Serialas elucijas metode metalu koncentracijas noteiksanai sunu sunas biomonitoringa veiksanai

Summary in English, Latvian, RussianAvailable from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi

Forest naturalness in northern Europe: perspectives on processes, structures and species diversity

Saving the remaining natural forests in northern Europe has been one of the main goals to halt the ongoing decline of forest biodiversity. To facilitate the recognition, mapping and efficient conservation of natural forests, there is an urgent need for a general formulation, based on ecological patterns and processes, of the concept of “forest naturalness”. However, complexity, structural idiosyncracy and dynamical features of unmanaged forest ecosystems at various spatio-temporal scales pose major challenges for such a formulation. The definitions hitherto used for the concept of forest naturalness can be fruitfully grouped into three dimensions: 1) structure-based concepts of natural forest, 2) species-based concepts of natural forest and 3) process-based concepts of natural forest. We propose that explicit and simultaneous consideration of all these three dimensions of naturalness can better cope with the natural variability of forest states and also aid in developing strategies for forest conservation and management in different situations. To become operational, criteria and indicators of forest naturalness need to integrate the three dimensions by combining species (e.g. red-listed-, indicator- and umbrella species) with stand and landscape level structural features that are indicative of disturbance and succession processes.</ja:p

Vegetation changes in boreo-nemoral forest stands depending on soil factors and past land-use during an 80-year period of no human impact

Information on the long-term changes in plant communities that occur without human interference is limited, due to insufficient studies where vegetation can be resurveyed. In 1912, a strict nature protection reserve, with non-intervention management, was established on Moricsala Island in Latvia, located in the boreo-nemoral forest zone. Prior to establishment of the nature reserve, part of the island area was used for agriculture. The island is now covered almost entirely by forest dominated by Quercus robur and Tilia cordata on sandy soils. Resurvey was conducted in 2011 in seventeen plots in which tree layers and the understory vegetation had been described in 1930. The plots were classified into two groups based on tree species composition in 1930, to determine changes in species composition. Differences in understory and tree canopy composition between these groups persisted over the period between the studies, in relation to soil factors and past stand history. Considerable turnover of species occurred, with decrease of species typical of open habitats and replacement by species typical of nemoral (temperate deciduous) forest plant communities. In the past, Quercus robur had likely established in open habitats created by agricultural land-use or past fire, but is presently not regenerating in the understorey.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Integrating ecosystem services into decision support for management of agroecosystems: Viva Grass tool

The area covered by low-input agroecosystems (e.g. semi-natural and permanent grasslands) in Europe has considerably decreased throughout the last century. To support more sustainable management practices, and to promote biodiversity and ecosystem service values of such agroecosystems a decision support tool was developed. The tool aims to enhance the operationalization of ecosystem services and address the challenge of their integration into spatial planning. The Viva Grass tool aims to enhance the maintenance of ecosystem services delivered by low-input agroecosystems. It does so by providing spatially explicit decision support for land-use planning and sustainable management of agroecosystems. The Viva Grass tool is a multi-criteria decision analysis tool for integrated planning. It is designed for farmers, spatial planners and policy makers to support decisions of management of agroecosystems. The tool has been tested to assess spatial planning in eight case studies across the Baltic States

Evaluating structural and compositional canopy characteristics to predict the light-demand signature of the forest understorey in mixed, semi-natural temperate forests

International audienceQuestions Light availability at the forest floor affects many forest ecosystem processes, and is often quantified indirectly through easy-to-measure stand characteristics. We investigated how three such characteristics, basal area, canopy cover and canopy closure, were related to each other in structurally complex mixed forests. We also asked how well they can predict the light-demand signature of the forest understorey (estimated as the mean Ellenberg indicator value for light [''EIVLIGHT''] and the proportion of ``forest specialists'' [''%FS''] within the plots). Furthermore, we asked whether accounting for the shade-casting ability of individual canopy species could improve predictions ofEIV(LIGHT)and %FS. Location A total of 192 study plots from nineteen temperate forest regions across Europe. Methods In each plot, we measured stand basal area (all stems >7.5 cm diameter), canopy closure (with a densiometer) and visually estimated the percentage cover of all plant species in the herb (7 m). We used linear mixed-effect models to assess the relationships between basal area, canopy cover and canopy closure. We performed model comparisons, based onR(2)and the Akaike Information Criterion (AIC), to assess which stand characteristics can predictEIV(LIGHT)and %FSbest, and to assess whether canopy shade-casting ability can significantly improve model fit. Results Canopy closure and cover were weakly related to each other, but showed no relation with basal area. For bothEIV(LIGHT)and %FS, canopy cover was the best predictor. Including the share of high-shade-casting species in both the basal-area and cover models improved the model fit forEIV(LIGHT), but not for %FS. Conclusions The typically expected relationships between basal area, canopy cover and canopy closure were weak or even absent in structurally complex mixed forests. In these forests, easy-to-measure structural canopy characteristics were poor predictors of the understorey light-demand signature, but accounting for compositional characteristics could improve predictions

Light availability and land-use history drive biodiversity and functional changes in forest herb layer communities

International audienceA central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land-use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variability in environmental change factors. We tested for interactions between land-use history, distinguishing ancient and recent (i.e. post-agricultural) forests and four drivers: temperature, nitrogen deposition, and aridity at the regional scale and light dynamics at the plot-scale. Land-use history significantly modulated global change effects on the functional signature of the herb layer (i.e. cover, SLA and plant height). Light availability was the main environmental driver of change interacting with land-use history. We found greater herb cover and plant height decreases and SLA increases with decreasing light availability in ancient than in recent forests. Furthermore, we found greater decreases in herb cover with increased nitrogen deposition in ancient forests, whereas warming had the strongest decreasing effect on the herb cover in recent forests. Interactive effects between land-use history and global change on biodiversity were not found, but species evenness increased more in ancient than in recent forests. Synthesis. Our results demonstrate that land-use history should not be overlooked when predicting forest herb layer responses to global change. Moreover, we found that herb layer composition in semi-natural deciduous forests is mainly controlled by local canopy characteristics, regulating light levels at the forest floor, and much less by environmental changes at the regional scale (here: warming, nitrogen deposition and aridity). The observed disconnect between biodiversity and functional herb layer responses to environmental changes demonstrates the importance of assessing both types of responses to increase our understanding of the possible impact of global change on the herb layer

Make EU trade with Brazil sustainable

Brazil, home to one of the planet's last great forests, is currently in trade negotiations with its second largest trading partner, the European Union (EU). We urge the EU to seize this critical opportunity to ensure that Brazil protects human rights and the environment