Use of National Forest Inventories to Downscale European Forest Diversity Spatial Information in Five Test Areas, Covering Different Geo-Physical and Geo-Botanical Conditions

The project ¿Use of National Forest Inventories to downscale European forest diversity spatial information in five test areas, covering different geo-physical and geo-botanical conditions¿, referred also as ¿forest downscaling¿ (JRC contract 382340 F1SC) covers one of the seven topics that have been studied in the frame of the Regulation (EC) 2152/2003 on the monitoring of forest and environmental interactions, the so-called "Forest Focus" Regulation. This study was conducted by a European consortium coordinated by the Italian Academy of Forest Sciences (Italy) and included partners from the Swedish University of Agricultural Sciences, the Institute of Forest Ecosystem Research of the Czech Republic, the German Federal Research Centre for Forestry and Forest Products, and the Swiss Federal Institute for Forest, Snow and Landscape Research. The overall supervision of the project and the processing of forest spatial pattern were done by the Joint Research Centre. This study addressed the link between field based forest biological diversity data and landscape-level forest pattern information. The former were made available from National Forest Inventories (NFIs) at plot level in five different countries; their harmonisation was implemented for the first time and benefited from outcomes of the COST Action-E43 on core biodiversity variables. For the latter, landscape level forest spatial pattern maps were automatically derived from available remote sensing based forest cover maps. The relation-ships between selected pattern and biodiversity variables available from the two different data sources were studied. Seven case studies for a total area of about 100,000 km2 were selected in five European ecological regions: one site in Germany (Atlantic zone), one in Sweden (Boreal zone), two in Czech Republic (Continental zone), one in Switzerland (Alpine zone) and two in Italy (Mediterranean zone).JRC.DDG.H.7-Land management and natural hazard

Relating remotely sensed forest damage data to wind data: storms Lothar (1999) and Vivian (1990) in Switzerland

This study compares the surface wind speed and forest damage data of two exceptionally severe winter storms, Vivian 1990 and Lothar 1999. The study area comprises the region that suffered damage in Switzerland. The wind speed data were derived from simulations of MeteoSwiss (Federal Office of Meteorology and Climatology), measurements during the storm periods and expert analyses of the data. The remotely sensed forest damage data were provided by the Federal Office for the Environment and the forest cover data by Swiss Federal Statistical Office. We compared data on the peak gust and maximum average wind speed, with data on the spatially related forest area and forest damage area, and found some clear differences in the correlations between the different wind data and forest damage. Our results point generally to the damage-causing role of near-surface gusts at maximum wind speeds during the storm. These tended to be spatially distributed on a fine scale. In only a few cases were the results statistically significant. However, these results could probably be improved with better wind data. For example, gust measurements spatially closer to forests or simulations of gusts at maximum wind speed could be produced with a spatially higher resolutio

Climate-driven introduction of the Black Death and successive plague reintroductions into Europe

The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via the land and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the second plague pandemic, which lasted in Europe until the early 19th century. This pandemic is generally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease established itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe and Asia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence of permanent plague reservoirs in medieval Europe

Development of Harmonized Indicators and Estimation Procedures for Forests with Protective Functions against Natural Hazards in the Alpine Space

The present study was developed in the context of Regulation (EC) 2152/2003 on the monitoring of forest and environmental interactions, the so-called "Forest Focus" Regulation. The specific objective of this study was to explore the possible contribution of the national forest inventories (NFIs) to assess protective functions of for-ests in the alpine space. Key components of protective functions could be determined with the help of on-going national and international studies and processes. In order to grant consistency, definitions of forest area, dam-age potential and hazard potential had to be harmonised. Based on those, a strategy for monitoring and report-ing aspects of protective functions of mountain forests in the alpine space was proposed. Estimation procedures based on existing NFI data and field assessments and their integration in different remote sensing techniques were tested for harmonised monitoring. Final results are presented in this report.JRC.DDG.H.7-Land management and natural hazard

A novel method to assess short-term forest cover changes based on digital surface models from image-based point clouds

Assessing forest cover change is a key issue for any national forest inventory. This was tested in two study areas in Switzerland on the basis of stereo airborne digital sensor (ADS) images and advanced digital surface model (DSM) generation techniques based on image point clouds. In the present study, an adaptive multi-scale approach to detect forest cover change with high spatial and temporal resolution was applied to two study areas in Switzerland. The challenge of this approach is to minimize DSM height uncertainties that may affect the accuracy of the forest cover change results. The approach consisted of two steps. In the first step, a ‘change index' parameter indicated the overall change status at a coarser scale. The tendency towards change was indicated by derivative analysis of the normalized histograms of the difference between the two canopy height models (DCHMs) in different years. In the second step, detection of forest cover change at a refined scale was based on an automatic threshold and a moving window technique. Promising results were obtained and reveal that real forest cover changes can be distinguished from non-changes with a high degree of accuracy in managed mixed forests. Results had a lower accuracy for forests located on steep alpine terrain. A major benefit of the proposed method is that the magnitude of forest cover change of any specific region can be made available within a short time as often required by forest managers or policy-makers, especially after unexpected natural disturbance