Impact of climate induced glacial melting on coastal marine systems in the Western Antarctic Peninsula region

IMCOAST is an international research program that features a multidisciplinary approach involving geo and biological sciences, field investigations, remote sensing and modeling and knowledge into the hydrographical and biological history of the marine coastal ecosystems of the Western Antarctic Peninsula region

Nitrogen Fertilization in \u3ci\u3ePaspalum dilatatum\u3c/i\u3e, Poir: Herbage Production, Nutritive Value and Structural Characteristics

It was studied the effect of nitrogen application on structural changes and quantity and quality characteristics of a Paspalum dilatatum Poir sward, under field conditions during two growing seasons. The nitrogen (N) rates were 0 and 440 kg ha-1 applied during the first year in split applications. The nitrogen fertilization increased leaf, stem and cumulative total dry matter yield, plant height, tiller density, cover ground and leaf crude protein yield

Legume Seedling Development in No Till Pasture Establishment

The objective of this study was to compare no-till and conventional seeding of pasture and their effects on legume establishment. The presence of residue cover reduced legume seedling establishment and weed population under no-till seeding. The reduction in establishment was associated with the physical impediment of the residue cover and the decay of seedling vigor when passing through that cover

State and Transition Model of Lowland Grassland in Flooding Pampa

Rainfall conditions are considered to be a major factor in determining vegetation structure in temperate grasslands with grazing playing a secondary role (Biondini et al., 1998; Sternberg et al., 2000). In order to analyse the relative importance of both factors on the lowland community of the Flooding Pampa we compared the responses of functional groups under both intermittent and continuous grazing regimes over a 3- year period of important inter seasonal rainfall variation. The results are presented in a state and transition model

Effects of Defoliation Frequency on Foraging Selective Behaviour in Pasture with Paspalum Dilatatum

The objective was to assess defoliation effects exerted by sheep grazing on a pasture composed by falaris and dallisgrass, at two phenological stages during spring and summer. A sown pasture of Phalaris aquatica and Paspalum dilatatum were grazed at two phenological stages: stage I (SI), with no more than 5% of reproductive tillers, and stage II (SII), with at least 70% of reproductive tillers. Tillers of both grass species were marked with plastic colour rings along two transects in each plot. Phenological stage of tillers, and the number, age and length of each leaf per tiller were registered. Tiller defoliation rates (TDR), Leaf defoliation rates (LDR) of young and old leaves and Defoliated tiller percent (DTP) were estimated for both species. The results obtained demonstrated that selective forage behaviour of grazing sheep showed the existence of mechanisms towards maximum forage consumption

Grassland Use and Plant Diversity in Grazed Ecosystems

Earth biomes are being deconstructed, through unprecedented rates of species disappearance or invasion (McCann 2000). This, added to the threat of global environmental change and changes in values of a developed society, caused that biodiversity became a topic that has captured the attention of the public as well as the scientific community. Such concern on the importance of biodiversity is based in four basic reasons clearly described by West (1993): (i) morality, that aims for the protection of species; (ii) aesthetics, as people desire to see and appreciate the living parts of nature; (iii) economics and, (iv) the array of “services” provided by the natural ecosystems. It is vital to know how badly is affecting ecosystem function human alarming rate of destroying the original diversity

Analysis of Some Farm Driving Variables and Its Relation with Milk Production in a Pastoral Dairy Farm of Buenos Aires, Argentina

The quantity of milk solids produced determines a dairy farm income and contributes to its profit. Total pasture production, forage quality and herd consumption are factors to be managed in this production system. The outcomes of two years were analyzed. Primary production showed its dependence on climatic conditions and use of technological inputs. Forage quality was promoted through interseeding legumes, applying fertilizer and maintaining the pasture young and leafy. Total forage removed by the herd was similar in both years although pasture production decreased. It was possible to cope with seasonal variations in forage production, by varying the grazing pressure and this allowed an increase in daily herd milk production and annual fat production per hectare. Changes in milk production per cow was not related to changes in stocking rate, however, although the nutritive value of the pasture was improved during the second period, daily milk production and forage consumption per animal decreased when grazing pressure increased. The relation between total milk produced and total dry matter consumed in both periods were similar