Projecting non-native Douglas fir plantations in Southern Europe with the Forest Vegetation Simulator

In Italy, Douglas-fir has great potential in terms of wood production and drought tolerance. However, a growth reference for mature stands is lacking. We calibrated and validated the Pacific Northwest variant of the Forest Vegetation Simulator (FVS) for Douglas-fir plantations in Italy and then ran the calibrated model to test management alternatives. We calibrated the height-diameter, crown width, crown ratio, and diameter increment submodels of the FVS using multipliers fitted against tree measurements (n 704) and increment cores (n 180) from 20 plots. Validation was carried out on tree-level variables sampled in 1996 and 2015 in two independent permanent plots (275 trees). Multiplier calibration improved the error of crown submodels by 7–19%; self-calibration of the diameter growth submodel produced scale factors of 1.0 –5.2 for each site. Validation of 20-year simulations was more satisfactory for tree diameter ( 6% to 1% mean percent error) than for height ( 10% to 8%). Calibration reduced the error, relative to that of yield tables, of the predicted basal area and yield after 50 years. Simulated responses to thinning diverged, depending on site index and competition intensity. The FVS is a viable option for modeling the yield of Douglas-fir plantations in Italy, reflecting the current understanding of forest ecosystem dynamics and how they respond to management interventions

Brief on forestry biomass production

This brief on forestry biomass production is one out of a series of Bioeconomy Knowledge Centre briefs which intend to provide independent evidence for EU policy in this field. The following are the key results: 1. The land area covered by forests in the EU has been expanding at an average rate of 0.26% or 0.4 million hectares (Mha) per year from 2000 to 2015 (slowing down in 2010-2015). It reached 161 Mha (38% of the EU territory) in 2015. Of this area, 84% is potentially available for wood supply. 2. The total aboveground biomass stocked in EU forests reached 18 600 Mt in 2013. It has been increasing since 2000 at a rate of approximately 1.3% per year (see section 2), although the forest growth has been slowing down slightly, mostly due to ageing of forests. 3. The average annual harvest level – 281 Mt (of which 224 Mt are removed from the forest) – amounts to 63% of the growth rate (measured as net annual increment) of EU forests – 444 Mt per year. Since fellings are underreported, the actual harvest rate is likely to be higher, but still not exceeding the growth rate. 4. Detailed and harmonised quantitative data on forest management, and especially wood removals, present severe gaps and uncertainties at EU level, with marked differences between Member States. While significant progress has been made, efforts to improve the current assessments should be pursued. 5. Sustainable wood production implies reconciling the full range of ecosystem services which the forests provide.JRC.D.1-Bio-econom

Silvicultural strategies for introduced tree species in Northern Italy

The bio-deterioration of the historical heritage by fast growing and vigorous introduced tree species, and the reduction of native diversity, mostly in riparian, forest, wetland, and coastal habitats are considered amongst particularly relevant impacts for Italy. According to a recent survey of EU Life+ projects, the introduced tree species most often targeted for eradication by conservation projects across Europe are black locust (Robinia pseudoacacia L.), tree of heaven (Ailanthus altissima (Mill.) Swingle), red oak (Quercus rubra L.), and black cherry (Prunus serotina Ehrh.). In this chapter, we report on the few field experiences and success stories of silvicultural control of these introduced tree species in urban and natural habitats in northern Italy