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Providing evidence to improve practice

Action: Other biodiversity: Use grazers to manage vegetation Mediterranean Farmland

Key messages

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Amphibians (0 studies)

Birds (1 study): One replicated, randomized, controlled study in grasslands in the USA found higher densities of dabbling duck nests, but similar nesting success, in cattle-grazed plots, compared to ungrazed plots.

Invertebrates (4 studies): Two replicated studies (one controlled, one site comparison) in grasslands in the USA and Spain found more invertebrates in sheep-, goat-, or cattle-grazed plots, compared to ungrazed plots, in some or all comparisons. One before-and-after study in grassland in the USA found that a threatened, endemic butterfly species did not recolonize a site after grazing was reintroduced. One replicated, randomized, controlled study in grasslands in the USA found fewer invertebrates in plots with simulated grazing, compared to ungrazed plots, but found similar numbers of invertebrate species. One replicated site comparison in forested grasslands in Spain found higher beetle diversity in grazed plots, compared to ungrazed plots, in one of two beetle groups. Two replicated studies (one randomized and controlled) in grasslands in the USA and Spain found different invertebrate communities in grazed and ungrazed plots.

Mammals (2 studies): Two replicated, controlled studies (one randomized before-and-after study) in grasslands in the USA found that abundances of some or all rodents were higher, or increased more, on sheep- or cow-grazed plots, compared to ungrazed plots. However, they also found that some species were less abundant or monthly survival was lower on grazed plots.

Plants (15 studies)

  • Abundance (14 studies): Eight studies (two meta-analyses; two replicated, randomized, and controlled) from grasslands, shrublands, and forests in the USA, Spain, and France found higher cover or higher abundance of some groups of plants (or lower cover of undesirable plants), on cattle-, sheep-, or goat-grazed plots, compared to ungrazed plots. Six studies (five replicated; one randomized and controlled) from grasslands in Spain and the USA found lower cover or lower abundance of some groups of plants on cattle-, sheep-, or goat-grazed plots, compared to ungrazed plots (or after grazers were reintroduced). Three replicated, controlled studies (two randomized) from grasslands in the USA found similar cover or biomass on grazed or ungrazed plots.
  • Diversity (7 studies): Three studies (one meta-analysis; two replicated site comparisons) from grasslands in the USA found more plant species on grazed plots, compared to ungrazed plots, in some or all comparisons. One of these studies also found fewer species of some plant groups on grazed plots, and two of these stuides also found more non-native species on grazed plots, compared to ungrazed plots. Two replicated, controlled studies (one randomized) in grasslands in the USA and France found no difference in the number of plant species between cattle- or sheep-grazed plots and ungrazed plots. Two replicated controlled studies (one randomized) from grasslands in the USA and France found no difference in plant diversity between cattle- or sheep-grazed plots and ungrazed plots. One replicated, randomized, controlled study grasslands and woodlands in the USA found that plant community composition varied between cattle-grazed and ungrazed plots.
  • Survival (3 studies): Of two studies on purple needlegrass mortality from grasslands in the USA, one replicated, randomized, controlled study found lower mortality on sheep-grazed plots, compared to ungrazed plots, in some comparisons, but found higher mortality in other comparisons, and one replicated, controlled study found no difference in mortality between cattle-grazed plots and ungrazed plots. One replicated, randomized, controlled study from grasslands in the USA found lower germination rates in purple needlegrass seeds from sheep-grazed plots, compared to ungrazed plots, in some comparisons.

Reptiles (1 study): One replicated, controlled study in grasslands in the USA found that the abundance of some lizard species increased at a greater rate on cattle-grazed plots, compared to ungrazed plots.

Implementation options (1 study): One study from the USA found more invertebrates on plots with simulated grazing, compared to ungrazed plots, when these plots were planted with non-native plants. One study in shrublands in Spain found lower gorse cover in plots grazed by goats, compared to sheep, as well as other differences in plant biomass and cover.

Supporting evidence from individual studies

1 

A before-and-after study in 1995–1998 in a serpentine grassland in the San Francisco Bay Area, California, USA, found that grass cover decreased and forb cover increased after grazers were reintroduced, but the threatened, endemic, Bay checkerspot butterfly Euphydryas editha bayensis did not recolonize the site. Invertebrates: Populations of the Bay checkerspot butterfly did not increase in the three years after grazers were reintroduced. Plants: In 1995, after cattle had been excluded for five years, grass cover was 75%. In 1998, after cattle had grazed for three years, grass cover was 45%. Cover of Plantago erecta (a host plant of the Bay checkerspot butterfly) did not increase after cattle were reintroduced, but cover of forbs (non-grass herbs) increased from 10% to 30%. Methods: Grazers were reintroduced to one site in Silver Creek in 1995. Postdiapause butterfly larvae and plant cover were sampled in 1995–1998 (sampling methods not reported).

 

2 

A replicated, randomized, controlled study in 1988–1999 in central California, USA, found that purple needlegrass Nassella pulchra seeds were less likely to germinate when they came from sheep-grazed plots, compared to ungrazed plots. Plants: Seeds were less likely to germinate if they came from grazed, unburned plots, compared to ungrazed, unburned plots (12% vs 23% germination). In burned plots, there was no difference in germination between grazed and ungrazed plots (26–32%). Seeds of similar sizes were found in grazed or ungrazed plots (0.6–0.8 vs 0.7 mg). Methods: In 1989, needlegrass seeds were collected from approximately 18 plants in each of 12 plots that had been either ungrazed or grazed by sheep in summer, since 1988. Half of the plots were burned in September 1988. In 1999, 5–10 seeds from each of 185 plants were germinated on germination paper.

 

3 

A replicated, randomized, controlled study in 1988–1995 in grassland in central California, USA, found no consistent differences in mortality or basal area of purple needlegrass Nassella pulchra plants in sheep-grazed plots, compared to ungrazed plots. Plants: Needlegrass mortality was lower in spring-grazed plots, compared to ungrazed plots, for one combination of burning and topography (5% vs 15% annual mortality), and was higher in summer-grazed plots, compared to ungrazed plots, for another combination (3% vs 0%). Density of plants did not differ between grazed and ungrazed plots (0.3–1.0 plant/m2). The basal area of plants increased less in summer-grazed plots, compared to ungrazed plots (0% vs 110% increase), but there was no difference between spring-grazed and ungrazed plots (86–110% increase). Methods: In 1988–1995, six 20 x 20 m plots were ungrazed, six were grazed by sheep in spring, and six were grazed in summer. Half of the plots were burned in 1988, 1991, and 1994. The survival of 629 needlegrass plants was monitored annually (except for 1993), and 126–130 plants were measured in 1992 and 1995.

 

4 

A replicated site comparison in 1998–2001 in grasslands in northern California, USA, found that the effects of cattle grazing on native and exotic plants depended on soil type. Plants: More native plant species were found in grazed sites, compared to ungrazed sites, on serpentine soils (22 vs 19 species/5 m2), but fewer native species were found in grazed sites on non-serpentine soils (11 vs 12). The same number of non-native species were found in grazed, serpentine sites, compared to ungrazed sites (4–5), but more were found in grazed, non-serpentine sites (10 vs 7). The abundances of one native and one non-native species were lower in grazed plots, compared to ungrazed plots (native: 0–3.0 individuals/m2; non-native: 1–2 vs 2–4), and another native species had lower abundances in grazed plots on serpentine soils (0–1). Four other species did not differ between grazed and ungrazed plots. Methods: Vegetation in 80 sites across two soil types was sampled in April-May 1998–2001 using five 1 m2 quadrats. An additional 20 sites were sampled in 2000–2001. Forty-three of the sites were grazed at an intensity of 1 cow-calf pair/10 ha, and 57 were ungrazed (having previously been grazed until 1985).

 

5 

A replicated, paired site comparison in 2000–2001 in coastal grasslands in central California, USA, found more plant species in cattle-grazed sites, compared to ungrazed sites, in three of eight groups, in at least one year, but found fewer plant species in two groups in one year. Cover of five groups varied between grazed and ungrazed sites. Plants: More species of native and non-native annual non-grass plants were found in grazed sites, compared to ungrazed sites (native: 6–8 vs 1–4 species/site; non-native 12–16 vs 7–12). More species of non-native annual grasses were found in grazed sites, compared to ungrazed sites, in one of two years (9 vs 7). Fewer species of native perennial non-grass and grass plants were found in grazed sites, compared to ungrazed sites, in one of two years (non-grass: 11 vs 16; grass: 4 vs 5). Three other groups showed no differences. Cover of three groups was higher in grazed sites (native annual non-grasses: 9–14 vs 1–3 m2/ha; non-native annual non-grasses: 73–76 vs 54–62 intercepts/250 sampling points; non-native perennial non-grasses: 45–77 vs 32–54), and cover of another group was higher in one of two years (non-native annual grasses: 170 vs 130). One group had lower cover in grazed sites (25–26 vs 41–52). Cover of three other groups did not vary. Vegetation height was lower in grazed sites (13–15 vs 25–27 cm). Methods: Between 17 (2000) and 25 (2001) pairs of sites were studied along the coast (670 km). One site in each pair had been grazed by cattle for at least 10 years, and the other had not been grazed for five years. Vegetation was sampled in March–June (five transects/site).

 

6 

A replicated, randomized, controlled before-and-after study in 1996–2000 in grasslands in southern California, USA, found that Stephen’s kangaroo rat Dipodomys stephensi increased in numbers on sheep-grazed plots, but not on ungrazed plots. Monthly survival was lower on grazed plots. Mammals: Similar numbers of kangaroo rats were found in grazed and ungrazed plots after two grazing sessions (13–38 individuals/ha), but fewer were found after one grazing session and in six of eight surveys before grazing (1–19 vs 21–39). Similar numbers were found in plots that were mown and then grazed, compared to ungrazed plots, after grazing (18–38), but fewer were found before grazing, in 14 of 15 surveys (3–14 vs 21–38). Monthly survival was lower on grazed plots, compared to ungrazed plots (data not provided). Methods: Eight 80 x 80 m plots were established in December 1996. Three were grazed in June 1998 (1,500 sheep for four hours) and 1999 (200 sheep for three days), three were mown in 1998 and grazed in 1999, and two were neither mown nor grazed. Kangaroo rats were trapped in 24 periods of three nights each.

 

7 

A replicated, controlled study in 1998–2000 in north-central California, USA, found no differences in purple needlegrass Nassella pulchra survival or density in grazed areas, compared to ungrazed areas. Plants had fewer reproductive stems and were shorter in grazed areas, compared to ungrazed areas. Plants: Needlegrass mortality and density did not differ between grazed and ungrazed plots (data reported as model results). Needlegrass plants in grazed plots had fewer reproductive stems, compared to in ungrazed plots (1.5–5.2 vs 0.4–4.1). Plants were shorter in grazed plots, compared to ungrazed plots (data not provided). Stem diameter did not differ between grazed and ungrazed plots (2.6–3.6 cm). Methods: Forty 20 x 20 m plots were either ungrazed, continuously grazed, or rotationally grazed from January (1998) or December (1999, 2000) until May, at a stocking density of 0.75 animal units/ha. Continuous grazing maintained animals on the plots at all times, whilst rotational grazing removed either 25% or 50% of plant biomass, with 35 days rest between rotations. Thirty individual plants were measured each year and plant density was estimated using 3–5 quadrats/plot (1 x 1 m).

 

8 

A replicated, randomized, controlled study in 1995–1997 in pastures in central California, USA, found that more dabbling ducks Anas sp. nested in rotationally grazed fields, compared to ungrazed fields, in one of two years. Birds: Nesting densities were higher in grazed fields, compared to ungrazed fields in 1996 (2.2 nests/ha vs 0.6, 4 replicates) but not in 1997 (0.7 vs 0.4). Nest success did not differ between grazed and ungrazed fields (5% success vs 3%). Methods: Half of each field (10–14 ha) was grazed by 70 cows and calves for 7–15 days at a time in July–November 1995–1996, after the duck nesting period. Fields were also mown at various times outside the nesting period to control milk thistles Silybum marianum and star thistles Centaurea solstitialis.

 

9 

A replicated study in 2001–2004 in shrublands in northwest Spain found that plant biomass decreased in plots grazed by sheep or goats. Plants: Cover of herbaceous vegetation declined in years three and four under both goat and sheep grazing (goat grazing: decline from 35% to 21%; sheep grazing: 34% to 11%). Implementation options: After two years of grazing, there was no difference in total biomass in plots grazed by goats, compared to sheep (9,000–14,400 kg dry matter/ha), but, after four years, less biomass was found on plots initially grazed by goats, irrespective of current grazers (10,900–11,400 vs 14,200–14,400 kg/ha). More biomass was herbaceous in plots grazed by goats, compared to those grazed by sheep, after both two and four years, and the biggest difference was between plots consistently grazed by goats or sheep (27% vs 14% after two years; 37% vs 14% after four). After both two and four years, cover of herbaceous vegetation was higher in plots grazed by goats in the first two years, compared to those grazed by sheep (42% vs 27% after two years; 21–35 vs 17–19% after four). Heather contributed more biomass after two years on goat grazed, compared to sheep grazed plots (23% vs 13%), but there was no difference after four years (9% in all). Cover of heather did not vary between goat and sheep grazed plots (1%). Less western gorse Ulex gallii was found in plots grazed by goats, after two and four years (the biggest differences between plots consistently grazed by goats, compared to sheep: 14% vs 20% cover after two years; 24% vs 44% cover after four years). Gorse was a smaller percentage of plant biomass in plots grazed by goats, compared to sheep, in the first two years (46% vs 70% after two years) but not in the last two years (73% vs 53% after four years). Methods: Four plots (1.2 ha each) in a gorse-dominated shrubland were burned in May 2001 and then grazed by either Gallega sheep or Cashmere and local-breed goats (two plots each, 12 animals/plot). Plots were grazed in two periods: first in October 2001–January 2002 and May–November 2002, and second in May–November 2003 (at a lower stocking density) and June–October 2004. In the second seasons the plots were split in half: one half received the same treatment and the other half was grazed by the other species. Vegetation cover was measured eight times/plot (six 13 m transects). Biomass was measured at six points in 2003 and 2004 (five 0.2 m2 transects).

 

10 

A replicated, controlled study in 1997–2006 in scrub and grassland in central California, USA, found more ground-dwelling invertebrates in cattle-grazed plots, compared to ungrazed plots. The abundances of one of five mammals and one of three reptiles increased faster in grazed plots, compared to ungrazed plots. The abundance of one mammal species was lower in grazed plots, in some years. Less vegetation was left in grazed plots. Invertebrates: Fewer ground-dwelling invertebrates were found in grazed plots, compared to ungrazed plots, in six of nine years (data not provided). Abundances of grasshoppers did not differ between grazed and ungrazed plots (8–1,600 individuals/count). Mammals: Abundances of giant kangaroo rats Dipodomys ingens increased by 1.6 individuals/year in grazed plots, but did not increase in ungrazed plots. The changes in abundances of four other species did not differ between grazed and ungrazed plots. Heerman’s kangaroo rats Dipodomys heermanni were less abundant in grazed plots in some years (0–3 vs 0–22 individuals). Abundances of San Joaquin pocket mice Perognathus inornatus inornatus differed between grazed and ungrazed plots, but not consistently. The abundances of three other mammals did not differ between grazed and ungrazed plots. Reptiles: The abundance of blunt-nosed leopard lizards increased at a greater rate in grazed plots (6.8 vs 1.4 extra individuals/year). The change in abundances of two other species, and the overall abundances of all three species did not differ between grazed and ungrazed plots. Plants: At the end of the grazing season, less vegetation was left in grazed plots, in eight of ten years (20–2,100 vs 900–4,000 kg/ha). Methods: Four 2.6 km2 plots were established and grazed from December to leave approximately 560 kg dry matter/ha by April. Therefore, grazing intensity varied over time, and plots were not grazed at all in 2002–2004. Within each plot, a 25 ha plot was left ungrazed. Mammals were surveyed using 64 traps in each plot for six days and six nights in July–September each year. Grasshoppers and day-active lizards were surveyed visually within 9 ha grids, on ten days in May–July each year. Ground-dwelling invertebrates were monitored with pitfall traps. Vegetation was monitored on the same grids as lizards and clipped to assess biomass.

 

11 

A replicated, randomized, controlled study in 1997–2006 in former farmland in central Spain found that the cover of three of seven functional groups of plants differed between sheep-grazed and ungrazed plots. Plants: Grazed plots had lower perennial cover than ungrazed plots (14–36% perennial cover vs 26–47%). Grazed plots had lower cover of spring annuals than ungrazed plots, but only with one of three irrigation treatments (year-round irrigation: 71–79% vs 100%). This pattern was driven by large-seeded annuals, which also had lower cover with a combination of spring grazing and no irrigation (29% vs 50% for ungrazed). There were no differences in cover for the other four functional groups investigated. Methods: Eighteen 162 m2 plots were established in 1997, with a combination of three grazing regimes (spring grazing in April, autumn grazing in November, or no grazing) and three irrigation regimes (none, spring and autumn, or year-round). Plots were grazed for one week each year, at 5.2 or 4.3 sheep/ha in spring and autumn, respectively. Plants were surveyed in six 50 x 50 cm quadrats in each plot, in May and September each year.

 

12 

A replicated site comparison in 2007 in montane forested pastures in northwest Spain found more ground beetles, and a higher diversity of ground beetles, in goat-grazed or sheep-grazed pastures, compared to ungrazed pastures. Invertebrates: Beetle diversity was higher in grazed pastures, compared to ungrazed pastures, in one of two groups (ground beetles, but not rove beetles: data reported as effective number of species). More ground beetles were found in grazed pastures, compared to ungrazed pastures (19–510 vs 9–220 individuals), but similar numbers of rove beetles were found (56–240). Similar communities of ground beetles, but different communities of rove beetles, were found in grazed and ungrazed sites (data reported as statistical results). Methods: In 2007, three grazed sites and three abandoned sites were selected (abandoned at least 20 years previously). Invertebrates were collected in June–October (10 pitfall traps/site).

 

13 

A meta-analysis from 2013 of 15 studies in coastal and interior grasslands in California, USA, found that native grasses had higher cover in grazed grasslands, and native forbs had higher cover in grazed interior grasslands but lower cover in grazed coastal grasslands, compared to ungrazed grasslands. More species of native forbs were found in grazed grassland, compared to ungrazed grassland, but so were more species of exotic grasses, and higher cover of exotic forbs. Plants: More species of native forbs were found in grazed grasslands, compared to ungrazed grasslands (data reported as the response ratio of grazed to ungrazed plants: 0.14), but similar numbers of native grass species were found. Native grasses had higher cover in grazed grasslands, compared to ungrazed grasslands (response ratio: 0.13), but native forbs did not. More species of exotic grasses were found in grazed grasslands, compared to ungrazed grasslands (data reported as the response ratio of grazed to ungrazed plants: 0.11), but similar numbers of species of exotic forbs were found. Exotic forbs had higher cover in grazed grasslands, compared to ungrazed grassland (response ratio: 0.43), but exotic grasses did not. Implementation options: Native forbs had higher cover in grazed interior grasslands, compared to ungrazed interior grasslands (response ratio: 0.66), but they had lower cover in grazed coastal grasslands, compared to ungrazed coastal grassland (response ratio: –0.38). Methods: The Web of Knowledge and Google Scholar databases were searched for publications from 1923 to 2011, using the keywords, “California” and “grassland” or “prairie”, or “grazing” or “livestock”, and 15 replicated studies from 1997 to 2009 were meta-analysed.

 

14 

A replicated, randomized, controlled study in 2008–2010 in lowland grasslands in northern California, USA, found that plant diversity did not differ between plots with simulated grazing and ungrazed plots. The cover of native species was lower in plots with simulated grazing, compared to ungrazed plots, for one of three plant assemblages. Plants: Plant diversity did not differ between plots with simulated grazing and ungrazed plots (results reported as Shannon diversity). Cover of native species was lower in plots with simulated grazing, compared to ungrazed plots, when plots were sown with native perennial grasses (17–22% vs 59% cover), but there was no difference in plots sown with two types of non-native assemblages (1–3%). Methods: In 2007, four experimental blocks were established across two pastures. Each block was split into three areas, sown with one of three vegetation types: native perennial grasses, non-native annual forage grasses, and a non-native, non-edible annual weed. These were then divided into six plots, which were subjected to one of three treatments, each replicated twice: no manipulation, mowing and trampling by cattle to simulate medium grazing, or to simulate heavy grazing. Plants were surveyed in a 1 m2 quadrat in May 2008–2010.

 

15 

A replicated, randomized, controlled, before-and-after study, in 2006–2011 in grasslands and oak woodlands in northern California, USA, found differences in the abundance of some plant species, and differences in the plant community, between grazed and ungrazed plots. One of two non-native plant species declined in grazed plots, compared to ungrazed plots, in dry years. Plants: One desirable forage species increased in grazed plots, but not ungrazed plots (change from 0% to 17% cover vs 1% to 0%). Another desirable forage species increased in both (change from 1% to 5–10% cover). By the end of the experiment, but not at the beginning, the plant community differed between grazed and ungrazed plots (results reported as ordination results). Cover of medusahead Elymus caput-medusae decreased in three dry years in grazed plots, but not in ungrazed plots (decrease from 48% to 22% cover vs increase from 44% to 52%). Overall, it decreased to similar levels in grazed and ungrazed plots (25–26%). Cover of yellow starthistle Centaurea solstitialis did not differ between grazed and ungrazed plots (8–18%). Two other non-native species that are poor forage increased in ungrazed plots, but not in grazed plots (ungrazed: increase from 0% to 5% and 0% to 8% cover; grazed: decrease from 2% to 0% and 1% to 0%). Methods: In 2006, rotational grazing at moderate stocking densities was started in 11 paddocks of 80–600 acres. Paddocks were grazed for up to two weeks in November–February and March–June. Paired 8 x 8 foot plots were established in each paddock and the plant community monitored in June 2006, 2009, and 2011.

 

16 

A replicated, randomized, controlled study in 2008–2009 in pastures in northern California, USA, found fewer arthropods in plots with simulated grazing, compared to ungrazed plots. Invertebrates: Similar numbers of arthropod species were found in plots with or without simulated grazing (data not reported). Overall, fewer arthropods were found in plots with simulated grazing (data not reported). More herbivorous arthropods were found in plots with simulated grazing (79% higher volume), but more predatory arthropods were found in ungrazed plots (13% higher in ungrazed plots). Similar numbers of parasitoids or decomposers were found in plots with or without simulated grazing (data reported as log volumes). Plants: Similar numbers of plant species (14 species/plot), and similar amounts of plant biomass (data not reported), were found in plots with or without simulated grazing. Implementation options: In plots that were planted with non-native plants, the volume of arthropods was higher in plots with simulated grazing (380 vs 190 mm3). Methods: In 2006, two tilled plots were planted with native bunchgrass species, and two tilled plots were sown with non-native annual grasses. In 2008–2009, simulated heavy grazing (30–45 minutes of disturbance by 40–42 cattle each spring/summer, and mowing the plots to 2 cm height, 2–3 times) was used on some sections of the plots (each 3 x 10 m). Arthropods and plants were sampled in May 2009 (suction sampling and visual surveys, respectively).

 

17 

A meta-analysis from 2015 of four studies from annual rangelands in California, USA, found that grazing decreased the abundance of medusahead Taeniatherum caput-medusae. Plants: The abundance of medusahead was lower in plots that were grazed, compared to ungrazed, one year after grazing (reported as the response ratio of grazed to ungrazed plots: –0.7 log response ratio), but not 2–4 years after grazing. Methods: The Web of Knowledge, Agricola, and Digital Dissertations databases (and others managed by the University of California) were searched for publications from 1960 to 2013 (keywords not reported). Five studies from 1969 to 2011 were meta-analysed. There were four studies from California (response ratios from –2.4 to 0.4) and one study from Oregon (response ratios from 0.17 to 0.48: all positive, and so grazing decreased the abundance of medusahead only in California). Sheep or cattle were used for grazing, for 5–180 days, with an average stocking rate of 5.6 animal unit months (AUMs). The average plot size was 0.21 ha.

 

18 

A replicated, controlled study in 2010–2013 in grasslands in southern France found that grazing by sheep had little effect on plant communities or elmleaf blackberry Rubus ulmifolius. Plants: Similar numbers of plant species and similar plant diversity were found in grazed and ungrazed plots (17–51 species; diversity reported as Shannon indices). Bramble cover was lower in grazed plots, compared to ungrazed plots, under one of four conditions, when plots were also cut and drained (25% vs 49% cover). Bramble height was lower in grazed plots, under two of four conditions, when plots were also cut (13–14 vs 35–38 cm). Vegetation height was lower in grazed plots, under one of four conditions, when they were also cut and drained (13 vs 36 cm). Methods: In 2010, 48 plots (10 x 10 m) were established in two areas of grassland grazed by sheep and goats. Half of the plots were fenced to prevent grazing. Half of the plots were also cut, and half were drained using drainage ditches. The grazers were a flock of 1,100 sheep and 20 goats, for 30 days in March–April and 15 days in May–June in 2011–2013 (2.7 days/sheep/ha/year). Vegetation was monitored in May (one 5 x 5 m quadrat/plot).

 

Referenced papers

Please cite as:

Shackelford, G. E., Kelsey, R., Robertson, R. J., Williams, D. R. & Dicks, L. V. (2017) Sustainable Agriculture in California and Mediterranean Climates: Evidence for the effects of selected interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK.