Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Abstract
No abstract has been registered
Authors
Sunil Mundra Håvard Kauserud Tonje Økland Jørn-Frode Nordbakken Yngvild Eidissen Ransedokken O. Janne KjønaasAbstract
The replacement of native birch with Norway spruce has been initiated in Norway to increase long-term carbon storage in forests. However, there is limited knowledge on the impacts that aboveground changes will have on the belowground microbiota. We examined which effects a tree species shift from birch to spruce stands has on belowground microbial communities, soil fungal biomass and relationships with vegetation biomass and soil organic carbon (SOC). Replacement of birch with spruce negatively influenced soil bacterial and fungal richness and strongly altered microbial community composition in the forest floor layer, most strikingly for fungi. Tree species-mediated variation in soil properties was a major factor explaining variation in bacterial communities. For fungi, both soil chemistry and understorey vegetation were important community structuring factors, particularly for ectomycorrhizal fungi. The relative abundance of ectomycorrhizal fungi and the ectomycorrhizal : saprotrophic fungal ratio were higher in spruce compared to birch stands, particularly in the deeper mineral soil layers, and vice versa for saprotrophs. The positive relationship between ergosterol (fungal biomass) and SOC stock in the forest floor layer suggests higher carbon sequestration potential in spruce forest soil, alternatively, that the larger carbon stock leads to an increase in soil fungal biomass.
Authors
Pierre-Adrien Rivier Dorina Jamniczky Attila Nemes Andras Mako Gyöngyi Barna Nikolett Uzinger Márk Rékási Csilla FarkasAbstract
Despite the increasing interest in applying composts as soil amendments worldwide, there is a lack of knowledge on short-term effects of compost amendments on soil structural and hydraulic properties. Our goal was to study the effect of compost and vermicompost-based soil amendments on soil structure, soil water retention characteristics, aggregate stability and plant water use efficiency compared to that of mineral fertilizers and food-waste digestate and examine if these effects are evident within a short time after application. We set up a pot experiment with spring wheat using a sandy and a loamy soil receiving either mineral fertilizer (MF); dewatered digestate from anaerobic digestion of food waste (DG), vermicomposted digestate (VC_DG); sewage sludge-based compost (C_SS) and sewage sludge-based vermicompost (VC_SS). We then monitored and calculated the soil water balance components (irrigation, outflow, evaporation, transpiration, and soil water content). At harvest, we measured shoot biomass, soil texture, bulk density, water retention characteristics and aggregate stability. The irrigation use efficiency (IE) and the plant water use efficiency (WUE) were calculated for each treatment by dividing the transpiration and the dry shoot biomass with the amount of water used for irrigation, respectively. For the sandy soil, we used X-Ray computed tomography to visualise the pore system after applying organic amendments and to derive metrics of the pore-network such as its fractal dimension, imaged macroporosity and critical pore diameter. X-Ray tomography indicated that composting and vermicomposting resulted in more complex and diverse porous system and increased soil macroporosity. The increased fractal dimensions also indicated that compost and vermicompost can contribute to structure formation and stabilization within a short time after their application. Despite the small application rate and short incubation time, the application of organic amendments to the two different soil types resulted in improved soil water holding capacity and water use efficiency. Composting and vermicomposting appeared to have the best effect at reducing the irrigation demand and evaporation losses and increasing the water use efficiency of the plant, likely through their effect on soil structure and the pore-size distribution.
Abstract
In a fertiliser experiment in a Norway spruce forest in SE Norway, four treatments were applied in a block design with three replicates per treatment. Treatments included 3 t wood ash ha−1 (Ash), 150 kg nitrogen ha−1 (N), wood ash and nitrogen combined (Ash + N), and unfertilised control (Ctrl). Treatment effects on understory plant species numbers, single abundances of species and (summarised) cover of main species groups were studied. Two years after treatment there were no significant changes for species numbers or abundances of woody species, dwarf shrubs or pteridophytes, nor for Sphagnum spp. in the bottom layer. The cover of graminoids decreased in Ctrl plots. Herb cover increased significantly in Ash + N and N plots due to the increase of Melampyrum sylvaticum. In Ash + N plots, mosses decreased significantly in species number, while their cover increased. Moss cover also decreased significantly in N plots. The species number and cover of hepatics decreased significantly in Ash and Ash + N plots. Hepatics cover also decreased in Ctrl plots. Both the lichen number and cover decreased in Ash + N plots. Single species abundances decreased for many bryophytes in fertilised plots. To conclude, fertilisation had modest effects on vascular plants, while bryophytes were more strongly affected, especially by Ash + N.
Abstract
Transpiration makes up the bulk of total evaporation in forested environments yet remains challenging to predict at landscape-to-global scales. We harnessed independent estimates of daily transpiration derived from co-located sap flow and eddy-covariance measurement systems and applied the triple collocation technique to evaluate predictions from big leaf models requiring no calibration. In total, four models in 608 unique configurations were evaluated at 21 forested sites spanning a wide diversity of biophysical attributes and environmental backgrounds. We found that simpler models that neither explicitly represented aerodynamic forcing nor canopy conductance achieved higher accuracy and signal-to-noise levels when optimally configured (rRMSE = 20%; R2 = 0.89). Irrespective of model type, optimal configurations were those making use of key plant functional type dependent parameters, daily LAI, and constraints based on atmospheric moisture demand over soil moisture supply. Our findings have implications for more informed water resource management based on hydrological modeling and remote sensing.
Abstract
No abstract has been registered
Abstract
SiTree is a flexible, cross-platform, open-source framework for individual-tree simulators intended to facilitate accurate and flexible analyses of forest growth and yield, or more generally forest dynamics simulations. SiTree provides generic functionality to build customized individual-tree simulators using additional user-written code. In the forestry literature there are a wide variety of individual models that describe the different parts of forest growth and dynamics and new models are continuously developed and published. The aim of SiTree is to provide a broad community of R-users within forestry with an easily adaptable individual-tree simulator framework and an easily accessible tool for testing and combining new and existing models describing parts of forest growth dynamics.
Authors
Michel VerheulAbstract
No abstract has been registered
Authors
Atle Wehn Hegnes Geir Wæhler Gustavsen Bianca Cavicchi Amandeep Kaur Bhatti Petter D. JenssenAbstract
No abstract has been registered
Authors
Lampros LamprinakisAbstract
No abstract has been registered