Project Number: 5325-22000-019-03
Project Type: Reimbursable

Start Date: Mar 28, 2006
End Date: Mar 14, 2009

Objective:
This proposal is part of the planned expansion of the CALFED-funded Arundo donax Eradication and Coordination Program, sponsored by Team Arundo del Norte (TAdN), a network of local, state, and federal organizations dedicated to the eradication of Arundo donax (giant reed) where it threatens rivers, creeks, and wetlands in Central and Northern California. We will test hypotheses regarding the timing and effectiveness of several treatment methods including: cut-stump; foliar; and cut, resprout, and spray (foliar). Cut stump treatment involves applying undiluted herbicide (glyphosate) to the freshly cut stump of Arundo. Foliar application is the application of a dilute solution (1.5%-8%) of glyphosate with a surfactant. The cut, resprout, and spray method involves cutting the plant down, removing the biomass, and allowing it to regrow to a desirable height to foliar spray with a dilute herbicide solution. These experiments will be conducted at several sites to evaluate spatial variation in the effectiveness of treatment methods including Cache Creek, San Joaquin River, Tule River, American River, Ash Slough (a tributary of the Chowchilla River), Cottonwood Creek, the Gray Lodge State Wildlife Area, Sonoma Creek, Walnut Creek, Napa River, Putah Creek, and San Francisquito Creek. In addition both passive and active re-vegetation will be evaluated at selected sites. Documents Trust with CalFed Bay Delta. Log 25834. Formerly 5325-22000-018-07T (9/05).

Approach:
The area to be treated will be inspected visually prior to treatment. Based on this, a portion of the area will be designated as control or untreated plants and a portion will be designated for treatment. In each area a number of 0.25 m x 0.25 m quadrats will be randomly located and the number of Arundo stems present in each will be counted. The location of each quadrat will be determined using a Trimble Pro XRS GPS. We will use a SPAD-502 to measure the chlorophyll content on selected leaves within the quadrats. This information will be used to assess leaf viability. The number of quadrats in each area will depend on the size of the treatment and control areas but will generally not be less than 50 or more than 200. This procedure will be repeated several times at selected intervals post-treatment. The effect of the particular treatment will be tested statistically using a repeated-measures analysis of variance design. Number of stems present before and after treatment will be used to estimate the percent killed. All statistical procedures will be calculated using SAS. To assess the impact of timing, treatments made at the same location but applied at different times in Arundo's growing season. Specifically, treatments will be applied in May, July, and September. Monitoring passive re-vegetation will be done using the permanent quadrats. We will record the presence of species which occur within the quadrats following treatments. Sampling will be at the same time that the number of Arundo stems are counted. A second method will be to run several transects in the treated area that are perpendicular to the stream course. The length of the transects will depend on the distance from the streamside that the treatment area includes, but will not be less than 25 m or greater than 100 m. Transects will be randomly placed, but the beginning and ending points will be recorded using a Trimble Pro XRS GPS. At each 1 meter interval along the transect the presence and cover (i.e., distance occupied along the transect) of species that intersect the transect will be noted. Data will be examined statistically by calculating linear regression of the number of species present or the cover versus sample date. A significant positive regression coefficient will indicate that re-vegetation is occurring. In addition, it will show the rate at which species are accruing or plant cover is increasing within the treated area. Effectiveness of active re-vegetation will involve establishing ten plots (5 m x 5 m) within a treated area. Five plots will be planted with appropriate propagules (cuttings, seeds, etc.) for species deemed to be desirable for that location. At selected intervals we will return to record the species present within the plots and to collect growth measurements and survival of the planted propagules. After 12 to 18 months depending on the time that the plots were established, we will compare species composition in the two sets of plots (plots without added propagules vs. plots with added propagules). The total number of species recorded over time for each plot will be used as the response variable in an analysis of variance (paired-comparison).