Statistical mapping of tree species over Europe

Abstract

In order to map the spatial distribution of twenty tree species groups over Europe at 1 km 9 1 km resolution, the ICP-Forest Level-I plot data were extended with the National Forest Inventory (NFI) plot data of eighteen countries. The NFI grids have a much smaller spacing than the ICP grid. In areas with NFI plot data, the proportions of the land area covered by the tree species were mapped by compositional kriging. Outside these areas, these proportions were mapped with a multinomial multiple logistic regression model. A soil map, a biogeographical map and bioindicators derived from temperature and precipitation data were used as predictors. Both methods ensure that the predicted proportions are in the interval [0,1] and sum to 1. The regression predictions were iteratively scaled to the National Forest Inventory statistics and the Forest map of Europe. The predicted proportions for the twenty tree species were validated by the Bhattacharryya distance between predicted and observed proportions at 230 plot data separated from the calibration data. Besides, the map with the predicted dominant species was validated by computing the error matrix. The median Bhattacharryya distance in the subarea with NFI plot data was 1.712, whereas in the subarea with ICP-Level-I data, this was 2.131. The scaling did not significantly decrease the Bhattacharryya distance. The estimated overall accuracy of this map was 43%. In areas with NFI plot data, overall accuracy was 57%, outside these areas 33%. This gain was mainly attributable to the much denser plot data, less to the prediction method.

Beauty and the beast: how a bat utilizes forests shaped by outbreaks of an insect pest

“…This underlines the potential of commercially managed spruce forests for the conservation of species, particularly since major parts of European forests have been transformed to spruce monocultures (Brus et al, 2011). Outbreaks of I. typographus in these managed forests can be utilized as restorative tool for forest management to improve habitat quality by an increase in structural diversity.…”

Trends in Spring Phenology of Western European Deciduous Forests

“…We focused on these species for two reasons. First, they were among the 20 dominant tree species in Europe [37]. Second, some of their phenological events particularly the leaf unfolding /first leaves separation were regularly recorded during the period of interest (2001-2011).…”

Alternative forest management strategies to account for climate change-induced productivity and species suitability changes in Europe

“…Apart from the five species, a generalised broadleaved and conifer response was calculated as the average between, respectively, beech and oaks, and spruce and pine, for each time slice. This average for broadleaves and conifers was calculated per environmental zone, weighted by the actual presence of each species (beech/oak and spruce/pine) as derived from the tree species map (Brus et al 2012). The broadleaved/conifers response was applied to those species present in EFISCEN, but not explicitly modelled by Reyer et al (2014).…”

“…To calculate a change in growth per species per region in EFISCEN, the map of the European environmental strata was overlain with the tree species map of Europe (Brus et al 2012). Based on this overlay, an area-weighted average relative NPP change was calculated for each species in each region in EFISCEN, for each time slice (Fig.…”