Published By US Fish and Wildlife Service, Department of the Interior
Issued over 9 years ago
Summary
Description
In spring 1998, studies were initiated to assess the ecological impacts of the invasive nonnative species leafy spurge Euphorbia esula on rangeland and natural areas in the northern Great Plains, and to evaluate the effectiveness of biocontrol insects released to reduce spurge populations. The primary objectives of the study were: 1 to conduct a vegetation survey to describe the composition and relative abundance of plant species on study sites, determine species dominance within the community and construct initial diversity indices such as species richness, 2 to determine the density and stage distribution of leafy spurge on permanent plots, and 3 to determine the abundance and distribution of biocontrol insects. Overall diversity tended to be relatively low, with all sites averaging less than nine species per 1 squaremeter plot. All sites were dominated by introduced species, with native forbs and grasses occupying less important roles in the community structure. In 1999, we will determine the extent to which the seed banks at the sites reflect the current abundance of native and exotic species.