The supply of wood in Europe on a sustainable basis is highly relevant for forestry and related policies, particularly in relation to (i) analysing global change mitigation strategies and carbon accounting (ii) establishing realistic forecasts and targets for wood resources, biomass and renewable energy and (iii) assessing and supporting strategies for an increased use of wood.Therefore, it is relevant to have robust information of the availability for wood supply. The main aim of this paper is to harmonize the concept of ‘forest available for wood supply’ (FAWS) at European level.The data employed in this study was acquired through two questionnaires. The first questionnaire, conducted under the framework of COST Action FP1001 and a second questionnaire was completed by national correspondents and members of the UNECE/FAO.The analysis showed that reasons for the exclusion of forest from FAWS are diverse. Legal restrictions and specifically ´Protected areas´ are considered by 79% of the countries while very few countries consider economic restrictions.A new FAWS reference definition is provided and the consequences of using this new definition in eight European countries were analysed. Application of the proposed definition will increase consistency and comparability of data on FAWS and will result in decreasing the area of FAWS at a European level

Invasive species currently pose a major environmental challenge. Understanding their development and the factors associated with their expansion is the first step towards developing effective control measures. This work proposes the use of detailed spatio-temporal information from forest monitoring systems to assess the demographic rates, spatio-temporal patterns and spread determinants of invasive plants in forest ecosystems. For this purpose, we selected two of the most widespread non-native plants in Europe: Acacia dealbata and Acacia melanoxylon. Focusing on the forested area of northwest Spain and based on the comparison of two cycles of the Spanish National Forest Inventory, this study analyzes the dynamics of Acacia species between 1998 and 2008 in regards to changes in their spatial distribution, dominance, abundance, diametrical (dbh) structure and regeneration. In addition, the forested area was classified into forest types to identify the forests which are more susceptible to invasion. Finally, through general linear models, this study analyzes the relative importance of abiotic and biotic factors determining the spread of Acacia species over the studied period. The results confirm a rapid expansion in the presence of Acacia species in the forests of NW Spain, with annual spread rates around 0.1%. These two species are increasing their dominance across most forest types in the study area, where they are becoming the dominant species in the regeneration of some of them. Environmental factors and connectivity between Acacia populations are identified as the main factors associated with their spread into new areas. Additionally, the combination of disturbances and biotic factors associated with stand structure (total basal area, richness and tree cover) appear to determine the vulnerability or resistance of some forest to their spread. The early stage of invasion detected highlights the potential of Acacia species to continue spreading. This aspect, in conjunction with the high degree of disturbances (mainly fires) in this region, could be critical in determining the configuration of future forest landscapes in NW Spain. This study demonstrates the value of considering broad-scale periodic forest surveys to monitor biological invasions in forests ecosystems. The spatially-explicit data obtained from these surveys can contribute not only to furthering our knowledge with regard to invasion biology but also to developing more efficient conservation and management strategies

• For the first time the harmonized forest availability for wood supply is quantified for Europe. • Economic viability is the main restriction to availability of forests for wood supply. • The harmonized forests available for wood supply (FAWS) represent 75–95 % of forest area and biomass. • The reference definition of FAWS is suitable for international reporting.

Aim of study: To present the evolution of the current multi-objective Spanish National Forest Inventory (SNFI) through the assessment of different key indicators on challenging areas of the forestry sector.Area of study: Using information from the Second, Third and Fourth SNFI, this work provides case studies in Navarra, La Rioja, Galicia and Balearic Island regions and at national Spanish scale.Material and methods: These case studies present an estimation of reference values for dead wood by forest types, diameter-age modeling for Populus alba and Populus nigra in riparian forest, the invasiveness of alien species and the invasibility of forest types, herbivore preferences and effects on trees and shrub species, the methodology for estimating cork production , and the combination of SNFI4 information and Airborne Laser Scanning datasets with the aim of updating forest-fire behavior assessment information with a high degree of accuracy.Main results: The results show the suitability and feasibility of the proposed methodologies to estimate the indicators using SNFI data with the exception of the estimation of cork production. In this case, additional field variables were suggested in order to obtain robust estimates.Research highlights: By broadening the variables recorded, the SNFI has become an even more important source of forest information for the development of support tools for decision-making and assessment in diverse strategic fields such as those analyzed in this study.