This study examined landscape change in the Peace-Athabasca Delta, northern Alberta, Canada. The proportion of the landscape covered by ten habitat types was determined for five vintages of air photos (1945–2001) from 24 randomly chosen study areas. To test for reproducibility, three vintages were analyzed by two independent teams, neither of which knew the dates or locations of air photos. Their results were highly correlated. Comparison with another air photo study focused in the southeastern delta revealed good agreement. Analysis of oblique air photos extended the reconstruction back to 1927. Of four cover types (water, marshes, willows, forests), only water differed significantly in area between vintages. Cover trends for the most general of types (wet communities and dry communities) indicated drying from 1927 to 2001. This trend may be due to multidecadal geomorphic evolution and climate change. Currently, the changes are statistically non-significant, but nevertheless may inform about the long-term future of the ecosystem. Large spatial and temporal variation in landscape cover is characteristic of the system. The types and ranges of change in the delta's vegetation post-Bennett Dam (1968) do not appear unusual relative to pre-Bennett Dam change. A multi-decadal perspective is necessary to encompass normal oscillations in abundance. Key to understanding change in the delta is to think at multiple scales and to remain aware that trends or patterns are scale-dependent. The delta may not be predictable on the meso-scales relevant to society and management.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 26 • No. 3