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... Plots in the L-C and F-CY species communities are grouped together in all methods (Fig. 4). This result supports the view expressed by several authors that F-CY should be included in the L-C community as a nutrient-poor variant of the latter[27,28]. The ModMax algorithm resulted in a slightly higher separation value of L-C community than the other algorithms because it succeeds in identifying a plot that is densely connected with 39 plots from other communities (the plot is marked by an arrow inFig. ...
... However, smooth transitions in plant community assembly between both communities occur frequently[34]. Consequently, several studies have considered the F-CY community as a nutrient-poor form of L-C community and included it into the latter[27,28]. The modularity structure of our network supports that view. ...
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Network modularity is a well-studied large-scale connectivity pattern in networks. The detection of modules in real networks constitutes a crucial step towards a description of the network building blocks and their evolutionary dynamics. The performance of modularity detection algorithms is commonly quantified using simulated networks data. However, a comparison of the modularity algorithms utility for real biological data is scarce. Here we investigate the utility of network modularity algorithms for the classification of ecological plant communities. Plant community classification by the traditional approaches requires prior knowledge about the characteristic and differential species, which are derived from a manual inspection of vegetation tables. Using the raw species abundance data we constructed six different networks that vary in their edge definitions. Four network modularity algorithms were examined for their ability to detect the traditionally recognized plant communities. The use of more restrictive edge definitions significantly increased the accuracy of community detection, that is, the correspondence between network-based and traditional community classification. Random-walk based modularity methods yielded slightly better results than approaches based on the modularity function. For the whole network, the average agreement between the manual classification and the network-based modules is 76% with varying congruence levels for different communities ranging between 11% and 100%. The network-based approach recovered the known ecological gradient from riverside - sand and gravel bank vegetation - to dryer habitats like semidry grassland on dykes. Our results show that networks modularity algorithms offer new avenues of pursuit for the computational analysis of species communities.
... A plant community dominated by P. alpinus has also been described, i.e., not at the rank of a plant association, but only at the rank of the plant community with the participation/predominance of this species [15][16][17]. The Potametum alpini association is listed among endangered plant communities in Europe (e.g., [8,9,13,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]). ...
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Natural water reservoirs are very valuable floristic sites, with springs particularly important for the preservation of floral biodiversity. This paper presents, as a case study, a community of water plants that is new to limnocrene karst springs in Europe: Potametum alpini (Potametea), found in Poland. The paper provides the floristic composition and ecological requirements of this plant association, which is rare and endangered in Europe. According to our knowledge, the habitat data presented here are unique as they are published for the first time for this plant community, and thus it is currently not possible to compare them with data from other authors. Our study confirms the importance of rare microhabitats for global biodiversity. Research on as yet unknown physical and chemical factors limiting the range and development of patches of different plant associations should be conducted intensively, because plant communities, including rare, endangered and protected examples, are an important element of biodiversity at both continental and local scales. All the issues discussed in the paper (rare microhabitats, endangered aquatic plant communities, global biodiversity) are important because they are related to the conservation and management of inland waters.
... It might be inferred that this sawfly species is largely dependent on the availability of alluvial forest dominated by Salix species (German: Weichholzauenwald ). The natural form of this habitat, dependent on inundation, is threatened with complete disappearance in Germany (Rennwald 2000). Throughout the whole catchment of the Elbe in Germany, only small such areas remain; they are normally only subject to flooding where they are situated outside the dykes (Burkart et al. 2003, Dziock et al. 2005). ...
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The sawfly Pseudoclavellaria amerinae was last found in Germany in 1976 and was treated as extinct in the latest national list of endangered species. Two recent occurrences in Saxony-Anhalt, Germany, are reported, and discussed in the context of older distributional data. Most records of P. amerinae in central Europe are from alluvial forest along lowland stretches of major rivers and their tributaries. In eastern Germany, historic and current occurrence is concentrated on the Elbe river system. Data on the larval host plants are reviewed: these are primarily smooth-leaved Salix species (particularly S. fragilis and S. alba), with Populus species as important secondary hosts.
... There is not much data on the distribution of this association, nor its real threat status in Croatia. However, this association is on the Red List of plant communities in Germany (Rennwald 2000). ...
Article
The vegetation communities of the trampled habitats in the Plitvice Lakes National Park were studied during 2005 and 2006. With the numerical classification of the relevés, six clusters were obtained, corresponding to the following specific communities: cluster 1 – ass. Matricario–Polygonetum arenastri– the intensively trampled and grazed habitats; cluster 2 – ass. Matricario–Polygonetum arenastri– the only intensively trampled habitats; cluster 3 – ass. Coronopodo–Polygonetum arenastri– very intensively trampled and grazed farmyards; cluster 4 –Trifolium fragiferum community – the trampled surfaces of moist habitats; cluster 5 – ass. Lolietum perennis– the moderately trampled surfaces of roads and yards; cluster 6 – ass. Prunello–Ranunculetum repentis– trampled surfaces of forest roads. The first three clusters belong to the vegetation of intensively trampled habitats of the class Polygono arenastri–Poetea annuae and the last three clusters belong to moderately trampled habitats of the class Molinio–Arrhenatheretea. In the analysis of the ecological factors it is established that separation of the relevés is influenced most greatly by the trampling intensity observed in the field, and of the Ellenberg indicator values, the most important are light, moisture, soil reaction and temperature. Using the analysis of the plant functional traits it is established that therophytes, annuals, biennials, species resistant to trampling and grazing, neophytes and archeophytes prevail in the intensively trampled habitats. In contrast, hemicryptophytes, perennials, and indigenous plant species prevail in the moderately trampled habitats. Representation of the C-S-R plant functional types shows also that trampling as a disturbance factor has a large influence on the differences in the relevés. In the intensively trampled habitats, there is a large proportion of ruderals, while in the moderately trampled habitats there is a large proportion of competitors.
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Senecio sarracenicus is a rare river corridor plant, featured on Red Data Lists of threatened flora in several European countries. The habitat typical for this species is protected in the European Union. The species constitutes its own association Senecionetum fluviatilis, but syntaxonomic separateness of this community was rejected by some authors who assigned it to the Convolvulo sepium-Cuscutetum europaeae. Comprehensive analysis of phytosociological material from different European countries was conducted using classification and ordination methods, and both associations from Poland were compared. The study showed a clear separation between both associations in terms of species composition and community structure as well as microhabitats they occupy in river valleys. The species composition of the Senecionetum fluviatilis is similar within Europe regardless of sample location. In Poland, Solidago gigantea is the most frequent neophyte among alien species penetrating the association under study. Although S. gigantea does not affect the diversity and total species richness, it does reduce the native species cover; when its coverage is large (>25%), it may in addition reduce the number of native species. This means that S. gigantea has a substitutive relation to native components of the association Senecionetum fluviatilis, particularly with respect to Senecio sarracenicus.
Chapter
This chapter describes the threats of charophytes and their habitats and specifies appropriate actions for their conservation and protection. Main reasons for endangering are habitat destruction, water pollution, increase of utilization (e.g. water management, river regulation, disturbances by fishery, recreation activities), drainage, lack of management, rarity, climate change, introduction of foreign plants and inadequate legal protection. Following the latest Red Data Books 81 % of the charophyte-species and 88 % of the charophyte-plant communities in Germany are threatened. An overview about the degrees of endangering of charophytes in other European countries is presented additionally. The legal foundations for protection of charophytes and their habitats in Germany are analysed with special emphasis to European directives (European Habitats Directive, European Water Framework Directive) and international conventions (e.g. Convention on Biological Diversity, Global Strategy for Plant Conservation). Different measures for conservation and protection of charophytes are discussed. The most important aim is the protection of extant populations against damage and their prevention from nutrient loading. Because many charophytes are poor competitors most of their sites (especially small water bodies and ditches) need a special management as periodical remove of vegetation/mud and creation of vegetation-free areas. Other measures discussed are e.g. an improvement or re-establishment of natural dynamics, development of seminatural fish stocks, creation of new waterbodies, implementation of buffer strips, improvement of legal protection and establishment of nature reserves. Alternative concepts (e.g. Important Stonewort Areas, Plant Micro-Reserves) must be verified, too. The continuous decline of charophytes requires urgent measures to stop the loss of species and habitats. Therefore the implementation of a valid national action plan for protection and conservation of charophytes and their habitats in Germany focussing on the most endangered species is proposed. A subdivision into 5 action plans for 15 threatened charophytes is suggested. In addition local action plans must be realized for 6 species with present occurrence in less than five sites. The proposed actions aim especially at an improvement of knowledge of the present and former occurrence of the target species, their ecological demands, the identification of the present national hot spots for conservation of charophytes in Germany, the promotion of public relations and the realization of management measures including transplantation of oospores.
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Forest preserves (‘Bannwälder’) within Baden-Württemberg are protected areas without direct human influence. Hunting is solely allowed to ensure substantially reduced impact of game animals. Our study area (‘Bannwald Flüh’; 50.4 ha; 513-740 m a.s.l.) is situated in the lower montane belt of the Southern Black Forest near Schönau/Wiesetal. It was established as a forest preserve in 1970. The most characteristic forest type is the Luzulo-Fagetum with an ecological amplitude from nutrient-poor (Luzulo-Fagetum vaccinietosum myrtilli) to richer and slightly moister sites (Luzulo-Fagetum with Abies alba). A former common grazing area (1970: about 4 ha) within the preserve was abandoned in 1960; the characteristic vegetation was the Festuco-Genistetum sagittalis. It provides an excellent opportunity to study the processes of secondary succession within a large area. Hence, the results give valuable information to design modified management approaches guaranteeing site-specific biodiversity in low-nutrient grasslands within the Black Forest. In 1977 we established four permanent plots within the forest area and one plot within the formerly grazed area. In 1996, additionally four pairs of fenced and non-fenced plots were created in the Festuco-Genistetum sagittalis. Fencing was necessary to compare processes of secondary succession with and without deer impact (here: roe deer Capreolus capreolus). We sampled the plots by means of phytosociological relevés until 2014. Ordination methods (Non-metric Multidimensional Scaling: NMDS) revealed that fenced and non-fenced plots in the former grazing area show similar developments of the vegetation in the course of succession. Strong decreases of total species numbers and numbers of Red-List species occurred, especially in plots enriched with Calluna vulgaris or Vaccinium myrtillus. Two pairs of plots were characterized by grass-encroachment; one is still disturbed by rodents and ants and shows higher species numbers. Only fenced plots within the neighbourhood of Luzulo-Fagetum showed higher shrub cover compared to non-fenced ones. The permanent plots in the forest area represent stands of Luzulo-Fagetum vaccinietosum myrtilli and Luzulo-Fagetum with Abies alba as well as planted Picea abies forest and pioneer forest with Betula pendula. It was possible to analyze effects of downed logs and gap dynamics in the two studied Luzulo-Fagetum stands. These gaps caused, e.g., an increased graminoid cover for some years. A planted Picea abies stand with only one species in 1977 (potential Luzulo-Fagetum site) gradually changed its floristic composition and showed more and more similarities with the ‘Luzulo-Fagetum with Abies alba’ which is characterized e.g. by ferns (Dryopteris dilatata and others). A pioneer forest with Betula pendula (potential Luzulo-Fagetum site) increasingly revealed a decrease of species in the field layer and the development of a forest type with Carpinus betulus and Quercus petraea. Fagus sylvatica had a long ‘lag phase’, but occurred after nearly 40 years in the lower tree layer. The floristic relationship between the studied forest types was analyzed by ordination methods (NMDS). Ellenberg indicator values (weighted) show a decrease for the factor ‘light’ in different community types. Nutrient indicator values are rather low without evidence for an increase throughout the studied time period. For the forest stands indicator values demonstrate the floristic relationship between ‘Luzulo-Fagetum vaccinietosum myrtilli’ and ‘Pioneer forest with Betula pendula’ as well as similarities between ‘Luzulo-Fagetum with Abies alba’ and later phases of the planted Picea abies forest.
Verzeichnis und Rote Liste der Pflanzengesellschaften Deutschlands
  • Erste Statistische Ergebnisse Von
Erste statistische Ergebnisse von "Verzeichnis und Rote Liste der Pflanzengesellschaften Deutschlands" 594
Die Gesellschaft hat sich in tieferen Lagen erheblich ausgebreitet
  • Mit Wolff Teilt
WOLFF teilt mit:,,Lemna turionifera ist erst seit 1965 in Deutschland bekannt". Die Gesellschaft hat sich in tieferen Lagen erheblich ausgebreitet (1991 erstmals auch im Saarland (WOLFF), aktuell in NRW in starker Ausbreitung (RAABE)), insgesamt ist i.iber die Verbreitung aber noch wenig bekannt. Eine Gefahrdung ist nicht zu erkennen.
Wolf notiert ftir Rheinland-Pfalz: ,in der Vorderpfalz stark gefahrdet, sonst weniger" und ftir das Saarland: ,viele Vorkommen seit 1850 bis in jilngere Zeit erloschen
  • Blomel Vermerkt Zu Mecklenburg-Vorpommem
BLOMEL vermerkt zu Mecklenburg-Vorpommem :,,Utricularia neglecta gibt es bei uns nicht. Alie vorliegenden Belege wurden <lurch J. CASPER (CASPER & KRAUSCH: SilBwasserflora Mitteleuropas Bde. 23, 24) revidiert." Wolf notiert ftir Rheinland-Pfalz:,,in der Vorderpfalz stark gefahrdet, sonst weniger" und ftir das Saarland:,,viele Vorkommen seit 1850 bis in jilngere Zeit erloschen; aktuell aber kaum gefahrdet".
Nach den Ausflihrungen von SCHMIDT et al. (1996) galte dies auch filr das Tiefland; mehrere Mitarbeiter sind aber der Meinung
  • Van Nach
  • De Weyer
  • Schmidt
Nach VAN DE WEYER ist die Gesellschaft ftir Nordrhein-Westfalen und wahrscheinlich ftir das gesamte Hi.igel-und Bergland als,,vom Verschwinden bedroht" anzusehen (vgl. auch SCHMIDT et al. 1996). Nach den Ausflihrungen von SCHMIDT et al. (1996) galte dies auch filr das Tiefland; mehrere Mitarbeiter sind aber der Meinung, dal3 hier die Rote Liste der Characeen zu korrigieren ware und Kategorie 2 ausreicht.
Unsere Mitarbeiter sehen die Situation der Gesellschaft als nicht ganz so dramatisch an. Aufmerksam zu machen ist allerdings auf die laut SCHMIDT et al. ( 1996) geringe Regenerierbarkeit der Vorkommen von Art und Gesellschaft
  • Schmidt
SCHMIDT et al. ( 1996) stuften Chara aspera als,,stark gefahrdet (regional starker gefahrdet)" ein und schrieben:,,Das Charetum asperae ist vom Aussterben bedroht (KNAPP et al. 1985)". Unsere Mitarbeiter sehen die Situation der Gesellschaft als nicht ganz so dramatisch an. Aufmerksam zu machen ist allerdings auf die laut SCHMIDT et al. ( 1996) geringe Regenerierbarkeit der Vorkommen von Art und Gesellschaft. WOLFF notierte ftir Rheinland-Pfalz:,,zunachst <lurch Anlage der Baggerseen stark gefordert, jetzt durch deren Eutrophierung zuriickgehend".
zu Chara strigosa ausdrilcklich schreiben ,arktisch-alpine Art
  • Hier Bestehen Noch Unklarheiten
  • Wahrend
  • Schmidt
Hier bestehen noch Unklarheiten. Wahrend SCHMIDT et al. (1996) zu Chara strigosa ausdrilcklich schreiben,,arktisch-alpine Art, in Deutschland nur in den Alpen", wird das Charetum strigosae hier im Tief-(Lausitz) und Hiigel-und Bergland (Alpenvorland) in Kategorie 2 gestellt.
Dort wurde Chara intermedia als
  • Von Schmidt
Hier bestehen erhebliche Abweichungen zur,,Roten Liste der Armleuchteralgen Deutsch lands" von SCHMIDT et al. (1996). Dort wurde Chara intermedia als,,vom Aussterben bedroht" geftihrt und die zugehorige Gesellschaft ausdriicklich kommentiert:,,Das Charetum intermediae ist vom Aussterben bedroht (KNAPP & al. 1985)". Die Zusammenschau der Mitarbeiter ergab dann doch ein positiveres Bild. Unsicherheiten bleiben.
Chara tomentosa m. macrotelis ist eine Modifikation des flachen Wassers. Ob die Diozie auch als eine Gefahrdungsursache zu werten ist
  • Schmidt
Zumindest regional starker gefahrdet oder gar ganz verschwunden (so in Rheinland-Pfalz nach WOLFF). SCHMIDT et al. (1996) schrieben:,,Das Charetum tomentosae ist stark gefahrdet, das Charetum macrotelis ist vom Aussterben bedroht (KNAPP et al. 1985). Chara tomentosa m. macrotelis ist eine Modifikation des flachen Wassers. Ob die Diozie auch als eine Gefahrdungsursache zu werten ist, kann derzeit noch nicht entschieden werden."
Geestkeminseln) selten und <lurch Tourismusintensivierung riicklaufig, hier 2!
  • Tork Nach
  • In Schleswig-Holstein
Nach TORK,,in Schleswig-Holstein (Geestkeminseln) selten und <lurch Tourismusintensivierung riicklaufig, hier 2!" Nach YON DRACHENFELS/ZACHARIAS in Niedersachsen:,,Vermutlich Flachenverluste <lurch Austrocknung feuchter Diinentaler und Riickgang extensiv beweideter Salzwiesen-Diinen-O kotone".
Wenn ilberhaupt Petasites albus-Gesellschaft, dann auch im Tiefland mit 2, aber nicht als Schuttflur-Gesellschaft, sondern auf Geschiebemergel
  • Dierijen
DIERIJEN vermerkt:,,Wenn ilberhaupt Petasites albus-Gesellschaft, dann auch im Tiefland mit 2, aber nicht als Schuttflur-Gesellschaft, sondern auf Geschiebemergel."