Bibliothèque Tour du Valat

Se connecter

Mot de passe oublié ?
Pas encore inscrit ?

La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Détail

Ajouter au panier

Ajouter au panier

Lien vers la notice

Titre :	Impact of salt marsh management on habitat utilisation and population development of Barnacle Geese Branta leucopsis in the Wadden Sea.
Auteurs :	Martin Stock, Auteur ; Frank Hofeditz, Auteur
Type de document :	Article
Dans :	Vogelwelt (Die) (123(6) 2002)
Article en page(s) :	265-282
Résumé :	The salt marshes along the Wadden Sea coast of Schleswig-Holstein have been grazed by sheep intensively for centuries. Within the Schleswig-Holstein part of the Wadden Sea National Park this farming practice has been reduced considerably since 1991. We studied the impact of different levels of sheep grazing on habitat utilisation, numbers and distribution of Barnacle Geese on a large salt marsh complex for an eleven years period following the change in management. Grazing levels of geese dropped after the management was altered. In spring in salt marshes without livestock, the grazing intensity decreased from a maximum of 3.3 to 0.7-1.6 goose min/m2/day. Within the moderately sheep-grazed parts of the salt marsh this value dropped from 1.7 to 0.6-1.5 goose min/m2/day. On the other hand an increase in grazing intensity from 0.7 to 1.1-2.4 goose min/m2/day was observed in the intensively grazed areas. Eleven years after the new management regime was introduced, the level of utilisation of the ungrazed and moderately grazed parts of the marsh by geese is comparable to that of natural island salt marshes. The initial reduction in grazing intensity was followed by a reduction in maximum numbers within the area, but since 1997 numbers are increasing again. The geese arrived and departed successively later each spring, with no significant change in the duration of stop-over. In autumn, the reduction in the level of salt marsh utilisation by geese was more pronounced than in spring. Within one year, the feeding intensity on ungrazed salt marshes dropped from 2.7 to 0.0 goose min/m2/day, while in moderately grazed salt marsh this decrease was delayed by several years. Goose utilisation of intensively sheep-grazed salt marsh increased in the first year (from 0.3 to max. 2.6 goose min/m2/day), but stayed at a medium level since 1997. The change in management regime did not coincide with a reduction in maximum goose numbers within the study area, since the birds made more use of the heavily sheep-grazed parts of the salt-marsh. In parallel with the ongoing growth of the Barnacle Goose population, the numbers in the traditional staging areas in Schleswig-Holstein increased slightly in recent years and new staging areas were colonised within the entire Wadden Sea area. We conclude that changes in salt-marsh management in Schleswig-Holstein have a local impact on the utilisation of ungrazed and moderately grazed salt marsh areas by geese. However, salt marsh management in Schleswig-Holstein in general should not have the protection of one species, the Barnacle Goose, as its main goal. Nonetheless, a protection of all habitats used by the birds on a flyway level is necessary.

FAQ

Infos pratiques

Heures d'ouverture et contact

Lundi , mardi et jeudi de 9h à 12h et de 13h à 17h00 : ouverture au public ...

Liens utiles

A-
A
A+