North Central Research Station

Global Change Research

Meteorological Effects

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.

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].

	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:    US Forest Service FACE FTP site
	The monthly averages of many of the meteorological variables have been graphed:   1998 1999 2000 2001 2002 2003 2004 2005 2006