Magnitude and Patterns of Change in Submerged Aquatic Vegetation of the Tidal Freshwater Hudson River
Magnitude and Patterns of Change in Submerged Aquatic Vegetation of the Tidal Freshwater Hudson River
复制标题
潮汐淡水哈德逊河水下植被变化的幅度和模式
DOI：
10.1007/s12237-013-9758-1
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发表时间：
2014
影响因子：
2.7
通讯作者：
N. Curri
中科院分区：
文献类型：
--
作者：
S. Findlay;D. Strayer;S. D. Smith;N. Curri
三个航空摄影库存被用来检查的变化淹没水生植被（SAV）在潮汐淡水哈德逊河在1997年至2007年的间隔。总体而言，SAV覆盖率净下降约30%，尽管也有许多个别领域的扩张。入侵的菱角（菱）没有明显的变化，在网覆盖的时间间隔，并有取代SAV的菱角沿着与SAV取代异国情调的情况略少。细尺度（100米乘100米的样方）分析表明，约30%的样方，支持植被变化超过10%的植物覆盖和整体SAV是相当动态的。哈德逊河的SAV受光照的限制，而光照又受悬浮泥沙的控制。SAV很少被发现在深度>1米以下的低水位，年际差异的清晰度影响SAV床的能力，以保持局部过饱和水平的溶解氧。我们发现，在河道内的位置（接近海岸）影响的幅度和变化的SAV之间的普查期间。邻近海岸线的物理性质也影响了变化的幅度，硬工程海岸类型附近地区的覆盖率下降幅度更大。SAV在哈德逊是高度动态的，显然是相当有弹性的，和控制光悬浮沉积物，而不是浮游植物的生长提供了一个对比的富营养化影响的变化，在其他河口。SAV栖息地的管理和保护必须认识到植物覆盖的高度可变性，并且在任何特定年份的缺失并不妨碍该位置未来出现沉水植物。
Three aerial photography inventories were used to examine change in submerged aquatic vegetation (SAV) in the tidal freshwater Hudson River over the interval 1997 to 2007. Overall, there was about a 30 % net decline in SAV coverage although there were also many individual areas of expansion. The invasive water chestnut (Trapa natans) did not change appreciably in net cover over the interval, and there was replacement of SAV by water chestnut along with slightly fewer cases of SAV replacing the exotic. A fine-scale (100 m by 100 m quadrats) analysis showed that about 30 % of quadrats that supported vegetation changed by more than 10 % in plant cover and overall SAV was quite dynamic. SAV in the Hudson is limited by light which is in turn controlled by suspended sediment. SAV was rarely found at depths >1 m below low water, and interannual differences in clarity affected the ability of SAV beds to maintain locally supersaturated levels of dissolved oxygen. We found that location within the River channel (proximity to shore) influenced the magnitude and variability in change in SAV between census periods. The physical nature of the adjacent shoreline also affected the magnitude of change with greater declines in cover in areas next to hard-engineered shore types. SAV in the Hudson is highly dynamic, apparently quite resilient, and the control of light by suspended sediment rather than phytoplankton growth offers a contrast to eutrophication-influenced changes in other estuaries. Management and protection of SAV habitat must recognize the highly variable nature of plant cover and that absence in any particular year does not preclude future appearance of submerged plants at that location.