• Effects of chemical and physical properties on variable milfoil are being evaluated, an 
effective monitoring tool is being developed, and optimal aquatic habitat for milfoil 
establishment and growth is being determined. Geophysical and vegetation surveys and 
water quality sampling also are being conducted, and data will be integrated. 
• Lake attributes that influence distribution of native and non-native milfoils are being 
identified, and multivariate statistics and logistic regression are being used to determine 
whether invasive milfoil species are correlated with chemical, morphological, biological, 
and spatial characteristics of New Hampshire lakes. Results of this study will identify 
classes of lakes that may be susceptible to invasion. 
• The effects of water and sediment chemistry, sediment physical properties, number and 
size of contiguous wetlands, and watershed geology on variable milfoil abundance or 
presence/absence are being investigated. 
• The Plant Replacement Program works to establish a native, non-nuisance assemblage 
dominated by low-growing species. This effort involves both removal of the current 
dominant milfoil population over a target area early in the growing season and planting or 
seeding with the desired species. 
• NHDES is studying the effectiveness of the herbicide 2-4D. NHDES did intensive GIS 
mapping of a lake and arranged 2-4D pellets in a consistent manner to target plants 
exactly where they are growing and to ensure that the chemical goes directly to the 
plants. NHDES is monitoring to ensure effectiveness. 
• NHDES partnered with Plymouth State University to conduct a research project on the 
effects of a 2-4D treatment on the chemistry, biology, and ecology of a small portion of 
Squam Lake. Data from pre- and post-herbicide treatment are included in the study. 
Data from this study were to be released in the fall of 2007. 
A.30.6. RESEARCH NEEDS 
• Variable milfoil research is needed. 
• Chemical and biocontrol methods are needed. 
• The biology and ecology of plants and what makes them invasive, as well as the habitat 
characteristics that invasive plants favor need to be researched. 
A-79 
