Documenting and estimating species richness at regional or landscape scales has been a major emphasis for conservation efforts, as well as for the development and testing of evolutionary and ecological theory. Rarely, however, are sampling efforts assessed on how they affect detection and estimates of species richness and rarity. In this study, vascular plant richness was sampled in 356 quarter hectare time-unlimited survey plots in the boreal region of northeast Alberta. These surveys consisted of 15,856 observations of 499 vascular plant species (97 considered to be regionally rare) collected by 12 observers over a 2 year period. Average survey time for each quarter-hectare plot was 82 minutes, ranging from 20 to 194 minutes, with a positive relationship between total survey time and total plant richness. When survey time was limited to a 20-minute search, as in other Alberta biodiversity methods, 61 species were missed. Extending the survey time to 60 minutes, reduced the number of missed species to 20, while a 90-minute cut-off time resulted in the loss of 8 species. When surveys were separated by habitat type, 60 minutes of search effort sampled nearly 90% of total observed richness for all habitats. Relative to rare species, time-unlimited surveys had ∼65% higher rare plant detections post-20 minutes than during the first 20 minutes of the survey. Although exhaustive sampling was attempted, observer bias was noted among observers when a subsample of plots was re-surveyed by different observers. Our findings suggest that sampling time, combined with sample size and observer effects, should be considered in landscape-scale plant biodiversity surveys.

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1. Recent evidence indicates that many native bee species are in decline due to the cumulative effects of multiple human-induced stressors such as habitat loss, pesticide exposure, pathogens, and climate change. These declines have raised interest in the status of native bees and in developing tools that support management of bee communities and the ecosystem services they deliver. 2. Native bees were surveyed using pan traps and netting over 2 years at 68 locations in croplands and rangelands across three ecological regions of Alberta's prairiesthe Grassland, Parkland, and Boreal Natural Regionsto evaluate patterns in bee communities in response to disturbance and ecological gradients. 3. Bee community composition was different across land use and ecoregions. While several cavity-nesting species had a strong association with rangelands, cavity-nesting bees tended to be less common in croplands and may be more sensitive to loss of rangeland habitat. 4. Response patterns in overall bee abundance and richness were driven by interactions between region and land use, highlighting the need for regional studies to understand how bee communities respond to these factors. 5. This survey is one of the first to sample the response of bee communities to landscape disturbance across a broad spatial area of the Canadian prairies. Large-scale compositional studies are essential for understanding the status of native bee communities, and for monitoring long-term trends over time. We recommend subsequent coordinated surveys using standardised methods across broad spatial scales.

Habitat loss and disturbance from industrial resource development may be contributing to declines in boreal bird populations. We applied hierarchical multispecies models to data from 31 bird species at 38 Monitoring Avian Productivity and Survivorship (MAPS) stations to assess 10-year (2011–2020) demographic trends and responses to energy sector disturbance (human footprint proportion) in the Athabasca oil sands region of Alberta, Canada. Adult captures, productivity, and residency probability all declined over the study period, and adult apparent survival probability also tended to decline. Consistent with the hypothesis that habitat loss may be driving declines, trends in adult captures, productivity, and survival were all more negative at stations with larger increases in disturbance over the study period. Species associated with early seral stages were more commonly captured at more disturbed stations, while species typical of mature forests were more commonly captured at less disturbed stations. Productivity was positively correlated with disturbance within 5-km of stations after controlling for disturbance within 1-km of stations, suggesting the importance of earlier successional habitat for post-fledging birds in the larger landscape. Adult apparent survival showed relatively little response to disturbance; stresses experienced beyond the breeding grounds likely play a larger role in influencing survival. Residency probability was negatively related to disturbance within 1-km scale of stations and could reflect processes affecting the ability of birds to establish or maintain territories in disturbed landscapes. We conclude that successional habitats that result from natural regeneration or restoration in disturbed areas, as well as decreased future footprint through recovery of mature forests and limiting of new disturbances, will both be important components of efforts to reverse population declines and maintain bird populations in the region.