Assessing forest availability for wood supply in Europe

The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The provision of harmonized forest statistics is necessary for the development of forest associated policies and to support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood supply (FNAWS) according to national and reference definitions by determining the restrictions and associated thresholds considered at country level to classify forests as FAWS or FNAWS. FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to 5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the European countries studied, thereby facilitating a consistent approach to assess forests available for supply for the purpose of international reportinginfo:eu-repo/semantics/publishedVersio

A simplified methodology for the correction of Leaf Area Index (LAI) measurements obtained by ceptometer with reference Pinus Portuguese forests

Forest leaf area index (LAI) is a very important structural parameter, controlling many biological and physiological processes associated with vegetation on the Earth’s surface. Its accurate estimation is extremely important for forest managers. There are a widely range of methods for its estimation. One of them is using ground-based instruments like the sunfleck ceptometers, with advantages because it is not a destructive method and is very easy to apply. Although, when applied to Pinus, the most important forest specie in Portugal, LAI is underestimated by these instruments, mainly because of its foliage clumping. Trying to correct this underestimation, some previous studies proposed the multiplication of the measured LAI value by a constant correction factor, while others have only proposed practical advice for a correct use of these instruments. Thus, although unquestionably a practical method for recording LAI, use of the ceptomer is problematic. Age of threes from this database ranged from 74 to 14 years old, representing heterogeneous Pinus stands, at it is usual in Portugal. As assumed by some authors, the LAI obtained from allometric equations is less problematic and was be used to generate a reference LAI in order to develop a new methodology for correcting ceptometer measurements, even considering that is not immune to error because it is site- and specie- specific. This way, LAI data from 102 sampling plots, established across all North of Portugal, representative of the Pinus pinaster forest in Portugal, was collected. This database was divided in 82 sampling plots for the adjustment of the LAI ceptometer correction model and 20 were used for the model validation. This new correction methodology does not assume a constant correction value, unlike previous ones, and indicates that the bias (the difference between the ceptometer and the reference LAI) is estimated as a function of the basal area per unit ground area and that this bias is summed to the estimated value. Being the basal area an easily structural obtainable from forest inventories, this new methodology can be easily applied. The observed LAI of this database ranged from 6.4 to 0.34, once again showing the heterogeneity of the Portuguese Pinus forest. Also in general the research has demonstrated a significant difference in the accuracy of LAI as estimated by ceptometer in relation to reference values, thus measurements for Pinus should be corrected. This study has shown that the estimated Pinus LAI needs a correction and that the new approach improves the LAI ceptometer estimations

Where are Europe's last primary forests?

Aim: Primary forests have high conservation value but are rare in Europe due to historic land use. Yet many primary forest patches remain unmapped, and it is unclear to what extent they are effectively protected. Our aim was to (1) compile the most comprehensive European- scale map of currently known primary forests, (2) analyse the spatial determinants characterizing their location and (3) locate areas where so far unmapped primary forests likely occur. Location: Europe. Methods: We aggregated data from a literature review, online questionnaires and 32 datasets of primary forests. We used boosted regression trees to explore which biophysical, socio- economic and forest- related variables explain the current distribution of primary forests. Finally, we predicted and mapped the relative likelihood of primary forest occurrence at a 1- km resolution across Europe. Results: Data on primary forests were frequently incomplete or inconsistent among countries. Known primary forests covered 1.4 Mha in 32 countries (0.7% of Europe’s forest area). Most of these forests were protected (89%), but only 46% of them strictly. Primary forests mostly occurred in mountain and boreal areas and were unevenly distributed across countries, biogeographical regions and forest types. Unmapped primary forests likely occur in the least accessible and populated areas, where forests cover a greater share of land, but wood demand historically has been low. Main conclusions: Despite their outstanding conservation value, primary forests are rare and their current distribution is the result of centuries of land use and forest management. The conservation outlook for primary forests is uncertain as many are not strictly protected and most are small and fragmented, making them prone to extinction debt and human disturbanceVytauto Didžiojo universitetasŽemės ūkio akademij