Einsatz von Pflanzenkläranlagen zur Behandlung von schadstoffbelastetem Oberflächenabfluß städtischer Straßen

A combination of retention pond and reed bed was tested for its effectiveness in reducing non-point source runoff pollution from an urban area. This paper presents data on the development of reed plants (Phragmites australis Cav. Trin.), on the effectiveness of runoff purification and on the accumulation of contaminants in the pond sediment and the reed bed for the years 1993–1995. P. australis was well established and grew according to normal development. The measured length and biomass values of P. australis were larger on sand than on gravel and coarse materials. Toxic levels of heavy metals in the plants were not reached. Harvested plants can be composted. The purification system is effective within the following ranges: The rate of retention of suspended solids and heavy metals varies between 16% and 91%. For chemical oxygen demand the average values is 25%. Poor retention rates usually occur along with very low input concentrations. Generally retention within the reed bed is higher than in the pond. Between 1993 and 1995 the concentration of contaminants within the organic layer of the reed bed increased by 50% for lead and by 90% for poly aromatic hydrocarbons. Until 1994 the concentrations of mineral oil hydrocarbons also increased by 60%. Between 1994 and 1995 however the concentration of mineral oil hydrocarbons in the reed bed decreased rapidly by more than 50%: Mineral oil hydrocarbons underlie biological degradation within the reed bed. In the pond sediment a significant accumulation of heavy metals, poly aromatic hydrocarbons and mineral oil hydrocarbons has also been found. The concentrations of these contaminants are still far from inhibiting the function of the system.     

The European research project on reed die-back and progression (EUREED)

Reeds (Phragmites australis (Cav.) Trin. ex Steudel) are dying back at a fast rate in sizeable areas of Europe, with significant impacts on important wetland functions (biodiversity, stability of river and lake margins, water quality) and local economy. EUREED is a European strategic fundamental research initiative that aims at analyzing the mechanisms which control the growth dynamics and stability of reed-dominated ecosystems, at modelling and predicting how the ecosystem is disturbed by human activities and climate change, and at developing remedial management options. Expected achievements include (i) assessment of the functional role of reed-dominated ecotones as nutrient accumulators and transformers and as sources for atmospheric greenhouse gases, (ii) an ecosystem model capable of predicting future changes in ecosystem functioning in relation to climatic conditions, trophic status and water table management, (iii) assessment of genetic diversity of reed populations and its relation to die-back, and (iv) development of management tools, including preventative and restorative measures in relation to die-back. The project is carried out by research groups with complimentary skills and expertise from nine European countries. A reference study site is selected in each country as the basis for the field studies. The reference sites cover boreal-mediterranean and oceanic-continental climatic gradients, and the observational and experimental studies at these sites will permit interpolation between sites and extrapolation of results to the European scale.     

Stickstoff- und Kohlenhydratspeicherung in Rhizomen von Phragmites australis (Cav.) Trin. ex Steudel an unterschiedlichen aquatischen Standorten oberbayerischer Seen

Nitrogen and carbohydrate utilization in Phragmites australis rhizomes was investigated under natural conditions at 10 sites in 5 lakes in Upper Bavaria over a period of two years. Nitrate and ammonium of surface and interstitial water was determined. The results indicate that conditions of habitat and environment, such as climate and fluctuation of water level, lead to different adaptations of reed. These parameters had an effect on the storage of nitrogen and carbohydrate. The reed stands exposed to high water level during spring and summer have a high carbohydrate content in the rhizomes. A positive correlation was shown between the aboveground biomass and the content of storaged carbohydrates during the vegetation period. No relationship could be demonstrated between the nitrogen availability of the habitats and the type of storage of carbohydrates and nitrogen. The nitrogen content in the rhizomes can be used as an indicator of the ability of reed stands to produce new secondary shoots after shoot loss. The differently established reed genotypes are not able to compensate short-term environmental changes, such as growing leisure problems and higher shoot loss by the increasing appearance of waterfowl, from their reserve storage.     

The impact of reed-protecting structures on littoral zones

The impact of several types of reed-protecting structures on hydrodynamic conditions, sediment properties and littoral water quality were investigated. All types of embankment lead to a dissipation of wave energy. The embankment with fagots (type 1) shows a limited porosity in contrast to the other types examined. All kinds of embankment enhance the accumulation of organic matter at the land/water-interface. Hence, they protect littoral accumulation zones from erosion. The embankment with fagots causes changes in sediment properties at the seaward side of reed belts. The surface of mineral sediments is turned into a fine-grained mud, with a high content of organic matter. Accelerated sedimentary microbial processes (oxygen demand) are produced by increasing nutrient availability (carbon, nitrogen). As a result, the O₂-saturation of water bodies is significantly reduced. This is in contrast to the embankment with wooden partitions and palisades (type 2 and 3), which had no significant effects on sediment conditions and water quality. The consequences of changes in type 1-protected reed stands are discussed. Practical recommendations are given for the further use of reed-protecting structures.     

太湖滨岸带芦苇区沉积物磷的特征

为了进一步揭示大型水生植物对湖泊滨岸带沉积物磷的生物地球化学影响,探讨芦苇(Phragmites austra-lis)群落对沉积物磷的生态效应,于2003年9月18日、10月17日和12月3日,用柱状采样器分别在太湖梅梁湾滨岸带芦苇区和无草对照区采样。用HClO4-H2SO4消化法和H2SO4-H2O2消煮法测定芦苇区和对照区沉积物及芦苇根、茎组织中的总磷含量。结果表明,在芦苇生长旺盛期(9月),芦苇区和对照区沉积物的总磷含量最高,在芦苇生长的衰弱期(10月),其总磷含量次之,在芦苇生长的枯萎期(12月),其总磷含量最低;对照区沉积物距地表0～2cm的表层是磷的富集峰值层,而芦苇生长区距地表4～7cm的沉积物层为磷的富集峰值层;芦苇须根对磷的富集效应大于其根状茎,而芦苇根状茎对磷的富集效应又大于其茎,但它们的总磷含量都小于距根0～2cm范围芦苇根际沉积物的总磷含量。     

芦苇形态结构对黄河三角洲不同生境的响应

植物的形态结构总是与环境相适应。采用光学显微技术和环境扫描电镜技术对黄河三角洲新生湿地河口区和内陆区两种生境下芦苇(Phragmites australis)根解剖结构、叶片解剖和超微结构进行了对比分析。研究结果表明,芦苇叶片和根的形态结构与生态环境有关;两种生境下,芦苇叶片上表皮均有明显泡状细胞群分布,芦苇上下表皮均有气孔分布,且下陷;在河口区,芦苇叶片维管束鞘细胞近上表皮处有较大程度延伸,下表皮处常延伸至近表皮,呈开放状态,叶片表面常有蜡质覆盖;在内陆区,芦苇叶片维管束鞘细胞较大,有的为两层;此外,河口区芦苇根的中皮层细胞分化为明显的通气组织,内皮层凯氏带明显,而内陆区芦苇根的中皮层细胞排列规则,呈辐射状。芦苇在适应不同生境时其形态结构所发生的变化是不同的。叶片维管束鞘细胞的延伸、表皮被蜡质和根中通气组织、凯氏带等结构是芦苇适应河口区盐胁迫的结果;而叶片维管束鞘细胞增大、细胞层数增加和根的中皮层细胞辐射状排列是芦苇适应干旱胁迫的结果。     

闽江河口湿地芦苇和互花米草氮、磷养分季节动态

于2007年对闽江河口湿地优势本地种芦苇(Phragmites australis)和外来入侵种互花米草(Spartina alterniflora)N、P养分含量与生物量进行1 a的观测.结果表明,两种植物地上部分N、P含量的器官分配模式为叶最高,花次之,茎最低,其中芦苇叶N含量显著高于互花米草(n=3,p<0.05);两种植物绿色部分N、P含量高于立枯部分;季节动态为冬、春季节高于夏、秋季节;N、P积累在不同器官的分布大致趋势为叶最高,茎次之,花最低,其中互花米草绿色茎和绿色叶N、P积累量显著高于芦苇(n=3,p<0.05);芦苇地下部分N、P含量变化趋势为0～15 cm最高,15～30 cm次之,30～60 cm最低,而互花米草与之相反;两种植物地下N、P积累量变化都为0～15 cm最高,15～30 cm次之,30～60 cm最低;芦苇地下部分N、P积累量在各个季节始终高于地上部分,但互花米草与之相反.从N/P看,N素为两种植物生产力的重要限制营养因子.     

盘锦湿地芦苇群落生物量动态特征研究

基于2005年4～9月盘锦湿地芦苇生态系统的观测资料,分析了盘锦湿地优势植物芦苇的群落学特性。结果表明:地上生物量峰值出现在7月,4～7月茎重与叶重呈显著的正相关;地下生物量存在明显的季节和垂直变化,其中0～30 cm的芦苇须根最大值出现在7月,根茎最大值出现在6月,30～40 cm深度为生物量变化在垂直剖面的分界线;根冠比以7月为最低,分层营养物质在30 cm以下积累。     

Evapotranspiration partitioning using a simple isotope‐based model in a semiarid marsh wetland in northeastern China

Partitioning evapotranspiration (ET) into evaporation (E) and transpiration (T) in wetlands is important for understanding the hydrological processes in wetlands and the contribution of wetland ET to local and regional water cycling and for designing effective wetland management strategies. Stable water isotopes are useful in the application of ET partitioning through the evaluation of the isotopic compositions of E (δ_E), T (δ_T), and ET (δ_ET) obtained from observation or modelling methods. However, this approach still suffers from potentially large uncertainties in terms of estimating the isotopic endmembers. In this study, we modified the traditional isotope‐based ET partitioning methods to include leaf‐level biological constraints to separately estimate the relative contributions of T from Scirpus triqueter and Phragmites australis and the relative contributions of E from the standing surface water in a semiarid marsh wetland in northeastern China. The results showed that although the δ_T values of S. triqueter and P. australis were rather similar, the mean δ_T values of the 2 species were different from the values of δ_E, making it possible to distinguish the relative contributions of E and T through the use of isotopes. The simulation of leaf water using a non‐steady‐state model indicated obvious deviations in leaf water enrichment (δ_Lb) from isotopic steady states for both species, especially during early mornings and evenings when relative humidity was highest. The isotopic mass balance showed that E accounted for approximately 60% of ET, and T from S. triqueter and P. australis each contributed approximately 20% to ET; this implied that the transpiration of one reed was equivalent to that of 5.25 individuals of S. triqueter. Using the estimated ratio of T to ET and the measured leaf transpiration, the total ET was estimated to be approximately 10 mm day^?1. Using the NSS‐Tr method, the estimated ET was higher than the water loss calculated from the water level gauge. This indicated that the river water and surrounding groundwater were the sources of the marsh wetland, with a supply rate of 8.3 mm day^?1.