Untersuchungen zur Einwanderung von Festuco-Brometea- und Koelerio-Corynephoretea-Arten in Brachflächen

Abstract

As a consequence of the structural changes in agriculture many fields were let rest in the past years and decades. This is a particular phenomenon in the New Laender. The present paper deals with fallow land on the Kleiner Fallstein in the northern foreland of the Harz (Saxony-Anhalt). The species migration patterns after five years rest is shown here by means of species lists, linear transects and a grid map. The question was which species are able to migrate into fallow land during five years and how far is the distance. The fallow land was chosen after the following criteria: areas directly above calcareous grassland, directly below calcareous grassland, and areas separated from calcareous grassland by broad shrubbery. Most prominent were Festuco-Brometea and Koelerio-Corynephoretea (Sedo-Scleranthetea) species as well as biennial species such as Echium vulgare and Cynoglossum officinale. Species with a high potential of dissemination such as Festuca rupicola migrated up to 204 meters, while Alyssum alyssoides and Bromus erectus were only found in the first 10 meters of the fallow land. 160 species were found in the fallow land but just one rare species (Asperula cynanchica). 21 Festuco-Brometea species und 15 Koelerio-Corynephoretea species migrated into fallow land. There is evidence that at least young fallow land may be a suitable habitat for these species. Many of the species are able to spread by stolones. The number of species migrated into the fallow land depends on the position of the fallow land relatively to the calcareous grassland. The highest number of Festuco-Brometea and Koelerio-Corynephoretea species migrated into fallow land below calcareous grassland, whereas less species migrated into fallow land above calcareous grassland. Broad shrubbery separating fallow land from calcareous grassland seems to delay the migration of Festuco-Brometea and Koelerio-Corynephoretea species into fallow land.