Principal Changes of Ecological Migration and Dispersal: Nature Conservation Consequences

Abstract

Migration of individuals is one of the major ecological processes for the survival of species. During the past 100 years human impacts fundamentally changed the amount and qualities of migration capabilities. This not only relates to structural phenomena like habitat fragmentation and population isolation but also to the process itself. Migrating individuals are impacted e.g. by collisions with vehicles, electromagnetic waves, light during night. Many vectors for passive dispersal, which may exceed active mobility by magnitude in many species, vanished (like nomadic livestock) or are disrupted by technical measures (like flowing waters). On the other hand globalized mobility of humans, including international trade, supports the extension of the area of distribution even trans-continentally (Neophytes, Neozoans). Due to changes in migration patterns and capabilities, we therefore face fundamental changes of the species sets all over the world in near future. Current human migration tendencies will also have severe effects on the regional biodiversity by the erosion and loss of sophisticated knowledge on the natural properties of rural areas and of related, traditional techniques of land use.