Tree growth and soil relations at the 1925 Wind River spacing test in coast Douglas-fir.

Testing a hypothesis of the relationship between productivity and water use efficiency in Patagonian forests with native and exotic species

“…Different letters indicate statistical differences between species (P < 0.05). (Acker et al, 2002;King et al, 2002;Miller et al, 2004). Mean current productivity of the Patagonian plantation was lower than that of a Douglas-fir forest of similar age (29-year-old, 6.8 tonnes ha À1 year À1 ) and slightly higher than that of a mature forest (100-year-old, 4.8 tonnes ha À1 year À1 ) both growing in the H.J.…”

Effects of planting spacing and site quality on 25-year growth and mortality relationships of Douglas-fir (Pseudotsuga menziesii var. menziesii)

“…Compared to the 1981 study, Douglas-fir planted at similar spacings in the Maple Ridge study (site index = 43.0 m; Reukema and Smith, 1987) averaged 5-9 m taller in height, whereas those planted in the 1925 study (site index = 30.4 m; Miller et al, 2004) averaged 1-3 m shorter (Table 2). For similar planting spacings, Douglas-fir at Maple Ridge averaged 3-8 cm larger in dbh than in the 1981 study, while in the 1925 Wind River study they averaged Comparisons with the Maple Ridge study suggest that competition intensity and associated mortality increased with site quality, resulting in less variability in tree size by years 23-25.…”

“…Net periodic annual increment (PAI) in stand volume (m 3 ha À1 year À1 ) and volume mortality (m 3 ha À1 year À1 ) were calculated for the period of years 21-25. Using data from year 25, breast height age and average height of the 100 trees of largest dbh ha À1 (i.e., top height) were calculated per plot (as per Miller et al, 2004) and applied to the procedures in King (1966) to calculate an average site index. The age at which trees reached breast height (1.37 m in King, 1966) was determined by fitting plot-specific regression models of age as a quadratic function of top height using combined data from all measurement years.…”

Patterns of conifer tree regeneration following an autumn wildfire event in the western Oregon Cascade Range, USA

“…The high seedling densities will result in intense intercohort competition, both within and between species. Diameter growth slows dramatically with increasing initial stand density, resulting in tall, thin and unstable trees (Oliver and Larson, 1996;Miller et al, 2004). Dense initial establishment can lead to poor differentiation and depressed height growth (Oliver and Larson, 1996), slowing structural development.…”