Syncrude Canada Ltd. Lease 17 is located in the boreal mixedwood forest ecosystem. It lies within an area of moderately-low biological productivity. Thirty per cent of the lease is in the muskeg habitat type. The winter climate is severe. Energy cycling between soils, plants and animals occurs at comparatively slow rates. There are relatively few steps between food-producing organisms and food-consuming organisms, in comparison with temperate zone ecosystems. Twelve terrestrial and aquatic habitat types exist on the lease. These plant communities offer a variety of cover to wildlife. Terrestrial habitats of mature forest cover are restricted to eastern and southern portions of the lease. Much of the lease has been burned by forest fires prior to our development. Aquatic habitats are limited on Syncrude Lease 17. The Beaver Creek drainage is good beaver habitat. Mildred and Horseshoe Lakes offer habitat to waterfowl, especially as feeding areas during migration; summer waterfowl nesting habitat is limited.