Urban ecosystems are an increasingly dominant feature of terrestrial landscapes. While evidence that species can adapt to urban environments is accumulating, the mechanisms through which urbanization imposes natural selection on populations are poorly understood. The identification of adaptive phenotypic changes (i.e. clines) along urbanization gradients would facilitate our understanding of th...

Chemical and mineral composition and the intramuscular fatty acid (IMF) profile of the Longissimus dorsi muscle (LM) of 60 purebred Hereford, 1/4 Braford and 3/8 Braford steers finished either in a feedlot or on improved pastures of the Pampa biome were evaluated. Pastures were improved with the introduction of Lolium multiflorum, Trifolium repens, and Lotus corniculatus. On average, beef from ...

ELF-INCOMPATIBILITY is the inability of a plant producing functional male and female gametes to set seed upon self-pollination. The best known genetic system effecting incompatibility in plants is that in which a single series of oppositional alleles governs pollen-tube growth, with pollen behavior under autonomous, or gametophytic, genetic control (EAST and MANCELSDORF 1926). Self-incompatibil...

BACKGROUND AND AIMS Although the causes and consequences of seedling herbivory for plant community composition are well understood, the mechanisms by which herbivores influence plant species recruitment to the established phase remain less clear. The aim was to examine how variation in the intensity of seedling herbivory interacts with growth-defence trade-offs and herbivore feeding preferences...

Recent studies suggest that plant roots can avoid competition with other roots of the same plant, but the mechanism behind this behavior is yet largely unclear and their effects on plant performance hardly studied. We grew combinations of two ramets of Trifolium repens in a single pot that were either intact, disconnected for a shorter or longer time, or that belonged to different genotypes. In...