Soil temperature is presently collected hourly at 5 cm, 12 cm, and 15 cm depths in the mineral soil in each plot.

Data for 5 and 15 cm depths is collected with a Campbell Scientificâ data logger and temperature probe system, which began operation on June 9, 1994 (Day of Year 159). These data were collected continuously through December 1997. Gaps exist in data for much of 1997, 1998, and 1999 due to datalogger malfunction. Therefore, soil temperature data are not given for 1997, 1998, and early 1999. The continuous data record resumed in April 1999.

In August 1999, Campbell Scientific probes were removed from No Roots and No Inputs plots when trenches were relined (exception: probes were left intact in plot 8, No Roots). Later in the month an Onset Optic Stowawayâ datalogger was installed in each No Roots and No Inputs plot to record soil temperature at 10 cm depth. These Onset datalogger data are given from August 8, 1999 through October 30, 2001.

On October 31, 2001, the rest of the plots each received an Onset Optic Stowawayâ datalogger in addition to the Campbell Scientific probes. Onset dataloggers in all 21 plots were positioned to record soil temperature at a depth of 12 cm thenceforward. These data are included in the data files for November 2001 and after.

Three Campbell Scientific probes (4a, 16a, and 16b) recorded air temperature (1.4 m above ground surface) near plots 4 and 16 from November 22, 1999, to July 13, 2003. These data are denoted as 'air temp'.

Beginning on August 1, 2003 air temperature data have been recorded by a single Onset datalogger in the same location that Campbell probe 4a had recorded air temperature.

Data presented are the average of all hourly temperature readings for each day of the year. Only data for functioning probes are included.

NOTE: Early spring frost heaving may partially eject probes from the soil and cause some probes to read air temperature instead of soil temperature.

Data:

Treatment
Block = block number
Plot = plot number
Depth = cm below mineral soil surface. 'Air temp' indicates air temperature 1.4 m above forest floor, near plots 4 and 16 (before July 13) and near plot 4 (from July 13 on).
Probe = denoted by plot number and depth: a = 5 cm, b = 15 cm, c = Onset datalogger, 10 or 12 cm as noted
YEAR = year collected
DOY = Day of year
Soil temperature = °C
nd = Accurate data not available due to probe malfunction or probe was removed from plot
tbd = data to be downloaded in the future