Eastern Slopes Grizzly Bear Project Habitat Studies (1998)

Habitat inventory, evaluation and mapping results from the Eastern Slopes Grizzly Bear Project have been presented within three different technical reports as of December 1998. Summarized below are the background and results of each report. More detail about the first two reports is available by following the links for each title.

“Grizzly Bear Population and Habitat Status in Banff National Park” (Gibeau et al. 1996)

This report was completed at the request of the Banff Bow Valley Task Force whose mandate it was to study the cumulative effects of human development and activities in the Bow River valley of Banff National Park, Alberta. At the time that this study was commissioned, habitat inventory and mapping had not been completed by the ESGBP within Banff National Park. The authors relied instead upon an existing food habits model for the 4 Mountain Parks by Kansas and Riddell (1995) as a basis for habitat effectiveness and security area analysis. This model was used to assess inherent food potential for 40 Bear Management Units (BMUs) encompassing 9,344 km2 of land in Banff, Kootenay and Yoho National Parks. Results showed that a significant portion of the study area was only moderately productive habitat, much of this due to the high percentage of rock, ice and high elevation tundra in the study area. Highest habitat quality occurred primarily in those BMUs encompassing a high percentage of valley bottom and Montane habitats. Habitat effectiveness modelling was completed by overlaying human use features onto habitat mapping to calculate “realized habitat potential” values per BMU. Disturbance coefficients and zones of influence from the Yellowstone Ecosystem were adopted for various types and intensities of human use. Average habitat effectiveness for the entire study area was 83.1% ranging from 46.6% to 97.9% per BMU. Forty-four (44%) of the BMUs in Banff National park were below 80% habitat effectiveness.

The authors also evaluated the effect of changing levels of human use and prescribed fire on security areas available to grizzly bears for the time periods 1950, 1995, and 2045. A successional model of grizzly bear habitat suitability of mapped ecosites was developed to aid in these assessments. Results showed that the lower elevation Montane ecoregion currently supports only 2.5% of its land area as security areas, as opposed to 45% and 41.2% for the Lower and Upper Subalpine regions respectively. Human land use activities occurring between 1950 and 1995 reduced grizzly bear habitat security in the Montane region greater than double the amount of lands at higher elevations. Under a 6% growth scenario when projected to 2045, secure habitat for grizzly bears in the Montane region of Banff National Park would be all but eliminated. By limiting human activities in selected areas secure habitat for grizzly bears could be increased by 31% for the current time period. Fire suppression over the last 60 years has significantly reduced the amount of high quality grizzly bear habitat in Banff National Park. Introduction of a hypothetical fire regime increased the amount of high quality grizzly bear habitat in secure areas approximately 1.5 orders of magnitude by the year 2045.

“Grizzly Bear Population and Habitat Status in Kananaskis Country, Alberta” (Eastern Slopes Grizzly Bear Project 1998)

This report was prepared by 4 members of the Eastern Slopes Grizzly Bear Project study team at the request of Alberta Environmental Protection, Natural Resources Service as part of their Kananaskis Country Recreation Policy Review. The analyses in this study benefited from 4 years of field research and preliminary analysis in Kananaskis Country. A 5712 km2 study area encompassing all of Kananaskis Country was subdivided into 13 Bear Management Units ranging in size from 206 km2 to 463 km2. Five hierarchically nested habitat maps were completed for the study area using digital overlays of vegetation and topographic maps (Kansas and Newyar 1998). Level 4 mapping resulted in 122 different recurring map units for the study area. This level of mapping formed the framework for grizzly bear habitat modelling. 1411 detailed ground sample plots that collected data on key grizzly bear foods fueled models. An average of 12.7 plots were collected per Level 4 map unit. Habitats with highest suitability for the pre-berry season (den emergence to July 15) included: 1) moderately to steeply sloping shrublands in the subalpine region; 2) riparian spruce and conifer-dominated mixedwood forests in the Lower Foothills and Lower Subalpine regions; 3) south to west facing, moderately sloping deciduous forests; 4) treed clearcuts; 5) gently sloping pine-mixedwood forest in the Lower Foothills and Lower Subalpine; and 6) steeply sloping, south to west facing grasslands in the Subalpine region. Patches of high suitability habitat in the pre-berry season were concentrated along the major river systems including the Kananaskis, Highwood and Bow River valleys. Highest suitability habitats during the berry-and-after season (July 16 to den entry) were: 1) treed and shrub sapling clearcuts; 2) moderately to steeply sloping south to west facing shrublands; 3) moderately to steeply sloping south to west facing Lodgepole pine forests and pine mixedwood forests in the Lower Foothills and Lower Subalpine regions; and 4) riparian Balsam Poplar and White spruce forests in the Lower Foothills and Lower Subalpine. High suitability habitat during the berry and after season was limited in the eastern portions of the Front Range BMUs.

Habitat effectiveness values were calculated for the 13 BMUs using the same disturbance coefficients and zones of influence that were used for the Banff Bow Valley Study (Gibeau et al. 1996). Values ranged from 49% to 82% and averaged 71%. Lowest habitat effectiveness values were found in BMUs that encompassed major river valleys in the western portion of Kananaskis Country. This was thought to be due to the concentration of human activities along highly suitable river valley habitats.

“Eastern Slopes Grizzly Bear Project: Habitat Mapping and Evaluation Component”(Kansas and Newyar 1998)

This progress report summarizes 4 seasons of habitat inventory and mapping and grizzly bear habitat use for the period 1994 to 1997. The habitat inventory and mapping data are focussed on a 5712 km2 study area on Alberta provincial lands surrounding Kananaskis Country. The habitat use analyses combined data from both Kananaskis Country and Banff National Park.

A total of 1400 detailed habitat availability plots were completed in the Kananaskis study area. These plots collected information on bear foods and security cover and form the basis for completing both grizzly bear and ungulate habitat models. Grizzly bear habitat use information was recorded at 951 feeding sites. These sample plots collected enough plant cover information to classify the plant association or micro-habitat inclusion type, and recorded type of use, intensity of use, approximate age of sign, and the particular plant or animal foods utilized. Along with radio-telemetry data these plots will be used to verify the accuracy of completed and evolving habitat suitability models.

Five hierarchically-nested habitat maps were completed for the study area. Each map was built from the next most detailed map through a progressive grouping and classification process. Digital overlays of 1:20,000 scale forest cover mapping and 1:20,000 scale digital elevation model derivatives (slope, aspect, elevation) formed the basis for this mapping. The purpose of this approach was to provide a wide range of map products and mapping scales for planning, evaluation and statistical analysis. This approach also will form the basis for John Kansas’ M.Sc. Thesis which will test the effects of habitat inventory and mapping scale on habitat evaluation output as this influences habitat effectiveness models. The report also summarizes the results of a Landsat-TM based classification and mapping of land cover for the study area.

Preliminary summaries of grizzly bear habitat use were done of 951 feeding sites throughout Kananaskis Country and Banff National Park. These summaries included relationships between feeding sites and aspect (5 classes), elevation (4 classes), ecological region (4 classes), vegetation cover type (24 classes), and food type (7 types). Also summarized were the extent to which and habitats within bears utilized non-mappable micro-habitat inclusions. Results of these summaries are preliminary and require further analysis at this point in time.

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