Cultivating birch for quality veneer logs under conditions of lasting transboundary pollution in Latvia | Kvalitatīvu bērzu izaudzēšana finierkluču ieguvei Latvijā ilgstoša pārrobežu gaisa piesārņojuma apstākļos
2006
Spalte, E., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Finding out the reasons for stand defoliation in birch plantations for veneer logs is essential to have pollution-resistant crops. Since the year 2000 the defoliation of birch has rapidly increased and over the past six years is substantially higher as compared to the period between 1994 and 1999. It is explained by the reduced amount of Ca, Mg, Cl, NO3 and NH4 in atmospheric precipitation. In 2000-2005, the defoliation of birch showed a significant negative correlation with the pH number (0.96), resulting in a significant negative correlation with SO4 (0.87).
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