Sow tree seeds after wildfire

Overall effectiveness category Likely to be ineffective or harmful
Number of studies: 3
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How is the evidence assessed?

Effectiveness

0%
Certainty

43%
Harms

40%

Calculating overall effectiveness category

Background information and definitions

One of the ways to restore trees community after wild is by direct seeding of new trees. This action can also affect the abundance of other plant species and consequently the composition of the whole forest.

Study locations

Key messages

Three studies (including one replicated, randomized, controlled study) in the USA examined the effect of sowing herbaceous plant seeds in burnt forest areas. One found it decreased the number and cover of native species and one found it decreased the density of tree seedlings. All three found no effect of seeding on total plant cover or species richness.

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 1994-1996 in temperate coniferous forest in Washington State, USA (Schoennagel & Waller 1999) found that spreading seeds in burnt forest areas decreased the number and cover of native species. The number of native plants species (unseeded: 17; seeded: 15/m²) and their cover (unseeded: 41%; seeded: 21%) were lower in seeded plots. Total plant cover was similar between treatments (unseeded: 41%; seeded: 48%). Thirty-two plots (15 × 15 m) were established in each control (unseeded) and seeded area (seeded in September 1994 with seed mix containing 80% annual grass, 15%, short-lived perennial species and 5% nitrogen-fixing legumes). Both areas (7 ha) burned in July 1994. Data were collected two years after seeding in eight quadrats (1 m²) in each plot.
Study and other actions tested
Referenced paper
Schoennagel T.L. & Waller D.M. (1999) Understory responses to fire and artificial seeding in an eastern Cascades Abies grandis forest, USA. Canadian Journal of Forest Research, 29, 1393-1401.
A replicated, randomized, controlled study in 2003-2005 in temperate coniferous forest in Washington State, USA (Dodson & Peterson 2009) found no effect of spreading seeds in burnt forest areas on total plant cover. Total plant cover was approximately 55% under both treatments. Seeded species cover was higher in seeded (8%) than in unseeded plots (1.5%). In 2002-2003, seeding (a mixture of perennial graminoids and forbs) and control treatments were randomly assigned to 8-16 plots (6×8 m) established at each of four sites in an area that was burnt by wildfire in summer 2002. Plant cover was measured in summer 2005.
Study and other actions tested
Referenced paper
Dodson E.K. & Peterson D.W. (2009) Seeding and fertilization effects on plant cover and community recovery following wildfire in the Eastern Cascade Mountains, USA. Forest Ecology and Management, 258, 1586-1593.
A replicated, controlled study in 2004-2006 in temperate mixed forest in Nevada, USA (Waitman, Draper & Esque 2009) found that spreading seeds of a sterile wheat-rye hybrid (triticale) in burnt forest area decreased the density of tree seedlings, but did not affect total species richness or cover of perennial plants. Numbers of tree seedlings was lower in seeded (14/m²) than unseeded plots (65/m²). Total number of species (seeded: 17; unseeded: 18/100 m² plot) and total cover of perennial plants (seeded: 24%; unseeded: 28%) were similar between treatments. Data were collected in 2006 in six pairs of seeded (seeded with triticale at ~92 seeds/m² in November 2004) and control (unseeded) plots (100 m²). Sites were in an area that was burnt by wildfire in July 2004.
Study and other actions tested
Referenced paper
Waitman B.A., Draper T.M. & Esque T.C. (2009) The effects of seeding sterile triticale on a native plant community after wildfire in a pinyon pine–mountain mahogany woodland. International Journal of Wildland Fire, 18, 659-664.

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

Related Actions

Actions	Effectiveness	Studies	Category
Remove burned trees Action Link	Unknown effectiveness (limited evidence)	2	Synopsis Link
Plant trees after wildfire Action Link	No evidence found (no assessment)	0	Synopsis Link
Sow tree seeds after wildfire Action Link	Likely to be ineffective or harmful	3	Synopsis Link