Study

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

  • Published source details Kiehl K., Eischeid I., Gettner S. & Walter J. (1996) Impact of different sheep grazing intensities on salt marsh vegetation in northern Germany. Journal of Vegetation Science, 7, 99-106.

Actions

This study is summarised as evidence for the following.

Action Category

Reduce intensity of livestock grazing: brackish/salt marshes

Action Link
Marsh and Swamp Conservation

Exclude or remove livestock from historically grazed brackish/salt marshes

Action Link
Marsh and Swamp Conservation
  1. Reduce intensity of livestock grazing: brackish/salt marshes

    A controlled study in 1988–1992 in a salt marsh in northern Germany (Kiehl et al. 1996) reported that plots under lower grazing intensities developed different cover of some key plant species to a plot that remained heavily grazed, and had taller vegetation. Statistical significance was not assessed. After four years, moderately grazed plots had 19–27% cover of seablite Suaeda maritima (vs heavily grazed: 5%) but only 0–4% cover of glasswort Salicornia europaea (vs heavily grazed: 24%). Cover of the dominant saltmarsh grass Puccinellia maritima was similar under all grazing intensities (moderate: 70–74%; heavy: 71%). The perennial herbs sea aster Aster tripolium and sea purslane Halimione portulacoides had low cover under both moderate and heavy grazing (<2%), but occurred in a greater proportion of quadrats across moderately than heavily grazed plots, especially closer to the sea (see original paper). Finally, the moderately grazed plots had taller vegetation on average (10–20 cm) than the heavily grazed plot (8 cm), with the difference most pronounced closer to the sea. Methods: In 1988, sheep grazing intensity was reduced in two sections of a historically grazed coastal salt marsh (1.5–3.0 sheep/ha, April–October). A high grazing intensity was maintained in a third section (10 sheep/ha, April–October). The marsh was intertidal (flooded 80–200 times/year) but had a dense artificial drainage system. The cover of each plant species was surveyed annually between 1989 and 1992 in permanent quadrats. Perennial herb frequency and overall vegetation height were recorded in 1992, in quadrats or along transects respectively.

    (Summarised by: Nigel Taylor)

  2. Exclude or remove livestock from historically grazed brackish/salt marshes

    A controlled study in 1988–1992 in a historically grazed salt marsh in northern Germany (Kiehl et al. 1996) reported that a plot where sheep grazing was stopped developed different cover of key plant species and taller vegetation than a plot that remained intensely grazed. Statistical significance was not assessed. After four years, the ungrazed plot had only 49% cover of the dominant saltmarsh grass Puccinellia maritima (vs grazed: 71%) and 0% cover of glasswort Salicornia europaea (vs grazed: 24%). Meanwhile, the ungrazed plot had 18% cover of red fescue Festuca rubra (vs grazed: 0%) and 18–21% cover of each of the perennial herbs sea aster Aster tripolium and sea purslane Halimione portulacoides (vs grazed: 0%). The perennial herbs also occurred in a greater proportion of quadrats across the ungrazed plot (see original paper for data). Finally, the ungrazed plots had taller vegetation on average (18 cm) than the grazed plot (8 cm). Methods: In 1988, sheep were excluded from one section of a coastal salt marsh. Another section of the marsh remained grazed by sheep (10 sheep/ha, April–October). The marsh was intertidal (flooded 80–200 times/year) but had a dense artificial drainage system. The cover of each plant species was surveyed annually between 1989 and 1992 in permanent quadrats. Perennial herb frequency and overall vegetation height were recorded in 1992, in quadrats or along transects respectively.

    (Summarised by: Nigel Taylor)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 19

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust