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Providing evidence to improve practice

Action: Rake to control grass Shrubland and Heathland Conservation

Key messages

Read our guidance on Key messages before continuing

  • A randomized, replicated, controlled, paired study in the USA found that cover of both invasive and native grasses, as well as forbs was lower in areas that were raked than in areas that were not raked, but that the number of annual plants species did not differ.

Supporting evidence from individual studies

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A randomized, replicated, controlled, paired study in 2005–2008 in creosote bush shrubland that was invaded by non-native grasses in California, USA (Steers & Allen 2010) found that raking reduced invasive grass cover but did not increase the number of annual plant species, and also reduced the cover of native grasses and forb species in two of four cases. In four of four cases areas that were raked had lower non-native grass cover (36–39%) than areas that were not raked (60–65%). In four of four cases the number of annual plant species in areas that had been raked (2–4 species/plot) did not differ significantly from the areas that had not been raked (3–4 species/plot). However, in two of four cases cover of native grass and forb species was lower in areas that had been raked (4–18%) than in areas that had not been raked (23–37%). In January 2006 and 2008 twelve 8 m x 8 m plots were raked to remove invasive grasses while twelve other plots were not raked. Plant cover was recorded in March-April 2006 and 2008 in 0.5 m2 quadrats located in each plot.

Referenced papers

Please cite as:

Martin P.A., Rocha R., Smith R.K. & Sutherland W.J. (2019) Shrubland and Heathland Conservation. Pages 493-538 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.