Data were collected between 1993 and 1999 as part of the Lichen Air Quality surveys on public lands in Oregon and southern Washington. Observations were obtained from 1-acre (0.4 ha) plots at Current Vegetation Survey (CVS) sites. Indicator variables denote the presences and absences of 7 lichen species. Data for each sampled plot include the topographic variables elevation, aspect, and slope; bioclimatic predictors including maximum, minimum, daily, and average temperatures, relative humidity precipitation, evapotranspiration, and vapor pressure; and vegetation variables including the average age of the dominant conifer and percent conifer cover. The data in lichenTest were collected from half-acre plots at CVS sites in the same geographical region and contains many of the same variables, including presences and absences for the 7 lichen species. As such, it is a good test dataset for predictive methods applied to the Lichen Air Quality data.
lichenA data frame with 840 observations and 40 variables. One variable is a location identifier, 7 (coded as 0 and 1) identify the presence or absence of a type of lichen species, and 32 are characteristics of the survey site where the data were collected.
There were 12 monthly values in the original data for each of the bioclimatic predictors. Principal components analyses suggested that for each of these predictors 2 principal components explained the vast majority (95.0%-99.5%) of the total variability. Based on these analyses, indices were created for each set of bioclimatic predictors. The variables with the suffix Ave in the variable name are the average of 12 monthly variables. The variables with the suffix Diff are contrasts between the sum of the April-September monthly values and the sum of the October-December and January-March monthly values, divided by 12. Roughly speaking, these are summer-to-winter contrasts.
The variables are summarized as follows:
Identifier of the section of forest from which the data were collected.
Lobaria oregana (Absent = 0, Present = 1)
Lobaria pulmonaria (Absent = 0, Present = 1)
Nephroma bellum (Absent = 0, Present = 1)
Nephroma helveticum (Absent = 0, Present = 1)
Pseudocyphellaria anomala (Absent = 0, Present = 1)
Pseudocyphellaria anthraspis (Absent = 0, Present = 1)
Pseudocyphellaria crocata (Absent = 0, Present = 1)
Average monthly potential evapotranspiration in mm
Summer-to-winter difference in monthly potential evapotranspiration in mm
Average monthly moisture index in cm
Summer-to-winter difference in monthly monthly moisture index in cm
Average monthly precipitation in cm
Summer-to-winter difference in monthly precipitation in cm
Average monthly relative humidity in percent
Summer-to-winter difference in monthly relative humidity in percent
Average monthly potential global radiation in kJ
Summer-to-winter difference in monthly potential global radiation in kJ
Average monthly average temperature in degrees Celsius
Summer-to-winter difference in monthly average temperature in degrees Celsius
Average monthly maximum temperature in degrees Celsius
Summer-to-winter difference in monthly maximum temperature in degrees Celsius
Average monthly minimum temperature in degrees Celsius
Summer-to-winter difference in monthly minimum temperature in degrees Celsius
Mean average daytime temperature in degrees Celsius
Summer-to-winter difference in average daytime temperature in degrees Celsius
Average monthly average ambient vapor pressure in Pa
Summer-to-winter difference in monthly average ambient vapor pressure in Pa
Average monthly average saturated vapor pressure in Pa
Summer-to-winter difference in monthly average saturated vapor pressure in Pa
Aspect in degrees
Transformed Aspect: TransAspect=(1-cos(Aspect))/2
Elevation in meters
Percent slope
Reserve Status (Reserve, Matrix)
Stand Age Class (< 80 years, 80+ years)
Average age of the dominant conifer in years
Percent vegetation cover
Percent conifer cover
Percent broadleaf cover
Live tree (> 1inch DBH) biomass, above ground, dry weight.