Proceedings of the Third International Conference on Invasive ...

##Chapter 2: Spartina Distribution and Spread<strong>Proceedings</strong> <strong>of</strong> <strong>the</strong> <strong>Third</strong> <strong>International</strong> <strong>Conference</strong> on Invasive SpartinaGenetic AnalysesGenetic analyses to confirm speciesidentification were done at each <strong>of</strong> <strong>the</strong> 28sites and at additional sites requested byconcerned landowners, managers orstakeholders (Fig. 2).Additional genetic surveys weredone at a few sites along <strong>the</strong> coast north<strong>of</strong> <strong>the</strong> Golden Gate in Point ReyesNational Seashore and Bolinas Lagoon.In order to confirm species identification,leaves from ambiguous plants and atleast 3-5 plants per monitoring site werecollected according to standard methodsused previously (Ayres et al. 2004) andconforming to recommendations inCollins et al. (2001). Where needed,transects were run <strong>the</strong> length <strong>of</strong> marshessampling every 10 meters to determine(1) if <strong>the</strong>re were any “hidden” S.alterniflora hybrids, or (2) <strong>the</strong> percentinvasion <strong>of</strong> a particular marsh. Fromeach individual clone <strong>of</strong> unknownspecies identification and from each 10-meter sample along <strong>the</strong> transects, asingle plant leaf was collected for geneticanalysis using RAPD (RandomAmplified Polymorphic DNA) nuclearmarkers (Daehler and Strong 1997;Ayres et al. 1999).#Coyote Creek,Mill Valley -100 % nativeS. foliosaEfficacy MonitoringISP staff monitored <strong>the</strong> efficacy <strong>of</strong> 13different treatments at eight sites. Sometreatments were done in 2002 withassessment <strong>of</strong> efficacy in 2003.Treatments done in 2003 will be assessedin 2004. Treatment monitoring data werecollected consistent with methodsdescribed in Collins et al. (2001). Prior totreatment <strong>the</strong> extent <strong>of</strong> non-native Spartina was mapped todetermine <strong>the</strong> total area <strong>of</strong> non-native Spartina. For largetreatment sites mapped as polygons with a percent cover <strong>of</strong>non-native Spartina <strong>the</strong> sampling scheme described byCollins et al. (2001) was modified from a graphicalinformation system (GIS) based sampling approach to afield-based approach. A stratified random sub-samplingmethod was applied. Transects were run across <strong>the</strong> length <strong>of</strong><strong>the</strong> treatment area parallel to <strong>the</strong> shoreline at selectedelevations and <strong>the</strong>n random points were sampled along <strong>the</strong>transects. For smaller treatment sites where individual cloneswere mapped as points all <strong>the</strong> mapped plants up to aSan Francisco BayNon-native Spartina Genetic Survey Map 2003Beach Drive,San Rafael -2S.alternifloraclones found (12%)Loch LomondMarina -3S.alternifloraclonesPetaluma Marsh -Wiloki Creek,Donahue Sloughand San Antonio Creek -100% native S. foliosaCrissy Field -3S.alternifloraseedlings foundand pulled fall 2003#########Yosemite Slough -89% S. alt-hyb point samples84% S. alt-hyb transect samplesLegendSpartina genetic survey points 2003# S. alternifloralab tested# S.alterniflora-hybrid lab tested# S. foliosa lab tested# no resultsSpartina genetic survey lines 2003S. alt-hybS. foliosano results6 0 6 12 MilesFig. 2 - Baywide Map <strong>of</strong> Genetics Sampling SitesW#NS##Meeker Slough - 100% native S. foliosaEEast and West Stege Marsh -100% native S. foliosaOutbound Stege Marsh -2S.alterniflora-hybrid clonesfound and treated fall 2003maximum <strong>of</strong> 30 plants per site were monitored. If more than30 plants were mapped, 30 were randomly selected tomonitor pre-treatment and post-treatment to determine <strong>the</strong>treatment efficacy. Measurements <strong>of</strong> overall plant vigorincluding plant height, density per 0.25 meter, plant vigor(high/medium/low), tide wash (yes/no), plant species percentcover (native and non-native plant species) per 0.25 meter,percent flower Spartina per 0.25 meter, sediment type,high/medium/low marsh, and burn (yes/no) were collectedfrom each sampling location. The entire treatment area wasmapped again one year post-treatment and <strong>the</strong> sametreatment efficacy data were collected.##Plummer Creek Mitigation Site-100% native S. foliosa## ## ## # # # ##Cooley Landing/RavenswoodPreserve - 19% S. alterniflora-hybrids,seedlings 100% native S. foliosa-76-