Remove midstorey from savannas

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Share Tweet Email

View assessment score

How is the evidence assessed?

Effectiveness

30%
Certainty

10%
Harms

30%

Calculating overall effectiveness category

Background information and definitions

Conservationists may wish to remove shrubs from savanna if they are dominating the habitat and excluding some open-habitat species. However, shrubs can also provide habitat complexity and additional niches for species.

Study locations

Key messages

A controlled study in Argentina found that in summer, but not overall, a control area had higher bird abundance and species richness than an area where shrubs were removed. There were also differences in community composition between treatments.

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 controlled study in 1998-1999 in one treatment (where shrubs were manually removed) and one control (shrubs left unmanipulated) area (both 200 ha) within the same Chacoan forest in Santiago del Estero, Argentina (Codesido et al. 2009) found that, overall, there was no difference in bird abundance or species richness between the two areas. However, the treatment area contained significantly lower species richness and abundance than the control area in summer. At the guild level, bark-feeding insectivores were more abundant in the treatment area; whereas foliage-gleaning insectivores and arboreal seed-eating species were less abundant in the treatment area. In December 1998, terrestrial insectivores were less abundant in the treatment. Birds were surveyed four times at 30 points within each area. In the treatment area, saplings of species that form the tree layer were not removed.
Study and other actions tested
Referenced paper
Codesido M., Drozd A.A., Gado P.A. & Bilenca D. (2009) Responses of a bird assemblage to manual shrub removal in a Chacoan subtropical semiarid forest, Argentina. Ornitología Neotropical, 20, 47-60.

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2020) Bird Conservation. Pages 137-281 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:

Bird Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Raise water levels in ditches or grassland Action Link	Trade-off between benefit and harms	7	Synopsis Link
Create scrapes and pools in wetlands and wet grasslands Action Link	Likely to be beneficial	6	Synopsis Link
Employ grazing in artificial grasslands/pastures Action Link	Trade-off between benefit and harms	10	Synopsis Link