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Abstract

Background: Forest management aims at obtaining a sustainable production of wood to be harvested to generate
products or energy. However, the quantitative influence of forest management and of removals by harvest on biomass
stocks has rarely been analysed on a large scale based on measurements. Two hypotheses prevail: management
induces a reduction of wood stocks due to cuttings, versus no impact because of increased growth of the remaining
trees.
Using data collected for 2840 permanent plots across Romania from the National Forest Inventory representing ~ 2.5
Mha, we have tested to what extent different management types and treatments can influence the biomass stock and
productivity of beech forests, and attempt to quantify these effects both on the short and long terms.
Three main types of beech forest management are implemented in Romania with specific objectives: intensive wood
production in production forests, protection of ecosystem services (e.g. watersheds, avalanche protection) in protection
forests, and protection of the forest and its biodiversity in protected forests. Production forests encompass
two treatments differing according to the stand regeneration method: the age class rotation management
and the group shelterwood management.
Results: We show that forest management had little influence on the biomass stocks at a given stand age.
The highest stocks at stand age 100 were observed in production forests (the most intensively managed
forests). Consequences of early cuttings were very short-termed because the increase in tree growth rapidly
compensated for tree cuttings. The cumulated biomass of production forests exceeded that of protected and
protection forests. Regarding the treatment, the group shelterwood forests had a markedly higher production
over a full rotation period.
The total amount of deadwood was primarily driven by the amount of standing deadwood, and no management
effect was detected.
Conclusions: Given the relatively low-intensity management in Romania, forest management had no negative impact
on wood stocks in beech forests biomass stocks at large scale. Stand productivity was very similar among management
types or treatments. However cumulated biomass in production forests was higher than in protection or protected
forests, and differed markedly according to treatments with a higher cumulated biomass in shelterwood forests.