Log/remove trees within forests: effects on young trees

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 2
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How is the evidence assessed?

Effectiveness

50%
Certainty

18%
Harms

10%

Calculating overall effectiveness category

Background information and definitions

Here logging is defined as the selective removal of trees with the aim of removing tree biomass. This helps to restore natural open woodland by creating gaps and increasing light availability within the forest, which may increase the growth of the remaining vegetation. Interventions where trees are removed to enhance the future condition of a forest and the development of remaining trees are discussed under ‘Thin trees within forests’. Studies comparing the effects of partial logging with clearcutting are discussed in ‘Use partial retention harvesting instead of clearcutting'.

Study locations

Key messages

One replicated controlled study in Canada found that logging trees in forests increased the density of young trees.One replicated controlled study in Costa Rica found mixed effects on the density of young trees.

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, controlled study in 1992-2001 in boreal forest in Ontario, Canada (Bebber et al. 2005) found that structural retention harvest increased tree sapling density. Average sapling density increased from 4,178 to 5,109 saplings/ha in harvested compared with unharvested plots. Harvesting was carried out in 1992. Remaining trees were healthy seed bearers and declining quality trees. Six unharvested control plots and 12 harvested plots, spread over an area of approximately 1,200 ha were monitored during August and September 2001. Plot areas varied from 3 to 104 ha (average 26 ha). Fifty five sample points were placed within control plots and 89 within harvested plots (3–20 points/plot). Tree saplings were recorded inside a 5 m radius ring around plot centre.
Study and other actions tested
Referenced paper
Bebber D., Cole W., Thomas S., Balsillie D. & Duinker P. (2005) Effects of retention harvests on structure of old-growth Pinus strobus L. stands in Ontario. Forest Ecology and Management, 205, 91-103.
A replicated, controlled study in 1997-2002 in tropical rain forest in Costa Rica (Lobo et al. 2007) found that selective logging decreased the density of seedlings and small juvenile trees but increased the number of larger trees. For Caryocar costaricense, the density (individuals/ha) of seedlings (<50 cm tall) (logged: 3.1; unlogged: 4.5) and small juveniles (<2 cm diameter at breast height) (logged: 5.2; unlogged: 8.0) was higher in unlogged plots. In contrast, the density of large juveniles (2-10 cm diameter at breast height) was higher in logged plots (logged: 4.3; unlogged: 2.4). For purpleheart Peltogyne purpurea, the density of seedlings (logged: 208.8; unlogged: 511.2) was higher in unlogged plots, while the density did not differe for small (logged: 2.2; unlogged: 3.1) and large juveniles (logged: 2.6; unlogged: 2.2). Data were collected in 2002 in three logged (selective logging in 1997-1998) and three unlogged plots (100 × 30 m) in each of 11 sites.
Study and other actions tested
Referenced paper
Lobo J., Barrantes G., Castillo M., Quesada R., Maldonado T., Fuchs E.J., Solís S. & Quesada M. (2007) Effects of selective logging on the abundance, regeneration and short-term survival of Caryocar costaricense (Caryocaceae) and Peltogyne purpurea (Caesalpinaceae), two endemic timber species of southern Central America. Forest Ecology and Management, 245, 88-95.

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
Log/remove trees within forests: effects on understory plants Action Link	Beneficial	12	Synopsis Link
Thin trees within forests: effects on young trees Action Link	Likely to be beneficial	13	Synopsis Link
Use brash mats during harvesting to avoid soil compaction Action Link	No evidence found (no assessment)	0	Synopsis Link