Author
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Branson, David - Dave |
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Sword, Gregory |
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Submitted to: National Entomological Society of America Annual Meeting
Publication Type: Abstract Only Publication Acceptance Date: 7/29/2006 Publication Date: N/A Citation: N/A Interpretive Summary: Crested wheatgrass (Agropyron cristatum) is the most common exotic grass in western North America. Areas planted to crested wheatgrass are resistant to colonization by native plant species and often remain relatively stable for decades, imposing problems for the restoration of native grasslands. Grasshoppers are generalist herbivores that are often abundant in crested wheatgrass dominated sites in the northern Great Plains. We conducted two manipulative experiments in a crested wheatgrass dominated grassland in western North Dakota to test the hypothesis that grasshopper herbivory influences local crested wheatgrass community composition by impeding the recruitment of native seedlings that germinate later in the season. Grasshopper herbivory negatively affected the species richness, numerical abundance and Shannon diversity of native plants in three of the four years examined. The effects of grasshopper herbivory may be an important consideration in the restoration of crested wheatgrass areas in northern Great Plains. The findings illustrate the importance of understanding the impact of native generalist invertebrate herbivores on the relationships between exotic and native plants. Technical Abstract: Crested wheatgrass (Agropyron cristatum) is the most common exotic grass in western North America. Areas planted to crested wheatgrass are resistant to colonization by native plant species and often remain relatively stable for decades, imposing problems for the restoration of native grasslands. Grasshoppers are generalist herbivores that are often abundant in crested wheatgrass dominated sites in the northern Great Plains. We conducted two manipulative experiments in a crested wheatgrass dominated grassland in western North Dakota to test the hypothesis that grasshopper herbivory influences local crested wheatgrass community composition by impeding the recruitment of native seedlings that germinate later in the season. Grasshopper herbivory negatively affected the species richness, numerical abundance and Shannon diversity of native plants in three of the four years examined. The effects of grasshopper herbivory may be an important consideration in the restoration of crested wheatgrass areas in northern Great Plains. The findings illustrate the importance of understanding the impact of native generalist invertebrate herbivores on the relationships between exotic and native plants. |
