Landscape Patterns of Rare Vascular Plants in the Lower Athabasca Region of Alberta, Canada

Abstract

Predicting habitat for rare species at landscape scales is a common goal of environmental monitoring, management, and conservation; however, the ability to meet that objective is often limited by the paucity of location records and availability of spatial predictors that effectively describe their habitat. To address this challenge, we used an adaptive, model-based iterative sampling design to direct four years of rare plant surveys within 0.25 ha plots across 602 sites in northeast Alberta, Canada. We used these location records to model and map rare plant habitats for the region using a suite of geospatial predictors including airborne light detection and ranging (LiDAR) vegetation structure metrics, land cover types, soil pH, and a terrain wetness model. Our results indicated that LiDAR-derived vegetation structural metrics and land cover were the most important individual factors, but all variables contributed to predicting the occurrence of rare plants. For LiDAR variables, rarity was negatively related to maximum canopy height, but positively related to canopy relief ratio. Rarity was therefore more likely in places with shorter canopy heights and greater structural complexity. This included fens, which overall had the highest rates of rare plant occurrence. Model-based allocation of sampling led to detections of uncommon species at nearly all sites, while the rarest species in the region were detected at an average encounter rate of 8%. Landscape predictions of rare plant habitat can improve our understanding of environmental limits in rarity, guide local management decisions and monitoring plans, and provide regional tools for assessing impacts from resource development.

“Learning Together”: Braiding Indigenous and Western Knowledge Systems to Understand Freshwater Mussel Health in the Lower Athabasca Region of Alberta, Canada

“…The lower Athabasca region (LAR) is in northeastern Alberta, Canada (Figure 2). The region is mostly covered with boreal forest, inhabited by a diversity of plants and animals, including fish, song birds, wolves, waterfowl, moose, deer, black bears, lynx, otters, muskrat, beavers, and fishers (Cichowski and Dzus 2010;Fisher and Burton 2016;Gilbert and Nancekivell 1982;Robichaud and Boyce 2010;Sharp et al 1975), and more than 500 vascular plant species (Nielsen et al 2017). In the LAR, there are two large river systems: the Athabasca River and the Clearwater River.…”

Predicting Occurrence, Abundance, and Fruiting of a Cultural Keystone Species to Inform Landscape Values and Priority Sites for Habitat Enhancements

“…Local occurrence of blueberry was quantified in the field at 845 quarter-hectare (50 × 50 m) plots sampled in the summer months between the years 2012-15 via two sampling campaigns. The first included 510 plots from a regional rare plant study that quantified presence/absence of all vascular plant species within plots (2012-2014) [40]. The second included 335 plots sampled in 2014 and 2015 for the specific purpose of quantifying regional fruiting shrub habitat; these were coded as presence/absence observations for the occurrence portion of this analysis (Appendix A, Figure A1).…”

“…The GOA has been purchasing licensed ALS data on an annual basis since circa 2008. The provincial-scale ALS program has resulted in a dataset with a range of dates, sensor types, and other acquisition parameters, but the adherence to the standard [53] results in a fairly consistent dataset that has been previously used successfully for vegetation analyses [6,40]. The acquisition dates in the study area range from 2007 to 2013, with typical point densities of 1-4 returns/m 2 .…”

The extent and magnitude of edge effects on woody vegetation in road‐bisected treed peatlands in boreal Alberta, Canada

“…They serve essential ecosystem and landscape functions, including playing major roles as habitat for other biota, acting in flood storage and desynchronization, groundwater recharge and discharge, and dissipating erosive forces (Adamus, 1983; Dahl & Zoltai, 1997; Winter & Woo, 1990). In the boreal forest, both treed and open peatlands support especially rare flora and fauna (Hedley et al, 2020; Nielsen et al, 2020). For example, rich treed fens are the primary habitat for Bog Adder's‐mouth ( Malaxis paludosa ), considered one of the rarest orchids in North America (Kershaw et al, 2001).…”