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Rhinanthus Minor (Rhinanthu + minor)

Distribution by Scientific Domains

Life Sciences	80%

Selected Abstracts

Plant species response to land use change ,Campanula rotundifolia, Primula veris and Rhinanthus minor

ECOGRAPHY, Issue 1 2005
Regina Lindborg
Land use change is a crucial driver behind species loss at the landscape scale. Hence, from a conservation perspective, species response to habitat degradation or improvement of habitat quality, is important to examine. By using indicator species it may be possible to monitor long-term survival of local populations associated with land use change. In this study we examined three potential indicator (response) species for species richness and composition in Scandinavian semi-natural grassland communities: Campanula rotundifolia, Primula veris and Rhinanthus minor. With field inventories and experiments we examined their response to present land use, habitat degradation and improvement of local habitat quality. At the time scale examined, C. rotundifolia was the only species responding to both habitat degradation and improvement of habitat quality. Neither R. minor nor P. veris responded positively to habitat improvements although both responded rapidly to direct negative changes in habitat quality. Even though C. rotundifolia responded quickly to habitat degradation, it did not disappear completely from the sites. Instead, the population structure changed in terms of decreased population size and flowering frequency. It also showed an ability to form remnant populations which may increase resilience of local habitats. Although P. veris and especially R. minor responded rapidly to negative environmental changes and may be useful as early indicators of land use change, it is desirable that indicators respond to both degradation and improvement of habitat quality. Thus, C. rotundifolia is a better response species for monitoring effects of land use change and conservation measures, provided that both local and regional population dynamics are monitored over a long time period. [source]

The conservation management of upland hay meadows in Britain: a review

GRASS & FORAGE SCIENCE, Issue 4 2005
R. G. Jefferson
Abstract Upland hay meadows conforming to MG3 in the National Vegetation Classification of the UK are a rare habitat in Britain and are largely confined to upland valleys in northern England. Agricultural intensification, particularly ploughing and reseeding and a shift from hay-making to silage production over the last 50 years, has resulted in large losses of species-rich upland hay meadows. Remaining species-rich meadows have been the focus of much nature conservation effort resulting in many of the species-rich sites being protected by statutory designations or through voluntary agri-environment scheme agreements. Research and monitoring has tended to confirm that species richness is maximized by management involving spring and autumn grazing, a mid-July hay cut, no inorganic fertilizer and possibly low levels of farmyard manure. Deviations from this regime result in a loss of species richness. Restoration of semi-improved grassland to swards resembling species-rich MG3 also requires a similar regime but is also dependent on the introduction of seed of appropriate species. The role of Rhinanthus minor as a tool for manipulating meadow biodiversity during restoration management is discussed. Suggestions for future research are outlined. [source]

Mobility of boron,polyol complexes in the hemiparasitic association between Rhinanthus minor and Hordeum vulgare: the effects of nitrogen nutrition

PHYSIOLOGIA PLANTARUM, Issue 1 2008
Fan Jiang
Boron (B) is an essential nutrient required for plant growth and physiological processes. Long-distance B transport is facilitated by the formation of B,polyol complexes. We investigated B uptake and distribution in response to differing levels of exogenous nitrogen supply in the hemiparasitic association between Rhinanthus minor and Hordeum vulgare (barley) and in unparasitised barley and single Rhinanthus plants. In this system, the polyol mannitol is the major assimilate in Rhinanthus, whereas polyols are not detectable in barley. Furthermore, previous studies have shown that the accumulation of polyols within Rhinanthus is negatively affected by the application of exogenous nitrogen. Within the association, the strongest accumulation of B was detected in lateral buds and inflorescences of Rhinanthus, consistent with the greatest B demand in strong sink organs supplied through the phloem that contain high concentrations of mannitol. In the host, the strongest B accumulation was found in xylem-supported leaf lamellae. Roots and sheaths did not accumulate substantial amounts of B, while re-circulation of B through the phloem vessels accounted for only 10% (unparasitised) and 8% (parasitised) of the xylem sap-imported B in the mannitol-free barley hosts. In contrast, 53% (attached) and 39% (in the absence of a host) of the xylem sap-imported B was re-circulated in the phloem in the mannitol-rich Rhinanthus. We therefore present the first quantitative uptake and flow models of long-distance B transport in polyol-rich and polyol-free plants. Our findings are consistent with a close relationship between B re-translocation and mannitol concentrations in phloem vessels. [source]