Apply herbicides after restoration planting

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

Effectiveness

45%
Certainty

25%
Harms

40%

Calculating overall effectiveness category

Background information and definitions

Harvesting and replanting have substantial effects on forest biodiversity conservation and maintenance of long-term productivity. Herbicides have been extensively evaluated for their potential to release planted trees from competing vegetation.

Study locations

Key messages

One replicated, randomized, controlled study in the USA found that controlling vegetation using herbicides after restoration planting decreased plant species richness and diversity.

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 replicated, randomized, controlled study in 1999-2006 in temperate coniferous forest in Washington State, USA (1) found that controlling vegetation using herbicides after restoration planting decreased plant species richness and diversity. Species richness (control: 24; herbicide: 17) and diversity (Simpson's index control: 0.83; herbicide: 0.35) were lower in treated plots. Data were collected in 2006 in two plots (30 × 85 m) of each control and herbicide (annual herbicide applications) treatments in each of four blocks that had been clearcut in 1999. In all plots tree trunks were removed and Douglas-fir Pseudotsuga menziesii seedlings were planted in 2000.
Study and other actions tested
Referenced paper
Peter D.H. & Harrington C. (2009) Six years of plant community development after clearcut harvesting in western Washington. Canadian Journal of Forest Research, 39, 308-319.

Please cite as:

Agra, H., Schowanek, S., Carmel, Y., Smith, R.K. & Ne’eman, G. (2020) Forest Conservation. Pages 323-366 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:

Forest Conservation

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Cover the ground using techniques other than plastic mats after restoration planting Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Use selective thinning after restoration planting Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Cover the ground with plastic mats after restoration planting Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link