Use grazing to control trees

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • One randomized, controlled, before-and-after study in Italy found that grazing to reduce tree cover reduced cover of common heather and the basal area of trees, but did not alter cover of purple moor grass.

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

  1. A randomized, controlled, before-and-after study in 2005-2009 in a heathland invaded by aspen Populus tremuloides and silver birch Betula pendula in Italy (Ascoli et al. 2013) found that grazing to reduce tree cover reduced the cover of common heather Calluna vulgaris and the basal area of trees but did not alter the cover of purple moor grass Molinia arundinacea. After five years, the cover of common heather in grazed areas was similar (77%) to than that in areas that were not burned (77%). Purple moor grass cover was similar between grazed (84%) and ungrazed areas (88%). The basal area of trees was lower in grazed (3.2 m2/ha) than in ungrazed areas (4.6 m2/ha). No statistical analyses were carried out in this study. Starting in spring 2006 nine 650 m2 plots were grazed by goats for five years, and another six plots were not grazed. Five 2 x 2 m quadrats were placed in each plot and diameter of trees within them measured. Cover of common heather and purple moor grass was estimated using a 10 m transect in each plot along which the presence of both species was noted every 20 cm.

    Study and other actions tested
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

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Shrubland and Heathland Conservation

This Action forms part of the Action Synopsis:

Shrubland and Heathland Conservation
Shrubland and Heathland Conservation

Shrubland and Heathland Conservation - Published 2017

Shrubland and Heathland synopsis

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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.

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