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 Spartinaany seeds and it has become shorter at all elevations.On <strong>the</strong> o<strong>the</strong>r hand, <strong>the</strong> range <strong>of</strong> S. alterniflora increasedby 10,000 times from 1980 to 1988. Alhough planting <strong>the</strong>species on a large scale was stopped in 1995, it stillincreased by 86 times from 1988 to 2000. The species is stillinvading coastal areas in China by natural dispersal and hasbecome a threat to <strong>the</strong> native ecosystems. From 1995 to2000, ca. 200,000 ha <strong>of</strong> S. alterniflora marshes and tidelandswere reclaimed, which did not stop <strong>the</strong> invasion <strong>of</strong> <strong>the</strong>species.Many native species, including plants, some endangeredbirds (Ma et al. 2004), and mollusks <strong>of</strong> economic value incoastal areas are threatened by S. alterniflora invasions. Itexcluded almost all <strong>the</strong> o<strong>the</strong>r native plants that wereoriginally dominant in wetlands, including Phragmitesaustralis, Typha spp., Scirpus spp., Suadae spp., and eveninvaded fishponds and young mangrove swamps (Qian andMa 1995). For example, in intertidal zones <strong>of</strong> <strong>the</strong> YangziRiver estuary, S. alterniflora invaded Scirpus mariquetercommunities. Through competition with <strong>the</strong> native species,S. alterniflora has greatly decreased native speciesabundance, and even excluded <strong>the</strong>m (Li et al. in thisvolume). Li et al. (this volume) also compared <strong>the</strong> structure<strong>of</strong> nematode communities among Spartina marsh and S.mariqueter and Phragmites marshes <strong>of</strong> Dongtan wetlands onChongming Island, and found significant differences introphic structure <strong>of</strong> nematode communities between <strong>the</strong>marshes.Spartina alterniflora is one <strong>of</strong> 16 notorious invasivepest plants in China as <strong>the</strong> species directly causes millions <strong>of</strong>dollars <strong>of</strong> economic loss per year (An et al, 2007). Spartinaalterniflora is still rapidly spreading, although <strong>the</strong> Chinesegovernment and scientists are doing <strong>the</strong>ir best to control oreradiate <strong>the</strong> species by physical, chemical, biological andintegrated methods (Lin 1997; Liu and Huang 2000).RESEARCH BEFORE 1995Since S. anglica arrived at Nanjing University <strong>of</strong> China,a series <strong>of</strong> studies (all <strong>the</strong> papers published before 1986 in<strong>the</strong> cited literature) had been carried out by <strong>the</strong> SpartinaResearch Group, which focused on S. anglica by 1985. Forexample:• 1963 to 1966: Asexual propagation from rhizome andramets; seed germination, tolerance <strong>of</strong> individuals tocold, hot, drought, water logging, silt sediment and saltstress; growth under different elevation; sexual andasexual reproduction from established individuals;transplanting and management techniques.• 1967 to 1973: Field transplanting; impacts <strong>of</strong> S. anglicagrowth on soil properties and planting techniques ininland riparian wetlands.• 1974 to 1978: Green manure for cropland, forage forsheep, goat and pig; height growth; fertilized flowersTable 5. Survivorship and growth <strong>of</strong> Spartina alterniflora at differentelevation levels. (Revised from Xu and Zhuo 1985.)Elevation(m)Inundationfrequency(days/month)Inundationtime(hours/day)Survivorship(%)Increase rate <strong>of</strong>individuals perclump (times)and seed production; biomass production, net biomassproduction; impacts <strong>of</strong> harvest on growth and reproductionand impacts <strong>of</strong> grazing by cows, sheep and goats.• 1979 to 1985: Silt sediment rate <strong>of</strong> Spartina plantation;uses in protection <strong>of</strong> dykes; prevention <strong>of</strong> tideland erosion;purification <strong>of</strong> polluted water; impact on beneathfauna; Gram negative bacteria composition; anatomy <strong>of</strong>roots and stems; germination <strong>of</strong> seeds produced inChina and impacts <strong>of</strong> puncture and air pressure on seedgermination; physiology; tissue culture; introduction toriparian wetlands in Yellow River <strong>of</strong> NorthwesternChina; biochemical composition and nutrient; impacts<strong>of</strong> fertilizer on growth and biomass production; foragefor fish; structures <strong>of</strong> salt glands; ultra-structures <strong>of</strong> leafcells; DNA contents; ecotype identification and methodsto increase <strong>the</strong> seed production.After 1985, most studies (in <strong>the</strong> cited literature between1986 and 1994) focused on biology and ecology <strong>of</strong> S.alterniflora, including survivorship and growth at differentelevations (Table 5); growth rate and growth form/type fromthree different origins; above- and below-ground biomassand biomass allocation <strong>of</strong> three growth-type populations;seed germination at different saline stresses; effect <strong>of</strong> N-fixed 4088 strain <strong>of</strong> bacteria on seed germination andindividual growth; transportation and distribution <strong>of</strong>phosphorus (P) in organs under salt stress; physiology andbiochemistry <strong>of</strong> leaf and root; effects <strong>of</strong> seed soaking onseed germination; enzyme activity, sugar contents, aminoacid and cold tolerance <strong>of</strong> <strong>the</strong> seedling under different saltstress; translocation <strong>of</strong> mineral elements; contents, allocationand uses <strong>of</strong> Selenium (Se) <strong>of</strong> plants; flavonoids andimmunity activity; isozyme differentiation; micromorphology<strong>of</strong> pollen grains; ultrastructure <strong>of</strong> mesophyllcells; anatomy <strong>of</strong> seeds; biomass dynamics, speciesstructures, energy storage and energy flow <strong>of</strong> ecosystem; <strong>the</strong>relationships between Spartina and clamworms; soil enzymeactivity in Spartina salt marsh; extraction method,toxicology, nutrient contents, functions and uses <strong>of</strong>biomineral beverages/tea.Height(cm)0.0 30 5.0 - 8.0 16.7 0 12.50.5 30 3.5 - 7.0 66.7 1.5 27.61.0 30 1.5 - 6.0 66.7 4.8 37.31.5 30 0.5 - 4.5 100.0 10.8 90.22.0 26 - 30 0.5 - 3.5 100.0 13.7 101.42.5 18 - 28 0.5 - 2.0 100.0 11.8 98.23.0 14 - 22 0.5 - 2.0 100.0 8.0 72.3-68-