SEE-UAtlantic Forest

Exercise 9: Edge Effects on Selected Aspects of Forest Microclimate
Module 9: Light and Temperature


Your Questions

  1. How far does an edge affect light intensity and temperature within the forest?

Background

A continuous vegetation cover can modify the light environment in different ways, depending on the geometry of the plants, the distribution of plant biomass and the spectral properties and orientation of the leaves. Plant cover also has a significant and complex effect on the modification of the temperature regime.

Tropical forests, especially in areas where human pressure is present, are subject to clearing, leaving sharp edges between two community types. The presence of a discontinuity in the vegetation cover can produce several effects on the microclimate of the forest. Many recent studies have shown that this effect extends variable distances into the forest, depending of the factor studied.

In this study we will collect data on variation in two abiotic factors, light intensity and temperature with distance from the edge of a forest fragment towards the interior. Light intensity is probably the most important factor controlling plant growth in the understory of a forest ecosystem, since

Your Assignment

  1. Measure light intensity and temperature variation along a transect from the forest edge into its interior and determine the extent of modification of the light and temperature regime in the forest as a function of distance from the forest edge.

Methodology

  1. Task A—Establish sample areas
  2. Task B—Data collection
  3. Task C—Data analysis and write up

Objectives

  1. Introduce measurement techniques for abiotic variables
  2. Study edge effects on selected abiotic factors (light intensity and temperature)

Key Skills

  1. Learning measuring techniques for two abiotic factors
  2. Reinforce capabilities in establishing transects
  3. Statistical comparisons

Timetable

Total time—1 day

  1. Morning
  2. Afternoon

Materials Needed

  1. Field notebook and writing equipment
  2. Material for establishing transects (stakes, hammer, flagging)
  3. Tape measures (50 m)
  4. Compass and GPS
  5. Collection equipment for environmental data — radiation intensity and temperature (wet and dry bulb)