The range expansion patterns of Spartina alterniflora on salt marshes in the Yangtze Estuary, China
The range expansion patterns of Spartina alterniflora on salt marshes in the Yangtze Estuary, China
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DOI：
10.1016/j.ecss.2010.03.015
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发表时间：
2010-06
影响因子：
2.8
通讯作者：
De-rong Xiao;Li-Quan Zhang;Zhenchang Zhu
中科院分区：
文献类型：
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作者：
De-rong Xiao;Li-Quan Zhang;Zhenchang Zhu
中国在长江口崇明东滩自然保护区对互花米草的活动范围扩展进行了调查，并对有性繁殖和无性繁殖在活动范围扩展中的作用进行了研究。互花草在其推进锋有两种范围扩展模式：(1)互花草-泥滩锋(S-M)和(2)互花草-马尾草-泥滩锋(S-S-M)。这项研究揭示的一个特征是，春季幼苗的大量更新和建立是互花米草在新的栖息地定居和实现快速范围扩展的关键途径。S-M战线平均招苗数远高于S-S-M战线。成苗后，无论是S-M战线还是S-S-M战线，苗木成活率都很高。已建立的幼苗通过营养分蘖和根茎的生长迅速形成新的草丛，并最终融入茂密的草甸。互花米草在S-M锋面经过一个生长季节后的平均射程扩展距离为25.4±3.1myr−1，在S-S-M锋面为2.7±0.5myr−1。互花米草苗木有性繁殖、分蘖无性繁殖和根茎生长是互花米草在长江口盐沼上保持较快范围扩张率的两种主要方式。互花米草在前进锋上的定殖行为不同，是对各种外部和内部因素的反应。讨论了控制互花米草范围扩展的非生物和生物因素的影响及其对潮汐湿地空间结构的影响。
The range expansion patterns of Spartina alterniflora and the roles which sexual reproduction and asexual propagation play in range expansion were investigated at the Chongming Dongtan nature reserve in the Yangtze Estuary, China. Two range expansion patterns of S. alterniflora at its advancing fronts could be found (1) S. alterniflora–mudflat front (S–M) and (2) S. alterniflora–Scirpus mariqueter–mudflat front (S–S–M). One feature revealed by this study was that a flush of seedling recruitment and establishment in spring was a crucial way for S. alterniflora to colonize new habitats and achieve a fast rate of range expansion. The mean number of seedlings recruited at the S–M front was much higher than that at the S–S–M front. Once established, the survivorship of seedlings was high, both at the S–M and S–S–M fronts. The established seedlings formed new tussocks quickly by vegetative tillering and growth of rhizomes and these finally merged into dense meadows. The mean distance of range expansion of S. alterniflora, after one growing season at the S–M front, was 25.4±3.1myr−1and 2.7±0.5myr−1at the S–S–M front. Sexual reproduction by seedlings and asexual propagation by tillering and growth of rhizomes were the two main means by which S. alterniflora could maintain a fast rate of range expansion on the salt marshes of the Yangtze Estuary. The colonization behaviors of S. alterniflora on advancing fronts differed as a reaction to various external and internal factors. The impact of abiotic and biotic factors governing the range expansion of S. alterniflora and its implications for the spatial structure of tidal wetlands are discussed.