1999 GSA Annual Meeting -- Denver, Colorado
1999 GSA Annual Meeting -- Denver, Colorado
Author(s): RADENBAUGH, Todd A., Canadian Plains Research Center, University of Regina, Regina, SK, S4S 0A2, ToddR@cas.uregina.ca.
Keywords: Ecosystem-Function, Agroecosystem, Prairies, Agricultural-Impacts, Birds
Since the early 1900s, the conversion of the northern prairies into agricultural lands has significantly changed the vegetation cover from a grassland (over 80 % cover in 1880s) to a cropland (presently over 60% cover) dominated region. Although many previous studies have shown significant impacts to ecological processes at the population and species assemblage levels, few studies have investigated functional alteration at the broader ecosystem level. An important concern is the degree that agriculture has reshaped the structure of the present prairie ecosystem, and how human controlled processes have reallocated energy, space, and habitat away from native components. To investigate broad agricultural impacts on ecosystem level functions, breeding bird guilds over the past 100 years were analyzed and compared on the Mixed Grassland Ecoregion of Saskatchewan. Results indicate that the conversion of this region to an agroecosystem has altered ecosystem level functions in bird guilds and is having major influences at all hierarchical levels. One major change is the creation of new ecospace that is altering broad-scale biotic interactions, as measured by the responses of bird guilds. Humans have become a major functional component of this prairie ecosystem. Therefore, overall ecosystem function and health must be addressed in the wider context to include human society and infrastructures.
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