Proceedings of the Third International Conference on Invasive ...

Chapter 4: Spartina Control and Management<strong>Proceedings</strong> <strong>of</strong> <strong>the</strong> <strong>Third</strong> <strong>International</strong> <strong>Conference</strong> on Invasive SpartinaWinter tilling provided <strong>the</strong> highest level <strong>of</strong> uniformcontrol across all sites <strong>of</strong> any mechanical effort (77%).Control achieved with crushing was highly variable (rangingfrom 0 to 92% Spartina-free quadrats), depending on type <strong>of</strong>sediment and location (Table 2). Highest control (92%)occurred on one site where <strong>the</strong> crushing pushed <strong>the</strong> crown <strong>of</strong><strong>the</strong> plant well below <strong>the</strong> surface <strong>of</strong> <strong>the</strong> sediment. No controlwas recorded at several sites with firm sediment. Averagecontrol was achieved from crushing on s<strong>of</strong>t and firmsediment at 52% and 26%, respectively (Table 2). Crushing<strong>the</strong> same site repeatedly over consecutive years did notprovide any marked improvement in control over a singleyear <strong>of</strong> treatment (Fig. 1). Control with disking wascomparable to control from a good crushing event (Table 2).Control results from multiple years <strong>of</strong> crushing or diskingsites have a level <strong>of</strong> uncertainty because only a few siteswere available for comparison.Seedling density data were also collected at all sites(data not shown). With two exceptions, density was low (20Winter tilling – silt 2004 SE 0.4± 0.1 75 25 0 0Winter tilling – silt 2001 S 1.5±0.3 77 13 8 2Winter tilling – silt 2001/02 S 3.2±0.6 67 19 10 4Crushing –sand 2002 N. Peninsula 6.7±1.0 34 31 6 1Crushing – sand 2002 N. Peninsula 4.0±0.6 47 29 21 4Crushing – sand 2002, 2003 N. Peninsula 5.0±2.0 55 27 8 10Crushing- sand 2002, 2003 N. Peninsula 3.0±1.0 60 15 22 3Crushing- sand 2001, 2002, 2003 N. Peninsula 32.0±3.0 5 3 25 67Crushing- s<strong>of</strong>t silt 2002, 2003 NE 37.0± 2.0 0 0 5 95Crushing- s<strong>of</strong>t silt 2002, 2003 NE 7.0± 2.0 45 8 33 5Crushing - s<strong>of</strong>t silt 2001, 2002, 2003 N 3.0±1.0 50 33 13 3Crushing - s<strong>of</strong>t silt 2002, 2003 N 5.0±1.0 55 17 20 8Crushing- firm silt 2003 N 10.0±2.0 54 20 20 6Crushing -firm silt 2001 SE 46.0±3.0 0 0 0 100Crushing- firm silt 2001 SE 25.0±3.0 22 16 29 33Crushing- firm silt 2001 N. Peninsula 41.0±7.0 0 4 17 80Crushing- s<strong>of</strong>t silt 2001 SE 6.1± 0.6 37 30 28 6Crushing- s<strong>of</strong>t silt 2002 SE 5.8± 1.0 26 31 38 5Crushing- s<strong>of</strong>t silt 2001 SE 0.2± 0.1 92 8 0 0Crushing- s<strong>of</strong>t silt 2001 SE 4.0± 0.5 53 15 30 2Disking + crushing 2001, 2002 SE 4.0± 0.7 71 19 10 0Disking- s<strong>of</strong>t silt 2001 N. Peninsula 3.8±1.2 53 30 10 7- 252 -