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Providing evidence to improve practice

Individual study: Understory abundance, species diversity and functional attribute response to thinning in coniferous stands

Published source details

Ares A., Neill A.R. & Puettmann K.J. (2010) Understory abundance, species diversity and functional attribute response to thinning in coniferous stands. Forest Ecology and Management, 260, 1104-1113


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Thin trees within forests: effects on understory plants Forest Conservation

A replicated, randomized, controlled study in 1997-2008 in temperate coniferous forest in western Oregon, USA (Ares,Neill & Puettmann 2010) found that thinning increased the number of understory species. The number of species/80 m2 was higher following fixed (high or moderate) density thinning (76 and 86 respectively) than following variable (high or moderate) density thinning (54 and 55 respectively) and unthinned (48). It was not different than the other five treatments following variable low density (60). A set of six thinning regimes, each comprising 20–44 ha, was applied in 1997 at each of three forest sites: unthinned; fixed high density treatment (300 trees/ha); fixed moderate density treatment (200 trees/ha); variable high density treatment (300 trees/ha); variable moderate density treatment (200 trees/ha); variable low density treatment (100 trees/ha). Between four and 20 permanent 0.1 ha plots were located randomly in each treatment (total of 77 plots/site). Four 20 m2 sub-plots were installed in each plot. Monitoring was carried out in summer 2003 and 2008.