Popis: |
Percentages of original dry mass lost annually and single exponential decay rates (k) for timothy (Phleum pratense L.) leaf litter decomposing on three reclaimed subalpine mine spoil plots (7, 3, and 1 years old) in Alberta, Canada, were compared with values predicted using generalized equations devised by Meentemeyer on the basis of an annual regional average of actual evapotranspiration (Thornthwaite) and a site-specific value (Christiansen). Measured decay rates on the more heavily vegetated plots (3 and 7 years old) were similar to k values predicted using Christiansen actual evapotranspiration values, while the decay rate on the plot with the least amount of vegetation cover (1 year old) was much greater than k values predicted using Christiansen or Thornthwaite actual evapotranspiration values. The actual evapotranspiration model severely underestimated annual percentage mass losses, regardless of whether Thornthwaite or Christiansen actual evapotranspiration values were used. |