167 research outputs found
Metsätalouden vesistökuormituksen seuranta- ja raportointiohjelma
Metsätalouden vesistökuormituksen seurantaverkon muodostavat luonnon taustakuormituksen ja normaalin metsätaloustoiminnan aiheuttaman kuormituksen seurantaan perustetut latvavaluma alueet. Verkon avulla voidaan tuottaa valtakunnalliset sekä vesienhoitoalue- ja jokivaluma-aluekohtaiset arviot metsätalouden aiheuttamasta kuormituksesta ja seurata esim. muuttuvista ilmasto-oloista tai metsätalouden intensiteetin muutoksista aiheutuvia trendejä. Seurantaverkko perustettiin vuonna 2014 ja seurantaa toteutetaan yhteistyössä Luonnonvarakeskuksen, Suomen ympäristökeskuksen (SYKE), Metsähallituksen, Suomen Metsäkeskusten, ELY-keskusten ja Tapio Oy:n kanssa. Näytteenottoa ja laboratorioanalyysejä on ulkoistettu yksityisille toimijoille. Tämä raportti kuvaa seurantaverkkoon kuuluvat valuma-alueet, aineiston keruumenetelmät ja tulosten laskennan.201
Long-term measurements of the carbon balance of a boreal Scots pine dominated forest ecosystem
Soil concentrations and soil-atmosphere exchange of alkylamines in a boreal Scots pine forest
Alkylamines are important precursors in secondary aerosol formation in the boreal forest atmosphere. To better understand the behavior and sources of two alkylamines, dimethylamine (DMA) and diethylamine (DEA), we estimated the magnitudes of soil-atmosphere fluxes of DMA and DEA using a gradient-diffusion approximation based on measured concentrations in soil solution and in the canopy air space. The ambient air concentration of DMA used in this study was a sum of DMA and ethylamine. To compute the amine fluxes, we first estimated the soil air space concentration from the measured soil solution amine concentration using soil physical (temperature, soil water content) and chemical (pH) state variables. Then, we used the resistance analogy to account for gas transport mechanisms in the soil, soil boundary layer, and canopy air space. The resulting flux estimates revealed that the boreal forest soil with a typical long-term mean pH 5.3 is a possible source of DMA (170 +/- 51 nmolm(-2) day(-1)) and a sink of DEA (-1.2 +/- 1.2 nmolm(-2) day(-1)). We also investigated the potential role of fungi as a reservoir for alkylamines in boreal forest soil. We found high DMA and DEA concentrations both in fungal hyphae collected from field humus samples and in fungal pure cultures. The highest DMA and DEA concentrations were found in fungal strains belonging to decay and ectomycorrhizal fungal groups, indicating that boreal forest soil and, in particular, fungal biomass may be important reservoirs for these alkylamines.Peer reviewe
Sea ice and related data sets from the Baltic Sea AICSEX : Metadata report
Julkaisu sisältää myös kolme muuta artikkelia:
Kimmo K. Kahma, Heidi Pettersson & Laura Tuomi: Scatter diagram wave statistics from the northern Baltic Sea
Matti Perttilä (Editor): Assessment — State of the Gulf of Finland in 2002
Tapani Stipa, Morten Skogen, Ian Sehested Hansen, Anders Eriksen, Inga Hense, Anniina Kiiltomäki, Henrik Soiland & Antti Westerlund: Short-term effects of nutrient reductions in the North Sea and the Baltic Sea as seen by an ensemble of numerical model
Eddies in motion : visualizing boundary-layer turbulence above an open boreal peatland using UAS thermal videos
High-resolution thermal infrared (TIR) imaging is opening up new vistas in biosphere-atmosphere heat exchange studies. The rapidly developing unmanned aerial systems (UASs) and specially designed cameras offer opportunities for TIR survey with increasingly high resolution, reduced geometric and radiometric noise, and prolonged flight times. A state-of-the-art science platform is assembled using a Matrice 210 V2 drone equipped with a Zenmuse XT2 thermal camera and deployed over a pristine boreal peatland with the aim of testing its performance in a heterogeneous sedgefen ecosystem. The study utilizes the capability of the UAS platform to hover for prolonged times (about 20 min) at a height of 500ma.g.l. while recording high frame rate (30 Hz) TIR videos of an area of ca. 430 x 340 m. A methodology is developed to derive thermal signatures of near-ground coherent turbulent structures impinging on the land surface, surface temperature spectra, and heat fluxes from the retrieved videos. The size, orientation, and movement of the coherent structures are computed from the surface temperature maps, and their dependency on atmospheric conditions is examined. A range of spectral and wavelet-based approaches are used to infer the properties of the dominant turbulent scene structures. A ground-based eddy-covariance system and an in situ meteorological setup are used for reference.Peer reviewe
Amount of carbon fixed, transit time and fate of harvested wood products define the climate change mitigation potential of boreal forest management—A model analysis
Boreal forests are often managed to maximize wood production, but other goals, among which climate change mitigation, are increasingly important. Hence, it is necessary to examine synergies and trade-offs between forest production and its potential for carbon sequestration and climate change mitigation in forest stands. To this aim, we develop a novel mass-balanced process-based compartmental model that allows following the carbon path from its photosynthetic fixation until its return to the atmosphere by autotrophic or heterotrophic respiration, or by being burnt as wood product. Following carbon in the system allows to account for how long forest ecosystems and wood products retain carbon away from the atmosphere (i.e., the carbon transit time). As example, we apply the model to four management scenarios, i.e., mixed-aged pine, even-aged pine, even-aged spruce, and even-aged mixed forest, and contrast metrics of performance relative to wood production, carbon sequestration, and climate change mitigation potential. While at the end of an 80 yr rotation the even-aged forests held up to 31% more carbon than the mixed-aged forest, the mixed-aged forest was superior during almost the entire rotation when factoring in the carbon retention time away from the atmosphere, i.e., in terms of climate change mitigation potential. Importantly, scenarios that maximize production or amount of carbon stored in the ecosystems are not necessarily the most beneficial for carbon retention away from the atmosphere. These results underline the importance of considering carbon transit time when evaluating forest management options for potential climate change mitigation
NutSpaFHy : A Distributed Nutrient Balance Model to Predict Nutrient Export from Managed Boreal Headwater Catchments
Responsible forest management requires accounting for adverse environmental effects, such as increased nutrient export to water courses. We constructed a spatially-distributed nutrient balance model NutSpaFHy that extends the hydrological model SpaFHy by introducing a grid-based nutrient balance sub-model and a conceptual solute transport routine to approximate total nitrogen (N) and phosphorus (P) export to streams. NutSpaFHy uses openly-available Multi-Source National Forest Inventory data, soil maps, topographic databases, location of water bodies, and meteorological variables as input, and computes nutrient processes in monthly time-steps. NutSpaFHy contains two calibrated parameters both for N and P, which were optimized against measured N and P concentrations in runoff from twelve forested catchments distributed across Finland. NutSpaFHy was independently tested against six catchments. The model produced realistic nutrient exports. For one catchment, we simulated 25 scenarios, where clear-cuts were located differently with respect to distance to water body, location on mineral or peat soil, and on sites with different fertility. Results indicate that NutSpaFHy can be used to identify current and future nutrient export hot spots, allowing comparison of logging scenarios with variable harvesting area, location and harvest techniques, and to identify acceptable scenarios that preserve the wood supply whilst maintaining acceptable level of nutrient export
Combined use of satellite image analysis, land-use statistics, and land-use-specific export coefficients to predict nutrients in drained peatland catchment
Highlights
• Nutrient and SS estimations were predicted by comparing different approaches.
• Peatland drainage strongly affected TN, TP, and SS loads and concentrations.
• Uncertainty in estimates captured 29–90% of measured TN, TP, and SS values.
• The uncertainty in export coefficients decreased with catchment size.Maintaining and improving surface water quality requires knowledge of nutrient and sediment loads due to past and future land-use practices, but historical data on land cover and its changes are often lacking. In this study, we tested whether land-use-specific export coefficients can be used together with satellite images (Landsat) and/or regional land-use statistics to estimate riverine nutrient loads and concentrations of total nitrogen (TN), total phosphorus (TP), and suspended solids (SS). The study area, Simojoki (3160 km2) in northern Finland, has been intensively drained for peatland forestry since the 1960s. We used different approaches at multiple sub-catchment scales to simulate TN, TP, and SS export in the Simojoki catchment. The uncertainty in estimates based on specific export coefficients was quantified based on historical land-use changes (derived from Landsat data), and an uncertainty boundary was established for each land-use. The uncertainty boundary captured at least 60% of measured values of TN, TP, and SS loads or concentrations. However, the uncertainty in estimates compared with measured values ranged from 7% to 20% for TN, 0% to 18% for TP, and 13% to 43% for SS for different catchments. Some discrepancy between predicted and measured loads and concentrations was expected, as the method did not account for inter-annual variability in hydrological conditions or river processes. However, combining historical land-use change estimates with simple export coefficients can be a practical approach for evaluating the influence on water quality of historical land-use changes such as peatland drainage for forest establishment
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