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Providing evidence to improve practice

Action: Use herbicides to thin trees Forest Conservation

Key messages

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  • One replicated, controlled study in Canada found no effect of using herbicide to thin pine trees on total plant species richness.


Supporting evidence from individual studies


A replicated, controlled study in 1993-1998 in temperate lodgepole pine Pinus contorta forest in British Columbia, Canada (Sullivan et al. 2002) found no effect of using herbicide to thin lodgepole pine on total tree density or on total plant species richness. There was no effect of herbicide on the number of trees (herbicide: 4,180; control: 7,648/ha) or number of plants species (herbicide: 24; control: 23/treatment unit). Data were collected in 1998 in herbicide (using glyphosate herbicide to retain 1,000 stems/ha) and control treatment units (2-13 ha). Units were established in 1993 in each of three study areas.


Referenced papers

Please cite as:

Agra H., Schowanek S., Carmel Y., Smith R.K. & Ne’eman G. (2019) Forest Conservation. Pages 331-347 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.