Browsing by Subject "PINE MIRES"

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  • Laurén, Annamari (Ari); Guan, Mingfu; Salmivaara, Aura; Leinonen, Antti; Palviainen, Marjo; Launiainen, Samuli (2021)
    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.
  • Minkkinen, Kari; Ojanen, Paavo; Penttilä, Timo; Aurela, Mika; Laurila, Tuomas; Tuovinen, Juha-Pekka; Lohila, Annalea (2018)
    Drainage of peatlands is expected to turn these ecosystems into carbon sources to the atmosphere. We measured carbon dynamics of a drained forested peatland in southern Finland over 4 years, including one with severe drought during growing season. Net ecosystem exchange (NEE) of carbon dioxide (CO2) was measured with the eddy covariance method from a mast above the forest. Soil and forest floor CO2 and methane (CH4) fluxes were measured from the strips and from ditches with closed chambers. Biomass and litter production were sampled, and soil subsidence was measured by repeated levellings of the soil surface. The drained peatland ecosystem was a strong sink of carbon dioxide in all studied years. Soil CO2 balance was estimated by subtracting the carbon sink of the growing tree stand from NEE, and it showed that the soil itself was a carbon sink as well. A drought period in one summer significantly decreased the sink through decreased gross primary production. Drought also decreased ecosystem respiration. The site was a small sink for CH4, even when emissions from ditches were taken into account. Despite the continuous carbon sink, peat surface subsided slightly during the 10-year measurement period, which was probably mainly due to compaction of peat. It is concluded that even 50 years after drainage this peatland site acted as a soil C sink due to relatively small changes in the water table and in plant community structure compared to similar undrained sites, and the significantly increased tree stand growth and litter production. Although the site is currently a soil C sink, simulation studies with process models are needed to test whether such sites could remain C sinks when managed for forestry over several tree-stand rotations.
  • Strakova, Petra; Larmola, Tuula; Andres, Javier; Ilola, Noora; Launiainen, Piia; Edwards, Keith; Minkkinen, Kari; Laiho, Raija (2020)
    Evidence of plant root biomass and production in peatlands at the level of species or plant functional type (PFT) is needed for defining ecosystem functioning and predicting its future development. However, such data are limited due to methodological difficulties and the toilsomeness of separating roots from peat. We developed Fourier transform infrared (FTIR) spectroscopy based calibration models for quantifying the mass proportions of several common peatland species, and alternatively, the PFTs that these species represented, in composite root samples. We further tested whether woody roots could be classified into diameter classes, and whether dead and living roots could be separated. We aimed to solve whether general models applicable in different studies can be developed, and what would be the best way to build such models. FTIR spectra were measured from dried and powdered roots: both "pure roots", original samples of 25 species collected in the field, and "root mixtures", artificial composite samples prepared by mixing known amounts of pure roots of different species. Partial least squares regression was used to build the calibration models. The general applicability of the models was tested using roots collected in different sites or times. Our main finding is that pure roots can replace complex mixtures as calibration data. Using pure roots, we constructed generally applicable models for quantification of roots of the main PFTs of northern peatlands. The models provided accurate estimates even for far distant sites, with root mean square error (RMSE) 1.4-6.6% for graminoids, forbs and ferns. For shrubs and trees the estimates were less accurate due to higher within-species heterogeneity, partly related to variation in root diameter. Still, we obtained RMSE 3.9-10.8% for total woody roots, but up to 20.1% for different woody-root types. Species-level and dead-root models performed well within the calibration dataset but provided unacceptable estimates for independent samples, limiting their routine application in field conditions. Our PFT-level models can be applied on roots separated from soil for biomass determination or from ingrowth cores for estimating root production. We present possibilities for further development of species-level or dead-root models using the pure-root approach.
  • Juutinen, Artti; Saarimaa, Miia; Ojanen, Paavo; Sarkkola, Sakari; Haara, Arto; Karhu, Jouni; Nieminen, Mika; Minkkinen, Kari; Penttila, Timo; Laatikainen, Matti; Tolvanen, Anne (2019)
    Economic development creates challenges for land-use planners in balancing between increasing the use of natural resources and safeguarding biodiversity and ecosystem services. We developed and utilized multi-objective numeric optimization models to analyze the trade-offs between biodiversity and ecosystem services (BES). The approach was used in the land-use planning process in northern Finland when selecting potential peat production sites as a part of the development of the regional master plan. We first quantified Net Present Value (NPV) of peat production, biodiversity, greenhouse gas (GHG) emissions, and water emissions of peatlands. Then we applied multi-objective optimization to examine the trade-offs between the variables as well as to determine a cost-efficient selection of potential peat production sites, that is, a selection which would simultaneously generate the greatest possible economic returns and environmental benefits. Our results showed that with a relatively small decrease in NPV, a substantial decrease in biodiversity loss and a reduction in water emissions compared to the benchmark level could be attained. However, a significant decrease in GHG emissions resulted in a substantial decrease in NPV. We conclude that it is possible to significantly improve land-use management by applying multi-objective optimization in land-use planning.