Papers by Gabriele Hofmann
Limnologica, Dec 1, 2004
A new assessment system for macrophytes and phytobenthos in German rivers meeting the requirement... more A new assessment system for macrophytes and phytobenthos in German rivers meeting the requirements of the Water Framework Directive (WFD) of the European Community is described. Biocoenotic types based on biological, chemical and hydromorphological data from over 200 river sites covering the main ecoregions, hydromorphological stream types and degradation forms have been defined. For developing a classification system the quality element macrophytes and phytobenthos was divided into three components: macrophytes, benthic diatoms and remaining phytobenthos. For macrophytes seven types including one subtype, for benthic diatoms 14 types including three subtypes and for the remaining phytobenthos five river types were identified. The benthic vegetation at reference condition was described for most of the river types. Degradation is characterised as deviation in benthic vegetation species composition and abundance from the reference biocoenosis. For classification in five ecological status classes, several metrics were developed and used in combination with existing indices. For some of the described river types additional investigations are necessary before a classification system can be developed.
Plant Ecology and Evolution, Nov 6, 2014
Nova Hedwigia, Jan 3, 2018
■ gut ■ nicht gut Ökologische Zustandsklassen nach WRRL ■ sehr gut ■ gut ■ mäßig ■ unbefriedigend... more ■ gut ■ nicht gut Ökologische Zustandsklassen nach WRRL ■ sehr gut ■ gut ■ mäßig ■ unbefriedigend ■ schlecht Die Wasserrahmenrichtlinie schreibt einheitliche Klassifizierungen für alle Mitgliedsstaaten vor. | 11 Makrophyten Haken-Wasserstern (Callitriche brutia var. hamulata)
Proceedings of the 1st Central European Diatom Meeting 2007, 2007
Rund 3.000 Arten zur Beschreibung des ökologischen Zustandes von Gewässern nach den Vorgaben der ... more Rund 3.000 Arten zur Beschreibung des ökologischen Zustandes von Gewässern nach den Vorgaben der Europäischen Wasserrahmenrichtlinie wurden bisher in Sachsen erfasst. Die größte Gruppe stellen Wasserpflanzen einschließlich Algen dar. Die reich bebilderte Broschüre stellt eine Auswahl in Sachsen vorkommender Wasserpflanzen und am Gewässerboden lebender Algen vor und gibt Einblick in eine faszinierende Unterwasserwelt. Sie ermöglicht wasserwirtschaftlichen Praktikern und interessierten Naturschützern einen Einstieg in die Interpretation des ökologischen Gewässerzustands
Biodiversity and Conservation, 2022
Freshwater biodiversity is disproportionally endangered and under-prioritized. Algal Red Lists li... more Freshwater biodiversity is disproportionally endangered and under-prioritized. Algal Red Lists literature is very limited, and there are only two editions of a single diatom-specific Red List (developed for Germany), in spite of the importance of diatoms for biodiversity and global ecosystem functioning. We used and analysed the new diatom Red List, compared to the previous edition, to show that these diatom microalgae threat status data allow, on one hand, a characterization of the ecological integrity and of the diatom diversity of the different types of inland-water ecosystems (also of practical importance to designate the most relevant habitats for conservation purposes), including a clear assessment of the threat status of the habitat, and, on the other hand, they offer ample possibilities to track the effects of stressors and of environmental change. Our results revealed, among other things, that: (1) threatened taxa concentrate in dystrophic-oligotrophic environments; (2) ‘not threatened’, i.e. tolerant and opportunistic, taxa are most frequent in eutrophic and saline ecosystems; (3) most local diatom extinctions happened in carbonate oligotrophic habitats. In this study, nitrates could be shown to possess a highly significant negative association with the cumulative percentage of diatom taxa in threat categories of the Red List. Having included heterogeneous studies (diverse inland-waters, different geographic areas, from close-to-pristine to impacted, neo- and paleolimnology etc.), we think that this strong negative association is noteworthy and points to the high potential of diatom-Red-List based approaches, especially if these would be tailored for the different biogeographic and climatic ecoregions.
Ein zentrales Umweltziel der Europäischen Wasserrahmenrichtlinie (WRRL, EUROPÄISCHE KOMMISSION 20... more Ein zentrales Umweltziel der Europäischen Wasserrahmenrichtlinie (WRRL, EUROPÄISCHE KOMMISSION 2000) ist das Erreichen des »guten ökologischen Zustands« der Oberflächengewässer. Die Erfassung des ökologischen Zustandes der Oberflächengewässer »Flüsse« erfolgt anhand nationaler Bewertungsmethoden mit Hilfe der Komponenten Gewässerflora (Makrophyten, benthische Diatomeen, sonstiges Phytobenthos, Phytoplankton) und Gewässerfauna (benthische Wirbellose, Fische). Löss-lehmgeprägte Fließgewässer außerhalb der Ökoregion Mittelgebirge sind bislang mit der Teilkomponente Diatomeen nach dem Bewertungsverfahren PHYLIB nicht zu bewerten. Unter Berücksichtigung der deutschlandweiten Verbreitung des Gewässertyps wurde ein Bewertungsmodell entwickelt, welches in der vorliegenden Schriftenreihe vorgestellt wird. Bezüglich der Bewertung der Teilkomponente Makrophyten stand die Beachtung regionaler Gesichtspunkte im Vordergrund. Dies betraf sowohl die Revision der Indikationsliste als auch die Prüfun...
Limnologica, 2004
A new assessment system for macrophytes and phytobenthos in German lakes according to the Water F... more A new assessment system for macrophytes and phytobenthos in German lakes according to the Water Framework Directive of the European Community is described. Based on biological, chemical and hydromorphological data from about 100 lake sites covering the main ecoregions, hydromorphological lake types and degradation forms, biocoenotic types could be defined. For developing a classification system the quality element macrophytes and phytobenthos was divided into two components: macrophytes and benthic diatoms. For macrophytes 4 and for benthic diatoms 4 lake types were identified. The benthic vegetation at reference conditions is described and degradation is characterised as deviation in benthic vegetation species composition and abundance from the reference biocoenosis. For classification in five ecological status classes, several metrics were developed and used in combination with existing indices. For a few of the described lake types further investigations are necessary before a classification can be developed.
Limnologica, 2004
A new assessment system for macrophytes and phytobenthos in German rivers meeting the requirement... more A new assessment system for macrophytes and phytobenthos in German rivers meeting the requirements of the Water Framework Directive (WFD) of the European Community is described. Biocoenotic types based on biological, chemical and hydromorphological data from over 200 river sites covering the main ecoregions, hydromorphological stream types and degradation forms have been defined. For developing a classification system the quality element macrophytes and phytobenthos was divided into three components: macrophytes, benthic diatoms and remaining phytobenthos. For macrophytes seven types including one subtype, for benthic diatoms 14 types including three subtypes and for the remaining phytobenthos five river types were identified. The benthic vegetation at reference condition was described for most of the river types. Degradation is characterised as deviation in benthic vegetation species composition and abundance from the reference biocoenosis. For classification in five ecological status classes, several metrics were developed and used in combination with existing indices. For some of the described river types additional investigations are necessary before a classification system can be developed.
Plant Ecology and Evolution, 2014
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Papers by Gabriele Hofmann