insects (see below); we will measure biomass in the lab.

Soils

• Measure soil moisture with TDR probe
• Measure soil temperature using thermometer

Insects

Insect Biomass

1. take a soil core and place it in a bin
2. mix the core well
3. pairs of students should place a portion of the soil and count the number insects in each group
4. after counting an insect, place it in a pre-weighed tube
5. weigh tubes with insects from each group and record
6. subtract original tube weight from weight of tube plus insects, this is the insect biomass

Plants

Biomass

1. Clip plants along a 150 cm by 10 cm strip at ground level.
2. collect plants in a paper bag that is labeled with your group number and site information
3. weigh plants and record mass

Results

1. Create a spreadsheet based on this template:
2. Fill in data for each sample site
3. Calculate biomass of plants and insects in units of g or mg per m²

Graphical summary

Graph plant and insect biomass, soil temperature, and soil moisture on a chart. Here is an example; example transect results

Analysis

1. Look at your graph and describe any patterns that you see
2. Are plant and insect biomass correlated along the gradient?
3. How are soil temperature and soil moisture related to plant and insect biomass?
4. What other patterns did you see?
5. Why do you think that these patterns exist?

Homework

Write a one paragraph summary of your analysis.