A 50-meter walk-up scaffolding tower rises 10 meters above the closed canopy. At the top are a rain gauge, net radiometer, up/down looking pyranometers, an anemometer and wind direction indicator, three-axis sonic anemometer and hygrometer, and a high-speed IRGA for CO2.
At each of eight levels (1.4 to 50 m) measurements are taken of temperature, relative humidity, wind speed, PAR (quantum flux), and CO2.
Eddy correlation: since January 1995
Profile microclimatology: since January 1992
Canopy structural observations: since September 1987
Stem growth dynamics on 1.56-ha plot around tower
Spatial distribution of all canopy trees within 200-300 meters