Bayesian and classical biomass allometries for open grown valonian oaks (Q. ithaburensis subs. macrolepis L.) in a silvopastoral system

Autor: Andreas Papadopoulos, Dimitris Zianis, Maria Rosa Mosquera-Losada, Anastasia Pantera, María Rosa Mosquera-Losada
Rok vydání: 2017
Předmět:
Zdroj: Agroforestry Systems. 93:241-253
ISSN: 1572-9680
0167-4366
DOI: 10.1007/s10457-016-0060-7
Popis: Allometric models predicting aboveground woody biomass for open grown valonian oak (Q. ithaburensis subs. macrolepis L.) trees growing in a Mediterranean silvopastoral system were built based on Bayesian and classical statistical techniques. The simple power model M = aDb was used for predicting aboveground woody biomass (M), stem (MS) and branch (MB) biomass through tree diameter (D). An informative Bayesian approach (IB) based on prior information about a and b and increasing variance of predicted values in relation to D was applied on 25 destructively sampled trees for estimating M. Non-informative Bayesian (NB), log-linear regression (LR) and non-linear regression were also built for M, MS and MB. Quite similar M distribution was derived from LR and NB across the D range, totally different from IB predictions which provided biologically sound estimates. Tree height, stem length and crown length did not substantially improve predictions for M, MS and MB. Comparisons to oak trees growing in closed stands indicated that open-grown oaks sustain much less stem biomass but maintain larger branch biomass than forest-grown counterparts. Comparisons to published values for open-grown green ash trees supported the hypothesis that open grown broadleaved specimens may sustain similar M values, irrespectively of species, growth conditions and tree size. On the contrary, allocation pattern of organic matter to stem and branches seems to vary by species and/or site conditions. Finally, predictions for b = 2.67 derived from a theoretical model was not supported by this dataset.
Databáze: OpenAIRE
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