Distribution and characteristics of silver fir natural regeneration grown in different light conditions in some Tuscany stands
1991
Paci, M. (Florence Univ. (Italy). Istituto di Selvicoltura) | Mazzini, A.
Some characters of silver fir natural regeneration were studied in 10 stands (11 plots). The stands (placed in Vallombrosa, Abetone, Maresca, La Verna and Piancastagnaio) show different specific compositions and structures. For a set of characters (some of them are easy to record) it is possible to separate the silver fir natural regeneration grown under a dense canopy (S) from the one grown under a thin canopy or grown on well lightened stand and clearing margins (L). Inside each area photosynthetically active radiation (PAR) measurements were carried out at breast height: the relative light values (IR) are - respectively for S and L - constantly under 3% or over 5%. The most distinctive characters are the F/L ratio (terminal shoot length/average length of first verticil laterals), the H/Pr ratio (total height/horizontal projection of the longest lateral), the apical bud size, the 100 needles weight and the Mg concentration in the needles. All these features are higher for L. In particular F/L ratio is the easiest parameter to record and it shows the highest correlations with light availability (r = 0.82** ). The regeneration index (Ir) is also highly correlated with IR (r = 0.80** )
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