Action: Use selective thinning after restoration planting
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- One replicated, paired sites study in Canada found that selective thinning after restoration planting conifers increased the abundance of herbaceous species and decreased the abundance of trees.
Harvesting and replanting have substantial effects on forest biodiversity conservation and maintenance of long-term productivity. Selective thinning after restoration planting can increase planted tree establishment success by reducing competition.
Supporting evidence from individual studies
A replicated, paired sites study in 1993-1998 in boreal forest in Ontario, Canada (Bell & Newmaster 2002) found that cutting of non-coniferous species following planting conifer tree species increased the cover, but not herbaceous species richness; increased species richness but not cover of grasses; decreased the abundance but not species richness of trees. Percentage cover of herbaceous species was higher in cut than in control plots while their species richness was similar (55 vs 44%, 70 vs 69 species). Species richness of grasses was higher in cut than in control plots while their percentage cover was similar (12 vs 8 species, 15 vs 11%). Species richness and percentage cover of trees 2-10 m were lower in cut than in control plots (15 vs 24 species and 19 vs 29% respectively). For trees 0.5-2 m percentage cover was lower in cut than in control plots while species richness was similar between treatments (50 vs 66%, 39 vs 42 species). Species richness and percentage cover of trees <0.5 m were similar in cut and control plots (44 vs 48 species and 44 vs 43%). Two cutting treatment (chain saw cutting and mechanical brush cutting) and one control plots (4-12 ha) were replicated in four blocks, which had previously been clearcut and planted with white spruce Picea glauca and black spruce Picea mariana 3-4 years before herbicide treatments. Monitoring was five years after treatment.