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.
2023
Sammendrag
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Forfattere
Belachew Asalf TadesseSammendrag
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Sammendrag
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Forfattere
Joel Abbey Sherin Jose David Percival Laura Jaakola Samuel K. AsieduSammendrag
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Forfattere
Fredrik Rustøen Klaus Høiland Einar Heegaard Lynne Boddy Alan C. Gange Håvard Kauserud Carrie Joy AndrewSammendrag
Det er ikke registrert sammendrag
Sammendrag
Quantifying the similarities and differences in atmospheric nitrogen (N) deposition between different ecosystems is important to develop effective measures to reduce air pollution and maintain biodiversity. Here we show that the constitution of N deposition differed significantly between a grassland and a desert ecosystem in Northwestern China. Flux of bulk (wet plus part of dry deposition) and dry (gaseous NH3 and NO2) deposition were continuously monitored from 2018 to 2020. The grassland and desert sites had similar amount of total N deposition, being 7.29 and 6.33 kg N ha−1 yr−1, respectively. However, N deposition at the grassland was dominated by the bulk deposition (4.44 kg N ha−1 yr−1, 61% of the total N deposition), whereas that at the desert was dominated by dry deposition (4.20 kg N ha−1 yr−1, 66% of total deposition). The desert had greater ambient concentrations of NH3 (3.66 μg N m−3) and NO2 (1.52 μg N m−3) than the grassland (2.73 μg NH3–N m−3 and 0.72 μg NO2–N m−3). The amount of reduced N deposition (NH4+ and NH3) was around 3 times of that of oxidized N deposition (NO3− and NO2) in both ecosystems. The N deposition rates in both ecosystems have exceeded the critical load for the fragile ecosystems (5–10 kg N ha−1 yr−1), highlighting the importance of reducing N emission sources that are related with anthropogenic disturbance.
Forfattere
Nicolas Valette Arnaud Legout Barry Goodell Gry Alfredsen Lucas Auer Eric Gelhaye Delphine DerrienSammendrag
In forest ecosystems, fungi are the key actors in wood decay. They have the capability to degrade lignified substrates and the woody biomass of coniferous forests, with brown rot fungi being common colonizers. Brown rots are typically involved in the earliest phase of lignocellulose breakdown, which therefore influences colonization by other microorganisms. However, few studies have focused on the impact of introducing decayed wood into forest environments to gauge successional colonization by natural bacterial and fungal communities following partial decay. This study aimed to address this issue by investigating the bacterial and fungal colonization of Norway spruce (Picea abies) wood, after intermediate and advanced laboratory-based, pre-decay, by the brown rot fungus Gloeophyllum trabeum. Using Illumina metabarcoding, the in situ colonization of the wood blocks was monitored 70 days after the blocks were placed on the forest floor and covered with litter. We observed significant changes in the bacterial and fungal communities associated with the pre-decayed stage. Further, the wood substrate condition acted as a gatekeeper by reducing richness for both microbial communities and diversity of fungal communities. Our data also suggest that the growth of some fungal and bacterial species was driven by similar environmental conditions.
Sammendrag
Soil nutrient contents and stoichiometric ratios are determinants for soil biogeochemical cycling and functions. Variable rock fragment contents (RFC) may shape the soil nutrient status and availability in mountain ecosystems. We need to better understand how and why soil nutrients and stoichiometry shift across the RFC gradients. To investigate patterns of soil nutrient stoichiometry and underlying mechanisms in rocky soils, we conducted a field experiment involving four RFCs gradients (0%, 25%, 50% and 75%, V/V) and five vegetation treatments (four indigenous species, Artemisia vestita, Bauhinia brachycarpa, Cotinus szechuanensis and Sophora davidii, plus a non-planted treatment). Soil total carbon (C), total nitrogen (N), total phosphorus (P) and their molar ratios were measured. The contents of soil C, N and P, and C:N, C:P and N:P decreased with increasing RFC in all treatments, despite their trends were inconsistent in certain soil layers. The averages of soil N content significantly increased by 13.8% and 14.8% in C. szechuanensis and S. davidii, respectively. A. vestita and B. brachycarpa had higher soil C:N than C. szechuanensis and S. davidii. Soil nutrients and stoichiometry were positively related to soil water content (SWC) and soil capillary porosity, and negatively to bulk density and soil non-capillary porosity in all vegetation treatments, but varying relationships with biomass of plant components. These results demonstrated negative effect of RFC and discrepant effects of the plants on soil nutrients and stoichiometry. Soil structure, SWC and vegetation were the main drivers of variations in soil nutrient stoichiometry. We further concluded that soil nutrient stoichiometry in rocky soils is shaped by two influencing paths; effects of RFC on soil physical properties (SWC and soil structure) and effects of different vegetations. Our findings advance knowledge and mechanisms of soil nutrient stoichiometry in rocky soils and provide theoretical support for improving and restoring nutrient status in stony regions.
Forfattere
Yi Zhang Yijing Feng Zhonghao Ren Runguo Zuo Tianhui Zhang Yeqing Li Yajing Wang Zhiyang Liu Ziyan Sun Yongming Han Lu Feng Mortaza Aghbashlo Meisam Tabatabaei Junting PanSammendrag
The ideal conditions for anaerobic digestion experiments with biochar addition are challenging to thoroughly study due to different experimental purposes. Therefore, three tree-based machine learning models were developed to depict the intricate connection between biochar properties and anaerobic digestion. For the methane yield and maximum methane production rate, the gradient boosting decision tree produced R2 values of 0.84 and 0.69, respectively. According to feature analysis, digestion time and particle size had a substantial impact on the methane yield and production rate, respectively. When particle sizes were in the range of 0.3–0.5 mm and the specific surface area was approximately 290 m2/g, corresponding to a range of O content (>31%) and biochar addition (>20 g/L), the maximum promotion of methane yield and maximum methane production rate were attained. Therefore, this study presents new insights into the effects of biochar on anaerobic digestion through tree-based machine learning.
Forfattere
Adam Eindride Naas Rune Halvorsen Peter Horvath Anders Kvalvåg Wollan Harald Bratli Katrine Marie Brynildsrud Eirik Aasmo Finne Lasse Torben Keetz Eva Lieungh Christine Olson Trond Simensen Olav Skarpaas Hilde Tandstad Michal Torma Espen Sommer Værland Anders BrynSammendrag
Questions Field-based ecosystem mapping is prone to observer bias, typically resulting in a mismatch between maps made by different mappers, that is, inconsistency. Experimental studies testing the influence of site, mapping scale, and differences in experience level on inconsistency in field-based ecosystem mapping are lacking. Here, we study how inconsistencies in field-based ecosystem maps depend on these factors. Location Iškoras and Guollemuorsuolu, northeastern Norway, and Landsvik and Lygra, western Norway. Methods In a balanced experiment, four sites were field-mapped wall-to-wall to scales 1:5000 and 1:20,000 by 12 mappers, representing three experience levels. Thematic inconsistency was calculated by overlay analysis of map pairs from the same site, mapped to the same scale. We tested for significant differences between sites, scales, and experience-level groups. Principal components analysis was used in an analysis of additional map inconsistencies and their relationships with site, scale and differences in experience level and time consumption were analysed with redundancy analysis. Results On average, thematic inconsistency was 51%. The most important predictor for thematic inconsistency, and for all map inconsistencies, was site. Scale and its interaction with site predicted map inconsistencies, but only the latter were important for thematic inconsistency. The only experience-level group that differed significantly from the mean thematic inconsistency was that of the most experienced mappers, with nine percentage points. Experience had no significant effect on map inconsistency as a whole. Conclusion Thematic inconsistency was high for all but the dominant thematic units, with potentially adverse consequences for mapping ecosystems that are fragmented or have low coverage. Interactions between site and mapping system properties are considered the main reasons why no relationships between scale and thematic inconsistency were observed. More controlled experiments are needed to quantify the effect of other factors on inconsistency in field-based mapping.