Rotation grazing as a conservation management tool: vegetation changes after six years of application in a salt marsh ecosystem

Published source details Lagendijk D.D.G., Howison R.A., Esselink P., Ubels R. & Smit C. (2017) Rotation grazing as a conservation management tool: vegetation changes after six years of application in a salt marsh ecosystem. Agriculture, Ecosystems & Environment, 246, 361-366.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Change season/timing of livestock grazing: brackish/salt marshes Action Link
	Change type of livestock grazing: brackish/salt marshes Action Link
	Reduce intensity of livestock grazing: brackish/salt marshes Action Link

Change season/timing of livestock grazing: brackish/salt marshes

A replicated, randomized, paired, controlled, before-and-after study in 2009–2013 on a salt marsh in the Netherlands (Lagendijk et al. 2017) found that annual low-intensity and biennial high-intensity cattle grazing had statistically similar effects on plant community composition and plant species richness, but that annual low-intensity grazing increased cover of one of two focal herb species. After six years, plots grazed under each regime contained a similar overall plant community (data not reported) and plant species richness (annual: 8.4 species/16 m²; biennial: 7.8 species/16 m²). Over six years, plots grazed under each regime experienced a similar turnover of plant species (data reported as a turnover index), similar increases in plant species richness (annual: gain of 1.9–2.9 species/16 m²; biennial: gain of 0.5–2.3 species/16 m²) and a similar lack of change in sea couch grass Elytrigia atheria cover (annual: 2% change; biennial: 3% change). However, sea aster Aster tripolium cover increased by 27% in annual low-intensity plots, but only 8% in biennial high-intensity plots. Methods: In 2009, two pairs of 11-ha plots were established on a coastal salt marsh. From 2010, one random plot/pair was grazed by 0.5 cattle/ha every summer, whilst one random plot/pair was grazed by 1 cattle/ha every other summer. Plant species and their cover were recorded in August/September 2009 (after a summer of intense grazing to standardize plots) and 2010–2015 (during cattle grazing treatments). Surveys were carried out in eight 16-m² quadrats/plot/year.

(Summarised by: Nigel Taylor)
Change type of livestock grazing: brackish/salt marshes

A replicated, randomized, paired, controlled, before-and-after study in 2009–2013 on a salt marsh in the Netherlands (Lagendijk et al. 2017) found that grazing by cattle and horses had statistically similar effects on plant community composition, plant species richness and two focal herb species. After six years, cattle-grazed and horse-grazed plots contained a similar overall plant community (data not reported) and plant species richness (cattle: 8.4–10.2 species/16 m²; horses: 8.3–10.2 species/16 m²). Over the six years, plots grazed by cattle and horses had experienced a similar turnover of plant species (data reported as a turnover index) and similar increases in plant species richness (cattle: gain of 1.7–5.9 species/16 m²; horses: gain of 1.1–5.2 species/16 m²). They had also experienced similar changes in cover of sea couch grass Elytrigia atheria (cattle: 2–11% change; horses: 0–9% change) and sea aster Aster tripolium (cattle: 1–27% change; horses: 13–15% change). Methods: In 2009, eight 11-ha plots were established (in two sets of four) on a coastal salt marsh. From 2010, four plots (two random plots/set) were grazed in summer by each livestock type: cows or horses. Half of the plots were grazed at high intensity (1.0 animal/ha) and half were grazed at low intensity (0.5 animals/ha). Plant species and their cover were recorded in August/September 2009 (after a summer of intense grazing to standardize plots) and 2010–2015 (during cattle/horse grazing treatments). Surveys were carried out in eight 16-m² quadrats/plot/year. Some or all of the plots in this study were also used in (1) and (2).

(Summarised by: Nigel Taylor)
Reduce intensity of livestock grazing: brackish/salt marshes

A replicated, randomized, paired, controlled, before-and-after study in 2009–2013 on a salt marsh in the Netherlands (Lagendijk et al. 2017) found that low and high grazing intensities typically had statistically similar effects on plant community composition and cover of two focal herb species, but that lower grazing intensities inhibited species richness. After six years, plots grazed at low intensity contained fewer plant species (7.8–8.4 species/16 m²) and had experienced a smaller increase in plant species richness (gain of 0.5–3.4 species/16 m²) than plots grazed at high intensity (10.2 species/16 m²; gain of 1.2–5.9 species/16 m²). In contrast, plots under both grazing intensities contained a similar overall plant community composition after six years (data not reported), had experienced a similar turnover of plant species (data reported as a turnover index), and had experienced similar changes – in at least two of three comparisons – in cover of sea couch grass Elytrigia atheria and sea aster Aster tripolium (see original paper for data). Methods: In 2009, ten 11-ha plots were established (in two sets of five) on a coastal salt marsh. From 2010, six plots (three random plots/set) were grazed at low intensity (0.5 cattle/ha every summer, 0.5 horses/ha every summer, or 1 cattle/ha every other summer). The other four plots were grazed at higher intensity (1.0 cattle/ha every summer or 1.0 horses/ha every summer). Plant species and their cover were recorded in August/September 2009 (after a summer of intense grazing to standardize plots) and 2010–2015 (during grazing treatments). Surveys were carried out in eight 16-m² quadrats/plot/year. Some or all of the plots in this study were also used in (6) and (8).

(Summarised by: Nigel Taylor)