Spread of exotic cordgrasses and hybrids (Spartina sp.) in the tidal marshes of San Francisco Bay, California, USA
Spread of exotic cordgrasses and hybrids (Spartina sp.) in the tidal marshes of San Francisco Bay, California, USA
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DOI：
10.1023/b:binv.0000022140.07404.b7
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发表时间：
2004-01-01
影响因子：
2.9
通讯作者：
Strong, DR
中科院分区：
文献类型：
--
作者：
Ayres, DR;Smith, DL;Strong, DR
本文报道了四种外来大米草（Spartina sp.）除了加州本地的Spartina foliosa之外，还出现在旧金山弗朗西斯科河口。我们的目标是绘制所有非本地米草在河口的位置和范围。S.互花米草S.叶状体是迄今为止数量最多的外来物种，并且正在迅速蔓延。从故意引入的地点辐射，S。互花米草和杂交种现在覆盖约1000公顷。190公顷，主要在南部和中部湾。对空中增长率的估计从一个恒定值到一个加速增长率不等。这可能是由于杂交克隆的增殖能够快速扩展，并具有上级的种子集和繁殖能力。总覆盖面积195公顷的杂交种和其他外来的大米草物种是略低于1%的海湾的潮汐泥滩和沼泽。大米草没有蔓延超出其原来的1970年代引进网站。密花米草已蔓延到中央湾的3个地点，覆盖面积超过5公顷。在休森湾，米草从1970年的2个工厂扩展到42个工厂。米草种子漂浮在潮汐上，使其有可能将这种入侵出口到整个旧金山弗朗西斯科河口，以及金门以外的河口。我们发现了S.互花米草S.在海湾北部的外海岸河口发现了密花，这表明旧金山弗朗西斯科湾种群在太平洋沿岸发现其他种群的可能性。
Four species of exotic cordgrass (Spartina sp.) occur in the San Francisco estuary in addition to the California native Spartina foliosa. Our goal was to map the location and extent of all non-native Spartina in the estuary. Hybrids of S. alterniflora and S. foliosa are by far the most numerous exotic and are spreading rapidly. Radiating from sites of deliberate introduction, S. alterniflora and hybrids now cover ca. 190 ha, mainly in the South and Central Bay. Estimates of rate of aerial increase range from a constant value to an accelerating rate of increase. This could be due to the proliferation of hybrid clones capable of rapid expansion and having superior seed set and siring abilities. The total coverage of 195 ha by hybrids and other exotic cordgrass species is slightly less than 1% of the Bay's tidal mudflats and marshes. Spartina anglica has not spread beyond its original 1970s introduction site. Spartina densiflora has spread to cover over 5 ha at 3 sites in the Central Bay. Spartina patens has expanded from 2 plants in 1970 to 42 plants at one site in Suisun Bay. Spartina seed floats on the tide, giving it the potential to export this invasion throughout the San Francisco estuary, and to estuaries outside of the Golden Gate. We found isolated plants of S. alterniflora and S. densiflora in outer coast estuaries north of the Bay suggesting the likelihood for the San Francisco Bay populations to found others on the Pacific coast.