Reed (Phragmites australis) decline in a brackish wetland in Italy
Reed (Phragmites australis) decline in a brackish wetland in Italy
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DOI：
10.1016/s0141-1136(02)00091-0
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发表时间：
2002-06-01
影响因子：
3.3
通讯作者：
Gerdol, R
中科院分区：
文献类型：
--
作者：
Fogli, S;Marchesini, R;Gerdol, R
在北方意大利半咸水湿地的两个试验点（健康试验点和衰退试验点）进行了对比研究，目的是调查导致该地区芦苇（Phragmites australis）衰退的症状和可能原因。下降的芦苇植物呈现出许多症状（丛生的习惯，较小的尺寸，较弱的秆，异常的根茎和根解剖，根茎中的淀粉含量低），包括在所谓的芦苇枯死综合征，经常观察到在中欧湿地，但从未记录以前在（亚）地中海地区。两个地点的土壤养分水平差别不大，健康地点土壤中的硝酸盐浓度甚至更高（1.54 mug g（-1）;枯死地点0.76 mug g（-1））。因此，富营养化似乎并不代表一个主要原因，在determinina芦苇下降，在这个地区。高浓度的硫酸盐与低的土壤氧化还原电位（-215 mV），由于涝渍导致土壤硫化物浓度高，有机酸，特别是乙酸的浓度，没有显着差异的网站之间。高硫化物水平大概占异常的解剖结构（愈伤组织阻塞acrenchyma通道），较低的净CO2交换率和减少储备存储，观察在枯死网站。这与芦苇秆较低的机械阻力有关，这加速了枯梢区芦苇的死亡。我们得出的结论是，高硫化物水平的永久性积水土壤可能会导致死亡的芦苇站在地中海湿地。(C)2002爱思唯尔科技有限公司。保留所有权利。
A comparative field study was carried out at two sites (a healthy site and a declining site) in a brackish wetland in northern Italy, with the objective to investigate the symptoms and the possible causes leading to reed (Phragmites australis) decline in this area. The declining reed plants presented many of the symptoms (clumping habit, smaller size, weaker culms, abnormal rhizome and root anatomy, tow starch levels in rhizomes) comprised within the so-called reed die-back syndrome, frequently observed in central European wetlands but never recorded previously in (Sub)Mediterranean regions. Soil nutrient levels did not differ much between the two sites, with nitrate concentrations in the soil being even higher at the healthy site (1.54 mug g(-1); die-back site 0.76 mug g(-1)). Hence, eutrophication did not seem to represent a major cause in determinina reed decline in this area. High sulphate concentrations in saltwater associated with low soil redox potentials (-215 mV) due to waterlogging resulted in high soil sulphide concentrations, Concentrations of organic acids, especially acetic acid, did not differ remarkably between sites. High sulphide levels presumably accounted for abnormal anatomical formations (callus blocking acrenchyma channels), lower rates of net CO2 exchange and reduced reserve storage, observed at the die-back site. This was associated with a lower mechanical resistance of reed culms which accelerated reed mortality in the die-back areas. We concluded that high sulphide levels in permanently waterlogged soils may result in die-back of reed stands in Mediterranean wetlands. (C) 2002 Elsevier Science Ltd. All rights reserved.