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18/06/2013
Pollination is an essential process in the sexual reproduction of seed plants and a key ecosystem service to human welfare. Animal pollinators decline as a consequence of five major global change pressures: climate change, landscape alteration, agricultural intensification, non-native species, and spread of pathogens. These pressures, which differ in their biotic or abiotic nature and their spatiotemporal scales, can interact in non-additive ways (synergistically or antagonistically), but are rarely considered together in studies of pollinator and/or pollination decline. Management actions aimed at buffering the impacts of a particular pressure could thereby prove ineffective if another pressure is present. Here, empirical evidence of the combined effects of global change pressures on pollination, highlighting gaps in current knowledge and future research needs are provided. informacion[at] González-Varo et al (2013) Combined effects of global change pressures on animal-mediated pollination. TREE Doi 10.1016/j.tree.2013.05.008
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13/06/2013
Several studies based on a variety of genetic markers have attempted to establish the origins of horse domestication. Thus far a discrepancy between the results of mitochondrial DNA analysis, which show high levels of diversity, and results from the Y-chromosome, with almost no genetic variability, has been identified. Additional genetic variation may be present in local breeds and ancient feral populations. In this study the Y-chromosome of the Retuertas horse was analyzed, a feral horse population on the Iberian Peninsula that is at least several hundred years old, and whose genetic diversity and morphology suggests that it has been reproductively isolated for a long time. No sequence variation among all individuals and all breeds studied was found. However, fifteen differences were discovered between the study data set and reference sequences in GenBank. These likely represent errors within the deposited sequences. informacion[at]ebd.csic.es: Brandariz-Fontes et al (2013) Y-Chromosome Analysis in Retuertas Horses. PLoS ONE 8(5): e64985. Doi 10.1371/journal.pone.0064985
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07/06/2013
For tropical lowland rain forests, Denslow hypothesized that in areas with large-scale disturbances tree species with a high demand for light make up a larger proportion of the flora; results of tests have been inconsistent. In six regions the proportion of tree species needing canopy gaps for establishment was compared with the frequency and/or extent of canopy disturbance. Only some of the significant differences in proportion of species were consistent with differences in the extent of disturbance; even in some of those cases other factors seem likely to have had a major determining influence during evolution. It also appeared that species that are ‘short-term persistent’ in the soil seed bank do not need canopy gaps for establishment; large numbers of seeds of some shade-tolerants accumulate in the soil, and these species are able to benefit from soil disturbance in deep shade. informacion[at]ebd.csic.es: Grubb et al (2013) Disturbance regimes, gap-demanding trees and seed mass related to tree height in warm temperate rain forests worldwide. Biol Reviews. Doi 10.1111/brv.12029
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