Bioturbation can modify the biogeochemical properties of cohesive sediments and affect sediment stability. Here, we investigate the effects of the clam, Scrobicularia plana, on the erodibility of estuarine sediments. Muddy sediments with different mud contents were collected with minimal disturbance at Ponta da Erva, Hortas and Samouco in the Tagus Estuary. S. plana 40.7±0.3 mm length, (mean ± ...

We thank Warrick et al. (2014) for the Comment on our recent synthesis of 10Be-derived denudation rates (Willenbring et al., 2013), in which we suggested that gently sloping areas, representing ∼90% of the Earth’s land surface, have sufficiently high rates of denudation to produce a majority of mass fluxes to the world’s ocean. First, Warrick et al. take issue with labeling our global cosmogeni...

the problems of land degradation and soil loss are among the major problems of watersheds in iran. for erosion andsediment estimation one can use statistical and empirical methods. for doing this, land unit map and the map of effectivefactors should be prepared. for erosion and sediment estimation one can use statistical and empirical methods. however,these empirical methods are usually time co...

Despite the complexity of natural systems, heterogeneity caused by the fragmentation of habitats has seldom been considered when investigating ecosystem processes. Empirical approaches that have included the influence of heterogeneity tend to be biased towards terrestrial habitats; yet marine systems offer opportunities by virtue of their relative ease of manipulation, rapid response times and ...

Benthic macroinvertebrate assemblages, environmental variables, and associated mine density were evaluated during the summer of 2000 at 18 reference and test sites in the Coeur d’Alene and St. Regis River basins, northwestern USA as part of the US Geological Survey’s National WaterQuality Assessment Program. Concentrations of Cd, Pb, and Zn in water and (or) streambed sediment at test sites in ...