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Arctic Science 2000 - Crossing Borders: Science and Community
Whitehorse, Yukon, Canada, Sept 21-24 2000
American Association for the Advancement of Science & Yukon Science Institute

Environmental Monitoring on Herschel Island, Yukon

Field inventories and mapping of soil and vegetation were conducted in 1985 on Herschel Island as part of the initial management activities subsequent to the establishment of the island as a territorial park. Fifteen years later, during park staff training during the summers of 1998 and 1999, we observed apparent increases in the abundance of a grass species (Arctagrostis latifolia) and lupine (Lupinus arcticus) in a vegetation community type (Arctic Willow-Dryas/Vetch), which comprises a significant proportion (40%) of the island’s vegetation cover. We have established a number of related projects to track these changes over the long-term with the objective to monitor several biophysical components of the Herschel Island ecosystem that may have possible implications for wildlife.

Three vegetation monitoring activities have been initiated. In 1999 an International Tundra Experiment (ITEX) site was established including long-term plant composition/biomass transects as well as annual phenology monitoring transects. Phenology plots for indicator species (Eriophorum, Dryas and Salix) are being monitored by Park Rangers. In order to quantify apparent recent changes in the vegetation cover, random sampling within map units containing the Arctic Willow-Dryas/Vetch community was conducted throughout the island and compared to previous cover values. A. latifolia cover values increased from a 1985 average value of 1% cover to approximately 10% cover in 2000. Similar increases were observed for L. arcticus. Associated with these increases was an invasion of mudboil (non-sorted circles) surfaces, suggesting a reduction in the amount of frost churning (cryoturbation) in soils underlying this vegetation type.

Permafrost active layer temperatures are being monitored using one deep (15 m) thermistor cable and two shallow (1.5 m) thermistor probes. Active layer and near-surface permafrost temperatures are logged at 6 hour intervals at 20, 50, 100 and 150 cm depths. Permafrost temperatures are measured semi-annually at 5, 7.5, 10, 12.5 and 15 m depth. Temperature changes at these depths will signal any long-term changes in the thermal regime of the island’s soil environment.

In 1998 we developed a system for documenting wildlife observations using published terrain and vegetation map units. Park Rangers were trained to use this system, particularly for recording muskox and caribou feeding locations and bird nesting sites. Observations of wildlife use of specific terrain and vegetation types together with long-term observations of change in plant cover and soil thermal regime of these types will provide an integrated view of environmental change and possible impacts on wildlife habitat on Herschel Island.

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