DIGITALNA ARHIVA UMARSKOG LISTA
prilagođeno pretraivanje po punom tekstu
|UMARSKI LIST 1-2/2015 str. 55 <-- 55 --> PDF|
and ONR (8.3% more than the mean of all populations) figure 4.
Conventional wood density (CWD) Standardna gustoæa drva (SGD)
The mean value of CWD in the two ONR trials was 6.5% higher than INR. However, the greater average value in the two tests ONR is due to Câmpina trial, which has the highest CWD value (0.374 g/cm3). The highest CWD value was recorded at the lowest altitude (Câmpina), whereas the lowest (0.329 g/cm3) at highest altitude, in Brețcu (Table 2). ANOVA (Table 4) revealed significant differences (P<0.001) of location and population. However, the population has significant effects in the two tests outside the natural range (P<0.001 at Câmpina; P<0.05 at Avrig), but also in one of the tests in the natural area of species (P<0.05 at Brețcu). In all trials, the populations associated with high RI values displayed lower wood density levels. This was also evident in the case of the IUFRO standard provenance (5-Moldovița), which was ranked 28th in terms of CWD value.
The correlations between analysed traits and the geographical gradients of seed stand origins (Table 5) were insignificant with altitude, while latitude, longitude and ecophysiological latitude determined some influences, but did not result clear trends or patterns to differentiate the behaviour INR or ONR. Thus, ecophysiological latitude was found to have a small influence on CWD value only in the INR trial carried out at Brețcu (r = -0.14*); northern Romanian populations displayed high increments in all tests, but the wood was found to be less dense. At the same time, the Brețcu trial (INR), where the highest mean annual RI value was recorded, was the only in which a significant but low correlation was observed between mean RI and latitude of population origin (r = 0.14*).
The differences between populations originating from different branches of Romanian Carpathians may be attributed to historical evolution of spruce in Holocene (Feurdean et al. 2011). The lower values obtained in Câmpina trial can