Use of Spectral Analysis to Detect Changes in Spatial Variability of Forest Floor Properties
- Catherine Périé *a,
- Alison D. Munsonb and
- Jean Caronc
- a Direction de la recherche forestière, Ministère des Ressources naturelles, de la faune 3700 rue Einstein, Sainte-Foy, QC G1P 3W8, Canada
b Centre de recherche en biologie forestière, Faculté de foresterie et de géomatique, Pavillon Abitibi-Price, Université Laval, Sainte-Foy, QC G1K 7P4, Canada
c Département des sols et de génie agroalimentaire, Pavillon Paul-Comtois, FSAA, Université Laval, Sainte-Foy, QC G1K 7P4, Canada
Understanding how silvicultural interventions affect soil spatial variability will improve our ability to predict forest ecosystem function in response to different degrees of management intensity. We demonstrate the use of spectral analysis, a geostatistical technique, to understand how management interventions affect soil spatial variability. The technique was applied to determine whether an intensive vegetation control treatment modifies the spatial patterns of soil microclimate and soil quality indicators: microbial biomass C (SMB-C) and N (SMB-N) as well as net N mineralization rate. A secondary objective was to investigate the contribution of soil microclimate factors to the explanation of spatial patterns of microbial biomass (C and N). Measurements were performed on transects laid out in two plots: a plot that was undisturbed since clearcut and replanted 11-yr earlier with white pine (Pinus strobus L.) and another plot which was subject to annual herbicide application during 4 yr following reforestation with white pine. Forest floor temperature (TEMP) and water content (WC), net N mineralization rate and SMB-C and SMB-N concentrations were measured every 25 cm along each transect. Spatial patterns were assessed using spectral analysis. In the two plots, microclimatic variables and SMB-N presented complex spatial patterns with several scales of spatial dependency, whereas SMB-C and net N mineralization did not demonstrate a spatial pattern at this scale of observation. In the herbicide-treated plot, the spatial pattern of SMB-N was influenced by the plantation grid. Herbicide applications markedly decreased spatial variability of forest floor properties. In some frequencies, SMB-N was markedly positively correlated with forest floor layer WC but not with forest floor TEMP.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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