|Dengler, J; Eisenberg, M; Schröder, J: Die grundwasserfernen Saumgesellschaften Nordostniedersachsens im europäischen Kontext - Teil II: Säume nährstoffreicher Standorte (Artemisietea vulgaris) und vergleichende Betrachtung der Saumgesellschaften insgesamt., Tuexenia, 27, 91-136 (2007)|
|Key words: biodiversity, Epilobietea angustifolii, Galio-Urticetea, nomenclatural revision, site conditions, syntaxonomy, vegetation classification|
The purpose of this study is to characterise the anhydromorphic forest edge communities of nutri- ent-rich sites in NE Lower Saxony (Germany) as regards their ecological conditions, their structure, and their floristic composition, and to compare them among each other and with the communities of nutrient-poor sites dealt with in part I. In addition, we aim to develop a phytosociological classification scheme for these communities which is both applicable regionally and on an European scale. On the basis of 200 of our own vegetation relevés, we distinguished 16 associations (or equivalent units) in NE Lower Saxony. We combined these with relevés and synoptic tables from 63 additional sources from 16 countries throughout temperate Europe for a total of 10,347 relevés, to develop and present a compre- hensive supraregional classification scheme of perennial ruderal and nitrophytic forest edge communities. Both the regional and the European data lead us to the conclusion that all of these communities (and thus also substantial parts of the communities commonly placed in the classes Epilobietea angustifolii and Galio-Urticetea) should be included in a broadly conceived class Artemisietea vulgaris. Within this class, the nitrophytic forest edge communities belong to two of the four subclasses. The acidophytic herbaceous forest-clearing communities (Senecioni sylvatici-Epilobienea angustifolii subcl. nov.) accor- ding to our present knowledge comprise only the order Galeopsio-Senecionetalia sylvatici with Epilobi- on angustifolii as its sole alliance (two associations in the study area). All other nitrophytic forest edge communities belong to two orders within the subclass Lamio albi-Urticenea dioicae. The Circaeo- Stachyetalia are comprised of the Atropion bellae-donnae (basiphytic herbaceous forest-clearing com- munities, two associations) and the Impatienti noli-tangere-Stachyion sylvaticae (inner edges influenced by waterlogging, three associations, including the Scutellario galericulatae-Circaeetum lutetianae ass. nov.), whereas the Galio-Alliarietalia consist of Geo-Alliarion (inner edges on mesic sites, five associati- ons, including the Bromo sterilis-Chelidonietum majoris ass. nov.) and Aegopodion podagrariae (outer edges, four associations). A comprehensive nomenclatural revision includes all syntaxa found in NE Lower Saxony and their synonyms. We document the nomenclatural types of all valid syntaxon names or – if they do not already exist – designate them and give reasons for scheduled proposals to the Nomenclature Commission. In a comparative analysis (mostly on alliance level), we finally work out common properties and dif- ferences of all forest edge communities dealt with in parts I and II as regards site conditions, vegetation structure, and plant diversity. Most forest edge communities show a higher species density than other phytocoenoses from the region. Communities on base-rich substrata are richer in plant species than are those from acidic sites. Mostly because of their high length-width proportion, woodland edges as a whole contain a large part of the vascular plant flora of a region although they only cover a very small part of its area. Therefore, they are highly valuable for nature conservation.