What is the role of local landscape structure in the vegetation composition of field boundaries?

Question: How distinct is the flora of field boundaries? How does the structure of field boundaries determine the composition of vegetation? Location: Estonia, six 4 km × 4 km agricultural areas. Methods: We studied the vegetation of fields and field boundaries using 2 m × 2 m sample plots. We estimated the frequency of species in both habitat types, applied an MRPP test to analyse the vegetation composition of field boundaries with various combinations of landscape features (ditches, roads, tree and bush layers) illustrating this by DCA ordination, and used indicator species analysis to determine the characteristic species of each boundary type. Results: Ca. 45% of the flora of field boundaries comprised species found on agricultural land. Most typical species in fields — agrotolerants — were also the most common in field boundaries. The vegetation of road verges and grassy boundaries consisted mainly of disturbance‐tolerant species. Woody boundaries were characterised by shade‐tolerant and nitrophilous species. Ditch banks included species typical of moist habitats and semi‐natural grasslands. Few threatened or protected species were observed. Conclusion: The vegetation composition of field boundaries varied due to the complex effects of landscape structure around and in these boundaries. Plant species in agricultural landscapes can be classified into two broad emergent groups on the basis of their different responses to agricultural disturbances — agrotolerant species and nature‐value species. Agrotolerant species are promoted by agriculture, nature‐value species include rare weeds and habitat specialists. We suggest that high‐nature‐value species should prevail in monitoring the effects of land‐use intensification on biodiversity rather than total species richness.     

X-ray diffraction of oriented amylose fibers. III. The structure of amylose–n-butanol complexes

Complexes of amylose with n-butanol were prepared both as crystalline precipitates and as oriented fibers. These complexes were subjected to x-ray analysis, their unit cells were calculated, and the space group of P2₁2₁2₁ was confirmed. n-Butanol complexes exist in both hydrated and anhydrous forms. There is no evidence for methanol, ethanol, or n-propanol structures similar to those shown by the n-butanol complex. The Complexes are unstable in the open air and revert to V-amylose hydrate on standing.     

Prediction of breast cancer prognosis using gene set statistics provides signature stability and biological context

Background  

Different microarray studies have compiled gene lists for predicting outcomes of a range of treatments and diseases. These have produced gene lists that have little overlap, indicating that the results from any one study are unstable. It has been suggested that the underlying pathways are essentially identical, and that the expression of gene sets, rather than that of individual genes, may be more informative with respect to prognosis and understanding of the underlying biological process.     

Temperate forest understorey species performance is altered by local arbuscular mycorrhizal fungal communities from stands of different successional stages

Plant and Soil - Arbuscular mycorrhizal (AM) fungal communities in plant roots vary in space and time. However, the effect of different fungal communities on plant performance and growth is poorly...