Agriculture

  2010 MAR 18 - (VerticalNews.com) -- "The effects of initial tree spacing on wood density at breast height were examined for 22-year-old Japanese larch (Larix kaempferi). The experiment involved the use of three plots with different initial tree spacing densities (300, 500, and 1000 trees/ha)," scientists in Asahikawa, Japan report.

  "For five trees selected from each plot, the total tree height, diameter at breast height, height to the base of the live crown, and crown diameter were measured. Ring width and wood density for individual growth rings were determined by X-ray densitometry. A mixed-effects model was applied for fitting the radial variation in wood density in relation to initial spacing. Models having various mean and covariance structures were tested in devising an appropriate wood density model. The model, consisting of the mean structure with quadratic age effects and heterogeneous first-order autoregressive covariance, was able to describe the radial variation in wood density," wrote T. Fujimoto and colleagues ...read more

  2010 MAR 18 - (VerticalNews.com) -- "Bramble is a prickly shrub that may facilitate the establishment of tree seedlings at sites where grazing animals are present, but its role in forest regeneration is less clear. This study took place in a beech woodland over the 5-year period immediately after a heavy thinning to leave a basal area of 6.5 m(2) ha(-1)," researchers in Farnham, the United Kingdom report.

  "Development of the ground flora and the growth and browsing of birch and willow seedlings were observed annually at the end of the summer. The ground flora became dominated by a dense thicket of bramble c. 60 cm tall. The tree species differed in their susceptibility to browsing with a greater percentage of willow being browsed than birch. Similarly, willow seedling mortality was greater. Over the 5-year period, the average height of birch reached c. 2 m compared with c. 0.6 m for willow. For both species, there were significant positive relationships between seedling height and diameter and bramble cover and heights indicating that bramble facilitates the establishment of both willow and birch. Bramble reduced the incidence of browsing, an effect which appeared to be due to its relationship with seedling size," wrote R. Harmer and colleagues ...read more

  2010 MAR 18 - (VerticalNews.com) -- According to recent research published in the Journal of Wood Science, "Constituents of tars formed during the aging of bamboo (Phyllostachys pubescens), oak (Quercus serrata), and pine (Pinus densiflora) wood crude vinegars were analyzed by pyrolysis-gas chromatography (Py-GC) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) to investigate their origination. The pyrolysate of tars obtained from the wood and bamboo crude vinegars were almost identical and were primarily composed of phenolic compounds and aromatic hydrocarbons. ...read more