The river Plate coastal plain is located in northeastern Buenos Aires province, where geological events such as sea transgressions and regressions in the Holocene have produced a stratigraphic column with marine-estuarine, fluviatile and continental sediments, as well as a variety of landforms and soils. The aim of this paper is to describe these different coastal settings and their influence in the distribution of plant communities.
Removal of topsoil, mainly for making bricks, is one of the main causes of soil loss around large urban centres of the Humid Pampa, Argentina. In about 7 per cent of La Plata County, the 20±40 cm thick A-horizon has been removed for that purpose. Most of the affected areas were originally prime farmland; however, with removal of the A-horizon they became unsuitable for agriculture, including grazing, since the exposed Bt-horizon is unsuited for plant growth due to its high clay content (45±65 per cent) and the low nutrient levels. Since trees survive better on poor soils than do agricultural crops, the possibility of afforestating desurfaced soils has been studied. Eucalyptus are one of the major species used in tree planting programmes aimed at reclaiming degraded soils since they are fast growing and can grow to commercial size in a wide range of soils and climatic conditions. The work reported here was done in a desurfaced Vertic Argiudoll and a similar non-desurfaced soil (control). Three Eucalyptus species were tested, i.e. E. camaldulensis, E. viminalis and E. dunnii. Their height and diameter (dbh) growth were 47Á9 to 75Á8 per cent less and timber volume 86Á5 to 98Á5 per cent less on the desurfaced soil. E. camaldulensis grew best in all the parameters in the desurfaced soil. Although tree growth was poor, afforestation may be an alternative use for desurfaced soils where agriculture and livestock breeding are not possible.
The River Plate coastal plain is a 160-km-long, 3-10-km-wide strip, located to o5 m a.s.l. on the right bank of the estuary. It is formed by sediments and landforms generated by the littoral transport and marine ingressions and regressions during the Holocene. The coastal plain faces heavy pressures from Buenos Aires Metropolitan Area, with about 13 million inhabitants, industrial, mining and rural activities. Here, we analyse the relations existing between landforms, soils and vegetation. Despite the anthropogenic influence, the natural landscape is more or less preserved in some areas, such as patches of the southernmost gallery forest in the world in natural levees, the xerophytic forests located in well-drained soils of beach ridges and other units such as Inland and Coastal Mudflats with wetland soils and vegetation, Tidal Flats with contrasting soils and plant communities among others.
The nature and amount of sediments in various lakes, intermittent swampy areas and river sectors in the humid Pampa (Buenos Aires Province, Argentina) were analysed. The aim was to determine whether recent sediments in such environments could serve as an alternative resource to the brick industry, for minimising the current, high environmental impact of soil mining. Sediment sequences were obtained, and the thicknesses of the upper sediment layers, corresponding to the suballuvial (approx. 1400-700 years BP) and alluvial (approx. 250 years BP to present) were determined. Sediment samples were collected and analysed for grain size and Atterberg limits. Suitable sediments were then selected to determine the optimal brick materials and their technical properties. Similarly, control bricks were prepared with ceramic pastes of local industries. The results show that the quality of the former is similar or superior to that of the latter. The initial estimates of the available resource indicate a long-term supply for the industry. Estimates of the current sedimentation rates indicate that resource renewal might occur at a rate comparable to current consumption. The sedimentation rates have increased significantly in the past two centuriesmore so in the past few decades (the Anthropocene?)with increasing human modification of geomorphic processes. If the results presented here are confirmed, a highly sustainable model can be implemented in the brick industry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.