Macrophyte distribution in the River Vils (Oberpfalz, Bavaria)
Transcription
Macrophyte distribution in the River Vils (Oberpfalz, Bavaria)
1 Macrophyte distribution in the River Vils (Oberpfalz, Bavaria) Alexander Kohler1, Esther Sonntag1, Matthias Köder1, Karin Pall2, Uwe Veit1, GeorgHeinrich Zeltner1 & Georg A. Janauer3 With 6 figures and 1 table in the text Abstract: The macrophyte vegetation of the eutrophic River Vils (Oberpfalz, Bavaria) was surveyed and mapped in summer 1999. Regarding carbonate content, the river is of medium to rather hard. The macrophyte diversity is relatively high. In the Vils 26 tracheophytic hydrophytes, 24 tracheophytic amphiphytes and 37 helophytic species were found. The picture is dominated by eutrophent elements like Potamogeton pectinatus, Ceratophyllum demensum, Sparganium emersum and others. Floristic specialities in the Vils are the hybrids Potamogeton x fluitans and Potamogeton x schreberi. The distribution diagram shows patterns for several species in the river course. According to changes in the floristic composition and river-morphological structures, the river could be divided into five reaches (A-E). These reaches were characterized regarding Relative Plant Mass (RPM) and species numbers as well as Mean Mass Index and Relative Area Length. The RPM values in combination with species numbers revealed important new aspects regarding biodiversity and the dominance of macrophyte species. Additionally the macrophyte distribution across the river was described by five transects. 1 University of Hohenheim, Institute of Landscape and Plant Ecology (320), D - 70593 Stuttgart, Germany Systema, Bio- und Management Consulting GmbH, Bensasteig 8, A – 1140 Wien, Austria 3 University of Vienna, Institute of Ecology and Conservation Biology, Department of Hydrobotany, Althanstrasse 14, A – 1090 Vienna, Austria 2 2 Introduction The eutrophic, carbonate-rich River Vils is a tributary to the Naab in the German Danube catchment. Industrial and urban pollution as well as diffuse loading from agricultural areas through which the river flows, results in a critically loaded system over long stretches. Some reaches have improved due to construction of sewage treatment plants. Several barrages and other management impacts have changed the river bed of the Vils to a great extent. In spite of these anthropogenic influences, the river still has a remarkable and especially rich macrophyte vegetation. This was surveyed for the first time in Summer 1990 (JUNGE et al. 1991) and the survey was repeated by our team in Summer 2000 (SONNTAG et al. 2000). The following problems were investigated: - What is the macrophyte composition in a eutrophic and turbid running water? - Are there species with a distinctive distribution pattern along the river and is it possible to differentiate floristic, ecological river zones? - In which way can the vegetation of the river with its five reaches be characterized quantitatively by means of the parameters Mean Mass Index, Relative Plant mass and species numbers? - Which additional information does the investigation of the macrophytic distribution across the river provide concerning the characterization of the vegetation? Survey area The Vils is a typical river in a hilly landscape of medium elevation. The catchment area is 1096 km2 and comprises the "Oberpfälzer Hügelland", which is dominated by sandstones (Keuper, Buntsandstein), and the "Nördliche and Mittlere Frankenalb" (Figure 1). South of the town of Amberg, the river runs through a deep cut valley in jurassic limestone. The 3 gradient is between 5 and 1.5‰. The main land use types are agriculture (47%) and forestry (42%). From the source to Vilshofen, the saprobic quality is "critically loaded" (quality class 2-3) and from there on to the confluence with the Naab it is "fairly loaded" (Quality class 2) (Figure 2, WWA-Info.1 1996, cited after SONNTAG et al. 2000). In the upper reaches the structural quality of the river is "near natural", and some reaches in the lower stretch of the river are of the same quality (Figure 2). Overall only 10% of the river is of near-natural quality. The total water hardness of the Vils is between 10 and 19.8° DH ("medium hard" to "rather hard" water, Höll, 1996). Water hardness, as well as carbonate hardness (8-16° K.H.), rises in the jurassic stretch. Electrical conductivity rises down river from 370-595 µS.cm-1. The pH is close to 8.0, which is typical for water rich in hydrogen-carbonate (SONNTAG et al. 2000). In several stretches, the aquatic vegetation was cut with electrical underwater scythes. After a severe decrease in the aquatic vegetation only a stretch in the middle of the river channel is now being cut. Methods The entire river from the source to its confluence with the Naab (87 km length) was surveyed following the method of KOHLER (1978). The quantitative assay is described by JANAUER et al. (1993), KOHLER & JANAUER (1995), PALL & JANAUER (1995). A more detailed description was given by SONNTAG et al. (2000). Results Occurrence of macrophytes in the River Vils 4 Macrophyte taxa and growth forms are collated in Table 1. The floristic list is divided into hydrophytes, amphiphytes and helophytes. Several macrophyte species of the Vils River are noted in the "red list of Germany". Butomus umbellatus, Groenlandia densa, Potamogeton alpinus, Potamogeton berchtholdii, P. nodosus, P. perfoliatus, and Eleocharis ovata and Matteuccia struthiopteris are endangered in Bavaria on level 3 ("endangered", Rote Liste gefährdeter Pflanzen Deutschland, 1996) (all authors of the species names are claimed in T. 1). The hybrids of Potamogeton, P. x fluitans and P. x schreberi are probably rare taxa (all authors of the species names are claimed in T. 1). Little is known about their distribution and habitat conditions in Southern Germany and they should be looked for in other water bodies. P. x schreberi was found in the Vils near Hahnbach in 1936 (GLÜCK 1936) (all authors of the species names are claimed in Table 1). Regarding neophytic species in the Vils, Elodea canadensis is the only agriophytic neophyte among the hydrophytes. The ubiquitous and spreading Elodea nuttallii was not (yet) found in the Vils by 1999 (all authors of the species names are claimed in T. 1). In the riparian reach Arch angelica and Impatiens glandulifera are notable neophytic plants. Pattern-building macrophyte species Some macrophyte species show distinctive distribution patterns in the run of the river (Figure 3). The highly eutraphent bleustophyte, Ceratophyllum demersum (indicator value 3.18, SCHNEIDER 2000) is widely distributed but it is missing in the upper reaches and near the mouth (from survey stretch 109 down river). Sagittaria sagittifolia is also eutraphent (IW 2.98), occurring down river of survey stretch 19 but is missing near the mouth. Potamogeton nodosus (highly eutraphent: IW 3.10) has two centres of occurrence. Ranunculus fluitans (IW 3.00) is found below the confluence of the Rosenbach into the town of Amberg. Several hydrophytic species are missing in the uppermost reach. These are Myriophyllum spicatum 5 (IW 2.83), P. pectinatus (IW: 2.88) and E. canadensis (IW 2.55). Callitriche hamulata (IW 1.80), P. crispus (IW 2.88) and Nuphar lutea (IW 3.15). In the lowermost reaches of the river. Berula erecta (IW 2.65) occurs only downriver of survey stretch 1.09. P. berchtholdii (IW 2.40) has its focus of occurrence in the lower half of the river. A direct ecological relationship between habitat parameters and the pattern of occurrence of species is not possible, because the number of chemical data are not sufficient. Yet, based on the changes in floristic composition and those of river morphology, the Vils could be divided into five reaches (A – E, SONNTAG et al. 2000). These reaches will be compared regarding their Relative Plant Mass (RPM)-diagrams, which only contain "higher" hydrophytes and amphiphytes (tracheophytic species). A more detailed comparison regarding Mean Mass Indices and other aspects is given by SONNTAG et al. (2000). Mean Mass Index and Distribution Ratio "d" In the entire river only five species occur with high MMO-and MMT-values (>3, Figure 4). These species are hydrophytic: M. spicatum, E. canadensis, and P. pectinatus, and the amphiphytes Phalaris arundinacea and Sparganium emersum (type 1, JANAUER et al. 1993). Clumped occurrence (type 2) is typical for P. perfoliatus, Ranunculus trichophyllus, R. peltatus and some amphiphytes like Glyceria maxima, Sparganium erectum and B. erecta. According to their respective MMO-/MMT-values P. lucens, G. densa, B. umbellatus, Schoenoplectus lacustris, Alisma plantago-aquatica, P. x fluitans, M. verticillatum, P. alpinus are rare taxa. This is not surprising regarding oligo-traphent species like G. densa (IW 1.83) and P. alpinus (IW 1.55) in a river with eutrophic conditions. Eutraphent taxa like B. umbellatus (IW 2.98) and P. lucens (IW 2.65) are dominant in other eutrophic rivers, e.g. in the province of Schonen in Southern Sweden (KOHLER et al. 2000, SIPOS et al. 2000, SONNTAG et al. 1999). 6 A quantitative expression for the proportion of individual river reaches inhabited by certain species is the Distribution Ratio (which is numerically equivalent to the Relative Area-Length Lr, Figure 2). A wide distribution in the river (> 50%) is typical for the hydrophytes M. spicatum, P. pectinatus, E. canadensis and C. hamulata, and the amphiphytes P. arundinacea and S. emersum. Values between 40-50% are reached by P. crispus, C. demersum, L. minor, P. berchtholdii, N. lutea, Spirodela polyrhiza, Callitriche cophocarpa, Myosotis scorpioides and S. sagittifolia, and the haptophyte, Fontinalis antipyretica. The distribution ratios (d) of all other species are much lower. Relative Plant Mass and Species Numbers The Relative Plant Mass (RPM)-values were calculated only for tracheophytic hydrophytes and amphiphytes. RPM-values >10% are only reached by the amphiphytes P. arundinacea, S. emersum and by the hydrophyte, P. pectinatus (Figure 5). Upon comparison, the river reaches A – E show remarkable differences regarding the dominance and diversity of the species. In river zone A, where no tracheophytes occurred, the amphiphytic P. arundinacea dominated (48% RPM). In river zone B the dominant species is the hydrophytic E. canadensis (28%), followed by P. arundinacea (19% RPM). River zone C has no highly dominant species. P. arundinacea, P. pectinatus and S. emersum reach values between 13%-10%. In river zone D, S. emersum dominates (23% RPM), followed by P. arundinacea, M. spicatum and E. canadensis (12-10% RPM). The lower reach of the river (zone E) is dominated by B. erecta (16% RPM). A highly interesting result is the species number of hydrophytes and amphiphytes in the river and in the floristic-ecological river zones A – E. 26 hydrophytic species out of a total of 50 recorded is a very high value regarding conditions in running waters in Southern Germany. With respect to the fact that only 10% of the Vils is 7 structurally close to natural conditions, this is a remarkable fact. In Southern Sweden, where the river structure is rarely ever influenced, but the rivers are similarly eutrophic, species numbers are between 61 (Kävlingean, hydrophytes 30), and 51 (Björkaän, hydrophytic species: 21, SIPOS 2001). River zones A – E show remarkable differences in species numbers in the field. In river zone, E only eight species occur, which comprise no tracheophytes. Species richness increases down-river (zone B: 26, zone C: 38 species), whereas the highest number of tracheophytic hydrophytes is reached in zone C, where 20 taxa were found. In addition to the longitudinal survey of the Vils five transects were mapped. Transects of one metre width and 1 x 0.4-1.5 m aerial units were placed in characteristic and/or floristically interesting locations. Within the survey units of the belt transect the cover (%) of the macrophyte species present was estimated, which is graphically displayed in a bar diagram (Figure 6). • the first transect was in the upper reach of survey stretch 80. The river is 3 m wide and a maximum of 0.275 m deep. The substrate is sandy, the flow is slow with little turbulence. only a few helophytes can live on the deep banks. Persicaria lapathifolia grows on the bank. R. peltatus forms thick swathes in the middle of the river (cover 75-100%). Neophytic E. canadensis is ubiquitous over the whole width of the river bed with changing cover. P. crispus grows in the southern half of the river only (cover up to 50%). • The 2nd transect was located in survey stretch 2.20 m north of the bridge at VilseckSorghof. The river is 9 m wide and 0.9 m deep. The flow is slow and the substrate is gravel. M. spicatum is distributed over the whole transect in all depths, E. canadensis occurs only near the banks. • Transect 3 was located in survey stretch 34. The river is 10.4 m wide. The side is close to the road between sewage treatment plants at Hallenbach and Kümmersbuch. The substrate in the centre of the channel is gravel, closer to the banks it is muddy. The southern bank 8 was filled in with large gravel. Maximum depth is 1.35 m. Flow is slow. Amphiphytic S. emersum is found across the whole transect, except in the fresh fill-in in the south. High cover is reached by P. crispus, P. pectinatus (up to 100%), and E. canadensis (up to 75%). • Transect 4 was located in survey stretch 46, 100 m south of the bridge in Traßelberg. The banks are constructed with rip-rap, the river bottom is comprised of gravel and / or stones. The river 11 m wide and maximum depth is 0.48 m. Flow is slow. M. spicatum and the haptophyte, F. antipyretica grow almost across the whole transect. R. fluitans is dominant in the middle of the channel (cover 25-75%). • The last transect was in the lower reach of the Vils, survey stretch 113, in Schmidmühlen. River width is 15.5 m, maximum depth is 0.7 m. Turbulent flow is found over gravel and stone substrates. In the river centre C. hamulata occurs with medium and high cover. All other species grow closer to the banks. There B. erecta and S. emersum can reach high cover (50-75%). Discussion The Vils represents a eutrophic, calcium, hydrogen-carbonate rich river of medium elevation. The species inventory is a mirror to the conditions imposed by water chemistry and the eutrophic background. Significant eutraphent species like P. pectinatus, C. demersum, S. sagittifolia, S. emersum, and S. erectum dominate the vegetation over large stretches. The analysis of the aquatic vegetation was surprising. In comparison with other eutrophic rivers, rich in calcium hydrogen carbonate in southern Sweden (SIPOS et al., 2000, SONNTAG et al., 1999), the species richness of the Vils is of quite the same order. The Rivers Björkanon and the Kavlingeön showed species numbers (tracheophytic hydrophytes and amphiphytes) of 51, and 61 taxa, respectively. In the Vils, 50 species occurred. Tracheophytic species are 26 taxa in the Vils, 21 taxa in Björkaän and 30 taxa in Kävlingeän. This is remarkable, because the 9 Vils has only 10% of river reaches in near natural conditions regarding river structure and morphology. In comparison the two rivers in southern Sweden are natural to near-natural over most of their length. Experience with the species inventory of eutrophic rivers makes it probable that they are a type of aquatic biotopes, which are not only characterised by high species numbers, but rather comprise ecosystems in which a number of rare and even endangered taxa have found a refuge. In the Vils several species were found, which are in the red list of Germany and Bayern (ROTE LISTE GEFÄHRDETER PFLANZEN DEUTSCHLANDS, 1996). Among them is the genus Potamogeton. It must be stated also, that in the Vils, Potamogeton hybrids are occurring for which there is no clear present knowledge regarding scarcity, endangerment, and habitat conditions, which should be investigated in the future. P. x fluitans and P. x schreberi are the two hybrids to be named for the Vils. In the Vils, as in other rivers, several species show distinct patterns of distribution along the river course. In originally oligotrophic rivers the distribution pattern of species is often an expression of different trophic conditions. In eutrophic rivers, the distribution pattern cannot be explained by habitat related parameters. This may be due, in part, to a lack of sufficient ecological data. In running waters the absence and / or the distribution of species may have different reasons than those based on habitat parameters (e.g. CAIRNS 1974). Although the Vils can be compared with eutrophic rivers in southern Sweden in terms of its florisitic compositions (e.g. occurrence of common eutrophic elements) definite floristic differences can be seen. A typical, highly dominant amphiphytic "Leitart" (characteristic species) Butomus umbellatus found in the rivers of the province of Schonen, was detected in the Vils only as a single individual. Another typical amphiphyte, S. latifolium, occurring in Swedish rivers, is totally absent in the Vils. 10 Some macrophyte species show distribution patterns in the river (Figure 3). No tracheophytic hydrophytes were present in the upper reaches near the source of the river. The distribution pattern of Ceratophyllum demersum, a highly eutraphent species, can be correlated with the high nutrient levels in the river reaches dominated by it. The occurrence of Sagittaria sagittifolia may be explained by impounded reaches and very fine sediments in the river bed. A very strict differentiation according to floristic-ecological river zones was not done in the Vils, because many of the distribution patterns could not be explicitly explained, even though five river zones (A – E) were distinguished. Several parameters were found to be characteristic (species number, relative plant mass, etc.). River zone A is characterised by the absence of tracheophytic hydrophytes and the dominance of amphiphytes. Very low discharges and, in part, extremely strong shading are the most probable reasons for this phenomenon. The species number is very low (8) in this reach near the source. The amphiophyte, Phalaris arundinacea dominates with 48% RPM. The adjacent river zone B already favours hydrophytes, among which Elodea canadensis is dominant (28% RPM). The total species number increases to 26 (12 hydrophytic) species. River zone C is the most species rich of the Vils: here 38 species occur, among which are 20 tracheophytic hydrophytes. The RPM diagram shows that no highly dominant species occur here and the respective ratios of the taxa vary across a wide range. The high biodiversity of this zone can be explained by the relatively high structural and morphological diversity in the numerous survey stretches in association with close to natural conditions. In river zones D and E the species number decreases again (total: 37, hydrophytic 30 species, total 17, hydrophytic 15 taxa, respectively). Zone D is dominated by Sparganium emersum, zone E by Berula erecta. The examples discussed above show that the RPM diagrams in combination with species numbers of tracheophytic, amphiphytes and hydrophytes are a valuable new instrument to evaluate and compare individual river reaches and to characterise different zones in a 11 qualitative and quantitative way. The Relative Area Length (which is equivalent numerically to the distribution ratio d) and the Mean Mass Indices have been found to be useful parameters for comparison of running waters and their ecological zones. All these parameters are tools for describing dominance, diversity, Mass Ratios and areas of macrophytes in rivers. They are not only a scientific tool for describing the ecology , but they are also useful for management tasks regarding biotopes and species in rivers. Long-term studies have shown that with the help of these numerical tools, definite statements about the effects of river pollution human impacts and restoration measures in rivers can be made (PALL et al. 1999, VEIT et al. 1997). Conclusion The macrophyte vegetation of the eutrophic River Vils (Oberpfalz, Bayern) was surveyed and mapped in Summer 1999. Regarding carbonate content the river is of medium to rather hard. Due to changes in river morphology over the pasted centuries only a few stretches are close to natural regarding the run of the river and its structural features. In spite of these changes the macrophyte diversity is relatively high in the Vils and comes close to eutrophic rivers in southern Sweden, which are structurally intact and close to natural conditions. In the Vils 26 tracheophytic hydrophytes, 24 tracheophytic amphiphytes and 37 helophytic species were found. The picture is dominated by eutraphent elements like Potamogeton pectinatus, Ceratophyllum demersum, Sparganium emersum and others. A few oligotraphent species like Potamogeton alpinus and Groenlandia densa were also detected. Floristic specialities in the Vils are the hybrids Potamogeton x fluitans, and P. x schreberi. The distribution diagram (Figure 3) shows patterns for several species in the river course. The mass development of Ceratophyllum demersum, Potamogeton nodosus and Ranunculus fluitans is probably based on higher nutrient levels. Sagittaria sagittifolia is focused in 12 impoundments with fine sediments and avoids reaches with sandy or gravel bed-sediments. Berula erecta occurs in turbulent, quick flowing and in shallow river reaches near the mouth. According to changes in the floristic composition and river-morphological structures, the river could be divided into five reaches (A – E). These reaches were characterised regarding Relative Plant Mass (RPM) and species numbers for tracheophytic amphiphytes and hydrophytes. The macrophyte distribution across the river was described by 5 transects. Important results were found using the RPM values and species number. The relationships of dominance and biodiversity of macrophytes were much different in five river zones, where the highest species number was found in zone C. However, in contrast to the other floristic zones, the RPM diagrams showed no real dominants here. The high species richness in this river reach may be due to the very near natural morphological and structural characteristics of the river. The methodology regarding the survey of the aquatic vegetation and the preparation of numerical derivatives of field data (KOHLER & JANAUER 1995) also proved successful for the eutrophic Vils River. The RPM values in combination with species numbers revealed important new aspects regarding biodiversity and the dominance of macrophyte species (see SIPOS 2001). Acknowledgements The authors received generous support by many institutions. The Wasserwirtschaftsamt Amberg is thanked for accommodation, boats and numerous background data on the hydrology and physical and chemical conditions of the river. Specials thanks go to Mr. Viehauser and his colleagues of Flussmeisterei Amberg, who supported us all the time in the best way possible. The investigation was financially supported by the Geschwister-StauderSchenkung. 13 References CAIRNS, J. (1974): Indicator species VS. The concept of community structure as an index of pollution. - Water Resources bulletin 10: 338-247. GLÜCK, H. (1936): Die Süßwasserflora Mitteleuropas: Pteridophyten und Phanerogamen. Jena, 486 pp. HÖLL, K. (1996): Wasser - Untersuchung, Beurteilung, Aufbereitung, Chemie, Bakteriologie, Virologie, Biologie. 7. Aufl. - de Gruyter Verlag Berlin, 592 pp. JANAUER, G. A., ZOUFAL, R., CHRISTOF-DIRRY, P. & ENGLMAIER, P. (1993): Neue Aspekte der Charakterisierung und vergleichenden Beurteilung der Gewässervegetation. - Ber. Inst. Landschafts- Pflanzenökologie Univ. Hohenheim 2: 59-70. JUNGE, M., MELZER, A. & ZIMMERMANN, S. (1991, n. p.): Submerse Makrophytenvegetation der Vils/Opf. - Endbericht über die Untersuchungen in der Vegetationsperiode 1990. KOHLER, A. (1978): Methoden der Kartierung von Flora und Vegetation von Süßwasserbiotopen. - Landschaft + Stadt 10: 23-85. KOHLER, A. & JANAUER, G. A. (1995): Zur Methodik der Untersuchung von aquatischen Makrophyten in Fließgewässern. - In: STEINBERG, CH., BERNHARDT, H. & KLAPPER, H. (Hrsg.): Handbuch Angewandte Limnologie. VIII-1.1.3. Ecomed Verlag. KOHLER, A., SIPOS, V., SONNTAG, E., PENKSZA, K., POZZI, D., VEIT, U. & BJÖRK, S. (2000): Makrophyten-Verbreitung und Standortqualität im eutrophen Björka-Kävlinge-Fluss (Skåne, Südschweden). - Limnologica 30: 281-298. PALL, K. & JANAUER, G. A. (1995): Die Makrophyten-Vegetation von Flußstauen am Beispiel der Donau zwischen Fluß-km 2552,0 und 2511,8 in der Bundesrepublik Deutschland. Arch. Hydrobiol. Suppl. 101, Large Rivers 9/2: 91-109. 14 PALL, K., JANAUER, G. A. & DOKULIL, M. (1999): Sanierung der Alten Donau in Wien Entwicklung der Makrophytenbestände. - Deutsche Gesellschaft für Limnologie, Tagungsber. 1998 Klagenfurt: 269-277. ROTE LISTE GEFÄHRDETER PFLANZEN DEUTSCHLANDS (1996): Bundesamt für Naturschutz Bonn-Bad Godesberg (Hrsg.). 744 pp. SCHNEIDER, S. (2000): Entwicklung eines Makrophytenindex zur Trophieindikation in Fließgewässern. - Shaker Verlag, Aachen, 182 pp. SIPOS, V., KOHLER, A. & BJÖRK, S. (2000): Makrophyten-Vegetation und Standorte im eutrophen Björka-Fluß (Südschweden). - Bot. Jahrb. Syst. 122: 93-152. SIPOS, V. (2001): Makrophyten-Vegetation und Standorte in eutrophen und humosen Fließgewässern - Beispiele aus Südschweden und Ungarn. Diss. Univ. Hohenheim. SONNTAG, E., POZZI, D., PENKSZA, K., ZELTNER, G.-H., BJÖRK, S. & KOHLER, A. (1999): Makrophyten-Vegetation und Standorte im eutrophen Kävlinge-Fluß (Skåne, Südschweden). - Ber. Inst. Landschafts- Pflanzenökologie Univ. Hohenheim, Beih. 9, 113 pp. SONNTAG, E., KÖDER, M., KOHLER, A., PALL, K. & ZELTNER, G.-H. (2000): MakrophytenVegetation und Standorte der Vils (Oberpfalz, Bayern). - Ber. Inst. LandschaftsPflanzenökologie Univ. Hohenheim, Beih. 10: 59 pp. VEIT, U., ZELTNER, G. H. & Kohler, A. (1997): Die Makrophyten-Vegetation des Fließgewässersystems der Friedberger Au (bei Augsburg). Ihre Entwicklung von 1972 bis 1996. - Ber. Inst. Landschafts- Pflanzenökologie Univ. Hohenheim, Beih. 4: 7-241. WWA-INFO (1996): Wasserwirtschaftsamt Amberg: Die Vils in der Oberpfalz. – Druckhaus Oberpfalz, Amberg, 4 pp. 15 Figures Fig. 1: Examination area of the River Vils with its catchment area and the natural land units. Fig. 2: Water quality (saprobity system) and structural quality of the River Vils according to WWA-INFO (1996). Fig. 3: Distribution diagram of hydrophytic, amphiphytic, helophytic and haptophytic species from the spring (left side) to the mouth (right side) of the River Vils. Fig. 4: Mean Mass Index (white: MMO, black: MMT) and „Relative Area Length“ (d) for the complete River Vils. Fig. 5: Relative Plant Mass (RPM) for the River Vils and its five reaches. Species with an RPM value < 1 % are represented in the „residual“. Fig. 6: Macrophytic distribution across the river at five different sites in the River Vils. 16 Tables Tab. 1: Species list of the River Vils. Fig. 1 Fig. 2 10 10 0 0 0 40 40 30 20 30 8 1996 Ran glu 10 residual Pot ber residual Gro den Cha his Jun sub Pot ber residual Spa eee Pot ber Jun art Cha vul Ran tri Elo can Ver ana residual Spa nat Cha his Ran tri Pha aru Jun sub Cha vul Pot pec Agr sto Gro den 1972 Myo sco Elo can Ran glu Jun sub Ran glu Pot pec Nas oem Ver ana Nas oem RPM [%] 1972 Gro den Jun art Spa eee Ran tri Pot pec Ran tri Nas oem Jun art Ver ana Agr sto Agr sto Pha aru Men aqu Pot col Ber ere residual Agr sto Ground water ditches residual Ran tri Lem min Jun sub Ran glu Cha vul Pot col Ran glu Pot pec Friedberger Ach residual 0 Pot pec 1992 Spa eee 10 Nas oem 1987 Pot ber 14 Pha aru 1982 Agr sto 30 Pot col 1978 Elo can 20 Cha vul 40 30 Jun sub 40 Ran glu 0 Jun sub 8 Ver ana 30 Pha aru 20 Nas oem 40 30 Pot col 40 Agr sto 0 Ver ana 0 Nas oem 10 Pot col 30 Ver ana 30 Pot pec 40 Pha aru 40 Pot col 0 Pha aru 0 Ber ere 30 Men aqu 40 30 Ber ere 0 Men aqu 0 Ber ere 40 RPM [%] 10 Men aqu 20 Ber ere residual Gly flu Ran flu Agr sto Spa eee 9 RPM [%] Zan pal Pot pec Pot cri Myo sco 30 Men aqu residual Gly flu Pot cri Myo sco 10 Pha aru Nas oem Myr spi Ber ere Zan pal Ran tri Elo can RPM [%] 40 30 Ber ere Ran glu Gro den 10 Men aqu Ran glu Cal obt Ver ana Nas oem Myr spi 20 RPM [%] 10 Men aqu Myo sco Pot cri Agr sto Ver ana Cal obt Pot pec 10 Pha aru Ber ere Ran tri Elo can RPM [%] 9 RPM [%] residual Agr sto 10 Pha aru Nas oem Myr spi Zan pal Ran tri Elo can Ber ere RPM [%] 40 Men aqu residual Spi pol Pot col Lem min Cal obt Nas oem Pot cri Elo can Ver ana Myr spi Ber ere Pha aru Myo sco Pot pec RPM [%] 20 RPM [%] 10 Pha aru Cal obt Myo sco Fon ant Nas oem Ver ana Lem min Pot cri Elo can Myr spi Pot pec Ber ere Ran tri Zan pal 10 residual Pot ber Fon ant Nas oem Myo sco Agr sto Myr spi Cal obt Ran glu Pot cri Elo can Myr ver Ber ere Ran tri Zan pal RPM [%] 0 Ver ana Pha aru Ran tri Zan pal Pot pec RPM [%] Fig. 3 20 12 1978 20 11 1982 20 8 1987 20 9 1992 20 16 1996 20 14 Fig. 4 Myr spi Myr spi Pot pec Pot pec Elo can Elo can Cal ham Cal ham Pot cri Pot cri Cer dem Cer dem Lem min Lem min Pot ber Pot ber Nup lut Nup lut Spi pol Spi pol Cal cop Cal cop Ran cir Ran cir Ran tri Ran tri Pot per Pot per Gro den Gro den Pha aru Pha aru Spa eme Spa eme Myo sco Myo sco Sag sag Sag sag Ver bec Ver bec Cal pal Cal pal Ror amp Ror amp Gly max Gly max Agr sto Agr sto Spa ere Spa ere Ber ere Ber ere Ver a-a Ver a-a Men aqu Men aqu Ang arc Ang arc But umb But umb Fon ant Fon ant 12 3 4 MMT 5 MMO 0 0,25 0,5 d 0,75 1 Pot per Spa ere 20 10 0 residual Pot cri Spi pol Ror amp Myo sco Pot ber Cal ham Gly max Myr spi Spa eme RPM (%) 20 residual Ran cir Cal pal Pot nod Ver bec Myo sco Cal ham Sag sag Spa ere Myr spi Spa eme Pha aru RPM (%) Pot nat Ver bec Per lap Spa eme Cal ham Elo can RPM (%) residual Cal pal Myo sco Agr sto Ver bec Gly dec Nas off Pha aru RPM (%) 48 Ror amp Myo sco Cal cop Myr spi Spa eme Ber ere RPM (%) residual Per lap Ror amp Cal cop Spi pol Lem min Ver bec Pot ber Spa ere Nup lut Ber ere Cer dem Myo sco Sag sag Pot cri Gly max Cal ham Myr spi Elo can Pot pec Spa eme Pha aru RPM (%) Fig. 5 30 Vils, all sections 20 H: 11+15=26 A: 10+14=24 10 G: 50 0 30 zone A 20 H: 0+0=0 A: 7+1=8 10 G: 8 0 30 zone B 20 A: 5+9=14 H: 6+6=12 10 G: 26 0 zone C 30 20 H: 11+9=20 A: 11+6=17 10 G: 37 0 30 zone D H: 10+7=17 A: 8+12=20 10 G: 37 0 30 zone E A: 8+7=15 H: 7+8=15 G: 30 Fig. 6 Transect 1 in section 80 S N 0 depth (m) 0,2 width (m) 0 1 2 3 Rumex aquaticus Epilobium roseum Persicaria lapathifolia Potamogeton crispus Callitriche hamulata Elodea canadensis Ranuculus peltatus W Transect 2 in section 2 O 0 depth (m) 0,2 0,4 0,6 0,8 1,0 width (m) 0 1 2 3 4 5 6 7 8 9 Callitriche hamulata Phalaris arundinacea Carex acuta Elodea canadensis Potamogeton pectinatus Potamogeton berchtoldii Myriophyllum spicatum Sparganium emersum Transect 3 insection 34 N S depth (m) 0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 width (m) 0 1 2 3 4 5 6 7 8 9 10 10,4 Spirodela polyrhiza Filipendula ulmaria Potamogeton crispus Ceratophyllum demersum Sagittaria sagittifolia Potamogeton pectinatus Elodea canadensis Sparganium emersum Transect 4 in section 46 NO SW 0 depth (m) 0,2 0,4 width (m) 0 1 2 3 4 5 6 7 8 9 10 11 Phalaris arundinacea Potamogeton pectinatus Fontinalis antipyretica Myriophyllum spicatum Callitriche hamulata Sparganium emersum Agrostis stolonifera Ranunculus fluitans Transect 5 in section 113 W/NW O/SO 0 0,2 0,4 0,6 width (m) 0 1 2 3 4 5 6 7 8 9 10 11 12 Potamogeton berchtoldii Phalaris arundinacea Chlorophyta indet. Fontinalis antipyretica Sparganium emersum Berula erecta Callitriche hamulata coverage (%) 0-25 25-50 50-75 75-100 13 14 15 15,5 depth (m) Tab. 1 Species list of the River Vils (Oberpfalz, Bavaria) Species Abbreviation Occurrence Growth form (Cal cop) (Cal ham) (Cer dem) (Elo can) (Gro den) (Lem min) (Lem gib) (Myr spi) (Myr ver) (Nup lut) (Pot alp) (Pot ber) (Pot xfl) (Pot cri) (Pot luc) (Pot nat) (Pot nod) (Pot xsc) (Pot per) (Pot pec) (Ran flu) (Ran pel) (Ran tri) (Ran spe) (Spi pol) z z z z z z z z z z z z z z z z z z z z z z z z z sr sr mp sr sr ac ac sr sr fl sr sr sr sr sr fl fl fl sr sr sr sr/fl sr (Agr sto) (Ali p-a) (Ang arc) (Bar vul) (Ber ere) (But umb) (Cal pal) (Gly dec) (Gly flu) (Gly max) (Men aqu) (Myo sco) (Nas off) (Per amp) (Per lap) (Pha aru) (Ror amp) (Ror pal) (Sag sag) z z z z z z z z z z z z z z z z z z z am am am, h am, h am am am am am am, h am am am am, f am am, h am am am Hydrophytes Callitriche cophocarpa Sendtn. Callitriche hamulata Kütz ex W.D.J. Koch Ceratophyllum demersum L. Elodea canadensis Michx. Groenlandia densa (l.) Fourr. Lemna minor L. Lemna gibba L. Myriophyllum spicatum L. Myriophyllum verticillatum L. Nuphar lutea (L.) Sibth. & Sm. Potamogeton alpinus Balb. Potamogeton berchtoldii Fieber Potamogeton x fluitans Roth Potamogeton crispus L. Potamogeton lucens L. Potamogeton natans L. Potamogeton nodosus Poir. Potamogeton x schreberi G. Fisch. Potamogeton perfoliatus L. Potamogeton pectinatus L. Ranunculus fluitans Lam. Ranunculus peltatus Schrank Ranunculus trichophyllus Chaix Ranunculus spec. Spirodela polyrhiza (L.) Schleid. ac Amphiphytes Agrostis stolonifera L. Alisma plantago-aquatica L. Angelica archangelica ssp. litoralis (Fr.) Thell. Barbarea vulgaris R. Br. Berula erecta (Huds.) Coville Butomus umbellatus L. Caltha palustris L. Glyceria declinata Bréb. Glyceria fluitans (L.) R. Br. Glyceria maxima (Hartm.) Holmb. Mentha aquatica L. Myosotis scorpioides L. Nasturtium officinale R. Br. Persicaria amphibia (L.) Delarbre Persicaria lapathifolia (L.) Delarbre Phalaris arundinacea L. Rorippa amphibia (L.) Besser Rorippa palustris (L.) Besser Sagittaria sagittifolia L. Tab. 1 Schoenoplectus lacustris (L.) Palla Sparganium emersum Rehmann Sparganium erectum L. Veronica anagallis-aquatica Veronica beccabunga (Sch lac) (Spa eme) (Spa ere) (Ver a-a) (Ver bec) z z z z z am, h am am, h am am (Bid tri) (Car acu) (Car ela) (Car bue) (Car pan) (Ele ova) (Epi hir) (Epi ros) (Equ flu) (Eup can) (Fil ulm) (Gna uli) (Imp gla) (Imp n-t) (Iri pse) (Jun buf) (Jun eff) (Jun inf) (Lys vul) (Lyt sal) (Phr aus) (Poa pal) (Poa tri) (Ran sce) (Rum aqu) (Rum hyd) (Rum pal) (Sci syl) (Scr nod) (Sol dul) (Sta pal) (Sym off) (Typ lat) (Val off) z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z he he he he he he he he he he he he he he he he he he he he he he he he he he he he he he he he he he (Chl ind) (Fon ant) z z Helophytes Bidens tripartita L. Carex acuta L. Carex elata L. Carex buekii Wimm. Carex paniculata L. Eleocharis ovata (Roth) Roem. & Schult. Epilobium hirsutum L. Epilobium roseum Schreb. Equisetum fluviatile L. Eupatorium cannabinum L. Filipendula ulmaria (L.) Maxim. Gnaphalium uliginosum L. Impatiens glandulifera Royle Impatiens noli-tangere L. Iris pseudacorus L. Juncus bufonius L. Juncus effusus L. Juncus inflexus L. Lysimachia vulgaris L. Lythrum salicaria L. Phragmites australis (Cav.) Trin. ex Steud. Poa palustris L. Poa trivialis L. Ranunculus sceleratus L. Rumex aquaticus L. Rumex hydrolapathum Huds. Rumex palustris Sm. Scirpus sylvaticus L. Scrophularia nodosa L. Solanum dulcamara L. Stachys palustris Symphytum officinale L. Typha latifolia L. Valeriana officinalis L. Haptophytes Chlorophyta indet Fontinalis antipyretica Hedw. ac: sp: sr: fl: acropleustophyte submersed pleustophyte submersed rhizophyte floating-leaved rhizophyte am: amphiphytes he: helophytes oe: other emergent species