Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Understory response to management treatments in northern Arizona ponderosa pine forests

Published source details

Griffis K.L., Crawford J.A., Wagner M.R. & Moir W. (2001) Understory response to management treatments in northern Arizona ponderosa pine forests. Forest Ecology and Management, 146, 239-245


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use thinning followed by prescribed fire Forest Conservation

A replicated, controlled study in 1999 in temperate mixed forest in Arizona USA (Griffis et al. 2001) found that thinning followed by prescribed burning increased the abundance of native grasses and species richness of exotic herbaceous species. The abundance index of native grass species was higher in thinned and burned (48) than in untreated plots (19). The number of species/375 m2 of exotic herbaceous species was higher in thinned and burned (4) than in untreated plots (2). The abundance index of native herbaceous species (30 vs 26), exotic herbaceous species (6 vs 3) and exotic grass species (6 vs 0), and the number of species/375 m2 of native herbaceous species (19 vs 18), native grasses (6 in both) and exotic grasses (1 vs 0) were similar between thinned and burned and untreated plots. Data were collected in ten 375 m2 plots in each of four thinned and burned forest fragments (30% of basal area removed between 1987 and 1993 and burned between 3-4 years of thinning) and four untreated forest fragments (20-80 ha).

 

Thin trees within forests: effects on understory plants Forest Conservation

A replicated, controlled study in 1999 in temperate mixed forest in Arizona USA (Griffis et al. 2001) found that thinning increased the abundance of native grasses but did not affect species richness for any under-canopy plant group. Abundance index of native grass species was higher in thinned (33) than in unthinned plots (19). Abundance index of native herbaceous species (23 vs 26), exotic herbaceous species (1 vs 3) and exotic grasses (4 vs 0), and the number of species (/375 m2) of native herbaceous species (17 vs 18), exotic herbaceous species (2 in both), native grasses (6 in both) and exotic grasses (1 vs 0) were similar between thinned and unthinned plots. Data were collected in ten 375 m2 plots in each of four thinned (30% of basal area removed between 1987 and 1993) and four unthinned forest fragments (20-80 ha).