Hopp til hovedinnholdet

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

As a way to estimate evapotranspiration (ET), Heat Field Deformation (HFD) is a widely used method to measure sap flow of trees based on empirical relationships between heat transfer within tree stems and the sap flow rates. As an alternative, the Linear Heat Balance (LHB) method implements the same instrumental configuration as HFD but calculates the sap flow rates using analytical equations that are derived from fundamental conduction-convection heat transfer equations.

To document

Abstract

Roadsides, in particular those being species-rich and of conservation value, are considered to improve landscape permeability by providing corridors among habitat patches and by facilitating species' dispersal. However, little is known about the potential connectivity offered by such high-value roadsides. Using circuit theory, we modelled connectivity provided by high-value roadsides in landscapes with low or high permeability in south-central Sweden, with ‘permeability’ being measured by the area of semi-natural grasslands. We modelled structural connectivity and, for habitat generalists and specialists, potential functional connectivity focusing on butterflies. We further assessed in which landscapes grassland connectivity is best enhanced through measures for expanding the area of high-value roadsides. Structural connectivity provided by high-value roadsides resulted in similar patterns to those of a functional approach, in which we modelled habitat generalists. In landscapes with low permeability, all target species showed higher movements within compared to between grasslands using high-value roadsides. In landscapes with high permeability, grassland generalists and specialists showed the same patterns, whereas for habitat generalists, connectivity provided by high-value roadsides and grasslands was similar. Increasing the ratio of high-value roadsides can thus enhance structural and functional connectivity in landscapes with low permeability. In contrast, in landscapes with high permeability, roadsides only supported movement of specialised species. Continuous segments of high-value roadsides are most efficient to increase connectivity for specialists, whereas generalists can utilize also short segments of high-value roadsides acting as stepping-stones. Thus, land management should focus on the preservation and restoration of existing semi-natural grasslands. Management for enhancing grassland connectivity through high-value roadsides should aim at maintaining and creating high-value roadside vegetation, preferably in long continuous segments, especially in landscapes with low permeability.

To document

Abstract

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.

To document

Abstract

Clarireedia spp., Fusarium culmorum, and Microdochium nivale are destructive and widespread fungal pathogens causing turfgrass disease. Chemical control is a key tool for managing these diseases on golf greens but are most effective when used in a manner that reduces overall inputs, maximizes fungicide efficacy, and minimizes the risk of fungicide resistance. In this study, sensitivity to eight commonly used fungicides was tested in 13 isolates of Clarireedia spp., F. culmorum, and M. nivale via in vitro toxicity assays. Fungicide sensitivity varied significantly among the three species, with isolates of F. culmorum showing the least sensitivity. The sensitivity of M. nivale to all tested fungicides was high (with the exception of tebuconazole), but only four fungicides (Banner Maxx®, Instrata® Elite, Medallion TL, and Switch® 62,5 WG) suppressed the growth of M. nivale completely at a concentration of 1% of the recommended dose. All three fludioxonil-containing fungicides either alone (Medallion TL) or in combination with difeconazole (Instrata® Elite) or cyprodinil (Switch® 62,5 WG) had the same high efficacy against isolates of both M. nivale and Clarireedia spp. On average, the Clarireedia isolates tested in this study showed high sensitivity to the tested fungicides, except for Heritage (azoxystrobin). The observed variation in sensitivity among isolates within the same fungal species to different fungicides needs further investigation, as an analysis of the differences in fungal growth within each fungal group revealed a significant isolate × fungicide interaction (p < .001).