Individual study: Understorey plant and soil responses to disturbance and increased nitrogen in boreal forests
Manninen O., Stark S., Kytöviita M., Lampinen L. & Tolvanen A. (2009) Understorey plant and soil responses to disturbance and increased nitrogen in boreal forests. Journal of Vegetation Science, 20, 311-322
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
A replicated, randomized, controlled study in 2000-2002 in boreal forest in Finland (6) found that fertilizing increased the relative weight of grasses (out of total weight of all plant) but not the total weight. Relative weight of grass was higher in plots treated with 40 and 80 kg/ha of nitrogen (N) than unfertilized plots (unfertilized: 5%; 20 kg N/ha: 7%; 40 kg N/ha: 15%; 80 kg N/ha: 16%). Relative weight of evergreen shrubs (25-40%), deciduous shrubs (53-67%) and herbaceous species (1-7%) and total above ground weight of all plants (12-190 g/m2) were similar in all treatments. Data were collected in 2002 in eight replicates of four treatments (3 × 3 m): unfertilized, 20, 40 and 80 kg N/ha in a year in 1998-2002, in each of two sites.
Use clearcutting to increase understory diversity
A replicated, randomized, controlled study in 2000-2002 in boreal forest in Finland (Manninen et al. 2009) found that clearcutting decreased total plant biomass and the relative biomass of evergreen shrubs, but not deciduous shrubs, grasses or herbaceous species. Total above ground biomass (clearcut: 12-20 g/m2; control: 140-190 g/m2) and relative biomass of evergreen shrubs (clearcut: 20-25%; control: 30-40%) were lower in clearcut. However, relative biomass of deciduous shrubs (53-67%) grasses (1-17%) and herbaceous species (1-7%) was similar between treatments. Data were collected in 2002 in 32 pairs of 0.5 × 0.5 m clearcut plots (biomass above the moss layer clipped each year 2002-2002) and 0.25 × 0.25 m control plots in each of two sites.