Rake to control grass

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

30%
Certainty

20%
Harms

12%

Calculating overall effectiveness category

Background information and definitions

Raking can be used to reduce the length of grass as well as pulling out individual plants. In addition, it may create disturbances to topsoil allowing shrubland species to establish.

Study locations

Key messages

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.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

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.
Study and other actions tested
Referenced paper
Steers R.J. & Allen E.B. (2010) Post-fire control of invasive plants promotes native recovery in a burned desert shrubland. Restoration Ecology, 18, 334-343.

Please cite as:

Martin, P.A., Rocha, R., Smith, R.K. & Sutherland, W.J. (2020) Shrubland and Heathland Conservation. Pages 483-525 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Shrubland and Heathland Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Use herbicide and prescribed burning to control grass Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Cut/mow to control grass and sow seed of shrubland plants Action Link	Unknown effectiveness (limited evidence)	3	Synopsis Link
Apply herbicide and remove plants to control grass Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link