Filtyp
The main aim of this paper is to study land-atmosphere exchange of carbon dioxide (CO2) for semi-arid savanna ecosystems of the Sahel region and its response to climatic and environmental change. A subsidiary aim is to study and quantify the seasonal dynamics in light use efficiency (epsilon) being a key variable in scaling carbon fluxes from ground observations using earth observation data. The n
Increased snow depth already observed, and that predicted for the future are of critical importance to many geophysical and biological processes as well as human activities. The future characteristics of sub-arctic landscapes where permafrost is particularly vulnerable will depend on complex interactions between snow cover, vegetation and permafrost. An experimental manipulation was, therefore, se
Phenological models have mainly been developed to capture the seasonal development of individual trees and local populations, using data from meteorological stations. Ecosystem models that incorporate phenology are however commonly driven by gridded climate data. Using two phenological models to simulate budburst of birch in Germany, we assessed how combining phenological point observations with g
Weathering of soil minerals is important for the recovery from acidification and for the sustainability of forestry. However, there is still substantial uncertainty about its absolute rate. This study presents a harmonized comparison of field weathering rates estimated with the mechanistic model PROFILE and the depletion method for 16 intensively sampled soil profiles across Sweden representing di
Plant communities differ in their species composition, and, thus, also in their functional trait composition, at different stages in the succession from arable fields to grazed grassland. We examine whether aerial hyperspectral (414–2501 nm) remote sensing can be used to discriminate between grazed vegetation belonging to different grassland successional stages. Vascular plant species were recorde
The objective of this study was to evaluate the concentrations of nutrients in stumps and coarse roots in Norway spruce, Scots pine and silver birch in Sweden, Finland and Denmark, and to assess how nutrient concentrations vary with site characteristics, stand age and root size. Concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) in spruce, p
Kettle holes are widespread in moraine landscapes. Their hydrological properties may be very vulnerable to changes in climatic conditions. To increase our knowledge of how kettle holes function and how they may be affected by climate change requires a model that can be applied to a variety of them regardless of their properties. We used the PIRFICT time series model to simulate the water levels in
It is frequently observed that the local relative abundances of aquatic microbial taxa are correlated with their average relative abundance at the regional scale, which results in the composition of different communities being more similar than expected by chance or invariant. The degree to which communities within a region match the regional average community is variable and likely depends on sev
The aim of this research is evaluation of land suitability for urban land-use planning. Four factors and fourteen criteria were selected for suitability analysis and land-use planning. Factors and criteria were defined based on literature survey, experts' opinions, local contexts and availability of data. GIS-based Analytical Hierarchy Process (AHP) was used as a Multi-criteria Decision Making mod
Seasonal patterns in assimilation of externally produced, allochthonous, organic matter into aquatic food webs are poorly understood, especially in brown-water lakes. We studied the allochthony (share biomass of terrestrial origin) in cladoceran, calanoid and cyclopoid micro-crustacean zooplankton from late winter to fall during two years in a small humic lake (Sweden). The use of allochthonous re
Forest protection is one of the main measures to prevent loss of biological and landscape diversity. This study aimed to assess to what extent forests are currently protected and how felling restrictions affect the potential annual wood supply within 27 European Union member states, Norway, and Switzerland and to discuss trade-offs between intensified use of forest biomass and forest protection ef
Natural disturbances play a key role in ecosystem dynamics and are important factors for sustainable forest ecosystem management. Quantitative models are frequently employed to tackle the complexities associated with disturbance processes. Here we review the wide variety of approaches to modelling natural disturbances in forest ecosystems, addressing the full spectrum of disturbance modelling from
High air concentrations of ammonium were detected at low and high altitude sites in Sweden, Finland and Norway during the spring 2006, coinciding with polluted air from biomass burning in eastern Europe passing over central and northern Fennoscandia. Unusually high values for throughfall deposition of ammonium were detected at one low altitude site and several high altitude sites in north Sweden.
The relationship between palynological diversity and floristic diversity was studied on the basis of sediment surface sample pollen data from nine small lakes and vegetation data within a 250 m radius from the lake shore of each. The nine study areas are situated in the patchy cultural landscape of Southern Estonia and were chosen to represent landscape changes along a gradient from closed forest
Abstract in UndeterminedThe aim of this study was to evaluate the extent to which water use efficiency (WUE) at leaf scale can be used to assess WUE at canopy scale, leaf WUE being assumed to be a constant function of vapor pressure deficit and to thus not be dependent upon other environmental factors or varying leaf properties. Leaf WUE and its variability and dependencies were assessed using lea
Recent studies have shown that the complexities of the surface features in mountainous terrain require a re-assessment of climate impacts at the local level. We explored the importance of surface-air-temperature based on a recently published 50-m-gridded dataset, versus soil variables for explaining vegetation distribution in Swedish Lapland using generalised linear models (GLMs). The results demo
Studies of climatic change and adaptation to climate change can include a wide range of methodologies and approaches. As one of such approaches, we here present meteorological measurement data from a site in the Demokeya experimental forest outside El Obeid in North Kordofan State of Sudan. We hope this descriptive note can inform about the available meteorological data, as well as to promote and
Ecosystem productivity is influenced by the start and end of the growing season, and ecosystem models that simulate productivity need reliable representations of the phenology. For the seasonal development, autumn events are less understood than spring events, with comparatively fewer modelling attempts have been made for leaf senescence than for budburst. The few existing models for autumn phenol
Forests are important from many perspectives. Forestry delivers products such as timber, fiber and fuel; forests are also important for recreational activities as well as for the global carbon balance. Consequently, it is important to develop methods that enable efficient monitoring of disturbances, such as insect attacks, over vast forested areas. These methods can be based on remote sensing, sin
Plants can influence methane emissions from wetland ecosystems by altering its production, consumption and transport in the soil. The aim of this study was to investigate how eight vascular plant species from mesotrophic to eutrophic wetlands vary in their influence on CH4 emissions from peat cores, under low and high N supply. Additionally, we measured the production of low-molecular-weight organ
