The purpose of this study was to expand an existing semi-mechanistic forest model, ANAFORE (ANAlysing Forest Ecosystems), to allow for the prediction of log quality and the accompanying uncertainty ...as influenced by climate and management. The forest stand is described as consisting of trees of different cohorts, either of the same or of different species (deciduous or coniferous). In addition to photosynthesis, transpiration, total growth and yield, the model simulates the daily evolution in vessel biomass and radius, parenchyma and branch development. From these data early and latewood biomass, wood tissue composition, knot formation and density are calculated. The new version presented here, includes the description of log quality, including red heart formation of beeches. A Bayesian optimisation routine for the species parameters was added to the stand model. From a given range of input parameters (prior), the model calculates an optimised range for the parameters (posterior) based on given output data, as well as an uncertainty on the predicted values. A case study was performed for Slovenian beech forests to illustrate the main model functioning and more in particular the simulation of the wood quality. The results indicate that the ANAFORE model is a useful tool for analyzing wood quality development and forest ecosystem functioning in response to management, climate and stand characteristics. However, the Bayesian optimization showed that the remaining uncertainty on the input parameters for the chosen stand was very large, due to the large number of input parameters in comparison to the limited stand data.
Beech (Fagus sylvatica L.) bark was wounded in early April of 1993 and tissue changes followed on days 7, 14, 21, 28, 35, 42, 49, 56, 84, 112, and 140. In 7 days, tissue at the wound surface became ...necrotic and discoloured. In 14 days the walls of the parenchyma cells immediately underneath the necrotic tissue became thickened and after 21 days became lignified. In 28 days these lignified cells showed intracellular suberisation. In 42 days the ligno-suberised layer was continuous with the phellem of the superficial periderm. In 35 days we first noted differentiation of the necrophylactic phellogen under the ligno-suberised layer. In 49 days suberised phellem of the necrophylactic periderm differentiated. At 112 days the phellem of the necrophylactic periderm had coalesced with that of the surface periderm. In 140 days abscission of the wound rhytidome began.
The formation of a ligno-suberised layer and the necrophylactic periderm started in the nonconducting phloem under the basal region of the wound and proceeded from there in two directions: toward the tissue under the original periderm and along the sclerified rays toward the cambium. Sclerified phloem rays protruding into the xylem rays did not prevent the formation of a ligno-suberised layer and necrophylactic periderm in beech. It is supposed that the ligno-suberised layer and the necrophylactic periderm in European beech is generated from living cells extant at the time of wounding as well as from recent phloic derivatives of the vascular cambium.
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