Rastna dinamika pragozdnega ostanka Rajhenavski Rog v obdobju 1984-2010
V pragozdnem ostanku Rajhenavski Rog so bile leta 1984 izločene tri stalne raziskovalne ploskve s skupno površino 1,91 ha, ki so bile izmerjene tudi leta 1994. Leta 2010 smo ponovili meritve na vseh treh ploskvah. Preučevali smo spreminjanje velikosti vrasti in smrtnosti v obdobjih 1984-1994 in 1994-2010. Skupna letna smrtnost se je v obdobju 1994-2010 v primerjavi z obdobjem 1984-1994 iz 1 % povišala na 1,2 %, stopnja smrtnosti jelke (Abies alba Mill.) pa je v obeh meritvenih obdobjih močno presegala stopnjo smrtnosti bukve (Fagus sylvatica L.). Do največjega povišanja smrtnosti je prišlo, tako pri jelki kot pri bukvi, pri drevesih s premerom večjim od 70 cm. Skupna letna vrast 1,8 % v obdobju 1984-1994 se je povišala na 2,6 % v obdobju 1994-2010. Prišlo je do izrazitega povečanja vrasti novih bukovih dreves v populacijo, vrasti jelke pa že od prvih meritev leta 1984 nismo zaznali. Skupna vrast se je povišala pri drevesih s premerom do 20 cm, pri debelejših drevesih pa se je vrast v obdobju 1994-2010, v primerjavi z obdobjem 1984-1994, znižala. Število bukev na ploskvah se viša in sedaj znaša 84 % vseh dreves, delež jelke pa se je znižal na 16 %. Rezultati nakazujejo na nadaljnje zmanjševanje deleža jelke v populaciji in vse večjo prevlado bukve v Rajhenavskem pragozdu.
In 1984 three permanent plots totalling 1,91ha were established in the Rajhenavski Rog old-growth forest. These plots were re-measured in 1994 and 2010. We quantified mortality and recruitment rates in two periods: 1984-1994 and 1994-2010. The annual mortality rate increased from 1% in 1984-1994 to 1,2% in 1994-2010. The mortality rate of silver fir (Abies alba Mill.) heavily exceeded that of European beech (Fagus sylvatica L.) in both of the analyzed periods. The highest increase in mortality was recorded for trees with dbh greater than 70 cm for both silver fir and European beech. The annual recruitment rate increased from 1,8% in 1984-1994 to 2,6% in 1994-2010. We recorded a large increase in the recruitment of beech trees in the 1994-2010 period, while there was no recruitment of silver fir in the last 26 years. For trees with dbh lower than 20 cm, we recorded an increase in annual recruitment, while a decrease in recruitment was found for trees with dbh greater than 20 cm. The number of beech trees on the plots increased and as a result beech currently represents 84% of all trees. The share of silver fir in the forest decreased and the results suggest this process will also continue in the future, leading to a further increase in beech in the Rajhenavski Rog old-growth forest.
2013
2015-07-10 13:09:41
1060
Rajhenavski Rog, pragozdovi, smrtnost, vrast, bukev, Fagus Sylvatica L., jelka, Abies alba Mill.,
m5
[J. Miklavčič]
Janez
Miklavčič
70
Thomas Andrew
Nagel
991
UDK
4
630*22(497.4Rajhenavski Rog)(043.2)=163.6___
COBISS_ID
3
3599014
UNI_Miklavcic_Janez_2013.pdf
717162
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2020-04-15 17:13:04