Project Number: 5325-22000-018-00
Project Type: Appropriated

Start Date: Jul 20, 2003
End Date: Aug 31, 2005

Objective:
1) Determine rates & characteristics of nutrient movement between sediments & target weeds & the water column. Determine rule of pore water and rhizosphere intractions. 2) Examine phenology of aquatic weeds to optimize biological/chemical control. 3) Develop IPM matrix for optimal weed management of target weeds. 4) Assess the effects of biological control agent releases on target and non-target plants.

Approach:
1) In situ pore water nutrient levels will be correlated with plant growth, nutritional status and sediment characteristics. Controlled flowing canals will be used to determine influence of water movement on uptake and pore water nutrient levels. 2) Sediments will be bioassayed for ability to support growth of M. spicatum in Lake Tahoe. 3) Root structure & associated microflora will be analyzed to determine influences on nutrient uptake. 4) Phenology of Arundo donaz and Egeria densa will be examined through seasonal sampling & analysis of CHN. 5) M. spicatum tissue will be analyzed for N and phenols which may affect herbivory. 6) optimal modes of applying herbicides (timing, manipulation of plants and regrowth) will be determined for Spartina alterniflora, Egeria and M. spicatum. 7) Data from phenology and environmental monitoring will be used to construct IPM matrices for management. 8) Conduct lab, greenhouse and field experiments to determine natural enemy impact and their effect on biodiversity, population structure and ecosystem functioning. Replacing 5325-22000-016-00D(7/03).