Maike Isermann

Lower Saxon Wadden Sea National Park Authority · Nature Conservation

In Germany, including Lower Saxony, Eryngium maritimum (Sea Holly) is a highly endangered plant species protected by law. The species is known mainly from shifting dunes with Ammophila arenaria (EU habitat type 2120) and from younger calcareous soils of fixed coastal dunes with herbaceous vegetation (EU habitat type 2130). Eryngium maritimum was re...

Within-species variation is a key component of biodiversity and linking it to climatic gradients may significantly improve our understanding of ecological processes. High variability can be expected in plant traits, but it is unclear to which extent it varies across populations under different climatic conditions. Here, we investigated seed trait v...

Aim The number of naturalized (i.e. established) alien species has increased rapidly over recent centuries. Given the differences in environmental tolerances among species, little is known about what factors determine the extent to which the observed size of the naturalized range of a species and hence the extent to which the observed richness of n...

Aim The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation‐plot records to the habitats of the EUNIS system, use it to classify a Eur...

Questions The spread of alien plant species is one of the main threats to the biodiversity of different natural habitats, and coastal dune habitats are among the most affected. There is a considerable local and regional variation in the level of alien plant invasion on coastal dunes. We asked what are the patterns of invasion across European coasta...

Increased performance of invasive plant species in their introduced range vs. their native range has been previously documented. However, performance differences among invasive populations have rarely been explored, despite this information being central to understanding the evolution of invasiveness as well as being a useful basis to inform manage...

Aims Although many phytosociological studies have provided detailed local and regional descriptions of coastal dune vegetation, a unified classification of this vegetation in Europe and the Mediterranean Basin has been missing. Our aim is to produce a formalized classification of this vegetation and to identify the main factors driving its plant sp...

Questions: To what extent does habitat similarity across different climatic regions support vegetation similarity at taxonomic, syntaxonomic and functional levels? Do different sand habitats share similarity patterns across regions? To what extent are sand habitats azonal with respect to taxonomic, syntaxonomic and functional similarity? What are t...

Es wird für Deutschland die erste konsequent kriterienbasierte Bewertung der naturschutzfachlichen Invasivität von gebietsfremden aquatischen Arten aus den Gruppen der Pilze, Niederen Pflanzen und Wirbellosen Tiere vorgelegt. Zusätzlich werden kommentierte Gesamtartenlisten aller in Deutschland wild lebend nachgewiesenen gebietsfremden aquatischen...

Case histories of aquatic non-indigenous and cryptogenic species [in German]

List of aquatic non-indigenous and cryptogenic fungi, plants and invertebrates in Germany with brief remarks.

Reliable distribution maps are crucial for the management of invasive plant species. An alternative to traditional field surveys is the use of remote sensing data, which allows coverage of large areas. However, most remote sensing studies on invasive plant species focus on mapping large stands of easily detectable study species. In this study, we u...

http://qsr.waddensea-worldheritage.org/reports/beaches-and-dunes

Aims: Red Lists of threatened species are a well-established conservation tool throughout the world. In contrast, Red Lists of ecosystems, habitats or plant community types have only recently found interest at the global level, although they have a longer tradition in Central Europe. We contribute to the debate by presenting and discussing the comp...

This account presents information on all aspects of the biology of Eryngium maritimum L. (Sea Holly) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factor...

Thiis publication represents an assessment of the invasiveness of nonnative plant species in Germany, including a Black List and a Grey List of invasive plant species

Die Beurteilung der Invasivität von 42 ausgewählten noch nicht in Deutschland vorkommenden Arten (Status fehlend bzw. unbekannt) ergab eine Liste von 26 Arten, die als invasiv bewertet wurden. Für diese Arten sind laut BNatSchG § 40 Abs. 1 vorbeugende Maßnahmen zur Verhinderung der Einbringung erforderlich.

Case histories of non-indigenous and cryptogenic plant species [in German]

Prioritisation of high-impact species is becoming increasingly important for management of introduced species (‘neobiota’) because of their growing number of which, however, only a small fraction has substantial impacts. Impact scores for prioritising species may be affected by the type of effect model used. Recent studies have shown that environme...

The humped-back relationship in species diversity during succession was tested using vegetation in a coastal sand dune system of the German Wadden Sea island of Spiekeroog. Permanent plots were studied over 15 years along a spatial chronosequence from young grey dunes to old brown dunes. Species diversity, succession rate, and environmental indicat...

On the German island Norderney rabbit grazing effects on vegetation, soil and microclimate were investigated with exclosures in different dune vegetation. Differences in species composition between grazed and ungrazed plots increased with grazing activity. A decline in growth height resulted in higher light availability and temperature on the graze...

Questions: Are negative invasion–diversity relationships due to biotic resistance of the invaded plant community or to post-invasion displacement of less competitive species? Do invasion–diversity relationships change with habitat type or resident traits? Location/species: Lowlands and uplands of western and southern Germany, Heracleum mantegazzian...

Invasive alien plants are a significant element of global change with negative effects on biodiversity. Climate change may contribute to the increasing distribution and abundance of invasive species, and these plants may serve as indicators for higher temperatures and changed precipitation patterns. Invasive alien plants are well studied in Denmark...

Variables determining species richness vary with scale; the larger the scale, the greater the role that they play, and the more complex are the processes involved in determining species richness. A more or less hierarchical structure of patterns and processes predict species richness. At the global scale large gradient complexes, at the landscape s...

Coastal dune ecosystems are among the most dynamic habitats with high conservation value in Europe but are also under strong anthropogenic pressure regarding coastal protection and recreation. Hence, it is of high importance to know about long-term natural and anthropogenic changes and development of protected dune habitats for nature conservation,...

The study analysed the effects of shrub expansion on vegetation composition and plant species diversity in coastal grey dunes on the North Sea island Spiekeroog, comparing Rosa rugosa and Hippophaë rhamnoides. Species composition was recorded in plots of two spatial scales, 1 and 16 m2, considering the full range of shrub cover from less than 10 to...

The Japanese Rose (Rosa rugosa) an invasive neophyte in Europe, builds up large dominant shrublands especially in coastal areas. To describe the vegetation invaded by R. rugosa 383 relevés out of NW Europe with R. rugosa were collected from literature and from vegetation databases. Different plant communities were evaluated by TWINSPAN classificati...

Rosa rugosa Thunb. has become naturalized in coastal dune vegetation. To assess the effects of R. rugosa invasion on different coastal dune vegetation types paired plots with and without R. rugosa were studied on the German North Sea islands Spiekeroog, Juist and Norderney. The complete dune series from Ammophila-dunes, through grey dunes with Cory...

The bryophyte flora on the Campus area of the University of Bremen was studied at various habitats. The habitats could be classified into two main types, soft substrates such as grasslands and hard substrates like walls and stones. Based on indicator values, both types showed different environmental conditions and related species compositions. Hard...

From a strictly statistical perspective, most of the commonly used statistical tests cannot be performed on vegetation data obtained using a non-random sampling design. Despite this, non-randomly sampled plots such as phytosociological relevés still make sense: because they may focus on objectives not appropriately addressed by random sampling, suc...

Question: Is the expansion of Hippophaë rhamnoides in coastal dunes associated with a decline in plant species richness, and is this decline best described by a hump‐backed relationship between species number and shrub cover? Location: Grey and yellow dunes on the East Frisian islands Spiekeroog and Norderney. Methods: Total plant species richness...

During recent decades, coastal ecosystems have been increasingly affected by large-scale land-use change and by sea level rise due to global warming (Doody 2001, 2004). Both salt marshes and dunes have an important function in protecting coastal regions from flooding and erosion and provide habi-tats for plant and animal species with special adapta...

Establishment and spreading of shrubs like Rosa rugosa and Hippophaë rhamnoides in coastal dunes resulted in a strong decline in light availability, followed by a shading-out of typical species of open dune grasslands as well as of dune heathland. Shrubland dominated by few species like R. rugosa or H. rhamnoides was characterized by a simple veget...

Soil pH was measured at two different spatial scales in coastal dunes on Norderney, North Sea, and in Mecklenburg-Vorpommern, Baltic Sea, Germany. Relationships between the variability in soil pH, species richness and species diversity are presented. Species richness and diversity were highest in grey dunes, where soil pH was at intermediate levels...

Within the project ‘Plant communities of Mecklenburg-Vorpommern and their vulnerability’, a current synopsis of all vegetation types (excluding one-layered cryptogam vegetation) from this federal state in NE Germany has been worked out and published in a two-volume monograph (Berg et al. 2001, 2004a). An extensive data base of vegetation relevés an...

The project "Die Pflanzengesellschaften Mecklenburg-Vorpommerns und ihre Gefährdung" (The plant communities of Mecklenburg-Vorpommern and their vulnerability) is published as a two-volume series consisting of a table volume (2001) and a text volume (2004). Based on a huge vegetation-plot database and a consistent and well-documented methodology, th...

This paper contains the original diagnoses of new syntaxa, typifications of existing names of syntaxa, and other decisions of nomenclatural relevance which have proved to be necessary within the project ‘Plant communities of Mecklenburg‐Vorpommern and their vulnerability’. The underlying syntaxonomic concept is documented in Dengler & Berg (2002)....

[Note that the date given in the imprint (2000) is wrong and this book was actually only published in 2002, which is the relevant date from the nomenclatural point of view] Here is the German Introduction: Das bisherige Fehlen einer Standardliste der Pflanzengesellschaften Deutschlands ist kein Zufall. Es beruht insbesondere auf der Tatsache, daß...

Comparison of two distribution maps of 1959 and 1989/90 shows of Spiekeroog (a German Wadden Sea island) clear changes of the plant communities in the dunes. Successional tendencies of these communities to climax stages are represented. Consequences for conservation strategies are discussed. -Authors