Impact of different sheep grazing intensities on salt marsh vegetation in northern Germany

Abstract

Abstract. Mainland salt marshes in Schleswig‐Holstein (northern Germany) have been grazed intensively by sheep for several decades. In 1988 experimental sites were established in the lower and middle salt marsh of Sönke‐Nissen‐Koog and subjected to different grazing intensities. From 1989 to 1993 the impact of sheep grazing on the composition and structure of the salt marsh vegetation was studied through the yearly analysis of permanent plots, vegetation mapping and measurements of the vegetation height. The intensively grazed site (10 sheep/ha) is covered by a short monotonous Puccinellia maritima sward with Salicornia europaea and Suaeda maritima. Halimione portulacoides and Aster tripolium, especially flowering plants, are rare. On the sites with 1.5 and 3 sheep/ha Puccinellia maritima remained dominant. The population density of Salicornia europaea decreases after reduction of the grazing intensity, whereas Suaeda maritima finds optimal growing conditions. Stands of Halimione portulacoides and flowering Aster tripolium plants are rare near the sea dike but their cover and size increases further away from the dike. In the plot with 1.5 sheep/ha the height of the vegetation increases along the gradient from the dike towards the tidal flats, due to local differences in actual grazing intensity. When grazing is stopped, Puccinellia maritima is successively replaced by Festuca rubra, Halimione portulacoides and Aster tripolium. High variability of vegetation height indicates structural diversity. Patches of higher and lower vegetation correspond with the distribution pattern of different plant species. In terms of nature conservation cessation of grazing is recommended.

Effect of cattle grazing a species-rich mountain pasture under different stocking rates on the dynamics of diet selection and sward structure

“…This has been confirmed by surveys of changes in the botanical composition of pastures following a reduction of management intensity or stocking rates (e.g. Kiehl et al, 1996;Hart and Ashby, 1998;Marriott et al, 2004). However, a very low stocking rate is also assumed to reduce plant diversity as a result of competitive exclusion, where the high productivity of some species dominates plant species that cannot compete for light (Grime, 1979).…”

Main Driving Factors for Seacoast Vegetation in the Southern and Eastern Baltic

“…Some research has demonstrated, however, that management type can be even more important than salinity in influencing vegetation patterns (Amiaud et al 1998;Jutila 2001;Piernik 2012). Moreover, the vegetation pattern can be affected in a different way by different intensities of cutting and grazing (Bakker 1989;Kiehl et al 1996). We investigated relatively small areas directly affected by salt/ brackish water and, there, it was difficult to determine if the area is permanently mown or grazed (sometimes both).…”

Postbreeding Movement and Habitat Use of the Plateau Brown Frog, Rana kukunoris, in a High-Elevation Wetland

“…More recently, however the number of livestock is increasingly oversized (Yang, 1999). Excessive grazing can affect not only the community structure of vegetation, influencing microhabitat selection and thermoregulatory behavior during terrestrial migration of frogs (Kiehl et al, 1996;Eccard et al, 2000;Hayes and Holl, 2003) but also threaten small waterbodies used for reproduction and overwintering by R. kukunoris through the actions of trampling and erosion (YQ, pers. obs.).…”