PASTURES

Author: ATILIO MORICI ERNESTO FRANCISCO.
Year: 2005.
University: CÓRDOBA [www.uco.es].
Place of defense: CAMPUS DE RABANALES.
Place of preparation: CAMPUS DE RABANALES.

Summary: Excessive use to which they were subjected communities herbaceous forest Prosopis caldenia and lack of fire has caused structural changes in the vegetation, transforming these areas into places very low receptivity livestock. The grazing herbivores causing the disappearance of forage species (Poa liguaris Nees ap. Steud., Piptochaetium napostaense (Speg.) Hack., Stipa longiglumis Phil., And Stipa tenuis Phil.) With a concomitant increase not forage species (stipa trichotoma Nees, S.tenuissima Trin., S.lchu (Ruiz and Pav.) Kunth and S.brachicaeta Gogron). In the thesis characterize the structural differences and the seed bank of the grasses, "patch" grazing and addresses the possible recovery of the "patches" dominated or codominado by not forage grasses. It identified coverage (total and by species), perennial grasses density, diversity and seed bank. Patches not fodder presented the maximum total coverage, the main one being kind Stipa tricótoma. The seed bank of perennial forage grasses (Piptochaetium napostaense, Poa ligularis and Briza subaristata) and not fodder (Stipa trichotoma and S.tenuissima) is persistent (type III). For this reason pasture of caldenal could recover after a disturbance. The seed bank of the annual forage grasses (Bromus brevis and Panicum bergii) and not forrjaera (Vulpia octoflora) is transitory. The high number of damaged seeds would indications that the feeding of this ecosystem is very important, especially after the release. Germination laboratory of the forage grasses and not fodder was not affected by the "patches" where were the cariopses. The increase in forage grass patches codominados for forage and fodder is not dominated by serious nearly impossible either by competition (water, light and nutrients), as well as by the low density of forage seed and the large number of non-seeds fodder.