2007_2011_small_mammals_vegetation

Small mammals were sampled in 53 sites in 2007 (37 logged stands, and 16 old-growth forests) and 34 sites in 2011 (17 logged stands and 17 old-growth forests). We calculated several indices to test the influence of habitat heterogeneity on species assemblages. Structural heterogeneity in each stand was described with five indices: (1) the number of diameter classes (2-cm classes) for standing trees, combining live and dead individuals; (2) the amount of CWD; and (3) time-since-logging (stand age). We also estimated compositional heterogeneity through (4) the number of tree and shrub species, and (5) the dominant tree species in the stand. Age classes: C1, C2, C3, and C4 represent 4–20, 21–30, 31–50, and 51–70-years-old clear-cut stands, respectively, and OF is for old-growth forest of at least 120-years-old. The last index representing the dominant tree species in the stand is composed of three mutually exclusive classes: stands that were dominated by either spruce (EE) or fir (SS) species (species representing more than 60 % of basal area); and stands co-dominated by both spruce and fir (ES) species (species representing 40 to 60 % of basal area). The “lemming and rock vole” category included both rock vole (Microtus chrotorrhinus) and southern bog lemming (Synaptomys cooperi).