MetadataWeevils2021

Here, we describe the results of a metadata analysis of all milfoil weevil (known) augmentation studies completed North America. Augmentation was completed in 133 experiments, and within the 133 cases, 34 lakes throughout the US and Canada are represented. The mifloil weevil is known to be a natural biocontrol for Eurasian Watermilfoil (EWM), and studies record lake characteristics, as well as augmentation strategy and if the weevil was successful at EWM reduction (studies completed within a single growing season).

The spreadsheet table consists of a list of a predictors (we call features), that are believed to predict milfoil weevil success at watermilfoil reduction (units are also stated in the spreadsheet). In addition, success (in terms of watermilfoil reduction) is recorded in one of 5 ways. The first, called "All Augments" below, is a the qualitative statement of EWM increase (marked 0 for failure) or EWM decrease (marked 1 for success).

1. All Augments - Contains values for all studies that augmented lakes with weevils (N=133).
2. Output Stem Density - Contains only studies that had data in the column “Difference dry Milfoil density (stems/m2)”. Here, N=47.
3. Output Dry Weight Density - Studies that had data in the column “Difference dry Milfoil density (g/m2)”. Here, N=44.
4. Output Percent - Studies with data in column “% Difference Milfoil density”. Here, N=95
5. Relative Abundance - Studies with data in column “Change % Relative Abundance”. This is the difference (as a percent) in the proportion of EWM in a m2 grid, from the start to the end of the experiment, compared with native plants. Here, N=50.

Estimates: Highlighted cells are estimated values for a certain feature.

For more information on data and methodology, please contact the contributors.