| 1. |
- Ampomah, Osei Y., et al.
(författare)
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Nodulation and ecological significance of indigenous legumes in Scotland and Sweden
- 2012
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Ingår i: Symbiosis. - : Springer Nature. - 0334-5114 .- 1878-7665. ; 57:3, s. 133-148
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Tidskriftsartikel (refereegranskat)abstract
- The ability of wild indigenous legumes to form root nodules capable of biological nitrogen (N 2) fixation has rarely been demonstrated for species in natural ecosystems in large parts of Europe. In order to understand and manage these ecosystems, it is important to demonstrate nodulation across a diverse range of environments, sites and climates. This study surveyed nodulation at a number of sites in Scotland and Sweden. Presence of nodules was noted and nodule structure and indicators of nitrogen fixation capacity were assessed using light and transmission electron microscopy. Soils from several sites were also sampled for carbon and nitrogen analysis. The collections comprised 24 species in Scotland, and 30 taxa in Sweden; 17 of these in common for both countries. Highest species numbers occurred in meadows, farmland margins, hedgerows, roadsides and wasteland. Coastal sites and sites in the mountainous region above the Arctic Circle hosted several rare species. All sampled species had features of N 2-fixing nodules such as pink colour (leghaemoglobin) when dissected and bacteroids. Nodule structure for a number of species is here reported for the first time and presence of the N 2-fixing enzyme nitrogenase is demonstrated in three previously not studied Swedish legume species. North European legumes may make significant contributions to the N-budgets of their ecosystems. Such species (and their symbionts) represent unique germplasm that may be adopted to empower advances in agriculture and conservation aimed at mitigation and adaptation to the effects of climate change.
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| 2. |
- Skarpe, C., et al.
(författare)
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Plant-Herbivore Interactions
- 2014
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Ingår i: Elephants and Savanna Woodland Ecosystems. - Chichester, UK : Wiley-Blackwell. - 9781118858615 - 9780470671764 ; , s. 189-206
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Bokkapitel (refereegranskat)abstract
- To a casual observer, the importance of large herbivores for ecosystem structure and dynamics can seem more obvious in African savannas than in many other ecosystems because of their high abundance, diversity and species richness of ungulates. African savannas have also had a long uninterrupted history of mammalian herbivory, leading to the evolution of plant traits adapted to herbivory and to reciprocal traits in herbivores. In nutrient-poor savannas such as those on Kalahari sand in the Chobe National Park, Botswana, elephants, Loxodonta africana, are a main agent creating spatial and temporal variation in the vegetation and ecosystems. Within this framework, elephants and smaller herbivores interact with individual plants and plant populations, exploiting and modifying heterogeneity at many scales. Intermittent grazing in systems of migratory or highly mobile herbivores provides food plants with a recovery period, and could be one reason for the 'success' and abundance of many migratory herbivore species.
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