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.
2025
Forfattere
Abel Gizaw Seid Dimitar Dimitrov Catherine Aloyce Masao Felly Mugizi Tusiime Tigist Woldimu Ahmed Abdikadir Abdi Desalegn Chala Galina Gusarova Virginia Mirré Mulugeta Kebede Rosalia Pineiro Mary Namaganda Pilar Catalan Manuel Pimentel Pereira Pierre Robert Michel Taberlet Hans Peter Linder Magnus Popp Gerald Eilu Pantaleo Munishi Geoffrey Mwachala Sileshi Nemomissa Christian BrochmannSammendrag
Aim It has been proposed that species diversity (SD) and genetic diversity (GD) co-vary across natural communities because both are shaped by processes such as immigration and drift. However, empirical reports are contradictory, and multispecies studies are rare. Here we test the hypothesis that the two diversity measures do not correlate in systems with high levels of immigration stochasticity and little GD caused by strong genetic drift. Location Tropical alpine habitats on six of the highest mountains in eastern Africa. Taxon Vascular plants. Methods We sampled 375 taxa in 75 plots in five habitat types, recorded ecological variables, and genotyped 1793 plants representing 20 species/species complexes. Results We confirmed that intrapopulation GD was exceptionally low in this system and found that most Species-Genetic Diversity Correlations (SGDCs) were weak and insignificant. Whereas SD was correlated with several environmental variables, GD was only correlated with mountain identity (geographical location) and mountain age. Main Conclusions Our findings support the hypothesis that SGDCs are lacking in habitat island systems such as the tropical alpine region in Africa, which is characterised by frequent population size fluctuations, extinctions, and colonisations via long-distance dispersal (LDD) during the glacial cycles. The stochastic nature of LDD combined with strong genetic drift and founder effects is likely to cause low GD and lack of SGDCs, implying that SD cannot be used as a proxy for GD in conservation management of such systems.
Forfattere
Juan Manuel Gorospe Eliska Zaveska Desalegn Chala Abel Gizaw Seid Felly Mugizi Tusiime A Lovisa S Gustafsson Lubomir Pialek Filip Kolář Christian Brochmann Roswitha SchmicklSammendrag
Mountains have highly heterogeneous environments that generate ample opportunities for lineage differentiation through ecological adaptation, geographic isolation and secondary contact. The geographic and ecological isolation of the afroalpine vegetation fragments on the East African mountain tops makes them an excellent system to study speciation. The initial diversification within the afroalpine endemic genus Dendrosenecio was shown to occur via allopatric divergence among four isolated mountain groups, but the potential role of ecological speciation within these groups and the role of gene flow in speciation remained uncertain. Here we extend the sampling of Dendrosenecio and use phylogenomics to assess the importance of gene flow in the diversification of the genus. Then, population genomics, demographic modelling and habitat differentiation analyses are used to study ecological speciation in two sister species occurring on Mount Kenya. We found that two sympatric sister species on Mt Kenya occupy distinct microhabitats, and our analyses support that they originated in situ via ecological speciation with gene flow. In addition, we obtained signals of admixture history between mountain groups. Taken together, these results suggest that geographic isolation shaped main lineages, while ecologically mediated speciation occurred within a single mountain.
Forfattere
Lucía D. Moreyra Cristina Roquet Alfonso Susanna Siri Birkeland Carme Blanco‐Gavaldà Christian Brochmann Desalegn Chala Mercè Galbany‐Casals Abel Gizaw Seid Juan Antonio CallejaSammendrag
Aim We investigated the biogeographic history and diversification dynamics of Afrocarduus, an Afromontane–Afroalpine genus endemic to eastern Africa. We aimed to assess the roles of geographic isolation, habitat transitions, and ecological speciation in shaping current diversity. Location The Afromontane and Afroalpine regions of East Africa and Ethiopia are situated along the Great Rift Valley system. Taxon Afrocarduus (Compositae: Carduinae), a genus comprising 18 endemic species. Methods We conducted a comprehensive taxonomic and geographic sampling of Afrocarduus, generating data from 489 nuclear loci. Phylogenomic and biogeographic ancestral estimation analyses were performed to infer the evolutionary history and historical biogeography of the genus. Results Afrocarduus originated in the Afromontane zone of eastern Africa during the Late Miocene (~10.7 Ma), with major diversification events occurring in the Early Pleistocene (~2.3 Ma). Most dispersal events occurred between neighbouring massifs, though occasional long-distance dispersal between disjunct mountain systems was detected. The Turkana Depression and the Great Rift Valley have acted as major biogeographic barriers. Phylogenetic structure shows distinct clades occupying different regions. Ecological divergence between Afromontane and Afroalpine environments contributed to speciation, with at least six independent adaptations to Afroalpine conditions and multiple cases of ecological reversal. Stem loss, a trait associated with alpine habitats, evolved convergently in two clades. Closely related species often segregate by elevation or microhabitat within the same massif. Main Conclusions The diversification of Afrocarduus has been shaped by a combination of historical climate change, geographic isolation, and ecological adaptation. Our results emphasise the importance of ecological speciation and habitat transitions in Afrotemperate plant evolution and highlight the need for further research on understudied Afromontane taxa, especially under the threat of ongoing climate change.
Forfattere
Lucía D. Moreyra Juan Antonio Calleja Cristina Roquet Siri Birkeland Carme Blanco‐Gavaldà Mercè Galbany‐Casals Abel Gizaw Seid Frederik Leliaert Christian Brochmann Alfonso SusannaSammendrag
Accurate species delimitation is crucial for biodiversity research, as it significantly impacts taxonomy, ecology, and conservation. Recent advances in molecular phylogenetics and integrative taxonomy have improved classifications and resolved long‐standing taxonomic uncertainties. Here, we use Hyb‐Seq (489 nuclear loci) and phylogenomic approaches to investigate Afrocarduus , a genus endemic to tropical Afromontane and Afroalpine regions. Our analyses reveal 16 evolutionary lineages within this relatively young genus (crown age 2.3 Mya), with new morphological data strongly supporting the recognition of each lineage as a distinct species. We demonstrate that the stemless habit evolved independently in species from the Ethiopian Highlands and the East African Rift System (EARS). Notably, we show that the concept of the stemless Afrocarduus schimperi adopted by the Flora of Tropical East Africa, in fact, comprises seven clearly recognizable species, which we formally reinstate. Unexpectedly, the stemmed Afrocarduus nyassanus was recovered as paraphyletic with Afrocarduus ruwenzoriensis nested within it, probably due to incomplete lineage sorting or hybridization. Additionally, the stemmed Afrocarduus keniensis may represent a complex of cryptic species, and we describe a new stemmed species from southern Ethiopia, Afrocarduus kazmi sp. nov. We expand the number of accepted species in Afrocarduus from eight, as recognized in the Flora of Tropical East Africa, to 18 (including two species for which we were not able to obtain molecular data). Our study thus highlights a substantial prior underestimation of the diversity of Afrocarduus in Afromontane and Afroalpine habitats.
Forfattere
F Durand-Maniclas H Heinemann F Seidel F Ciulla Teresa Gómez de la Bárcena M Camenzind S Corrado Z Csűrös Zs Czakó D Eylenbosch Andrea Ficke C Flamm J M Herrera V Horáková A Hund F Lüddeke F Platz B Poós Daniel Rasse M da Silva-Lopes M Toleikienė A Veršulienė M Visse-Mansiaux K Yu A Don J HirteSammendrag
Background and aims: Understanding the relationship of root traits and crop performance under varying environmental conditions facilitates the exploitation of root characteristics in breeding and variety testing to maintain crop yields under climate change. Therefore, we (1) evaluated differences in root length and surface area between ten winter wheat varieties grown at 11 sites in Europe covering a large pedoclimatic gradient, (2) quantified differences in root response to soil, climate and management conditions between varieties, and (3) evaluated variety-specific relationships of grain yield and root length and surface area under diverse environmental conditions. Methods: At each site, we sampled the roots to 1 m soil depth after harvest and determined various root traits by scanning and image analysis. The impacts of soil, climate and management on roots and yield of the ten varieties were analysed by means of multivariate mixed models. Key results: Root length averaged 1.4 m root piece−1, 5007 m root m−2 soil, and 5300 m root m−2 soil and root surface area 0.039 m2 root piece−1, 40 m2 root m−2 soil, and 43 m2 root m−2 soil in 0.00–0.15 m, 0.15–0.50 m, 0.50–1.00 m soil depth, respectively. The variation in both traits was 10 times higher between sites than varieties, the latter ranging by a factor of 2 within sites. Irrespective of variety, temperature was a major driver of subsoil root traits, suggesting that warmer climates promoted root growth in deeper soil layers. Other soil and climate variables affected root length and/or root surface area of individual varieties, highlighting different degrees of root plasticity. The varieties displayed distinctly different relationships between yield and root traits under varying pedoclimatic conditions, highlighting genetic differences in yield response to environmentally driven root plasticity. Conclusions: These findings suggest that breeding efforts should target flexible root–yield relationships in the subsoil to maintain crop performance under climate change.
Sammendrag
Etter oppdrag fra Miljødirektoratet gjennomfører NIBIO nasjonal overvåking av jordbrukspåvirket grunnvann. Overvåkingen omfatter prøvetaking i 7 grunnvannsområder: Haslemoen i Våler, Rimstadmoen i Larvik, Horpestad i Klepp på Jæren, Nedre Eri i Lærdal, Skogmo i Overhalla, Grødalen i Sunndal samt Lofthus i Ullensvang. Gjennom finansiering fra «Handlingsplan for bærekraftig bruk av plantevernmidler 2022-2025» har det blitt utført supplerende prøvetaking i overvåkingsfeltene. Alle lokalitetene ligger innenfor nasjonale grunnvannsforekomster. Rapporten gir oversikt over resultatene for perioden 2022-2024.
Forfattere
Erik J. JonerSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Xueli Chen Xingzhu Ma Zhuxiu Liu Haidong Gu Hairui Fang Zongzhuan Shen Huibo Zhang Shuming Wan Weiqun Li Xiaoyu Hao Nicholas Clarke Junjie LiuSammendrag
Background: Soil microbes play a central role in nutrient recycling in soils: however, the genetic mechanisms governing their responses to long-term fertilization remain poorly understood. While the agronomic benefits of long-term fertilization are well-documented, the genetic mechanisms and ecological processes underlying microbial community responses to different fertilization regimes remain poorly understood, particularly in unique soil systems such as black soils (Mollisols), which are critical for global food security. A deeper insight into how organic and inorganic fertilizers influence microbial assembly, functional potential, and community stability is essential for developing sustainable soil management practices. Results: This study deciphers microbial assembly mechanisms, functional gene dynamics, and community restructuring in black soils subjected to 44 years of chemical fertilizer (CF), manure amendment (M), and integrated chemical fertilizer with manure (CFM) treatments. Results revealed that CF significantly enhances functional gene abundance related to carbon (C) degradation (e.g., starch, cellulose, chitin and lignin) and nitrification, accelerating the conversion of recalcitrant C to labile C pools and ammonium to nitrate. Conversely, M and CFM treatments promote microbial diversity and stability while decelerating nutrient transformation processes. In addition, microbial assembly mechanisms shift from stochastic to deterministic processes with long-term fertilizer application in CF. The structural equation modeling (SEM) indicated that soil chemical properties shape both the diversity and composition of taxonomic and functional gene communities which subsequently regulate microbial -mediated nutrient cycling processes and crop yield. Conclusions: Our findings highlight the trade-offs between microbial functional potential and community stability under contrasting fertilization strategies, emphasizing the need to integrate microbial metrics into sustainable land management frameworks.
Forfattere
Zahra Bitarafan Wiktoria Kaczmarek-Derda Rafael De Andrade Moral Pierre-Adrien Rivier Therese With Berge Christian AndreasenSammendrag
Weed seeds are potential contaminants of composts derived from biowastes. We assessed the effect of steam treatment alone and in combination with composting on the mortality of barnyardgrass [ Echinochloa crus-galli (L.) P. Beauv.] seeds in a biowaste substrate consisting of a mixture of onion ( Allium spp.) waste (60%), horse ( Equus spp.) manure (20%), and wood shavings (20%). In the first study, seeds of six populations of E. crus-galli exposed to temperatures ranging from ca. 60 to 99 C followed by a 3-min residence time exhibited a decline in seed germination from approximately 25% to 0%. The E. crus-galli populations varied greatly in germinability and responded differently to high temperatures. Samples with lower germinability as assessed in controls were killed at lower temperatures than samples with higher initial germinability. However, to ensure an almost 100% kill of all seeds in the populations, a mean temperature of 100 C was necessary. In another study, seed germination was assessed after steaming the biowaste mixture to a mean temperature of about 60 C and subsequently composting. A short steaming period of the biowaste mixture at approximately 60 C before composting was unnecessary, as all composted seed samples, including the non-steamed control seeds, died during the composting process.