ESSCOSMOS/2009:FieldSampling

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
 * Meter stick
 * LICOR LI-800 gashound, with chamber for measuring soil respiration, 12V battery, and pump
 * Clippers for harvesting aboveground plant biomass
 * Trowel for harvesting roots
 * Water bath for rinsing roots
 * Portable scale for measuring plant biomass

Methods
Class will survey a 100m transect at 20m intervals. Five groups of four will take turns conducting the following measurements:
 * 1) Soil CO2 efflux
 * 2) Aboveground plant biomass
 * 3) Root biomass
 * 4) Soil Moisture and insect biomass
 * 5) Plant diversity

Soils

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

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

Biomass

 * 1) Clip plants along a 150 cm by 10 cm strip at ground level.
 * 2) 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 the 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.