Filtyp
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
Bioavailable phosphorus (BAP) concentrations were determined nine times between April and October 2010 in two humic boreal headwater streams draining forest-and mire-dominated catchments. BAP was analyzed in a bioassay in which natural P-limited bacterioplankton grew with natural P as the sole P source. In both streams, approximately 90% of the BAP occurred as dissolved species (passing a 0.2-mu m
The boreal forest carbon balance is predicted to be particularly sensitive to climate change. Carbon balance estimates of these biomes stem mainly from eddy-covariance measurements of net ecosystem exchange (NEE). However, a full net ecosystem carbon balance (NECB) must include the lateral carbon export (LCE) through discharge. We show that annual LCE at a boreal forest site ranged from 4 to 28%,
We studied bacterial and fungal colonization of submerged plant litter, using a known Si-accumulator (Equisetum arvense), in experimental microcosms during one month. We specifically addressed the microbial decomposer role concerning biogenic silica (bSiO2) dissolution from the degrading litter. To vary the rates and level of microbial colonization, the litter was combined with a range of mineral
Wildfires are a major driver of ecosystem development and contributor to carbon emissions in boreal forests. We analyzed the contribution of fires of different fire size classes to the total burned area and suggest a novel fire characteristic, the characteristic fire size, i.e., the fire size class with the highest contribution to the burned area, its relation to bioclimatic conditions, and intra-
P>Many ecological, physical and geographical processes affected by climate in the natural environment are scale-dependent: determining surface-air-temperature distribution at a scale of tens to hundreds of metres can facilitate such research, which is currently hampered by the relative dearth of meteorological stations and complex surface temperature characteristics, particularly in mountain areas
Global environmental changes and human activity influence wildland fires worldwide, but the relative importance of the individual factors varies regionally and their interplay can be difficult to disentangle. Here we evaluate projected future changes in burned area at the European and sub-European scale, and we investigate uncertainties in the relative importance of the determining factors. We sim
Field measurement data on greenhouse gas (GHG) emissions are still scarce for many land-use types in Africa, causing a high level of uncertainty in GHG budgets. To address this gap, we present in situ measurements of carbon dioxide (CO2 ), nitrous oxide (N2 O), and methane (CH4) emissions from the lowlands of southern Kenya. We conducted eight chamber measurement campaigns on gas exchange from fou
Terrestrial carbon cycle models have incorporated increasingly more processes as a means to achieve more-realistic representations of ecosystem carbon cycling. Despite this, there are large across-model variations in the simulation and projection of carbon cycling. Several model intercomparison projects (MIPs), for example, the fifth phase of the Coupled Model Intercomparison Project (CMIP5) (hist
The central role that ectomycorrhizal (EM) symbioses play in the structure and function of boreal forests pivots around the common assumption that carbon (C) and nitrogen (N) are exchanged at rates favorable for plant growth. However, this may not always be the case. It has been hypothesized that the benefits mycorrhizal fungi convey to their host plants strongly depends upon the availability of C
Fire at the dry southern margin of the Amazon rainforest could have major consequences for regional soil carbon (C) storage and ecosystem carbon dioxide (CO2) emissions, but relatively little information exists about impacts of fire on soil C cycling within this sensitive ecotone. We measured CO2 effluxes from different soil components (ground surface litter, roots, mycorrhizae, soil organic matte
The decomposition of large stocks of soil organic carbon in thawing permafrost might depend on more than climate change-induced temperature increases: indirect effects of thawing via altered bacterial community structure (BCS) or rooting patterns are largely unexplored. We used a 10-year in situ permafrost thaw experiment and aerobic incubations to investigate alterations in BCS and potential resp
There is growing evidence of ongoing changes in the statistics of intra-seasonal rainfall variability over large parts of the world. Changes in annual total rainfall may arise from shifts, either singly or in a combination, of distinctive intra-seasonal characteristics -i.e. rainfall frequency, rainfall intensity, and rainfall seasonality. Understanding how various ecosystems respond to the change
