Accounting for forest condition in Europe based on an international statistical standard

Abstract

Covering 35% of Europe’s land area, forest ecosystems play a crucial role in safeguarding biodiversity and mitigating climate change. Yet, forest degradation continues to undermine key ecosystem services that forests deliver to society. Here we provide a spatially explicit assessment of the condition of forest ecosystems in Europe following a United Nations global statistical standard on ecosystem accounting, adopted in March 2021. We measure forest condition on a scale from 0 to 1, where 0 represents a degraded ecosystem and 1 represents a reference condition based on primary or protected forests. We show that the condition across 44 forest types averaged 0.566 in 2000 and increased to 0.585 in 2018. Forest productivity and connectivity are comparable to levels observed in undisturbed or least disturbed forests. One third of the forest area was subject to declining condition, signalled by a reduction in soil organic carbon, tree cover density and species richness of threatened birds. Our findings suggest that forest ecosystems will need further restoration, improvements in management and an extended period of recovery to approach natural conditions.

Multi-decadal trend analysis and forest disturbance assessment of European tree species: concerning signs of a subtle shift

“…While this overall trend is in agreement with the results of Maes et al (2023), who showed that forest conditions across Europe have been even improving from 2000 to 2018, the areas with a prevalence of negative trends can't be ignored. Multiple studies have shown that climate change, by the end of the century, will considerably alter the distribution of European tree species (Mauri et al, 2022) and will be especially threatening for coniferous species (Dyderski et al, 2017), so it becomes crucial to scrutinize any signs of possible range contractions to differentiate between localized phenomena and large-scale shifts.…”

“…These results align with a long list of studies assessing either stress or decline for the two species in those areas (Aguadé et al, 2015;Kolář et al, 2017;Rigling et al, 2013;Sedmáková et al, 2019). In contrast, the negative trends hot spots in the moderate (40-50%) range found in the northernmost part of Scandinavia for the same two species align with the results of Maes et al (2023), which indicate a general reduction in ecosystem productivity (NDVI) and soil organic carbon (SOC) in the area rather than a species-specific issue. Hot spots for Scots pine extend further in the northern part of Finland, while spruce stays stable in the area: both trends have been confirmed by a tree-ring analysis conducted by Mäkinen et al (2022) on the data from the last finnish National Forest Inventory (NFI), which found a declining trend for Scots pine especially in sites with mineral soils and in peatlands.…”

“…These disturbances have increased consistently over the last century (Patacca et al, 2023;Schelhaas et al, 2003;Seidl et al, 2011) with the most pronounced intensification occurring in the last two decades (Senf et al, 2018). This intensification has caused extensive tree loss and drastic changes in the structure and dynamics of European forests (Maes et al, 2023;Popkin, 2021;Senf and Seidl, 2021a). Several studies identified positive correlations between tree species diversity and abundance and the provision of ecosystem services (Brockerhoff et al, 2017;Gamfeldt et al, 2013;Himes et al, 2020).…”

Multi-decadal trend analysis and forest disturbance assessment of European tree species: concerning signs of a subtle shift

“…These results align with a long list of studies assessing either stress or decline for the two species in those areas (Aguadé et al, 2015;Kolář et al, 2017;Rigling et al, 2013;Sedmáková et al, 2019). In contrast, the negative trends hot spots in the moderate (40-50%) range found in the northernmost part of Scandinavia for the same two species align with the results of Maes et al (2023), which indicate a general reduction in ecosystem productivity (NDVI) and soil organic carbon (SOC) in the area rather than a species-specific issue. Hot spots for Scots pine extend further in the northern part of Finland, while spruce stays stable in the area: both trends have been confirmed by a tree-ring analysis conducted by Mäkinen et al (2022) on the data from the last Finnish NFI, which found a declining trend for Scots pine especially in sites with mineral soils and in peatlands.…”

Revisiting the Landscape Mosaic model

“…The LM model has been used extensively to assess land cover composition at various scales to map and analyze landscape patterns [7][8][9][10], plant invasions [11], forest area changes [10,12], and identification of candidate areas for ecological restoration [13]. It has been employed in European ecosystem assessments [14,15], the assessment of green infrastructure of European cities [16], in the United States Resource Planning Act (RPA) forest assessments [17,18] and was recommended as the primary indicator of landscape pattern by the "The H. John Heinz III Center for Science, Economics and the Environment" [19]. Such research and applications have emphasized the well-established concepts that landscape pattern is scale-dependent and that a multi-scale approach is required if the goal is to inform a variety of management and policy questions in a consistent way [20,21].…”