《Wetland》杂志刊登“美国华盛顿州山地湖三角洲植被对水位变化的响应”

作者：David M.Chapin;Dwayne K.Paige

刊物：《湿地》，2013年6月

关键词：水文周期；莎草科；杨柳；三角洲植被；受控湖泊

摘要：水位波动对河湖岸边湿地植被结构的意义是众所周知的，但是对驱使植被群落变化的水文周期组分却不甚明了。本研究以河流三角洲植物群落为特点，探究了变化水位下的主要物种的分布和其水文周期。在三个超过18年的时间段中，我们绘制了植物群落图，并沿高程分布按可比点制作出主要植被群落的水文周期图。这些多样性较低的群落类型(莎草,柳树,杨木/桤木)通常随着湖泊水位上升而转移到上坡。水文周期图显示占主导地位的莎草科物种（胀囊苔草）随湖泊水位上升而向上坡移动，从而维持相似水文周期，但是占主导地位的灌木物种（柳树）却没有这种现象。莎草下边界与夏末的水位呈现较好的关联关系，这表明洪水持续时间和生长期长度可能控制着莎草植被的下限。高山柳的分布可能最初受到最大深度的控制，其次是受洪水持续时间的控制。水文周期图非常简便的把湿地植被分布和关键水文变量关联起来，并能预测植被对未来水库水位的响应。

Response of Delta Vegetation to Water Level Changes in a Regulated Mountain Lake, Washington State, USA

Authors:David M.Chapin;Dwayne K.Paige

Journal: 《Wetland》,June,2013

Keywords: Hydroperiod;Sedges;Willows;Delta vegetation;Regulated lake

Abstract: Water level fluctuations are well known to structure wetland vegetation along lakeshores, but the hydroperiod components that drive plant community change are often not differentiated. This study characterized river delta plant communities and examined the distribution and hydroperiods of dominant species in response to a changing, hypervariable lake water regime. At three intervals over an 18 year period we mapped plant communties and developed hydroperiod graphs of dominant plant species at comparable points along their elevation distribution. These low diversity community types (sedge, willow, and cottonwood/alder dominated) generally shifted upslope as lake water levels increased. Hydroperiod graphs showed that the dominant sedge species (Carex vesicaria) moved upslope enough to maintain a similar hydroperiod as lake water levels increased, but the dominant shrub species (Salix spp.) did not. The lower sedge boundary was best correlated to late summer water levels, indicating that inundation duration and growing season length was likely controlling the lower limit of sedge vegetation. Salix spp. distribution was likely controlled primarily by maximum depth and secondarily by inundation duration. Hydroperiod graphs provide a simple way of relating key hydrologic variables to the distribution of wetland vegetation, and to predict vegetation response to future reservoir water levels.

链接：http://link.springer.com/article/10.1007/s13157-013-0401-5