The growth of intensively thinned or sparse young grey alder stands | Intensīvi izretināto vai reto baltalkšņa jaunaudžu augšanas gaita
2009
Zalitis, P., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
To recognize thinned or sparse grey alder stands in our mature forests a following regularity was used: at the same mean stand height the mean diameter of these stands is greater compared to forests that are originated from overstocked young stands (about 55 thousand trees haE-1). The objects for this research are located in Vidusdaugava (VD) and Zemgale (Z) regional forestry, selecting stands starting from the mean height of 10 m. In total sample plots were established and measured in 31 stand. In such stands that were thinned to 4000 trees haE-1 before the mean height had reached 3 m, now, at the mean height of 15 m, the number of trees in dominant stand is by 2000 trees in Vidusdaugava regional forestry and by 1000 trees in Zemgale regional forestry greater than given in the yield tables of Pauls Mūrnieks (in the fully stocked 1st site class stands that have reached the height of 5 m the number of trees is 16 thousand trees haE-1). It is important to mention that there is no suppressed stand in the thinned grey alder forests. Also the stem volume of the dominant stand changes equally with the basal area. In the thinned stands at the mean stand height of 10 m the stem volume is similar to that in the unthinned stands (around 100 m**3haE-1) but later the volume accumulation in the thinned stands is almost twice as fast as given in the data base: in 20 m high stands the standing volume reaches 344 m**3haE-1 (in the data base - only 218 m**3 haE-1). It is important to mention that the standing volume dynamics in the thinned stands fully conforms to the standing volume changes given in the yield tables for fully stocked stands of 1st site class.
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