Asian Journal of Plant Sciences1682-39741812-5697Asian Network for Scientific Information10.3923/ajps.2008.700.709Heshmatol VaezinS.M. AttarodP. BayramzadehV. 8200878The objective was to provide a pilot increment model
for major species in the Caspian forests including Common Hornbeam (Carpinus
betulus L.), Oriental Beech (Fagus orientalis Lipsky) and Heart
Leaved Alder (Alnus cordata Desf.) by routinely measured variables
in forest inventories. The only published and reliable data of an accomplished
inventory in the western Caspian forests have been used to construct a
database including all available explanatory variables of volume increment.
Potential*reducer method was applied in this research to develop tree
volume increment models. Volume increment models have been well-estimated
for major species according to diameter at breast height (DBH), ecological
aspects (ASP) and stand density (SD). Based on coefficient of determination,
the models explained between 45 to 83% of volume increment variability.
The results showed a descending ranking of volume increment from alder,
hornbeam to beech for trees having DBH inferior to 70 cm. The average
elasticity (E%) of volume increment to ASP indicated that hornbeam trees
(0.85%) were approximately two times more sensitive than beech trees (0.46%)
while no sensitivity was observed in alder trees. In the same way, hornbeam
trees were appeared to be a bit more sensitive (0.41%) than alder (0.32%)
to SD whereas no sensitivity was observed in beech trees. Although the
presented increment models can be employed for applied purposes in the
western Caspian region, model enhancement is expected if more detailed
and larger dataset including soil, microclimate and forest structure data
are incorporated.]]>Attarod, P., V. Bayramzadeh and A. Shirvany,20076927933Attarod, P. and V. Bayramzadeh,2003Quercus castaneifolia) in the mixed broadleaf forests of the caspian region (North of Iran).]]>2003pp: 97102Bouchon, J.,1995XLVII2334 (In French)Danjon, F. and J.C. Hervé,199451589598Franc, A., S. Gourlet-Fleury and N. Picard,20002000Gersonde, R.F. and K.L. O'Hara,200521995108Gustavsen, H., R. Heinonen, E. Paavilainen and A. Reinikainen,1998107117Hamilton, G.J.,196942133144Heshmatol Vaezin, S.M.,20062006Houllier, F., J. Bouchon and Y. Birot,1991XLIII87108 (In French)Loetch, F. and K.E. Haller, 19643rd Edn.pp: 285-301pp: 285-301Marvi Mahadjer, M.R.,20071st Edn.pp: 65-85 and 85-90 (In Persian)pp: 65-85 and 85-90 (In Persian)Murphy, P.A. and M.G. Shelton,199626327331O’Hara, K.L., E. Lähde, O. Laiho, Y. Norokorpi and T. Saksa,199956237247Paquette, A., A. Bouchard and A. Cogliastro,2007241278287Pave, A.,19941994Peyron, J.L. and F. Houllier,19971143842 (In French)Ruiter, J.H.,1987207996Saeed, A.,19951st Edn.pp: 116-118pp: 116-118Seynave, I., J.C. Gégout, J.C. Hervé and J.F. Dhôte,20061674145 (In French)Schroder, J., R.R. Soalleiro and G.V. Alonso,20021575564Wenk, G.,199469259268Zeide, B.,199339596616Zobeiry, M.,19931st Edn.pp: 25-32, 65-113, 121-180 and 210-215 (In Persian)pp: 25-32, 65-113, 121-180 and 210-215 (In Persian)