Assessment of Forest Wood and Carbon Stock at the Stand Level: First Results of a Modeling Approach for an Italian Case Study Area of the Central Alps

Abstract

Models for carbon (C) stock assessment are widely applied in forest science, and mainly differ according to the scale of application, the required data, and the objectives for their implementation. This work presents the methodology implemented into the second version of an empirical model, WOody biomass and Carbon ASsessment (WOCAS v2), that uses the data of forest management plans (FMP) to calculate the mass of wood (t∙year−1 of dry matter, DM) and C (t∙year−1 C) at the stand level and from the year in which the FMPs came into force until a predefined reference year, for an Italian Case Study Area of Central Alps. The mass of wood and C are computed for (i) aboveground wood biomass (AWB), (ii) belowground wood biomass (BWB), and (iii) dead organic matter (DOM; i.e., dead wood and litter) according to the 2006 IPCC Guidelines. WOCAS v2 was tested for the first time for 2019 public forest stands (3.67 × 104 ha) of Valle Camonica for the period 1984–2018. Results showed that, in 2018 and at the landscape level, the total living wood biomass (TLB; AWB + BWB) reached 5.35∙106 t DM. TLB yield (t·ha−1·year−1 DM) ranged from 44.72 ± 44.42 t·ha−1·year−1 DM (1984) to 145.49 ± 70.76 t·ha−1·year−1 DM (2018). In the same year, DOM amounted to 6.12∙105 t DM, ranging from 8.28 ± 7.79 t·ha−1·year−1 DM (1989) to 17.11 ± 12.03 t·ha−1·year−1 DM (2015). The total weighted C yield, computed as the sum of C yield in AWB, BWB, and DOM of each stand, ranged from 26.63 ± 26.80 t∙ha−1∙year−1 C (1984) to 80.28 ± 41.32 t∙ha−1∙year−1 C (2018). The results demonstrated that FMPs data can be useful in estimating wood and C mass at the stand level and their variation over space and time for AWB as well as for BWB and DOM, which are not considered in the FMPs. This can represent a starting point for defining sustainable forest management policies and practices to improve forest vitality and conservation in compatibility with ecosystem services provision. Moreover, as the model is based on a standardized methodology it can be applied in any other forest area where the same input data are made available; this may constitute the basis for further applications on a broader scale.