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.
2024
Sammendrag
Context In high-latitude regions, variable weather conditions during the growing season and in winter cause considerable variation in forage grass productivity. Tools for predicting grassland status and yield, such as field measurements, satellite image analysis and process-based simulation models, can be combined in decision support for grassland management. Here, we calibrated and validated the BASic GRAssland (BASGRA) model against dry matter and Leaf area index data from temporary grasslands in northern Norway. Objective The objective of this study was to compare the performance of model versions calibrated against i) only region-specific ground data, ii) both region-specific ground and Sentinel-2 satellite data and, iii) field trial data from other regions. Methods Ground and satellite sensed data including biomass dry matter, leaf area index, and autumn and spring ground cover from 2020 to 2022 were acquired from 13 non-permanent grassland fields at four locations. These data were input to BASGRA calibrations together with soil and daily weather data, and information about cutting and nitrogen fertilizer application regimes. The effect of the winter season was taken into account in simulations by initiating the simulations either in autumn or in early spring. Results Within datasets, initiating the model in spring resulted in higher dry matter prediction accuracy (normalised RMSE 22.3–54.0 %) than initiating the model in autumn (normalised RMSE 41.1–93.4 %). Regional specific calibrations resulted in more accurate biomass predictions than calibrations from other regions while using satellite sensing data in addition to ground data resulted in only minor changes in biomass prediction accuracy. Conclusion All regional calibrations against data from northern Norway changed model parameter values and improved dry matter prediction accuracy compared with the reference calibration parameter values. Including satellite-sensed data in addition to ground data in calibrations did not further increase prediction accuracy compared with using only ground data. Implications Our findings show that regional data from farmers’ fields can substantially improve the performance of the BASGRA model compared to using controlled field trial data from other regions. This emphasises the need to account for regional diversity in non-permanent grassland when estimating grassland production potential and stress impact across geographic regions. Further use of satellite data in grassland model calibrations would probably benefit from more detailed assessments of the effect of grass growth characteristics and light and cloud conditions on estimates of grassland leaf area index and biomass from remote sensing.
Sammendrag
Forests, especially in the northern latitudes, are vulnerable ecosystems to climate change, and tree-ring data offer insights into growth-climate relationships as an important effect. Using the National Forest Inventory plot network, we analysed these correlations for the two dominant conifer species in Norway – Norway spruce and Scots pine – for the 1960–2020 period. For both species, the June climate was an important driver of radial growth during this period. Countrywide, the climate-growth correlations divided the Norwegian forests into spatial clusters following a broad shift from temperature- to water-sensitivity of growth with latitude and altitude. The clusters were delineated by a mean 1960–2020 June temperature of ca. 12°C for Norway spruce and Scots pine. The annual mean growing season and July temperatures – but not June temperature – has increased by 1.0 °C between the 1960–1990 and 1990–2020 periods, with a slight increase in precipitation. Despite this warming and wetting trend, the long-term growth-climate relationship has remained relatively stable between 1960 and 1990 and 1990–2020 for both species. The threshold between temperature and water-sensitive growth has not changed in the last two 31-year periods, following the stability of the June temperature compared with other months during the growing season. These findings highlight geographically coherent regions in Norway, segregating between temperature- and water-sensitive radial growth for the two major conifer species, temporally stable in the long-term for the 1960–2020 period studied.
Forfattere
Xiao-Yan Ma Jin-Wei Li Qing Li Zi-Han Yan Xi Cheng Min-Rui Wang Zhibo Hamborg Lu Bao Dong Zhang Min-Ji LiSammendrag
The presence of viral diseases poses a significant challenge to the high-quality, efficient, and sustainable production of apples. Virus eradication and the use of virus-free plants are currently the most crucial method for preventing viral diseases. Among the viruses affecting apples, apple stem grooving virus (ASGV) and apple chlorotic leaf spot virus (ACLSV) present particular challenges in efficient eradication from apples. This study investigated the effects of exogenous salicylic acid (SA) treatment on the efficient eradication of ASGV and ACLSV from apple cultivar ‘Yanfu 8’. Shoots were excised from in vitro 4-week-old stock and cultured in shoot proliferation medium supplemented with 10 μM SA combining thermotherapy with shoot tip culture or cryotherapy for ASGV and ACLSV eradication. The results showed that including of 10 μM SA in thermotherapy significantly reduced the concentrations of ASGV and ACLSV by 33% and 14% in shoots compared to thermotherapy without SA. SA treatment also improved the shoot tips survival and regrowth after combining 2 or 4 weeks of thermotherapy followed by shoot tip culture or shoot tip cryotherapy, while maintaining the higher (75–100%) of virus eradication efficiencies. Therefore, the application of SA in combination with thermotherapy followed or not by cryotherapy proves to be a promising approach for enhancing the efficiency of virus eradication in apple.
Forfattere
Angelina Lo Giudice Maria Papale Carmen Rizzo Stefania Giannarelli Gabriella Caruso Paul Eric Aspholm Giovanna Maimone Maurizio AzzaroSammendrag
This explorative study was aimed at first characterizing the sponge Spongilla lacustris (Linnaeus, 1759) from the sub-Arctic Pasvik River (Northern Fennoscandia), in terms of associated microbial communities and pollutant accumulation. Persistent organic pollutants were determined in sponge mesohyl tissues, along with the estimation of the microbial enzymatic activity rates, prokaryotic abundance and morphometric traits, and the analysis of the taxonomic bacterial diversity by next-generation sequencing techniques. The main bacterial groups associated with S. lacustris were Alphaproteobacteria and Gammaproteobacteria, followed by Chloroflexi and Acidobacteria. The structure of the S. lacustris-associated bacterial communities was in sharp contrast to those of the bacterioplankton, being statistically close to those found in sediments. Dieldrin was measured at higher concentrations in the sponge tissues (3.1 ± 0.4 ng/g) compared to sediment of the same site (0.04 ± 0.03 ng/g). Some taxonomic groups were possibly related to the occurrence of certain contaminants, as was the case of Patescibacteria and dieldrin. Obtained results substantially contribute to the still scarce knowledge of bacterial community diversity, activities, and ecology in freshwater sponges. Practitioner Points * Microbial community associated with Spongilla lacustris is probably shaped by the occurrence of certain contaminants, mainly dieldrin and heavy metals. * A higher accumulation of dieldrin in the sponge mesohyl tissues than in sediment was determined. * S. lacustris is suggested as sponge species to be used as a sentinel of pesticide pollution in the Pasvik River. * S. lacustris, living in tight contact with soft substrates, harbored communities more similar to sediment than water communities.
Forfattere
Markus A. K. Sydenham Anders Nielsen Yoko L. Dupont Claus Rasmussen Henning Bang Madsen Marianne Strand Torvanger Bastiaan StarSammendrag
Pollinator conservation schemes are typically focused on conserving existing-, restoring degraded- or establishing new wild bee habitats. The effectiveness of such conservation schemes depends on the presence of dispersal corridors that allow habitat colonization by bees. Nonetheless, we lack an understanding of the role of semi-natural habitats edges on the connectivity of pollinator communities across intensively managed landscapes. Here, we use data from wild bee communities comprising 953 occurrences from 79 species of non-parasitic bees, sampled at 68 locations distributed across a Norwegian and a Danish landscape to show that the proportion of semi-natural habitat edges is positively correlated to bee species richness and habitat connectivity. Specifically, we found that wild bee species richness sampled along roadsides increased with the proportion of semi-natural habitat edges within1.5 km of the study sites and with local plant species richness. We combined maps showing the proportion of seminatural habitat edges with least cost path analysis to find the most likely dispersal route between our bee communities. We find that these least cost path lengths provide better models of bee species compositional similarity than geographic distance (|ΔAICc| > 2), suggesting that seminatural habitat edges act as dispersal corridors in intensively managed landscapes. However, we also find that compositional similarity between communities depend on site-specific plant species richness stressing the importance of improving the habitat quality of edge habitats if they are to function as dispersal corridors. We discuss potential management options for improving wild bee habitat conditions along seminatural habitat edges and illustrate how maps of least cost paths can be used to identify dispersal corridors between pollinator habitats of conservation priority. Maps of dispersal corridors can be used to direct wild bee habitat management actions along seminatural habitat edges to facilitate the dispersal of bees between larger grassland habitats. Bees, Connectivity, Conservation planning, Pollinators, Restoration, Grassland
Forfattere
Ralf RautenbergerSammendrag
During the cultivation of Ulva fenestrata in a land-based aquaculture system, the colonisation of the water tanks’ surfaces and eventually the macroalgal biomass by the biofouling diatom Fragilariopsis oceanica compromises the production process. Since germanium dioxide (GeO2) is an effective growth inhibitor of diatoms, this study aimed to understand how it affects the presence of F. oceanica and the photosynthesis and growth of U. fenestrata as a primary parameter contribution to the biomass production. A toxicological dose-response experiment showed that the diatom’s growth was inhibited at the low GeO2 concentration of 0.014 mg l−1. In contrast, the photosynthetic performances and growth rates of U. fenestrata remained unaffected under a wide GeO2 concentration range (0.022–2.235 mg l−1) in small- and large-scale experiments in 1-l glass beakers and 100-l Plexiglass water tanks, respectively. In the latter, the diatom density in the tanks was reduced by 40 %. The costs arising from the use of GeO2 can range between €2.35 and €8.35 kg−1 fresh weight of produced U. fenestrata biomass under growth conditions resulting in growth rates of 20 and 11.5 % d−1, respectively. GeO2 is an effective agent to control biofouling diatoms such as F. oceanica during the land-based biomass production of U. fenestrata.
Forfattere
Eivind Handegard Ivar Gjerde Rune Halvorsen Robert John Lewis Ken Olaf Storaunet Magne Sætersdal Olav SkarpaasSammendrag
Multiple ecological drivers, along with forest age, determine the species composition of boreal forest ecosystems. However, the role of age in successional changes in forests cannot be understood without taking site conditions, the disturbance regime and forest structure into account. In this study, we ask two research questions: 1. What is the relationship between forest age and overall species composition in older near-natural spruce forests, i.e. forests of age beyond harvest maturity? 2. Do species associated with different forest habitats respond similarly to variation in forest age? Data were collected in 257 Norway spruce dominated 0.25 ha plots from three study areas in Southeastern and Central Norway. Species inventories were conducted for lichens and bryophytes on trees and rocks, vascular plants on the forest floor, and for deadwood-associated bryophytes and polypore fungi. Although NMDS ordination analyses of the total species composition identified a main axis related to the age of the oldest trees in two of the study areas, variation partitioning analyses showed that age explained a small fraction of variation of the species composition compared to site conditions, logging history, forest structure, and differences between the sites in all habitats. The unique variation explained by forest age species was, however, significant for all habitats. The fraction of variation in species composition explained by forest age was the largest for lichens and bryophytes on trees, and for deadwood-associated bryophytes and polypore fungi. Our results suggest that practical mapping of near-natural forests for management purposes inventories should include site conditions, forest structure and between site differences in addition to forest age.
Forfattere
Jan Peter George Mari Rusanen Egbert Beuker Leena Yrjänä Volkmar Timmermann Nenad Potočić Sakari Välimäki Heino KonradSammendrag
Ash dieback (ADB) has been threatening populations of European ash (Fraxinus excelsior & F. angustifolia) for more than three decades. Although much knowledge has been gathered in the recent past, practical conservation measures have been mostly implemented at local scale. Since range contraction in both ash species is likely to be exacerbated already in the near future by westward expansion of the emerald ash borer and climate change, systematic conservation frameworks need to be developed to avoid long-term population-genetic consequences and depletion of genomic diversity. In this article, we address the advantages and obstacles of conservation approaches aiming to conserve genetic diversity in situ or ex situ during tree pandemics. We are reviewing 47 studies which were published on ash dieback to unravel three important dimensions of ongoing conservation approaches or perceived conservation problems: i) conservation philosophy (i.e. natural selection, resistance breeding or genetic conservation), ii) the spatial scale (ecosystem, country, continent), and iii) the integration of genetic safety margins in conservation planning. Although nearly equal proportions of the reviewed studies mention breeding or active conservation as possible long-term solutions, only 17 % consider that additional threats exist which may further reduce genetic diversity in both ash species. We also identify and discuss several knowledge gaps and limitations which may have limited the initiation of conservation projects at national and international level so far. Finally, we demonstrate that there is not much time left for filling these gaps, because European-wide forest health monitoring data indicates a significant decline of ash populations in the last 5 years.
Forfattere
Behailu Etana Disasa Anagaw Meshesha Atickem Peter Fashing Diress Tsegaye Alemu Matthias De Beenhouwer Luc Lens Afework Bekele Nils Christian StensethSammendrag
Understanding the effects of variation in resource availability and habitat disturbance on the ecology of mammals is vital for successful conservation management. In this study, we examined how human disturbances, resource availability and elevation gradients influence mammal assemblages in both managed coffee forest and natural forest of the Belete-Gera National Forest Priority Area, southwestern Ethiopia. We surveyed mammals using motion-detecting infrared camera traps in 90 locations for a total of 4142 camera days. We measured distance from main roads and settlements as disturbance factors, and distance from water sources, key grazing sites, and forest edges and woody plant diversity as resource variables. We assessed the mammal assemblages in coffee forest and natural forests using generalized linear models. Further, we used linear modelling to compare the relationships of mammal detection rates by feeding guilds and body size to resource variables. In total, we recorded 8815 videos identifying 23 different mammal species. The mammal assemblages in coffee forests were negatively associated with increasing distances from key grazing sites, water sources, and elevation. In contrast, the association with increasing distance from the road and woody plant diversity was positive. In addition, herbivores and large (25–200 kg) and very large (≥200 kg) mammals, were all negatively associated with increasing distance from the natural forest edges. With the conversion of natural forest to coffee forest and the intensification of coffee forest management, sustainable management of key grazing sites, water sources, and diverse woody plant species will be essential to the conservation of mammals. In addition, to ensure mammal conservation, adjacent natural forests around coffee forests should also be protected.
Forfattere
Attiq ur Rehman Terhi Iso-Touru Jakob Junkers Marja Rantanen Saila Karhu Daniel Fischer Muath K Alsheikh Stein Harald Hjeltnes Bruno Mezzetti Jahn Davik Alan H. Schulman Timo Hytönen Tuuli HaikonenSammendrag
The cultivated garden strawberry (Fragaria × ananassa) has a rich history, originating from the hybridization of two wild octoploid strawberry species in the 18th century. Two-step reconstruction of Fragaria × ananassa through controlled crossings between pre-improved selections of its parental species is a promising approach for enriching the breeding germplasm of strawberry for wider adaptability. We created a population of reconstructed strawberry by hybridizing elite selections of F. virginiana and F. chiloensis. A replicated field experiment was conducted to evaluate the population's performance for eleven horticulturally important traits, over multiple years. Population structure analyses based on Fana-50 k SNP array data confirmed pedigree-based grouping of the progenies into four distinct groups. As complex traits are often influenced by environmental variables, and population structure can lead to spurious associations, we tested multiple genome-wide association study (GWAS) models. GWAS uncovered 39 quantitative trait loci (QTL) regions for eight traits distributed across twenty chromosomes, including 11 consistent and 28 putative QTLs. Candidate genes for traits including winter survival, flowering time, runnering vigor, and hermaphrodism were identified within the QTL regions. To our knowledge, this study marks the first comprehensive investigation of adaptive and horticultural traits in a large, multi-familial reconstructed strawberry population using SNP markers.