Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2022
Forfattere
Bert van der Veen Francis K. C. Hui Knut Anders Hovstad Robert Brian OHaraSammendrag
1. In community ecology, unconstrained ordination can be used to indirectly explore drivers of community composition, while constrained ordination can be used to directly relate predictors to an ecological community. However, existing constrained ordination methods do not explicitly account for community composition that cannot be explained by the predictors, so that they have the potential to misrepresent community composition if not all predictors are available in the data. 2. We propose and develop a set of new methods for ordination and joint species distribution modelling (JSDM) as part of the generalized linear latent variable model (GLLVM) framework, that incorporate predictors directly into an ordination. This includes a new ordination method that we refer to as concurrent ordination, as it simultaneously constructs unconstrained and constrained latent variables. Both unmeasured residual covariation and predictors are incorporated into the ordination by simultaneously imposing reduced rank structures on the residual covariance matrix and on fixed-effects. 3. We evaluate the method with a simulation study, and show that the proposed developments outperform canonical correspondence analysis (CCA) for Poisson and Bernoulli responses, and perform similar to redundancy analysis (RDA) for normally distributed responses, the two most popular methods for constrained ordination in community ecology. Two examples with real data further demonstrate the benefits of concurrent ordination, and the need to account for residual covariation in the analysis of multivariate data. 4. This article contextualizes the role of constrained ordination in the GLLVM and JSDM frameworks, while developing a new ordination method that incorporates the best of unconstrained and constrained ordination, and which overcomes some of the deficiencies of existing classical ordination methods.
Sammendrag
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Sammendrag
Prediction of the relative phosphorus (P) fertiliser value of bio-based fertiliser products is agronomically important, but previous attempts to develop prediction models have often failed due to the high chemical complexity of bio-based fertilisers and the limited number of products included in analyses. In this study, regression models for prediction were developed using independently produced data from 10 different studies on crop growth responses to P applied with bio-based fertiliser products, resulting in a dataset with 69 products. The 69 fertiliser products were organised into four sub-groups, based on the inorganic P compounds most likely to be present in each product. Within each product group, multiple regression was conducted using mineral fertiliser equivalents (MFE) as response variable and three potential explanatory variables derived from chemical analysis, all reflecting inorganic P binding in the fertiliser products: i) NaHCO3-soluble P, ii) molar ratio of calcium (Ca):P and iii) molar ratio of aluminium+iron (Al+Fe):P. The best regression model fit was achieved for sewage sludges with Al-/Fe-bound P (n = 20; R2 = 79.2%), followed by sewage sludges with Ca-bound P (n = 11; R2 = 71.1%); fertiliser products with Ca-bound P (n = 29; R2 = 58.2%); and thermally treated sewage sludge products (n=9;R2=44.9%). Even though external factors influencing P fertiliser values (e.g. fertiliser shape, application form, soil characteristics) differed between the underlying studies and were not considered, the suggested prediction models provide potential for more efficient P recycling in practice.
Sammendrag
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Forfattere
Jason Tyler Magnuson Ivo Havranek Zoe Longenecker-Wright Monticelli Giovanna Brekken Hans Kristian Roland Kallenborn Daniel Schlenk Magne Olav Sydnes Daniela Maria PampaninSammendrag
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Forfattere
Fride Høistad ScheiSammendrag
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Forfattere
Marie-Therese Krieger Julia Ditton Harald Albrecht Barteline Martina Baaij Johannes Kollmann Leonardo Henrique TeixeiraSammendrag
Aim: In this study, we tested plant community-based management methods to reduce the abundance of the invasive native plant Jacobaea aquatica (marsh ragwort). As J. aquatica mainly occurs in species-rich wet grasslands, our aim was to define management measures that do not reduce the conservation value of the resident communities. Location: Data were collected from 20 independent sites which varied in productivity and management intensity across the pre-alpine Allgäu region (South Germany). Methods: We monitored effects of temporary abandonment and decreased mowing intensity in very low- and low-productive sites, as well as of decreased mowing and fertilization at moderately productive sites. Abundances of J. aquatica and the co-occurring species were recorded at start and end of two experiments (2018–2021: very low- and low-productive conservation grasslands; 2017–2020: moderately productive agricultural grasslands), while functional traits data of all species were gathered from the literature and specific databases. Generalized linear mixed-effects models (GLMMs) were used to analyse the effects of management intensity on the abundance of J. aquatica, functional diversity and species richness of the resident communities. Results: At all productivity levels, the abundance of J. aquatica declined under reduced management. Changes in community composition and species richness of the resident community were less pronounced than the reduction of J. aquatica, but species richness declined under lowest management intensities. Thus, moderate reduction in management intensity provided the most benefits in terms of reduction of J. aquatica, and maintenance of species richness and composition of the resident plant community. Conclusions: Reducing management intensity in wet grasslands decreases the abundance of J. aquatica and thus is a suitable method to control this species. As plant community responses were only partially consistent, management plans must account for the productivity of invaded sites. To avoid negative effects on grassland biodiversity, only moderate suppression of J. aquatica is recommended.
Forfattere
Lu FengSammendrag
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Forfattere
Rolf Larsson Antti Belinskij Bjørn Kløve Diana Meilutyte-Lukauskiene Elve Lode Eva Skarbøvik Vytautas AkstinasSammendrag
The European Union (EU) Water Framework Directive is of paramount importance for water management. According to the legal text, coordination with other directives like the Floods Directive is imperative and motivated by potential synergy effects. In this paper, the degree to which such coordination is achieved is evaluated for five Nordic and Baltic countries. The evaluation is based on legal documents, management plans, as well as on organizational structure in the five countries. The results show that the coordination between the Water Framework Directive and the Floods Directive (or flood management for Norway's case), have been successful for Estonia and Lithuania, whereas Norway, Finland, and especially Sweden need to improve more.
Forfattere
Bjørn Tobias BorchseniusSammendrag
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