USDA Forest Service

North Central Research Station

[Chart]: April, 1998 Wind Rose spacer

Global Change Research

Meteorological Effects

What's natural today may not be the norm in an atmospherically altered future.  If greenhouse gases affect only certain tree species or clones, selection may favor the tolerant ones, thereby changing the makeup of our forests.

The microenvironment inside a stand affects the survival rates not only of seedlings, but also of many other forest organisms.  Replacing one tree species or growth pattern with another could change basic processes such as evaporation, transpiration, and variations in diurnal temperature and humidity.  Canopies that are more or less dense will change the way light penetrates, affecting how warm, cool, moist, or dry the forest floor is.  This will in turn affect surface-dwelling birds, mammals, amphibians, insects, and even the below-ground microbial community.

To get a handle on the combined within-stand effects of high CO2 and ozone on forest microclimates, researchers are measuring the micrometeorology inside and outside individual rings at the Forest-Atmosphere Carbon Transfer and Storage (FACTS-II) Aspen FACE Experiment being conducted in northern Wisconsin.  By studying small-scale boundary layer processes, scientists hope to make inferences about forest conditions under increased greenhouse gas concentrations.

A micrometeorological monitoring network has been set up to measure a variety of near-surface atmospheric and below-ground variables that are critical for describing the dynamics of forest-atmosphere interactions.

[Chart]: Site map showing meteorological instrumentation locations.

spacer [Chart]: ring layout

Meteorological conditions are measured in five locations at the Aspen FACE site:  in four of the twelve rings [diagrammed above] and at an ambient tower [below].
[Chart]: tower layout

  Meteorological measurements in rings 1.2 (CO2 fumigation), 2.1 (Control), 3.3 (O3 fumigation), and 3.4 (CO2 and O3 fumigation) at the Aspen FACE site were gradually phased in during 1998, while the ambient tower measurements were phased in during the winter and spring of 1999.  This data is available in XLS (Microsoft Excel) format:
link to US Forest Service FACE ftp site  US Forest Service FACE FTP site
The monthly averages of many of the meteorological variables have been graphed:

For more information:

  • Warren Heilman  Project Leader rwu4401/Research Meteorologist
     Microclimate characterization inside and outside FACE rings.
  • Ron Teclaw  Biologist rwu4152
     Manager of meteorological instrumentation.

USDA Forest Service - North Central Research Station
Last Modified: February 17, 2005