Aquatic and Riparian Weed Management to Protect U.S. Water Resources in the Far West United States
Exotic and Invasive Weeds Research
Project Number: 5325-22000-026-00
Start Date: Sep 01, 2010
End Date: Aug 31, 2015
Objective 1: Improve understanding of weed life history and population dynamics (including effects of habitat alteration and assessment in canals and managed wetlands), biosystematics, and molecular biology to develop tools to undermine the success of weeds such as water primrose-willow species, perennial pepperweed, purple loosestrife, cordgrass, giant reed, and Eurasian milfoil, and to restore invaded riparian, marsh, and aquatic ecosystems.
Objective 2: Determine the effectiveness of integrated weed management, including potential new herbicides on weeds such as hydrilla (Hydrilla verticillata), pondweeds (Potamogeton, nodosus, P. crispus, Stuckenia pectinata), Eurasian watermilfoil (Myriophyllum spicatum) and exposed sediments during seasonal drawdown (dewatering) for weeds such as M. spicatum, Western milfoil (M. hippuroides) in irrigation systems.
Objective 3: Determine the applicability of biological control agents for water primrose-willows, Mexican mosquito fern, Brazilian waterweed, giant reed (including tricin host production effects on natural enemies), M. spicatum, and water hyacinth (Eichhornia crassipes), including plant ecology in relation to biological control for L. hexapetala and E. crassipes.
Objective 4: Develop effective rapid response methods for new introductions of aquatic invasive weeds such as E. densa, P. crispus, and Undaria, or Japanese kelp (Undaria pinnatifida), and adapt these technologies to control invasive freshwater plant species, marine macroalgae and invasive marine plants.
1) A demographic study will determine how temporal and spatial variation in factors affecting Uruguayan water primrose contribute to overall population dynamics and improved management and restoration at Lagun de Santa Rosa. 2) Egeria Carbon Hydrogen Nitrogen (CHN) and associated insect communities will be determined monthly at invaded/ non-invaded sites at in the Sacramento/San Joaquin Delta using presence/absence and hydroacoustical and videographic methods. 3) Eurasian watermilfoil will be sampled (weekly to monthly) in the Truckee and Fall Rivers along streamflow gradients. 4) Effects of simulated herbivory on Giant reed and effects on root growth (abundance, life span) will be quantified from images recorded with a video camera system within the minirhizotrons at weekly intervals. Success of active (planting desirable species) versus passive (recruitment from resident propagules) re-vegetation will be assessed in giant reed managed sites. 5) Effects of native and non-native submersed plants on rhizosphere microflora will be assessed in replicated mesocosms and natural populations. 6) Replicated applications of fluridone, copper will be made in water and with penoxsulam, or acetic acid to canals and canal sediment. 7) Methods to eradicate Curlyleaf pondweed will be evaluated in indoor and outdoor tanks using diquat, endothall, and penoxsulam under short and long-day conditions.