Maria Holmberg

Nebulin mutations in autosomal recessive nemaline myopathy: an update

We report mutational analysis of the last 42 exons of the nebulin gene (NEB) in 77 patients with various forms of nemaline myopathy. In addition to the previously described six mutations in five families, we identified 12 novel recessive mutations in 13 families. Affected individuals were homozygous for the mutations in five families and compound heterozygous in two, while in the remaining cases only one heterozygous mutation was identified. The majority of the mutations were frameshifts due to small deletions or insertions; also common were point mutations causing premature stop codons or abnormal splicing, while missense mutations appeared rare. There were no obvious mutational hotspots, although four unrelated patients showed mutations in the differentially expressed exon 177d, and another three showed mutations in exon 184. Most of the mutations are predicted to result in truncated or internally deleted proteins. Mutations in the differentially expressed exons are expected to reduce the nebulin isoform diversity necessary for normal muscle development.

Long-term base cation balances of forest mineral soils in Finland

Long-term base cation balances (Ca, Mg and K) for forest mineral soils in Finland were calculated with mass balance methods. The aim of the study was to identify the areas in which weathering and base cation deposition do not support leaching and uptake of base cations by vegetation. The effect of stem harvesting and whole-tree harvesting on the base cation balances was studied and preliminary calculations were made about the amounts of ash needed for compensation of the potential base cation depletion. The effect of sulphur emission reduction till 2010 was also considered. The study demonstrated that there would be depletion of base cations in forest mineral soils in southern, central and northeastern Finland (40–50% of the grids) in the long term if whole-tree harvesting would be practised. Theoretical calculations showed that ash application would be most useful in those areas to compensate the base cation depletion. If stem harvesting is practised, only small areas (20%) in southwestern and southeastern Finland and northeastern Lapland would show depletion of base cations in the long term.

Critical Loads of Acidity for Forest Soils: Tentative Modifications

We reviewed the current methods for calculatingcritical loads of acidity for forest soils. The consequencesof four sets of assumptions concerning the soil modelstructure, parameter values and the critical loads criterionwere explored by comparing the values of the averageaccumulated exceedance (AAE) calculated for Finland withdeposition values for the year 1995. The AAE index is given inthe unit of deposition and is a measure of how far a region isfrom being protected in terms of fulfilling a certaincriterion, taking into account the size of the ecosystem areas.Using a critical limit for the molar ratio of theconcentrations of base cations to aluminium in soil solutiongave the lowest average accumulated exceedance. Assumingorgano-aluminium complexes and leaching of organic anions gaveAAE = 4 eq ha-1 a-1, which was close to the valueobtained with the standard approach used in Finland, assuminggibbsite equilibrium and no leaching of organic anions,yielding AAE = 5 eq ha-1 a-1. With a critical basesaturation limit, instead of the concentrations criterion, theAAE index was 17 eq ha-1 a-1. The highest averageaccumulated exceedance (AAE = 25 eq ha-1 a-1),corresponding to the lowest critical load, was obtained whenthe effects-based criterion (critical concentration or criticalbase saturation) was substituted with one restricting thedeterioration of the neutralizing capacity of the soil, ANCle(crit) = 0. These tests illustrate the variabilityof the critical load values for acidity that can be introducedby changing the criterion or by varying the calculation method,without, however, representing the extreme values of criticalloads that could be derived.

ESLab application to a boreal watershed in southern Finland: preparing for a virtual research environment of ecosystem services.

Abstract We report on preparatory work to develop a virtual laboratory for ecosystem services, ESLab, and demonstrate its pilot application in southern Finland. The themes included in the pilot are related to biodiversity conservation, climate mitigation and eutrophication mitigation. ESLab is a research environment for ecosystem services (ES), which considers ES indicators at different landscape scales: habitats, catchments and municipalities and shares the results by a service that utilizes machine readable interfaces. The study area of the pilot application is situated in the boreal region of southern Finland and covers 14 municipalities and ten catchments including forested, agricultural and nature conservation areas. We present case studies including: present carbon budgets of natural ecosystems; future carbon budgets with and without the removal of harvest residues for bioenergy production; and total phosphorus and nitrogen future loads under climate and agricultural yield and price scenarios. The ESLab allows researchers to present and share the results as visual maps, statistics and graphs. Our further aim is to provide a toolbox of easily accessible virtual services for ES researchers, to illustrate the comprehensive societal consequences of multiple decisions (e.g. concerning land use, fertilisation or harvesting) in a changing environment (climate, deposition).

A Regional GIS-Based Model to Predict Long-Term Responses of Soil and Soil Water Chemistry to Atmospheric Deposition: Initial Results

The aim of this study was to develop GISSMART, a GIS-based model, for estimating relative regional changes in soil andsoil water chemistry for given atmospheric deposition and nutrient uptake scenarios. The regional application was performed by dividing the study area into grid cells, the size and the form of the pixels being determined on the basisof the available GIS data bases of Finnish soil and vegetationtypes. GISSMART is the biogeochemical model SMART, extended forhandling GIS data in space and time. The Kangasvaara catchment(56 ha) in eastern Finland was used as the first test site. Data from four other nearby catchments were also used, togetherwith Multisource National Forest Inventory data (25 × 25 m2) from an area of 10 × 40 km2 for estimating soil chemistry. Multisource forest inventory datafrom the Finnish Forest Research Institute, including tree species, age and growth by tree species was based on LandsatTM-images and field measurements. The same satellite based estimation method was applied to obtain regional soil chemistry input data for GISSMART. Base saturation was the key state variable and nutrient uptake the key driving variablein this application of GISSMART. The results of the model testruns were reasonable. A slight decrease in base saturation waspredicted for the assumed deposition and nutrient uptake scenarios. In future work, the aim is to improve the description of hydrological processes and land use management in the model. This would also enable assessment of the effectsof climate change and land use management scenarios.

Sensitivity of soil acidification model to deposition and forest growth.

We report an investigation concerning the impacts of acid deposition and forest growth scenarios on simulated soil effective base saturation for a forested catchment in eastern Finland. These forests have not been managed during the last 150 yr and the area receives low levels of acidifying deposition. The fluxes of sulphur, nitrogen and base cations were assessed with models simulating historic and future deposition, stand uptake and leaching. We tested the effects of calibrating the modelled deposition time series to high and low estimates of current levels of deposition. The highest future soil base saturation was predicted when using the year with the lowest observed sulphur and nitrogen deposition (1993) as representative of the present deposition. The lowest historical and future soil base saturation resulted for using the year with the highest observed deposition of sulphur and nitrogen (1988). All scenarios concerning nutrient uptake, emission reduction levels and timing of the reductions resulted in simulated future soil base saturation values located between those predicted with the high and low observed present deposition. The standard deviation in the soil base saturation introduced by varying the present forest biomass and growth was smaller than that produced by varying the present deposition values.

Boreal forests can have a remarkable role in reducing greenhouse gas emissions locally: Land use-related and anthropogenic greenhouse gas emissions and sinks at the municipal level

Ecosystem services have become an important concept in policy-making. Carbon (C) sequestration into ecosystems is a significant ecosystem service, whereas C losses can be considered as an ecosystem disservice. Municipalities are in a position to make decisions that affect local emissions and therefore are important when considering greenhouse gas (GHG) mitigation. Integrated estimations of fluxes at a regional level help local authorities to develop land use policies for minimising GHG emissions and maximising C sinks. In this study, the Finnish national GHG accounting system is modified and applied at the municipal level by combining emissions and sinks from agricultural land, forest areas, water bodies and mires (land use-related GHG emissions) with emissions from activities such as energy production and traffic (anthropogenic GHG emissions) into the LUONNIKAS calculation tool. The study area consists of 14 municipalities within the Vanajavesi catchment area located in Southern Finland. In these municipalities, croplands, peat extraction sites, water bodies and undrained mires are emission sources, whereas forests are large carbon sinks that turn the land use-related GHG budget negative, resulting in C sequestration into the ecosystem. The annual land use-related sink in the study area was 78tCO2eqkm(-2) and 2.8tCO2eq per capita. Annual anthropogenic GHG emissions from the area amounted to 250tCO2eqkm(-2) and 9.2tCO2eq per capita. Since forests are a significant carbon sink and the efficiency of this sink is heavily affected by forest management practices, forest management policy is a key contributing factor for mitigating municipal GHG emissions.

Model of Ion Dynamics and Acidification of Soil: Application to Historical Soil Chemistry Data from Sweden

A dynamic model of soil processes was applied to soil chemistry data from four forest sites in southern Sweden. The sites were sampled in 1949 and resampled in 1984. The model simulates transport of ions with percolating water, cation exchange, weathering of base cations and dissolution of Al3+. The model is driven by deposition of H+ and base cations which cause changes in the simulated base saturation and the concentration of ions in solution. After calibration, the model results are in reasonable agreement with observed changes in base saturation whereas the changes in pH are underestimated. The simulated trends are correct, and the results correspond qualitatively to those obtained by another model, the RAINS soil model.

Changes in soil carbon stock predicted by a process-based soil carbon model (Yasso07) in the Yanhe watershed of the Loess Plateau

ContexSoil carbon sequestration is an ecosystem process that can provide important ecosystem services such as climate regulation and mitigation of global warming. Spatiotemporal variation in the soil organic carbon (SOC) stock is the basic information needed for landscape management and determination of regional carbon budgets.ObjectivesThe objective of this study was to evaluate the effect of ecological restoration on SOC stocks and determine the influences of multiple factors in the Yanhe watershed of the Loess Plateau.MethodsWe coupled the Yasso07 soil carbon model with remote sensing indices as model input. The model performance was evaluated by uncertainty and sensitivity analyses as well as validation against field measurement.ResultsThe modeling captured the spatial pattern of SOC variability across the landscape generally well. Net primary productivity (NPP) was the foremost factor that affecting the spatiotemporal variation of SOC density. Converting cropland to grassland was the most efficient restoration type in soil carbon sequestration in the study period. Land use change influenced the spatial correlation between NPP and SOC density by altering both litter quantity and quality. The changes in land use area tended to have higher contributions to the changes in SOC stock than did the changes in SOC density for different land use types.ConclusionsThe overall effect of ecological restoration on soil carbon sequestration was dependent on the main vegetation restoration type and the time of recovery. Human-derived land use changes could have more substantial effects on soil carbon budgets compared to natural factors in a short period of time.

An Approach to Analyse the Dynamics of Environmental Change and its Effects on Forest Growth

The anthropogenic emissions into the atmosphere have changed the material flows in the system formed by the atmosphere, vegetation, soil, ground and surface waters. The concentrations of several nutrients and toxic compounds are changing. These concentrations are environmental factors and forests are reacting to the changes in the environment.