21 research outputs found
Testing the Effect of Relative Pollen Productivity on the REVEALS Model : A Validated Reconstruction of Europe-Wide Holocene Vegetation
Reliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1° × 1°) over the Holocene (last 11.7 ka BP) using the 'Regional Estimates of VEgetation Abundance from Large Sites' (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity
Linking forest management, policy and biodiversity indicators – a comparison of Lithuania and southern Sweden
Lithuania and Southern Sweden share similar natural conditions, but differ considerably in forest policies and management; thereby providing an opportune basis for comparative studies. Since the 1990s, Sweden has attempted to reduce the negative impact of its forest management on biodiversity, after decades of intensive production forestry. In contrast, Lithuania has been intensifying forestry practices associated with the post-soviet socio-economic transition. Here we assess the actual outcomes by comparing selected forest structure and composition variables known to be indicators for forest biodiversity; and estimate the prospective trends by scrutinising current forest policies and management.
Our results indicate that Lithuanian forests consistently possessed higher rankings in six indices related to tree species composition, stand age, and deadwood quantities that are positively associated with forest biodiversity. The reverse is indicated by those data on stand age and tree diameter that are associated with centennial dynamics in forest utilisation intensity. With respect to policy instruments, Lithuania designates a substantially greater share of forest area to non-timber functions and legislates more severe management restrictions in forests targeting timber production. Concurrently, all estimates of forestry activities indicate more intensive forest management in Southern Sweden, including a higher share of artificial regeneration and shorter rotations. This allows concluding that, if current forest management practices persist, then an increased “biodiversity gap” may be expected between the two countries. The study concludes with discussing to what degree the identified trends are the direct product of targeted policies versus merely by-products of other factors