Search results for "boreaalinen"
showing 10 items of 58 documents
The importance of novel ecosystems for biodiversity : a study of ground beetles (Carabidae) on afforested fields
2014
Metsien hävittäminen, maanviljely ja muut ympäristöä muokkaavat toimet muuttavat ekosysteemejä kasvavissa määrin. Tämän seurauksena syntyy poikkeuksellisia, ihmisen toiminnasta peräisin olevia ekosysteemejä. Näiden uusekosysteemien merkitys monimuotoisuudelle kasvaa lähitulevaisuudessa kun ihmisen vaikutus Maahan lisääntyy. Metsitetyt pellot voidaan monessa tapauksessa lukea uusekosysteemeihin: lannoituksella on pitkäaikaisia vaikutuksia maaperän fysikaalisiin ominaisuuksiin ja ravinteiden määrä on metsitetyillä pelloilla suurempi kuin tavallisissa metsissä. Kasvillisuuden sukkession tarkkaa lopputulosta ei vielä tiedetä. Metsitetyt pellot käsittävät 300 000 hehtaaria Suomen pinta-alasta ja…
Species richness of polypores can be increased by supplementing dead wood resource into a boreal forest landscape
2019
1. To prevent local species extinction and to counteract population declines, we must ensure species have access to resources they require for life. This can be done through ecological restoration where previously depleted resources are reintroduced. If the restoration is conducted as a one-off action in a large area, it resembles a natural resource pulse, which should lead to increased abundance of individuals, accompanied possibly by increased species richness. Species–energy relationship and underlying theory enable predictions about how different features of resource pulses affect species richness. 2. We conducted a large-scale, controlled, randomized and replicated field experiment to …
Periphyton as a key diet source of essential fatty acids for macroinvertebrates across a nutrient and dissolved organic carbon gradient in boreal lak…
2022
We studied how physiologically important long-chain polyunsaturated fatty acids (PUFA) in benthic macroinvertebrates (Asellus aquaticus, Chironomidae, and Oligochaeta) were related to those in periphyton and terrestrial organic matter (tree leaves), collected from littoral areas of 17 boreal lakes that differed in their dissolved organic carbon (DOC) and nutrient (phosphorus and nitrogen) concentrations. We also analyzed fatty acid (FA)-specific stable carbon isotopes (δ13CFA) to investigate the dietary origin (periphyton vs. terrestrial organic matter) of PUFA in the consumers. In contrast to periphyton, terrestrial organic matter was deprived of long-chain PUFA, such as eicosapentaenoic a…
Sunlit surface waters : exploring the photochemical reactivity of dissolved organic carbon
2017
In surface waters, solar radiation can photochemically mineralise the dissolved organic carbon (DOC, a measure of dissolved organic matter, DOM) to dissolved inorganic carbon (DIC). This DIC photoproduction constitutes an essential yet vague flux in the aquatic carbon cycling. The present thesis is based on the empirical assessment of the DOC photochemical reactivity, which was determined as the spectral apparent quantum yields (AQY) for DIC photoproduction. First, AQYs were determined in DOM solutions to quantify the impact of pH and DOM-associated iron. Then boreal lake waters were used for assessing the alteration of DOC photoreactivity due to water quality and catchment property. By sim…
Coupling of iron and dissolved organic matter in lakes–selective retention of different size fractions
2023
AbstractIncreasing concentration of iron (Fe) is observed in many boreal lakes, such as for the present study in Oslo Østmark, SE-Norway (1983–2018). As Fe-regulating processes are complex and dynamic, the link between mobilizing and retention processes is still not well understood. A seasonal study (2017–2018) from two headwaters, with medium and high dissolved organic matter (DOM) concentrations, showed that the loading of Fe to the lakes was highly dependent on flow conditions. Significantly higher values of Fe were related to autumn and winter periods with high runoff of highly colored and aromatic DOM compared to a severe drought period with minimum Fe values in the lakes. Compared to …
National high-resolution conservation prioritisation of boreal forests
2023
The continuous decline of forest biodiversity highlights the importance of the development of cost-effective and ecologically sustainable land-use planning approaches. Spatial conservation prioritisation (SCP) can be regarded as a useful tool for this challenge. We produced high-resolution, national scale SCP analyses to identify unprotected forest areas that host valuable forest biodiversity. We used stand-based modelled dead wood potential (DWP) data as a primary surrogate for conservation value. In addition, data on forestry operations that have negative impacts on biodiversity, connectivity between forest areas, the observations of red-listed forest species, connectivity to forest habit…
Predicting valuable forest habitats using an indicator species for biodiversity
2020
Intensive management of boreal forests impairs forest biodiversity and species of old-growth forest. Effective measures to support biodiversity require detection of locations valuable for conservation. We applied species distribution models (SDMs) to a species of mature forest, the northern goshawk (Accipiter gentilis, goshawk), that is often associated with hotspots of forest biodiversity. We located optimal sites for the goshawk on a landscape scale, assessed their state under intensified logging operations and identified characteristics of goshawks' nesting sites in boreal forests. Optimal sites for the goshawk covered only 3.4% of the boreal landscape and were mostly located outside pro…
Biotic oxidation of methane in landfills in boreal climatic conditions
2010
This study focused on the biotic oxidation of methane in landfill covers as a technology for reducing greenhouse gas emissions from landfills, particularly those located in the boreal climatic zone. First, methane oxidation was studied in laboratory batch assays in a landfill cover soil consisting of a composted mixture of sewage sludge and chemical sludge which had been installed on the landfill surface 4-5 years earlier. Second, methane oxidation was studied using mechanically-biologically treated municipal solid waste (MBT residual) as a material for methane-oxidizing landfill covers both in continuously methane-sparged laboratory columns and in an outdoor pilot lysimeter. Finally, meth…
Trade-offs among intensive forestry, ecosystem services and biodiversity in boreal forests
2018
Finnish forests are used extensively for timber production but are also providers of other ecosystem services and harbor unique biodiversity. The ecosystem services approach has so far been used marginally in the context of Finnish forestry; however, due to the multiple values associated with Finnish forests and the impacts forestry operations have on forest ecosystems, it is clearly applicable in this context. In this thesis, I studied the occurrence and severity of trade-offs among ecosystem services and biodiversity conservation in Finnish forests. I used forest inventory data, forest growth simulations, and multi-objective optimization to reveal how the severity of the trade-offs varies…
Adaptive Management as a Vehicle to Achieve Sustainability of Boreal Forests : A Historical Review from Fennoscandia to Minnesota
2021
Located solely in the northern hemisphere, boreal forests contain an estimated one-third of Earth’s forested land. The purpose of this work aimed at reviewing the evolution of approaches in land planning and management of boreal forests in Finland and Northern Sweden, while comparing these to those developed in Minnesota. The nature of this work is historical research of forests use and management during the last 200 years. The knowledge from past histories is valuable to improve management approaches that aim at retaining the economic viability of logging, without jeopardizing the regenerative capabilities of forest ecosystems. Various methods and restoration efforts aimed at recovering fr…