Data files are presented of plant and lichen survey data, pitfall trap catches of carabid beetles (Coleoptera: Carabidae), light trap catches of moths, and hand net catches of moths and butterflies (Lepidoptera) from a mature mixedwood Boreal forest in northwestern Alberta, Canada. Plant and lichen data are in an EXCEL file of species coverages in 32 10Ha compartments, at eight 5m x 5m plots per compartment, surveyed in 1997 and 1998. Carabid data are in an EXCEL file of counts of males and females of each species, from six pitfall traps in each of 16 compartments. The pitfall traps were run continuously for 3.5 months in 1997, 1998, 1999, and 2002, and samples were removed from the traps for tabulation every two to three weeks. Lepidoptera data are in an EXCEL file listing catches from light traps run for one night, approximately every 7-21 days, in 16 compartments, for 3.5 months in 1997, 1998, and 1999, augmented by incidental net catches of day-flying species.  A total of 7 tree species, 18 shrub species, 7 grasses, 41 forbs, 49 mosses, 19 lichen species, 26 carabid species, and 453 Lepidoptera species are reported.

In 1996, a silvicultural experiment was launched in northwestern Alberta, Canada, to test whether thinning of White Spruce (Picea glauca (Moensch) Voss) trees would improve the remaining trees’ resistance to Spruce Budworm (Choristoneura fumiferana (Clemens)) outbreaks (Volney et al. 1999). The experiment was intended to run for 70 years, to assess the long-term effects of the thinning treatments on tree health, but due to budget constraints, it was terminated after a few years, and in 2012, the entire study area was burned by a wildfire. Here we present associated biodiversity datasets from the pre-treatment year (1997) and early post-treatment years (1998-2002).

The location of the study is northeast of Zama City in extreme northwestern AB, at 59.44°N 118.31°W, in mature mixedwood forest in the Lower Boreal Highlands natural subregion. Approximately 85% of the stems were White Spruce, with an average age of approximately 133 years at the time of first sampling. The experiment was set up with 32 plots of approximately 10ha each, comprising four randomly assigned replicates of seven silvicultural treatments and a control, for a total of 32 plots (Figure 1; Table 1).

Figure 1. Zama experiment plot layout in northern Alberta (59.44°N 118.31°W).

Figure 1 file: Zama expt plot layout.jpg

Table 1. Compartment treatment assignments.

The forest thinning treatments were applied to the experiment via selective harvesting in the winter of 1997-1998. In 1999, the cleared areas were prepared for planting by mounding topsoil into rows 1-2m high to expose mineral soil and create optimal conifer seedling growing conditions.

A biodiversity component of the project included a vegetation (plants and lichens) survey at all 32 plots, as well as sampling of moths and butterflies (Lepidoptera) and ground-dwelling beetles (Coleoptera: Carabidae) at 16 plots (two randomly selected plots of each treatment). Here we present the baseline (pre-treatment) and early post-treatment vegetation and non-target arthropod datasets.

For the vegetation survey, overstory trees were defined as plants with stems > 5 cm diameter at breast height (dbh); smaller woody plants were defined as tall shrubs (> 150 cm in height) or low shrubs (< 150 cm in height). To survey plants and lichens, eight permanent 2 x 50m tree assessment plots were established in each of the 32 compartments. Midway along the length of each tree assessment plot, a 5 x 5 m understory vegetation plot was established to determine the height and species of tall shrubs. A "low stature" vegetation 1 x 1 m subplot was nested within a corner of each understory plot to estimate cover of low shrubs, forbs, mosses, and lichens. Plant names follow the nomenclature of Moss (1983). Vegetation cover was assessed in 1997 and 1998.

Moths were sampled via 12V battery-operated ultraviolet light traps, one in each plot, deployed regularly (approximately every 7 days in 1997; every 14-21 days in 1998 and 1999) from May to September each year. Additionally, day-flying moths and butterflies were opportunistically collected by net to augment the Lepidoptera species list.

Moths and butterflies were sorted and identified by CFS personnel. Identifications were made via taxonomic publications summarized in Pohl et al. (2018), and comparison to the research collection in the Northern Forestry Centre (CFS) insect collection. Lepidoptera names follow the nomenclature of Pohl & Nanz (editors) (2023). Vouchers are deposited at the CFS Edmonton insect collection.

In 1998 and 1999, only larger moths were identified. As well, larger intervals between trapping nights resulted in incomplete sampling in those years, so the resulting post-treatment datasets are not directly comparable to the pre-treatment 1997 data.

Carabid beetles were sampled via pitfall traps, sunk with the rims at ground level to catch active insects (Spence and Niemelä 1994). Six traps were deployed, approximately 35m apart, in each compartment from 1997-1999; 12 traps were deployed in each compartment in 2002. Traps were operated continuously from May to September, with samples removed every two to three weeks for sorting and identification. The resulting catches were sorted by CFS personnel. Identifications were made by CFS personnel and contractors, using Lindroth (1961-69). Carabid names follow the nomenclature of Bousquet et al. (2013). Vouchers are deposited at the Northern Forestry Centre (CFS) insect collection.

The post-treatment pitfall trap samples in 1998 and 1999 were compromised by some misplaced traps. Additionally, the 1999 and 2002 samples were placed on a complex mosaic of ridges and furrows resulting from post-harvest soil treatments, rendering comparison to the 1997 data problematic.