Competition and Facilitation in Three Marsh Plants in Response to a Water-Level Gradient
Competition and Facilitation in Three Marsh Plants in Response to a Water-Level Gradient
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三种沼泽植物响应水位梯度的竞争与促进
DOI：
10.1007/s13157-010-0064-4
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发表时间：
2010-06-01
期刊：
影响因子：
2
通讯作者：
Qin, Xianyan
中科院分区：
文献类型：
--
作者：
Luo, Wenbo;Xie, Yonghong;Qin, Xianyan
以毛果苔草（Carex lasiocarpa）、穗花甜茅（Glyceria spiculosa）和小叶章（Deyeuxia angustifolia）3种湿地植物为研究对象，采用相对邻体效应指数（NEI），研究了3种湿地植物在3个水位（0、20和40 cm）下的生物量积累和邻体效应。这三个物种沿着水位梯度自然发生在三江平原，中国最大的淡水沼泽。种内和种间的竞争进行了测量，使用目标邻居设计，这三个物种进行不同强度的种间和种内竞争。生物量的积累和NEI的差异水位和竞争处理表明，种内和种间的竞争是最强的淹没在0 cm。相反，邻近植物刺激C。lasiocarpa和D.在40厘米的水位下，这些结果表明，随着水位的增加，种内和种间竞争的强度降低，促进的强度增加。我们的研究结果支持的压力梯度假说（SGH）的预测，植物-植物的相互作用应该切换从竞争到促进沿着增加水位应力梯度。
Biomass accumulation and neighbor effects (measured with a relative neighbor effect index, NEI) were investigated in three marsh plant species (Carex lasiocarpa, Glyceria spiculosa, and Deyeuxia angustifolia) grown at three water levels (0, 20, and 40 cm relative to the soil surface). The three species occur naturally along a water-level gradient in the Sanjiang Plain, the largest freshwater marsh in China. Both intraspecific and interspecific competition were measured using a target-neighbor design, which subjected the three species to different intensities of inter- and intra-specific competition. Biomass accumulation and NEI differences among water levels and competition treatments suggested that intra- and inter-specific competition was strongest at 0 cm inundation. In contrast, neighboring plants stimulated the growth of C. lasiocarpa and D. angustifolia at the 40 cm water level. These results indicate that the strength of intra- and inter-specific competition decreases and the strength of facilitation increases with increasing water levels. Our results support the prediction of the stress-gradient hypothesis (SGH) that plant-plant interactions should switch from competition to facilitation along an increasing water-level stress gradient.