Bulkley Valley Research Centre - Science in the Public Interest

MSMA Impacts on Non-Target Plant Species

Project Reference Number: 2004-07

Project Status: Complete

Led by: Ken White, Regional Entomologist, Ministry of Forests and Range, Smithers

Mountain View Silviculture Ltd., Smithers

Funder: Ministry of Forests, Transfer Payment

This project was designed to gather data on the possible impact of MSMA (Monosodium Methanearsonate – a pesticide previously used against mountain pine beetle) on non-target plants. The sampling protocol involved collecting herbaceous plant information (% cover, species diversity, etc.) on 1.78 m diameter plots centred on treated and untreated trees. Foliage was also sampled from under treated and untreated trees for later analysis. The data was collected from areas treated in three different years (1994, 1999 and 2001).

A total of 60 plots (at 14 separate sites) were sampled for each treatment year, for a total of 180 plots. These plots were evenly divided between treated and untreated trees. The results of the plant cover data has not been fully analyzed, but initial analysis suggests that there is little, if any, difference between the plant abundance/diversity around treated and untreated trees.

A selection of the foliage samples were finally tested in early 2008 for their arsenic content (the long delay was due to the analysis being cost prohibitive). The resulting data shows high variability, likely due to the small number of samples analyzed (four sites). However, the results of this analysis have played an important part in the development of a larger sampling protocol that is being undertaken on a provincial scale. This provincial sampling will help to fulfill a requirement outlined in a 2007 Forest Practices Board letter that outlines the issues around provincial MSMA policy development.